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SpaceX's CRS-14 Mission to the Space Station: What's On Board?

NASA

Опубликовано: 2 апр. 2018 г.

Over 5,800 pounds of NASA science, crew supplies and hardware will launch to the International Space Station on SpaceX's Dragon spacecraft. It's scheduled to launch April 2, 2018 at 4:30 p.m. EDT, and you can watch live on NASA Television. This will be SpaceX's 14th cargo mission to the station.

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What's Onboard the SpaceX CRS-14 Dragon Spacecraft

Space Videos

Опубликовано: 1 апр. 2018 г.

Mission scientists discuss with the media what experiments the unmanned SpaceX Dragon CRS-14 spacecraft is bringing up to the International Space Station when it launches tomorrow at UTC, April 2nd 2018 on a Falcon 9 rocket.

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Pre-launch News Conference for SpaceX CRS-14 Dragon Mission

Space Videos

Опубликовано: 1 апр. 2018 г.

Mission managers discuss tomorrow's SpaceX CRS-14 Dragon launch. Liftoff is set for UTC, April 2nd 2018.

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ISS Updates‏ @ISS101 30 мин. назад

#Dragon SpX-14 is carrying a total cargo upmass of 2,647 Kilograms - 1,721 kg are riding up in the craft's pressurized compartment and three payloads installed in the Trunk Section weigh in at 926 kg. Detailed Dragon Cargo Overview: http://spaceflight101.com/dragon-spx14/cargo-overview/ ...

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30 мин. назад

Packed into the #Dragon is the largest satellite to be deployed from ISS. #RemoveDebris will test out innovative technologies for active space debris removal including a net capture system, a harpoon and vision navigation for uncooperative rendezvous: http://bit.ly/2GKk46P 

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30 мин. назад

ESA's ASIM, the Atmosphere-Space Interactions Monitor, combines UV/VIS/IR imagers & radiometers + X/Gamma-Ray detectors to capture the high-speed signatures of transient luminous events and help understand the processes between the atmosphere & space: http://bit.ly/2H0sVix 

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30 мин. назад

The MISSE Flight Facility offers a new state-of-the-art platform for commercial materials science outside ISS. It has 14 slots for exchangeable sample modules & can support powered & actively data-gathering payloads over exposure durations up to 3 years: http://bit.ly/2EeMSPS 

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30 мин. назад

The third element riding in the trunk is not a utilization payload but a potentially critical spare part for ISS: a Pump Flow Control Subassembly tasked with regulating the temperature of the photovoltaic power generation components. Details: http://bit.ly/2pUdCAS 

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30 мин. назад

Packed into the Dragon are samples for various experiments, including live specimens, a new water delivery system for the Veggie facility, additions to the TangoLab, NanoRacks Microscopes, & a Variable G-Platform. Dragon also carries a German time capsule & a new printer for ISS.

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SpaceX‏Подлинная учетная запись @SpaceX 42 мин. назад

Liftoff!

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http://www.spacex.com/webcast

DRAGON RESUPPLY MISSION (CRS-14)

On Monday, April 2 at 4:30 p.m. EDT, SpaceX had a successful liftoff of its fourteenth Commercial Resupply Services mission (CRS-14) to the International Space Station. Dragon separated from Falcon 9's second stage about 10 minutes after liftoff and will attach to the space station on Wednesday, April 4.

Both Falcon 9 and the Dragon spacecraft for the CRS-14 mission are flight-proven. Falcon 9's first stage previously supported the CRS-12 mission in August 2017 and Dragon previously supported the CRS-8 mission in April 2016. SpaceX did not attempt to recover Falcon 9's first stage after launch.

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http://spaceflight101.com/dragon-spx14/falcon-9-launches-dragon-crs-14-mission/

Science-Laden Dragon Lifted to Orbit by 5th Expendable Falcon 9 in a Row
 April 2, 2018

Photo: SpaceX

Still covered in soot fr om a previous supply run to the International Space Station, a SpaceX Falcon 9 took to the skies over Florida's Cape Canaveral Monday afternoon – lifting a flight-proven Dragon spacecraft into orbit for a critical delivery of science gear, supplies and maintenance hardware to the orbiting laboratory as the first of at least six cargo ships inbound to the U.S. Segment of ISS this year.

The fourteenth operational Dragon is packed with over two and a half metric tons of cargo, including equipment for over 50 scientific studies and two new science facilities for the Station's exterior, studying the energetic processes ongoing where Earth's atmosphere meets space and offering a new state-of-the-art exposure facility for commercial materials science. Dragon is also carrying the largest satellite to be deployed from ISS to date, setting sail on an innovative demonstration of active space debris removal technology.

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Photo: NASA TV

The 65-meter tall Falcon 9 rose from its sea-side launch pad at 20:30 UTC, 4:30 p.m. local time and swung to the north east under the power of its nine Merlin 1D engines, propelling the rocket to a speed of over two Kilometers per second when the first stage dropped away. SpaceX decided against recovering the booster and instead used it for experimenting with extreme flight envelopes to help fine-tune future recoveries of flight-worthy stages.

As the first stage used its remaining life for a data-gathering exercise, it was up to Falcon's factory-new second stage to boost Dragon into orbit via a six-minute engine burn. The once-flown Dragon was set free a second time ten minutes after blastoff and successfully spread its wings by deploying its power-generating solar arrays. Dragon is expected to begin breathing fire around five hours after launch for a major orbit-raising maneuver on its climb up to the Space Station, en-route to a robotic capture on Wednesday to kick off a month-long stay.

Monday's launch was SpaceX's seventh mission of the year, the sixth with Falcon 9 and the fourth to ride into orbit on used hardware – a major step toward the routine re-use of rocket parts that SpaceX envisions will slash launch prices. Another re-use element involved in this mission is the Dragon capsule itself, having spent 33 days in orbit back in 2016 when it supported the Dragon SpX-8 mission that delivered the BEAM expandable module to ISS.


Photo: Erik Kuna, erikkuna.com

Only a year ago, on March 30, 2017, did SpaceX re-fly its first Falcon 9 booster on the SES-10 mission. Now, seven of the last ten Falcon 9 missions relied on first stages with one prior flight – an impressive demonstration of re-use finding its way into regular spaceflight operations at SpaceX, so far with a spotless success record.

The company's spacecraft branch is also enjoying the early successes of re-use as Dragon C110 is the third Dragon cargo vehicle to make a second trip into orbit, following up on the SpX-11 and 13 missions of 2017 that also flew used capsules. SpaceX and NASA plan to fly out the remaining six missions under the extended Commercial Resupply Services-1 contract with flight-proven Dragons, allowing SpaceX to focus all resources on ramping up production of Dragon 2 vehicles that will handle crew and cargo missions in the future.


Dragon SpX-14 Trunk Configuration – Photo: SpaceX / ESA

Monday's launch marked the first of at least three cargo Dragons headed to the ISS this year, to be joined by two Cygnus, three Progress and one HTV mission to keep up a steady chain of supplies for the six crew members living and working off the planet. Additional traffic is expected to arrive in the form of the uncrewed test flights of SpaceX's Dragon 2 and Boeing's Starliner which will also ferry some cargo items before the two spacecraft upgrade to crewed transport either late this year or early 2019.

The 14th operational Dragon mission is carrying a total cargo upmass of 2,647 Kilograms, including 1,721 kg of pressurized cargo packed into the Dragon and 926 Kilograms between the three eternal payloads bolted into the Trunk Section of the craft. Cargo items loaded into Dragon range from the seemingly mundane like everyday-life supplies for the crew and a new printer for the Station to state-of-the art experiment facilities, a German time capsule, numerous human research and materials science experiments, as well as live specimens like cell cultures and a group of Japanese lab mice.

>> Dragon SpX-14 Cargo Overview


One of the first high-resolved images of a Blue Jet emanating from a thunderstorm cell – Credit: ESA


Image: Alpha Space

The three trunk payloads comprise a pair of external research facilities and a potentially critical spare part for the Station's thermal control system.

ASIM, the Atmosphere and Space Interactions Monitor, is a 314-Kilogram package taking up residence on the exterior of ESA's Columbus module to employ a series of cameras, high-speed radiometers and specialized X- and Gamma-ray sensors to capture the ultra-fast signatures of Transient Luminous Events like Blue Jets shooting up from thunderstorms or Red Sprites flashing up in the ionosphere. Data from the Danish-led experiment is hoped to provide insights into the energy exchange processes between the dense gaseous atmosphere and the Mesosphere/Thermosphere wh ere charged particles roam.

MISSE-FF, the second utilization payload riding in the Trunk, will open new possibilities for Materials Science outside the Space Station. A product of Alpha Space, the MISSE Flight Facility takes the original MISSE concept as a basis which had a successful run of over a decade starting in 2001 and exposed over 1,500 samples to the space environment.

While the original MISSE required spacewalking astronauts to deploy & remove the samples, MISSE-FF re-packages the experiment onto a central module hosting up to 14 exchangeable sample carries that can be transferred robotically, no-longer taking up precious crew time. Additionally, MISSE-FF can support powered payloads and offers regular image collection of deployed samples to permit an in-detail study of how different materials degrade in the challenging space environment.

The third Trunk Payload is a spare Pump Flow Control Subassembly to be pre-staged outside ISS in case one of the Station's eight operating PFCS units encounters a failure and requires replacement. These units are tasked with circulating ammonia coolant through the photovoltaic power-generation system and build an integral part of the Station's functionality as a world-class laboratory.


Mixed Crops inside Veggie – Photo: NASA

While the Station's external robots will be dealing with moving the trunk payloads, the four U.S. Segment crew members will enter a busy sprint to empty out the Dragon, perform dozens of experiments, and then re-pack the craft with items for return to Earth – penciled in for May 2nd if all goes according to plan.

Research heading up on this mission includes a study exploring how gravity affects the process of hardening materials through heat treatment, how prolonged exposure to microgravity changes bone marrow production in humans, and whether luminous cells can be used as a tracer for tracking metabolic activity for future drug development studies.

Also riding up on the Dragon is new equipment for the Station's Veggie facility to test out new watering and nutrient delivery hardware in a bid to increase the harvests of lettuce and other vegetables grown on ISS for crew consumption and a learning curve for future missions actively relying on plant growth as a food source.


RemoveDebris – Photo: SSTL

Taking up a large portion of Dragon's internal volume is the RemoveDebris satellite, the largest and heaviest to be deployed from ISS via the Japanese Airlock. After deployment some weeks after arriving on ISS, the SSTL-built satellite will be setting out on a mission testing tools for active space debris removal including a net capture demonstration, a harpoon mechanism and a vision-based navigation system for approaching uncooperative targets in space.

Getting this precious cargo on the way toward ISS fell to a flight-proven Falcon 9 rocket, employing Booster 1039 that first flew in August 2017 on the SpX-12 mission and was paired with a factory-new Block 4 second stage. Processing the sooty booster after its successful Return-to-launch-site landing half a year ago was smooth and the second stage was shipped to Cape Canaveral on March 1st to begin the build-up for the mission.


Photo: Erik Kuna, erikkuna.com

Falcon 9 completed its Static Fire Test on Wednesday and received its payload on Friday and Saturday before returning to the launch pad for the customary late cargo load – a feature of Dragon that permits time-critical items to be loaded inside 24 hours to launch. Late-load items for the SpX-14 mission included one JAXA Rodent Module, a pair on InVitroBone modules and various time-critical experiment samples riding to ISS in a Polar freezer or double cold bags.

Taking its vertical position atop SLC-40 before dawn, Falcon 9 started its countdown with a multi-hour checkout campaign before computers took over at the T-70-minute mark to load over 500 metric tons of sub-cooled Liquid Oxygen and chilled Rocket Propellant 1 into the two-stage rocket. Operations continued like clockwork as Falcon 9 headed into the tail-end of the count, comprising the fast-paced sequence of chilling down the nine Merlin 1D engines, exercising actuators and engine valves one last time, switching the rocket to internal power and closing out the process of loading propellant and pressurization gas onto the vehicle inside T-120 seconds to liftoff.

>> Falcon 9 FT Overview


Photo: NASA TV

Falcon 9 came to life at the T-3-second mark when its redundant engine controllers commanded the nine powerplants to fire up and throttle to a collective launch thrust near 700 metric-ton-force. Hold-down systems released the vehicle at precisely 20:30:38 UTC and Falcon 9 thundered away from its Atlantic-side launch pad, balancing in a vertical posture before pitching to the north-east to deliver Dragon into the orbital plane of the Space Station.

Burning 2,500 Kilograms of propellant per second, Falcon 9 accelerated beyond the speed of sound in less than 66 seconds and encountered Maximum Dynamic Pressure only moments later, placing the used airframe of the core stage through peak stress on the way out of the atmosphere.


Photo: NASA TV

The nine Merlins revved back up to full thrust after passing MaxQ and continued pushing Falcon 9 until T+2 minutes and 41 seconds – employing a slightly altered thrust profile that throttled back toward the end of the burn (likely in an effort to set the proper separation mass of the 1st stage to create the desired starting conditions for its descent test).

MECO, Main Engine Cutoff, occurred after the seasoned booster accelerated the vehicle to a speed of 2,191 meters per second followed four seconds later by the separation of the stages at an altitude of 78 Kilometers. Four pneumatic pushers sent the two stages on separate ways with B1039.2 headed into a data-gathering exercise toward a mock landing target in the Atlantic while Stage 2 was tasked with lifting Dragon into orbit.


Photo: NASA TV

Monday's mission was SpaceX's fifth Falcon 9 launch in a row that flew the first stage in throw-away mode. Of those, four were by choice while one was by necessity due to rough seas preventing a Drone Ship Recovery attempt on the Hispasat mission. This recent streak of expendable missions is due to SpaceX shifting gears toward the inauguration of the finalized Falcon 9 Block 5 version later this month – allowing Block 3 and 4 first stage that are deemed unsuitable for a third mission to be expended to clear storage room for what is expected to be a flood of recovered boosters once Block 5 gets going at full speed.

Opting for a string of expendable missions with leftover performance also afforded SpaceX some opportunities for data collection not possible on operational recovery missions. Going through the motions of a mimicked sea-based return, the boosters of recent Falcon 9 missions were flown in different profiles – testing out alterations to the boost-back and entry burn profiles, though particular focus was on the atmospheric leg of the booster's return.


Stage Separation – Photo: SpaceX Webcast

Flight dynamics assessments looked at different angle-of-attack profiles that may allow for additional reduction of fuel needed for the final deceleration maneuver toward landing.

According to SpaceX, Booster 1039 was to continue exploring the bounds of what will be considered acceptable angle-of-attack profiles during atmospheric descent and collect data on the more-aggressive landing burns needed for fuel-constrained drone ship landings. Signals from the first stage were lost around eight minutes into the mission and SpaceX is not expected to comment on the of the planned data collection.

While the booster found its watery grave, Falcon's second stage was tasked with earning the money – firing up its 95,000-Kilogram-force MVac engine two minutes and 53 seconds into the flight on a planned burn of six minutes and 11 seconds to lift Dragon into orbit. The protective nose cone separated at T+3:25 when the vehicle had crossed 115 Kilometers in altitude, continuing to push toward an injection speed of 7.7 Kilometers per second.


Photo: SpaceX Webcast

Propulsive flight ended at T+9 minutes and ten seconds and SpaceX confirmed a good orbit was achieved by the Falcon 9 rocket. The Dragon was released on its chase of the Space Station at the T+10:12-mark and successfully primed its propulsion system shortly after separation followed by the deployment of the power-generating solar arrays.

Embarking on a 25-orbit, 38-hour rendezvous with the Space Station, Dragon will be tasked with its first and largest orbit-raising maneuver around five and a half hours after launch. Another pair of engine burns around mid-day on Tuesday (UTC) will place the Dragon in a position to slowly catch up with ISS from behind and below before initiating its rendezvous in the overnight hours to Wednesday.

If all goes well, Dragon will arrive in the Station's vicinity at 9 UTC for a straight-up approach to the planned capture point just ten meters from ISS. JAXA Astronaut Norishige Kanai will be at the controls of the Station's robotic arm for the planned 11 UTC capture on Wednesday to mark the start of Dragon's month-long stay.

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https://blogs.nasa.gov/spacex/2018/04/02/successful-liftoff-begins-spacex-dragon-mission-to-space-station/

Successful Liftoff Begins SpaceX Dragon Mission to Space Station

Bob Granath
Posted Apr 2, 2018 at 6:22 pm


The two-stage Falcon 9 launch vehicle lifts off Space Launch Complex 40 at Cape Canaveral Air Force Station carrying the Dragon resupply spacecraft to the International Space Station.
Photo credit: NASA

A care package with more than 5,800 pounds of supplies from Earth is on its way to the International Space Station aboard a SpaceX Dragon spacecraft. The company's 14th commercial cargo mission to resupply the space station began at 4:30 p.m. EDT with liftoff aboard a SpaceX Falcon 9 rocket from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida.

The Dragon spacecraft now is in orbit with its solar arrays deployed and providing power.

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With the countdown clock in the foreground, a SpaceX Falcon 9 rocket lifts off from Cape Canaveral Air Force Station launching a Dragon spacecraft with supplies for the International Space Station.
Photo Credit: NASA/Dan Casper

During a prelaunch news conference, Pete Hasbrook, NASA's associate program scientist for International Space Station Program Science Office at the agency's Johnson Space Center in Houston, praised the work of Commercial Resupply Services companies.

"The International Space Station is a world-class and multi- disciplinary laboratory in space," he said. "Our commercial providers help in bringing our sciences forward and keep it going on space station and bringing benefits back to Earth."

The Dragon spacecraft will deliver science, research, crew supplies and hardware to the orbiting laboratory. Read more about science experiments on board at:
https://blogs.nasa.gov/spacex/2018/04/02/whats-on-board-dragon-for-spacex-crs-14/


Project scientists Matthew Romeyn, left, and Dr. Ye Zhang place seeds in Veggie Passive Orbital Nutrient Delivery System (PONDS) units inside a laboratory at the Space Station Processing Facility at NASA's Kennedy Space Center.
Photo credit: NASA/Daniel Casper

Live NASA TV coverage of the rendezvous and capture will begin at 5:30 a.m. EDT on April 4 on http://www.nasa.gov/live

Expedition 55 Flight Engineers Norishige Kanai of the Japan Aerospace Exploration Agency, backed up by NASA astronaut Scott Tingle, will supervise the operation of the Canadarm2 robotic arm for Dragon's capture. After Dragon capture, ground commands will be sent from mission control in Houston for the station's arm to rotate and install it on the bottom of the station's Harmony module.

The Dragon spacecraft will spend approximately one month attached to the space station. Unberthing and release of the Dragon from the space station is targeted for May 2. About five hours after Dragon leaves the station, it will conduct its deorbit burn, which lasts up to 10 minutes. It takes about 30 minutes for Dragon to reenter the Earth's atmosphere and splash down in the Pacific Ocean off the coast of Baja California.

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https://spaceflightnow.com/2018/04/02/spacex-supply-ship-departs-cape-canaveral-for-space-station/

SpaceX supply ship departs Cape Canaveral for space station
April 2, 2018 | Stephen Clark


A SpaceX Falcon 9 rocket lifts off Monday fr om Cape Canaveral Air Force Station, Florida. Credit: SpaceX

Hauling nearly three tons of supplies, hardware and experiments, a SpaceX Falcon 9 rocket shot into orbit Monday fr om Cape Canaveral, with a previously-flown Dragon cargo carrier riding a reused first stage booster to kick off a nearly two-day journey to the International Space Station.

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The commercial cargo delivery flight departed Cape Canaveral with a roar from the Falcon 9's Merlin 1D main engines, producing 1.7 million pounds of thrust to dispatch the 213-foot-tall (65-meter) rocket toward the northeast over the Atlantic Ocean.

The Falcon 9's on-board guidance computer pivoted the rocket on a trajectory to align with the space station's orbital track, and the slender kerosene-fueled launcher climbed through wispy high-level clouds, broke the sound barrier, and arced away from Florida's Space Coast trailing a flickering tongue of orange exhaust.

Nine minutes later, the Falcon 9's upper stage delivered the Dragon supply ship into orbit, followed by deployment of the SpaceX-owned cargo capsule. The Dragon spacecraft extended its solar arrays to begin generating electricity a few minutes later.

"Dragon is in a good orbit, solar arrays have deployed, and the propulsion system is operating nominally," said Jessica Jensen, director of Dragon mission management at SpaceX.

The robotic supply ship will fine-tune its approach to the space station Tuesday, setting up for a laser-guided rendezvous Wednesday that will culminate in the Dragon's capture by the lab's Canadian-built robotic arm around 7 a.m. EDT (1100 GMT).

The supply haul is the 14th cargo mission to the space station launched by SpaceX under a contract with NASA valued at more than $2 billion, covering 20 logistics deliveries through 2019. SpaceX also has a follow-on contract, along with competitors Orbital ATK and Sierra Nevada Corp., for additional resupply missions through 2024.

Monday's launch was the second time SpaceX has flown a reused rocket booster and a reused cargo capsule on the same mission. In sum, SpaceX has launched previously-flown Falcon 9 rocket stages 11 times, all successfully, including two modified boosters on the maiden flight of the company Falcon Heavy rocket.

And all of SpaceX's upcoming resupply missions to the space station, at least for this year and 2019, will employ reused Dragon capsules plucked from the sea and refurbished for future flights.

"What's really neat about this is it's becoming the norm," Jensen said in a pre-launch press conference. "And we like that.

"Reusability is really important for the future of spaceflight," she said, echoing the ethos of SpaceX founder Elon Musk. "It's the only way we're going to get thousands of people to space, to explore the stars, the moon, Mars and to make life multi-planetary. Otherwise, it's just going to be a cost-prohibitive dream."


SpaceX's Falcon 9 rocket climbs into space after liftoff Monday. Credit: Stephen Clark/Spaceflight Now

The first stage of the Falcon 9 rocket launched Monday first flew in August 2017 on SpaceX's 12th space station resupply mission, then returned to a landing at Cape Canaveral a few minutes later. The Dragon capsule made a round-trip journey to the space station and back to Earth in April and May of 2016, and the craft was the first to debut improved sealing to prevent sea water from infiltrating critical internal components after splashdown in the Pacific Ocean.

The water sealing upgrade "really paid off," Jensen said. "We were able to ... reuse many more components on this vehicle compared to previous Dragons. On this vehicle that's flying ... there are only a handful of things that we are not reusing. Obviously, the trunk is all new, and we still have to have a new heat shield, as well as new parachutes, but almost everything on the interior of the capsule we were able to reuse."

SpaceX did not try to land the first stage on Monday's mission, electing to use the rocket for experimental maneuvers downrange from Cape Canaveral over the Atlantic Ocean.

"We are looking forward to reuse in the long term, and it's always good for us if we can get data that is sort of pushing the bounds," Jensen said before the launch. "In this case, we have a booster that has already flown. We were looking at the service lifetime of that and trading should we bring it back to land or the drone ship, or should we do a demonstration mission.

"This one seemed like a really good opportunity to fly a trajectory a little bit out more toward the limits, and that way our engineers can collect additional data not only during re-entry, but for the landing, that will be useful for the future."

The rocket was expected to make a hard splashdown in the Atlantic Ocean, Jensen said.

Monday's blastoff was the second by a Falcon 9 rocket in three days.

A Falcon 9 rocket, also powered by a previously-flown first stage booster, launched Friday from Vandenberg Air Force Base, California, with 10 commercial Iridium communications satellites. The quick turnarounds from coast-to-coast are nothing new for SpaceX, which conducted Falcon 9 flights from Cape Canaveral and Vandenberg as close as two days apart last year.

SpaceX's next rocket launch is scheduled for April 16, when a newly-manufactured booster will hurl NASA's Transiting Exoplanet Survey Satellite into an orbit that eventually will each the beyond the moon. The science probe will try to find planets orbiting bright, relatively nearby stars, worlds that might be ripe for follow-up by bigger observatories like the James Webb Space Telescope.

Engineers at SpaceX's headquarters at Hawthorne, California, will keep busy in the coming days with the Dragon mission.

After its arrival at the space station Wednesday, the Dragon will be maneuvered to a parking port on the Harmony module for a month-long stay. Astronauts will open hatches leading to the cargo freighter, then begin unpacking the approximately 3,794 pounds (1,721 kilograms) of equipment and provisions inside Dragon's pressurized compartment.

Cargo loaded inside Dragon's internal cabin includes food, clothing, care packages, and more than a ton supplies related to scientific investigations.

The experiments carried in Dragon's pressurized module include a robotic testbed satellite that will be released from the space station in the next few months to study the effectiveness of techniques to capture a chunk of space junk and move it out of Earth orbit.

Developed in a public-private partnership between the European Commission and European industry, the RemoveDebris mission will test the utility of nets and harpoons to capture tumbling objects in space, repurposing devices commonly used in fishing to pluck debris out of orbit and bring them into Earth's atmosphere to burn up.

Guglielmo Aglietti, principal investigator for the RemoveDebris mission, calls the project a "proof-of-concept."

Scientists also developed experiments to look at the effects of microgravity on bone marrow and wound healing. Lessons from those studies could help researchers develop ways to counteract negative health effects of long-duration spaceflight or bedrest, and investigate treatments for wounds soldiers suffer in combat.

There is also an experiment in sintering that could help engineers fabricate or repair tools and spacecraft components on future missions.

New high-definition cameras and a custom HP printer for station astronauts also launched inside the Dragon capsule Monday.


A view inside the Dragon spacecraft's trunk, housing (clockwise from upper left) the Atmosphere-Space Interactions Monitor, the Materials ISS Experiment Flight Facility — a materials exposure experiment platform — and the Pump and Flow Control Subassembly. Credit: SpaceX

While astronauts transfer cargo delivered inside the Dragon module, mission control will command the station's robotic arm to pull three payload packages out of the spaceship's unpressurized trunk section.

One of the payloads is the Atmosphere-Space Interactions Monitor, or ASIM, an instrument funded by the European Space Agency and led by Danish scientists to study lightning from the space station.

The instrument's optical, X-ray and gamma ray sensors will observe electrical discharges high above thunderstorms — with names like blue jets, red sprites and elves — that extend up to the edge of space.

Scientists know little about how the discharges are triggered, said Torsten Neubert, ASIM science team coordinator at the Technical University of Denmark.

Lightning processes are slowed at high altitude, Neubert said, making it a good laboratory for studying how electrical discharges emanate through the atmosphere.

"They are really lightning, except they are lightning processes in the upper atmosphere," Neubert said of sprites and jets. "So they look a little bit different, but if we understand them, we'll also understand normal lightning much better."

Once mounted outside the European Columbus module, the lightning monitor may help scientists pinpoint the sources of flashes of gamma rays detected coming from Earth's atmosphere by some astronomical instruments in space. Scientists also hope to study lightning's effects on ozone and other gases in the atmosphere during the instrument's two-year observing campaign.

Also inside the trunk: A platform to expose materials like polymers, coatings, fabrics, computer chips, and solar cells to the harsh environment of space, helping engineers design future spacecraft. The Materials ISS Experiment Flight Facility, or MISSE-FF, was developed by Alpha Space, a Houston-based company that wants to offer the platform to companies seeking to test the resilience of materials to extreme temperatures, ionizing radiation, space junk and other hazards of spaceflight.

NASA is also sending up a refurbished coolant pump for staging outside the space station as a spare for the orbiting lab's huge power truss segments.

The Dragon spacecraft is scheduled to remain at the space station until May 2, when the robotic arm will detach the capsule and release it for a re-entry back into Earth's atmosphere. Parachutes will slow the ship's descent into the Pacific Ocean, wh ere SpaceX recovery crews will stand by to retrieve Dragon and its contents.

The Dragon spacecraft will return to Earth with more than 4,000 pounds of equipment and experiment specimens, including a humanoid robot named Robonaut that has been on the space station since 2011. Engineers want to bring Robonaut back home for repairs.

"Robonaut has had some issues with being able to power up on-orbit ... and after a lot of troubleshooting on-orbit and a lot of analysis on the ground, they've concluded pretty conclusively that there's a short of some sort on one of the circuitboards, and they need to bring it home in order to repair that," said Pete Hasbrook, NASA's associate space station program scientist.

Developed as a testbed to see whether robots could help astronauts clean and maintain the space station, Robonaut launched aboard the final flight of the space shuttle Discovery in 2011. A SpaceX Dragon cargo capsule delivered legs for Robonaut in 2014.

Robonaut could be re-launched on a future mission after the repairs are finished.

"The plan is to bring this one down, understand why it failed, and then make the decision of wh ere we want to go in the future," said Joel Montalbano, NASA's deputy space station program manager.

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https://blogs.nasa.gov/spacestation/2018/04/03/resupply-ship-midway-to-station-amid-maintenance-and-science-work/

Resupply Ship Midway to Station Amid Maintenance and Science Work

Mark Garcia
Posted Apr 3, 2018 at 11:38 am


The "Horn of Africa" is seen through one of the seven windows that make up the Cupola, a dome-shaped module on the International Space Station. The space station crew will be inside the Cupola Wednesday morning operating a robotics workstation to capture the upcoming SpaceX Dragon.

The SpaceX Dragon space freighter is midway on its trip to the resupply the International Space Station's Expedition 55 crew. Waiting to capture Dragon Wednesday morning are Flight Engineers Norishige Kanai and Scott Tingle.

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The two astronauts have been reviewing procedures and training on a computer for Dragon's capture for a few weeks now. Kanai will command the Canadarm2 robotic arm to reach out and grapple Dragon about 7 a.m. EDT Wednesday when it reaches a point about 10 meters away from the station. Tingle is backing up Kanai and will monitor Dragon's approach and rendezvous from inside the Cupola. Flight Engineer Ricky Arnold will be assisting the duo by overseeing approach telemetry from a communications unit on the space station. NASA TV will begin its live mission coverage starting at 5:30 a.m.

Dragon is carrying a variety of cargo including new science experimentsresearching the human body, plants and how materials react when exposed to space. The Marrow study will explore bone marrow and the blood cells it produces. PONDS will explore ways to achieve uniform plant growth as astronauts supplement their diets with fresh space-grown greens. The Materials ISS Experiment Flight Facility, or MISSE-FF, will observe what happens to materials exposed to outer space phenomena such as ultraviolet radiation, charged particles and micro-meteoroids.

Meanwhile, the six space station residents are keeping the orbital lab in tip-top shape today while continuing ongoing scientific studies. Commander Anton Shkaplerov stayed focused on maintenance duties in the station's Russian segment. New Expedition 55 crew members Ricky Arnold, Drew Feustel and Oleg Artemyev had time set aside to get used to their new home in space.

Tingle swapped out Combustion Integrated Rack hardware in the Destiny lab module. Kanai readied mouse habitat gear for a rodent study being delivered on Dragon. Kanai and Tingle later ended the day with more Dragon robotics practice.

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http://spaceflight101.com/dragon-spx14/asim/

ASIM – Atmosphere-Space Interactions Monitor

ASIM Instrument Payload – Photo: NASA

ASIM, the Atmosphere-Space Interactions Monitor, is an ESA science instrument taking up residence outside the Columbus Module of the International Space Station to study Transient Luminous Events (TLEs) in Earth's upper atmosphere like Blue Jets, Red Sprites and Elves via a suite of cameras and photometers sensitive in a broad wavelength range to reveal previously unknown details of the electrical and chemical processes ongoing where the atmosphere and space interact.

Спойлер

The first proposal for the ASIM concept came fr om the Danish National Space Center (DNSC) back in 2007 and, since then, the project has been worked on by Danish, Norwegian and Spanish institutions to advance its design. ESA eventually provided approval for the instrument to be flown as an ISS external payload, operating fr om an Earth-pointed position on the Columbus External Payload Platform.

Transient Luminous Events were first observed in 1989, occurring in the Stratosphere and Mesosphere as companions of thunderstorms in the Troposphere.


Blue Jet Photographed from ISS – Credit: ESA

These events are of particularly short duration, hence their name, and can be broken down into blue jets, sprites and elves by their appearance and the altitude at which they occur. Researching these phenomena from space has been a difficult endeavor given the relatively low frequency and spatial distribution, though ISS is considered a perfect platform due to its non-synchronous orbit, allowing locations to be observed at different times of day.

In recent years, the first proper still images and videos of sprites and blue jets were collected by astronauts aboard the International Space Station and there have been attempts to study these phenomena via small satellite missions (e.g. the Firefly CubeSat and Japan's Rising 2) or through observation posts set up on mountains above thunderstorm clouds. In 2012, a bright red sprite was captured over a thunderstorm above Myanmar and in 2015, the Thor experiment, operated by ESA Astronaut Andreas Mogensen, captured the first-ever high-resolution video of a pronounced blue jet – illustrating how little is actually known about these phenomena.


Image: Danish Space Research Institute

ASIM combines two cameras, three photometers, an X-ray detector and a gamma-ray instrument to study the atmosphere as one system from the surface to the edge of space to help understand the coupling between phenomena in the dense atmospheric layers and responses in the upper atmosphere.

ASIM is looking back at a fairly lengthy road to launch, starting development in 2007 with involvement of DNSC and the universities of Valencia, Spain and Bergen, Norway. The instrument moved through Phase B of its design process in 2009 and entered the production phase in 2010 after Critical Design Reviews were passed. Initially working toward a launch in 2014, ASIM suffered a combination of delays – most notably a complete re-integration of the structure after the failure of the Columbus External Payload Adapter (CEPA) that had to be replaced in full.

The primary objectives of ASIM are several-fold: 1) study the physics of TLEs through optical detection with high spatial and temporal resolution in sel ected spectral bands; 2) study Terrestrial Gamma-ray Flashes (TGFs) and their connection to TLEs and thunderstorms via X- and gamma-ray detection with high temporal resolution and a broad energy range down to 10 keV; 3) simultaneous detection of thunderstorms, TLE and TGF activity to enable a study of the coupling to the mesosphere, thermosphere and ionosphere, and 4) collect at least one full year of observation data across all local times to allow seasonal and local time variations to be assessed.


Sprites seen from ISS – Photo: ESA

In addition  to its main objectives, ASIM is hoped to address secondary objectives like the spectroscopic study of the aurora, measurements of greenhouse gas concentrations above thunderstorms (particularly ozone and oxides of nitrogen), and detecting the optical and spectral signatures of meteors to reveal their chemical composition and origin.

The combination of optical instruments, photometers and specialized instruments for X- and gamma-rays allows ASIM to collect a wide range of measurements: auroral displays will be studied with the optical and X-ray instruments, differential absorption of lightning-illuminated thunderstorm clouds will allow a measurement of ozone column density, NOx generation in TLEs can also be measured photometrically, and a combination of optical imaging and photometry will be used to detect meteors.


Image: ASIM Project

The integrated ASIM payload weighs 314 Kilograms and comprises the CEPA (Columbus External Payload Adapter) as its central structural element, three modules making up the MMIA (Miniature Multispectral Imaging Array) and the single MXGS module (Miniature X-ray and Gamma-ray Sensor). Two of the MMIA modules are pointed to the ram direction (forward) while one is nadir-oriented (Earth-facing) to match the boresight of MXGS.

The CEPA provides structural attachment to the Columbus External Payload Platform through its FRAM (Flight Releasable Attachment Mechanism) which also forms the electrical and data bridge between ISS and the ASIM payload. ASIM receives raw ISS power at 120 Volts, routed to the Data Handling and Power Unit (DHPU) that builds the central element of the instrument payload, tasked on the one hand with converting the operational ISS power supply to the 28-Volt instrument power bus and on the other hand with handling all instrument data – processing commands from the ground relayed via the ISS data system and delivering housekeeping telemetry and pre-processed image data from the various detectors of the ASIM instrument. Data interfaces used by ASIM include a 1553-MIL-STD bus for housekeeping data and time synchronization, an Ethernet connection for science data and a serial line that allows for updating the DHPU firmware by the ISS crew.


Image: Terma

ASIM has a nominal power consumption of 200 Watts during science operations plus an additional 230 Watts needed for the survival heaters; its downlink data allocation is a continuous stream of 200 kbit/s which will be fully utilized and the instrument also employs onboard data prioritization since the link will not be sufficient to deliver all collected data to the ground.

The scientific payload carried by ASIM is made up of the three MMIA modules and the single MXGS module – all in all comprising six optical cameras, six photometers, one X-ray and one gamma-ray instrument. MMIA has two groups of optical instruments pointed to the limb/ram direction and directly towards nadir, operating in carefully sel ected bands to filter out data with Transient Luminous Events and reject ordinary lightning events through the use of a sophisticated onboard algorithm.


MMIA – Image: ASIM Project

Two MMIA units, each with two optical imagers and two photometers, point toward the ISS direction of motion to view Earth's limb while one unit points nadir (directly to Earth), co-aligned with the MXGS instrument. The cameras are all identical with the exception of their spectral bands and bandwidths which have been uniquely sel ected for each camera; the same is the case for the photometers.

The Cameras have baffles for straylight rejection and employ 1024 x 1024-pixel frame-type Charged Coupled Device detectors. All MMIA cameras collect 12 frames per second across a 20 x 20-degree field of view for the limb cameras and 80 x 80° for the wide-field cameras pointing nadir, translating to a ground resolution of 300-600 meters for the limb cameras and 300-400 meters for the nadir cameras.

The four limb cameras employ three narrow-band channels at 336.2, 391.4 and 762.2 nanometers with a bandpass of 5.0 nm and one wide-band channel sensitive from 650 to 740 nanometers. The nadir-viewing cameras operate at 337.0 and 777.4 nanometers with a bandwidth of 5 nm.


MXGS – Image: ASIM Project

The MMIA photometers are tasked with the measurement of rapid time variations which is not possible with the cameras. They view the exact same region as the cameras but measure only the total photon flux across their field of view at a frequency of 100 Hz. The limb-pointing photometers operate narrow-band channels at 236.6, 337.0 and 391.4 nanometers plus the same wide-band channel as the cameras at 650-740 nm while the nadir-viewing photometers comprise a narrow-band unit sensitive at 337.0 +/-5 nm and a broadband UV photometer at 145-250 nanometers.

MXGS is in a nadir-viewing position to look directly down upon terrestrial thunderstorms to detect radiation fr om Terrestrial Gamma Flashes (TGFs) and lightning-induced electron precipitation. The instrument has an active area of 32 by 32 centimeters and employs BiGe (Bismuth Germanate) scintillator and CZT (Cadmium-Zinc-Telluride) semiconductor detectors to collect spectral data. One critical requirement for MXGS was a fast electronic circuitry since the events to be detected and recorded only last for one to five milliseconds and additional provisions are needed to have an event synchronization trigger between the nadir-pointed MMIA module and MXGS.

MXGS is only available in a nadir-pointed configuration for the simple fact that a limb-viewing version would not be effective given the atmosphere's attenuating properties for X- and gamma-rays. Pointing nadir, MXGS has a minimum of atmosphere between the detector and the source within its field of view.


Image: Birkeland Centre for Space Science


Image: ASIM Project

The MXGS instrument has a low-energy detector sensitive fr om 15 to 400 kilo-electronvolt (CZT) and a high-energy detector covering energies of 200 keV to 40 MeV (BGO). The low-energy detector is pixelated through a 128 x 128 array and has a high-density coded mask placed in front of it so that post-processing algorithms can locate the TGF source with sufficient accuracy for correlating with MMIA imagery.

The MXGS detector consists of a 1024 cm² CZT crystal array that is protected against the background by a passive shield surrounding the detector housing on all sides except the optical axis. The 80 x 80° field of view is defined by an 11-centimeter hopper-shaped collimator assembly.

Placed right underneath the detector plane is the Electronics Box containing the Detector Front End Electronics (DFEE) comprising four Detector Assembly Units (DAUs), each in turn facilitating 16 Detector Modules (DMs) and one Detector Assembly Board.

The Detector Module hosts 256 CZT pixels (16 x 16, 2.5 mm pitch) tiled together on Arlon substrate and connected to an Application-Specific Integrated Circuit tasked with the fast read-out needed for the detection of the short-lived events of interest. The DAU arranges the 16 DMs to create a 64 x 64-array, all connected to the Detector Assembly Board wh ere the events are read-out and transferred to the DPU.

Underneath the 4096 x 4096-pixel, 0.5 mm thick CZT layer sits the high-energy BGO scintillator detector, 900 cm² in area and 3.2 centimeters thick to support detection energies up to 40 MeV. BGO converts particle energy to photons at visible wavelengths and photomultiplier tubes coupled to the BGO bars on each end detect the light impulses which are converted to electrical signals that can be digitized and recorded.


Photo: Terma

The BGO detector layer comprises four BGO Detector Assembly Units, each consisting of three BGO crystals with their corresponding photomultiplier tubes (PMTs) and read-out electronics. The PMTs are connected to preamplifiers to multiply the electrical signal and transmit it to the analog-to-digital conversion stage fr om wh ere the digitized data is sent to a Field Programmable Gate Array, one in each BGO Detector Assembly Unit.

The FPGA performs offset subtraction and peak detection to identify pulses of interest which are then processed into a data packet with a 1 µs resolution time-tag and delivered to the Data Processing Unit through an 18 Mbps serial link.

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http://spaceflight101.com/dragon-spx14/misse-ff/

MISSE-FF

Image: AlphaSpace

The Materials on ISS Experiment – Flight Facility (MISSE-FF) builds on the success of the original MISSE Passive Experiment Container concept which consisted of smaller and larger sample plates containing a variety of surface materials for exposure to the space environment outside the International Space Station for varying durations to inform satellite designers on how different materials degrade over time.

Спойлер

The first two MISSE experiments spent four years outside the Quest Airlock from 2001 to 2005; the MISSE-5 experiment contained over 200 flexible materials and a solar cell experiment exposed to space for 14 months; MISSE-3 and 4 spent one year on the outside of ISS with 875 specimens; MISSE-6A and 6B contained 400 samples and were exposed for one and a half years; the MISSE-7 PECs spent close to 1.5 years in space and the final of the original MISSE experiments, MISSE-8 and the special-purpose ORMatE exposure plate, spent over 2.5 years outside and were the first MISSEs to return on the SpaceX Dragon after the retirement of the Space Shuttle. In total, over 1,500 samples have been tested under the original MISSE program.


MISSE PECs in Orbit – Photo: NASA

The MISSE-FF project takes one large step further than the original MISSE, creating a platform capable of holding 14 exchangeable sample modules for powered & heated payloads as well as passive experiments, supporting non-materials and materials experiments, and allowing for regular servicing and payload exchange at six-month intervals via robotics. MISSE-FF is a project of NASA's Goddard Spaceflight Center, the University of Colorado and commercial partner Alpha Space Test & Research Alliance, LLC. Data collected by non-proprietary MISSE-FF experiments will be made available to the global community of researchers via NASA's Physical Sciences Informatics (PSI) system.

Testing materials in space is of utmost importance to spacecraft designers since the various factors combining to create the unique space environment can not be recreated on Earth and testing is only possible for a few of the conditions found in space.


Image: AlphaSpace

MISSE-FF enables samples to be brought into the space environment for a defined period of time, be monitored at various stages of exposure and then return to the ground for detailed laboratory analysis to get a full picture of their post-flight state.

Components built for long-term operation in space have to deal with vacuum conditions, extreme variations in temperature, direct ultraviolet radiation influx from the sun without protection from the atmosphere, a varying plasma environment depending on a vehicle's orbit, atomic oxygen that is extremely corrosive, high-energy radiation, micrometeoroid and orbital debris strikes and factors introduced by aspects of operational missions like contamination by visiting vehicle exhaust plumes which can deposit corrosive propellant residuals on surfaces.


MISSE-FF Location – Image: AlphaSpace
 

MISSE MSC – Image: AlphaSpace


MISSE-FF Operations Concept – Image: AlphaSpace

The MISSE-FF is a box-shaped payload hosting MISSE Sample Carriers (MSCs) on all external side panels. The physical size of experiments facilitated on the MSCs can vary from 2.5 x 2.5 centimeters to the full MSC size of 19.9 x 35.6 centimeters, supporting exposure durations from six months to three years. MSCs are controllable, allowing them to open and close to protect samples that do not tolerate visiting vehicle plumes, etc. An additional feature that was unavailable for previous MISSE flights are on-demand, high-resolution photo surveys of exposure samples via a Scanner Trolley Assembly that is part of each sample carrier assembly.

A MISSE Transfer Tray allows up to eight MSCs to be transferred to the outside via the Kibo Airlock and deliver MSCs that have completed their stay to the interior of ISS for return to Earth. Replacement of the MSCs will be completed by the Dextre robot that will hold the Transfer Tray with one arm while the other handles the MSCs.

A streamlined integration process has been developed for samples, allowing experiment operators to request non-standard features like electrical power and RS-422 data interfaces for active experiments and also chose the viewing direction of their experiment (ram [face on towards the velocity vector], wake [toward the anti-velocity vector], nadir [toward Earth] and zenith [toward space] ) .

The first MISSE-FF will be installed on ExPRESS Logistics Carrier 2, Payload Site 3, providing unobstructed views to ram and zenith, a partially obstructed view aft (wake) and a nadir view into ISS structure.

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http://spaceflight101.com/dragon-spx14/pfcs/

PFCS – Pump Flow Control Subassembly

Image: NASA

The third Trunk Payload riding on the Dragon SpX-14 mission is not a science/utilization instrument like its two companions but a potentially critical spare part for the Space Station's Thermal Control System. The Pump Flow Control Subassembly, PFCS for short, is a critical component of the ISS Photovoltaic Thermal Control System (PVTCS) in that it routes ammonia coolant to transport heat fr om the various electrical assemblies located within the Integrated Equipment Assembly to a Photovoltaic Radiator wh ere it is dissipated into space.

Спойлер

Without a functioning PFCS, its corresponding power channel has to be turned off since heat from solar power generation can no-longer be radiated overboard. ISS management desires to have a stockpile of critical parts like the PFCS available on board ISS to ensure a spacewalk on short notice can return the power channel to service via replacement of the PFCS.


ISS PVTCS Components – Image: NASA

Such a spacewalk occurred once to date in ISS history when ISS Power Channel 2B went down in 2013 due to a major ammonia leak on the PFCS, necessitating a five-and-a-half-hour spacewalk by Tom Marshburn and Chris Cassidy who successfully swapped the failed PFCS with a functioning, but used spare.

In total, ISS has eight PFCS units in operation – one for each power channel. At present (March 2018 ), there are two viable PFCS spares on ISS – a new unit installed on External Stowage Platform 1 which was among the first two external spare parts delivered to ISS back in March of 2001 on the STS-102 mission; and one previously used PFCS resides on the P6 truss of ISS after functioning within the Early External Thermal Control System (EETCS) from 2000 to 2007. The spare installed as part of the 2013 contingency EVA was also a former EETCS component with seven years of service under its belt.


Image: NASA

Having one used spare and one new but 17-year old unit leaves some uncertainty on their functionality and created the desire of launching a pristine unit to ISS to protect for the case of PFCS failures. Such failures are not fully unexpected since they were designed for a service life of 15 years which some that are currently in operation have already exceeded.

The 107-Kilogram PFCS is the heart of the PVTCS system as it consists of all the pumping capacity, valves and controls needed to circulate the heat transfer fluid, anhydrous ammonia, through the heat exchangers and the radiator, also regulating the temperature of the loop through setting the appropriate flow rates. Each unit is 102 by 74 by 48 centimeters in size.


Image: NASA

The eight individual Power Channels of the International Space Station are cooled by the Photovoltaic Thermal Control System (PVTCS) that circulates ammonia through Photovoltaic Radiators (PVRs) to dissipate excess heat generated by solar power generation in the Solar Arrays Wings and keep the EPS (Electrical Power System) at a stable temperature. There are four PVRs on ISS, one on each Truss Segment that features Solar Array Wings. Each PVR has two Decks, each supporting an individual PVTCS channel corresponding to the two power channels fed by the two SAWs. In case of the P6 PVR, channels 2B and 4B share one radiator.

The other ISS Systems are thermally controlled by the External Thermal Control System (ETCS) that uses Heat Rejection Subsystem Radiators (HRSRs) that cool all other electronics that are not part of the Photovoltaic System.


PFCS Handling during EVA – Photo: NASA TV

The systems are strictly separated to reduce the overall operating temperature of the ETCS Loops and to avoid technical challenges coming with cooling fluid being transferred through the rotating SARJs (Solar Alpha Rotary Joint). HRSRs and PVRs are not compatible due to a different cooling loop architecture.

The P6 Truss Segment is also outfitted with two EETCS Radiators (Early External Thermal Control System) that were used from 2000 to 2007 when the P6 Truss was located on top of the Z1 Segment as part of the early Space Station configuration. P6 has a TTCR (Trailing Thermal Control Radiator) and a STCR (Starboard TCR). These names are coming from the system's past life, back when they were deployed in position on top of Z1.

The EETCS provided thermal control to the ISS Modules while the assembly phase of ISS was still underway and the HRS was still under construction. Back in 2007, on Space Shuttle Mission STS-120, the two EETCS radiators were stowed and the P6 Truss took its spot next to P5. At that time the HRS was in place and the EETCS was no longer needed.


ISS PVTCS Flow Diagram – Image: NASA

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http://spaceflight101.com/dragon-spx14/removedebris/

RemoveDebris Satellite Overview

Photo: SSTL

RemoveDebris is a small satellite mission by Surrey NanoSatellite Technology Ltd. under a European Union Framework 7 research project to develop and fly a low-cost demonstrator for the key aspects of Active Debris Removal missions on a quest to address the growing space debris problem. The 100-Kilogram, cube-shaped satellite – the largest deployed fr om the International Space Station to date (2018 ) – will demonstrate active debris removal techniques by releasing, tracking and capturing two small CubeSats called DebrisSATs, in the process demonstrating different rendezvous, capture and deorbiting techniques to evaluate their feasibility for operational debris removal missions of the future.

Спойлер

The RemoveDebris mission comprises three principal components: RemoveSAT, the parent spacecraft based on the SSTL-50 platform, and two DebrisSATs, both complying with the 2U CubeSat form factor. DebrisSAT-1 is to be captured by means of a deployable net while a harpoon-based capture system will be tested on a boom-deployed target. DebrisSAT-2 will serve as a target for an optical navigation/tracking system and RemoveSAT will be tasked with an expedited deorbit with a deployable drag sail once its mission ends.


RemoveDebris Demonstration Milestones – Image: SSTL

ESA has taken a leading role in the field of space debris mitigation through a number of initiatives to develop clean space roadmaps and fund initial demonstration missions to acquire the tools needed for establishing an operational space debris management capability. These efforts are focused on two areas: a) debris mitigation through the removal of active satellites after their mission ends and b) debris mediation through the removal of passive debris objects. One particular area of focus is the removal of Envisat, an eight-metric-ton satellite in a near-800-Kilometer orbit that has been identified as a potential initiator of the Kessler Syndrome – a cascading formation of a large debris population making entire orbit regimes unusable.

The active removal of Envisat or any other sizeable space debris object is by no means a trivial matter and best completed as part of a step-wise evolution that allows for initial low-cost testing of technology and techniques in a realistic mission environment to reduce risk for the large-scale active removal mission. A number of elements are involved in active debris removal, including the need for optical rendezvous with a non-cooperative object, the secure capture of the object and the deorbiting technique for the combined spacecraft.


Image: Airbus/SSTL

The primary objective behind the RemoveDebris mission is raising the Technology Readiness Level (TRL) for four elements: 1) a capture system based on a net, 2) a capture system based on a harpoon, 3) a Visual Based Navigation System (VBN) using optical, infrared and LIDAR imaging, and 4) a deployable drag augmentation device for rapid removal fr om orbit (drag sail).

The net experiment to be performed by RemoveDebris will employ DebrisSAT-1, released from RemoveSAT at a relative speed of 0.05 m/s. The CubeSat will be tasked with inflating a balloon which increases its area to act as a deorbit device but also provides the "attack point" for the net. RemoveSAT will eject a net designed to wrap around the balloon by means of end masses and motor-driven winches to reel in the neck of the net and avoid re-opening. The CubeSat will then be left to decay on its own by means of increased drag.


RemoveDebris Payload Panel – Photo: SSTL

The harpoon experiment was originally planned to fire at a CubeSat but the hardware was later changed to extend a 10 x 10-centimeter target assembly around 1.5 meters from the RemoveSAT satellite body and fire the harpoon at that while cameras document the activity. DebrisSAT-2, originally planned to be harpooned in, will instead be allowed to float freely to serve as a target for the VBN navigation exercise.

At the end of these experiments, the satellite will deploy a 10 m² drag sail to remove itself from orbit in an accelerated fashion and demonstrate the sail design for future operational missions.

The RemoveDebris platform employs Surrey's SSTL-X50 satellite platform that builds on three decades of experience at SSTL to realize a low-cost satellite bus for a wide range of missions, satisfying the lifetime requirements for Earth Observation and LEO Communications operators.


SSTL-X50 Range – Image: SSTL

Initially, RemoveDebris was planned to employ the X50L configuration creating an envelope of 62 by 62 by 78 centimeters with a total mass of 150 Kilograms, but when it became clear the satellite would be launched from ISS, a reduction in size and mass was necessary to comply with the planned deployment using the Kibo Module's airlock and the NanoRacks Kaber deployment mechanism – switching to the smaller X50 platform and eliminating mass by removing a cold-gas propulsion system and switching to a less massive separation panel in the aft of the satellite.

RemoveSAT measures 55 by 55 by 76 centimeters in size and weighs around 100 Kilograms, making it the heaviest satellite to be deployed from the International Space Station.

The X50 platform is based on four aluminum-honeycomb-sandwich side panels, a payload panel dividing the internal volume in two tiers, and a separation panel made from machined aluminum to build the primary load-carrying element between the satellite and launch vehicle. The side and separation panels provide the mounting structure for the various satellite platform systems while payload equipment is installed on the payload panel, the upper section of the side panels and atop the avionics bay.


Image: Airbus/SSTL

Three of the four side panels are covered with solar cells to generate electrical power delivered to three Battery Charge Modules that control the central Li-Ion battery of the spacecraft from wh ere power is distributed via three Power Distribution Modules. The typical payload power of RemoveDebris is 8 Watts with peaks during operation of the payload.

SSTL-X50 employs a highly modular power and data handling architecture, relying on a pair of card frames – one for the electrical power system and one for the bulk of onboard avionics, holding the central Onboard Computer, data storage, attitude control and communication cards with backplane interconnections. This design approach provides a high degree of modularity while also simplifying manufacturability, integration and testing as well as redundancy – possible through the simple duplication of the relevant cards. The use of central card frames also reduces the mass of the cable harness used by conventional systems and reduces complexity and failure points.

While the use of CardFrames is a new element introduced by SSTL-X50, the rest of the satellite's systems rely on flight-proven components that have been used on previous SSTL platforms including attitude determination and control, communications and power systems.


100 SP-O Reaction Wheel – Photo: SSTL

The vast majority of RemoveDebris platform systems reside within the lower tier inside the satellite body, leaving the upper half of the spacecraft completely free for use by the various payload components including deployers for the CubeSats, the net, the harpoon and the drag sail which all point to the satellite +Z axis (the Orbit Normal Vector +Y).

The Attitude Determination and Control System of the RemoveDebris satellite uses reaction wheels and magnetic torquers as actuators and a suite of magnetometers, sun sensors and gyros for attitude determination to keep the satellite flying in its duty attitude with reasonable accuracy (allowing a stellar-free navigation scheme to be employed).

Four 100-SP-O reaction wheels are the primary attitude actuator, arranged to be able to tolerate the loss of one wheel without impact on satellite attitude control. The  reaction wheels are 13.1 centimeters in diameter and 12 cm tall with a mass of 2.6 Kilograms.


MTR-5 – Photo: SSTL

They are rated for 7.5 years of LEO operation and support a broad thermal environment. The RWA uses oil-lubrication and can deliver a maximum torque of 110 mNm which corresponds to a peak power demand of 113 Watts at max. torque. In standby mode, the wheels require 1.2W of power and the on-orbit average is around 10W. The wheels spin at up to 5,000RPM, limited by micro-vibration requirements.

The magnetic torquers chosen for Remove Debris are SSTL's MTR-5, each measuring 66 x 252 x 39 millimeters in size, weighing 500 grams and delivering a magnetic moment of +/-6.2 Am² at a power consumption of only 1 Watt. Magnetic Torque Rods create angular momentum by running a current through coils in the presence of Earth's magnetic field. The torquers are regulated by computers that control the current that is passing through the coils in order to control the force generated on each axis. The magnetic torquers are used during momentum dumps and for attitude control in spacecraft safe mode.


OBC750 – Photo: SSTL

Two AOCS Interface Modules are tasked with collecting and pre-processing data from the various actuators and delivering it to the central Data Handling System wh ere commands for the actuators are conditioned.

RemoveDebris relies on an SGR-20 Space-Based GPS Receiver and four patch antennas for position determination, precise orbit determination and time synchronization across the satellite.

The Onboard Data Handling Subsystem, facilitated within the OBDH CardFrame, consists of two redundant OBC750 onboard computers tasked with command and control of all satellite functions and a pair of redundant Payload Interface Units (PIUs) responsible for commanding of the various payloads and processing their data for storage and downlink. Additionally, a General Purpose Input/Output Board provides the interfaces with the various satellite subsystems through a CAN and LIN network and a Payload Power Supply Module conditions the payload-specific voltages.


SSTL CDH Architecture – Image: SSTL

The OBC750 is built around a BM PPC750FL processor and tasked with receiving and processing commands from Earth and controlling all satellite subsystems.

The computer has a memory of 6MB EEPROM (boot software), 256MB EADS, 16MB MRAM and 16MB Flash. It supports the 1553B high-speed data bus as well as two dual CAN buses, eight LVDS inputs and outputs, four opto isolated inputs and four opto isolated outputs. The OBC measures 32 by 32 by 6 centimeters and weighs under 2.5 Kilograms requiring 20 Watts of power during operation and 3W in standby.

Internally, X50 employs a Controller Area Network (CAN) to transmit and receive data from CAN-equipped components while a dual-redundant Local Interconnect Network (LIN) communicates with the power system modules and distributed switches with a dedicated STRx card tasked with bridging telemetry and telecommands between CAN and LIN.


Image: Airbus/SSTL

Two S-Band transceivers are employed for command uplink and data downlink with switchable downlink rates of 38.4 kbit/s in housekeeping mode and up to 4 Mbit/s when playing back science data and imagery.

The RemoveDebris payload panel holds the following components: two ISIPod deployers holding DebrisSAT-1 and 2, a Net Deployment Mechanism, a Harpoon and Target Assembly, the VBN optical navigation sensors and electronics, the DeOrbit Sail Deployer, two Supervision Cameras and the S-Band and inter-satellite communications antennas.

Most of the payload elements are affixed to the side panels above the payload panel; the net is attached to the payload panel through a cylindrical tube to place it as close to the satellite's center of gravity to avoid rotation torques as it is ejected. The Supervision cameras are mounted to provide the best possible views of what is occurring in front of the satellite (+Y).

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DebrisSAT-1 (DS-1)

Спойлер

DebrisSAT-1 & Deployable Structure – Image: SSC/SSTL/Airbus

The DebrisSAT-1 CubeSat is 10 x 10 x 22.7 millimeters in size, compliant with the 2U CubeSat platform to enable a standard-size ISIPod deployment mechanism to be utilized. It comprises a 1U avionics section while the rest of its internal volume is used up by the inflatable structure. To simplify its design, DS-1 only relies on batteries and does not employ solar cells since its lifetime can be limited to only a few minutes, covering the release and initial flyaway, the deployment of the balloon and the transmission of data to the parent spacecraft.

The avionics stack comprises the battery module, a camera to film the main spacecraft as the CubeSat drifts away, and a burn wire assembly that holds the deployable structure in place. Deployment of the DS-1 structure is accomplished in a two-stage process beginning with cutting the burn wire to release torsion springs which deploy six booms intersecting with a central structural component which facilitates the Cold Gas Generator that inflates the booms and membrane. The balloon is stabilized with wires to enter the shape of an octahedron.

Separation from RemoveSAT is accomplished through loaded springs within the ISIPod deployer creating a relative separation rate of only 0.05 meters per second which gives DS-1 a two-minute window for the deployment of its balloon.

RemoveSAT will eject the Airbus-built net once DS-1 is at a distance of seven meters. Once the net makes contact, it will wrap around the balloon with end masses and motorized winches reel the neck of the net to secure the satellite within it. The Supervision Cameras will document the net deployment and the dynamics occurring when it makes contact with the target.

The intersatellite link between DS-1 and RemoveSAT is employed for the deployment trigger sent by the parent spacecraft and the transmission of imagery from the DS-1 camera to RemoveSAT.

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DebrisSAT-2 (DS-2)

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DebrisSAT-2 Avionics – Image: SSC/SSTL/Airbus

DebrisSAT-2, involved in the VBN navigation exercise, is more complex than its 2U CubeSat Companion, featuring a power-generation system and an active attitude control system. DS-2 shares the same 2-Unit structure of DS-1 but incorporates a larger avionics stack borrowed from the QB50 project developed by Surrey in cooperation with Electronic Systems Laboratory at Stellenbosch University.

The satellite will deploy four 1U panels from its sides to remove the CubeSat Symmetry and so enable the VBN payload to identify its attitude. Internally, the QB50 stack comprises three boards: the CubeComputer, CubeControl and the CubeSense Boards.

The cubeComputer is in charge of data processing via a 32-bit ARM Cortex-M3 processor, a Field Programmable Gate Array builds the primary interface with the various satellite systems and a MicroSD Card is available for data storage. CubeControl facilitates a magnetometer and magnetic torquer unit and interfaces with the sun and nadir sensors installed on the CubeSense board to calculate the craft's orientation in space and command the torquers for attitude actuation. An additional board holds three reaction wheels to act as the primary attitude control device during the experiment; a dedicated GPS board provides position information relevant for putting the information collected by VBN into context.

The inter-satellite link with DS-2 will be used to relay telemetry and sensor data and to allow RemoveSAT to command the CubeSat into different orientations to collect data in different relative pointing modes. (Neither DS-1 nor DS-2 are equipped for space-to-ground communications.)

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Deployers

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Baseline ISIPod Design – Image: Innovative Solutions in Space

Both DebrisSats are released by dispensers provided by ISIS – Innovative Solutions In Space based on the company's standard deployment devices that have extensive flight heritage. However, the specific mission requirements of RemoveDebris resulted in a number of modifications needed on the deployment mechanisms.

In a typical launch vehicle mission, CubeSats are released within a handful hours of launch while Remove Debris will spend days if not weeks waiting for deployment from ISS followed by several days in free flight until the first CubeSat deployment event. One particularly important change was the integration of a power interface that allows the parent satellite to fully charge the CubeSat batteries prior to deployment and offering a data interface to the CubeSat computer to allow for a functional check before release.

The most significant alteration to the ISIPod deployers arises from the need of separating the two DebrisSATs at glacial speeds of 2 to 5 centimeters per second relative to the RemoveSAT parent to provide sufficient time for proximity operations. Typically, when launching on an upper stage, CubeSats are released at relative speeds of 1 to 2 meters per second.

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Net Demonstration

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Net Capture Mechanism – Image: Airbus/SSTL

Developed by Airbus Defence and Space, the Net Demonstration is a small-scale demo of a method for capturing uncooperative space debris that may not have the suitable external features for being captured with a robotic arm or a harpoon.

Within the framework of this demonstration mission, the starting conditions of the net capture are precisely controlled by placing a mock debris object (DebrisSAT-1) in a predictable position in front of the net release mechanism. Also, the demonstration will not actually capture the satellite by reeling in the net.

The basic working principle of the net relies on the fundamentals of physics: featuring end masses, the net will be released such that it expands to full size while traveling to its target and then wraps around it by means of the end masses which will wind the net closed while a motorized winch will tighten the neck area to prevent the net from unwinding again.

The Net Demonstration will be initiated upon ground command after DS-1's batteries are fully charged. Separation of the satellite will occur at a speed of around 5 centimeters per second and the parent spacecraft will send a command via inter-satellite-link to initiate the deployment of the octahedral structure from the CubeSat to provide the target for the net. When DS-1 is at a distance of seven meters, around 140 seconds after deployment, RemoveSAT will deploy the net from the Net Capture Mechanism directed along the same axis as the CubeSat separation vector.


Photo: SSTL

The Net Capture Mechanism is 27.5 centimeters in diameter and 22 centimeters tall, weighing 6.5 Kilograms. For a normal capture, the net would remain tethered to the parent spacecraft to reel in the captured debris, but RemoveDebris will release the net altogether to avoid two-body dynamic impacts.

The net chosen for this mission is a hemispherical spider-web type net with a fully expanded diameter of five meters using Kevlar for the net line material. It weighs around 600 grams and has a mesh size of 80 millimeters with a total of 196 meridian lines around the open edge of the net; less at the lid of the net. The winching mechanism connects the deployment masses with the lid and should provide a secure capture of the CubeSat and the inflated balloon, to be documented by the two Supervision Cameras along the +Y vector of the satellite.

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Harpoon Test Assembly

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Image: SSTL


Image: SSC/SSTL/Airbus

The Harpoon payload comprises two components: the Harpoon Capture System that delivers the harpoon and the Harpoon Target Assembly that extends from the satellite body to provide the impact target for the harpoon. The deployable target was developed by Surrey Satellite Center after the original mission design with three CubeSats was changed. The Harpoon Capture System is a design of Airbus DS Stevenage, UK.

The Harpoon Capture System is designed to establish a hard point attachment and provide a link to the debris collection satellite via a flexible coupling, chosen to reduce risk to the active spacecraft by capturing the debris from a safe stand-off distance and keeping the debris at safe distance for towing.

The advantages of the harpoon-based system are seen in its low mass that could allow a debris satellite to fly with multiple harpoon systems, a low development and operational risk through a simple design, a fast delivery of the harpoon to capture objects spinning at fast rates, and an ability to perform characterization of the capture in ground-based tests.

The Harpoon Target Assembly consists of a coiled Carbon-Reinforced Polymer mono-stable boom contained in a closed compartment. When released, the boom will deploy by means of a motor to place the 10 by 10-centimeter target panel at a distance of 1.5 meters to the Harpoon Capture System, in view of the dual supervision cameras. When the experiment is complete, the target panel (with the harpoon in it) will be retracted to avoid interference with the Drag Sail later in the mission.


Image: Airbus/SSTL

The Harpoon Capture System itself comprises three main elements: deployer, projectile and tether. The deployer imparts sufficient velocity to the projectile for penetration of the target structure, delivering it at a speed of over 20 meters per second which has been determined to be needed to reliably penetrate the typical aluminum honeycomb material used on modern-day satellites. The energy needed to send off the projectile is delivered by a one-use gas generator that directs high-pressure gas into a chamber to apply force against a piston which is held by a tear-pin until a force threshold is crossed. It then propels the projectile out of the deployer.

The projectile is designed to penetrate the 10 x 10 cm panel and deploy four barbs on the other side of the target, establishing the required locking interface that would enable pulling of a high-mass object. A shroud protects the barbs during penetration and allows the harpoon to successfully enter a structure at misalignments up to 45 degrees.

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Vision Based Navigation

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Image: SSTL

The Vision Based Navigation System VBN sets out to demonstrate a suite of sensors and onboard algorithms capable of providing rendezvous guidance with targets that have no provisions to assist with the rendezvous (non-cooperative targets). A number of previous missions carried such sensors in a shadow-mode while conducting orbital rendezvous maneuvers to collect real-world data feeding into the development of image processing and navigation algorithm techniques for non-cooperative rendezvous.

The VBN demonstration on the RemoveDebris Mission marks the next step to test out the equipment and algorithms in a scenario representative of an Active Debris Removal mission. Three objectives have been outlined for VBN: a) demonstrating state of the art image processing and navigation algorithms based on actual flight data, acquired through a standard camera and a flash imaging LIDAR, b) advancing the LIDAR to Technology Readiness Level 7 and c) demonstrating on-board processing of data to support real-time, autonomous navigation.


Image: Airbus/SSTL

The VBN hardware installed on the payload deck of the RemoveSAT spacecraft combines a conventional 2D camera (passive imager) with a flash-imaging LIDAR (Light Detection and Ranging) developed by CSEM (Swiss Centre for Electronics and Microsystems). This combination will allow for ranging capability by measuring the phase difference of the two signals.

VBN will be active for the release of DebrisSAT-1 for the collection of 3D and 2D validation images. The main target for the VBN demo is DS-2 that will be monitored over a long duration to capture data over a range of distances, relative attitudes, lighting conditions and background properties, attempting to track the small satellite for as long as possible. Ground-truth data to compare the VBN measurements to will come through GPS measurements from RemoveSAT and DS-2 that transmits its GPS readings via the inter-satellite link.

All data collected during the VBN experiment will be processed on the ground through 2D/3D and 3D/3D matching as well as tuned navigation algorithms running through Extended Kalman Filters to fuse data from different sensors including the two visual cameras and attitude sensing information.

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Supervision Cameras

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Photo: SSTL

RemoveSAT hosts two Supervision Cameras on its payload deck, one with a wide field of view of 65 by 54 degrees to capture the satellite separation events and the net demonstration and a narrow FOV camera to capture the harpoon demonstration across a 17 x 14° FOV. The two cameras employ a heritage design from the TechDemoSat-1 mission launched in 2014 and largely rely on Commercial Off The Shelf (COTS) technology that includes the CMOS sensor coupled to a standard machine vision lens.

Both cameras have been modified to withstand the launch and space environment and additional optimization with regard to their depth of field characteristics was made to meet the required performance for the demonstrations. The cameras collect 1280 x 1024-pixel imagery at a frame rate of ten frames per second.

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Drag Sail

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Image: Airbus/SSTL

The Drag Sail hosted by RemoveDebris is a Surrey Satellite Center design using the typical arrangement of four triangular sail areas held in place by four booms deploying axially from the satellite body. It comprises two components: an inflatable mast deployer which moves the sail away from the platform and an extension mechanism that drives the four booms holding the sail membrane to their fully extended position to create a 10m² sail area.

A burnwire sets in motion the mast deployment by means of two gas generators which deliver the force needed to inflate the mast and position the sail around one meter from the satellite body. After this, the deployment motors are powered up to unfurl the carbon-fiber booms and drag sail. This process is again covered by the supervision cameras to provide information on the performance of the deployment system and potentially unforeseen dynamics within the sail.

Because of the sail size, communications and power generation may become limited. Particular focus during the deployment will be on the performance of the sail itself as well as possible attitude disturbances introduced during deployment. The efficiency of the drag sail will be assessed through GPS orbit determination data from the satellite as well as orbit tracking data coming from different sources.

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http://spaceflight101.com/dragon-spx14/cargo-overview/

Dragon SpX-14 Cargo Overview

Dragon SpX-14 is the fourteenth operational mission of SpaceX's Dragon spacecraft to the International Space Station under NASA's Commercial Resupply Services contract. It is the first of at least three Dragon cargo missions planned in 2018.

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Loaded with more than two and a half metric tons of cargo, Dragon will be delivering the typical mix of utilization hardware, maintenance gear and cew supplies to the Space Station to keep up its capability of serving as a world-class laboratory in Low Earth Orbit. The 14th regular Dragon flight will carry three external payloads to the Space Station: the MISSE Flight Facility as a new state-of-the-art exposure facility for materials science outside the Space Station, the ASIM instrument to study interactions where Earth's atmosphere meets space, and a spare pump assembly for the Station's photovoltaic power-generation system.

The Dragon SpX-14 mission is part of the CRS-1 contact extension awarded by NASA to bridge a gap to the second round of Commercial Resupply Services contracts that cover the Space Station's cargo requirements for the first half of the 2020s. Under the CRS-1 extension, SpaceX will keep flying Dragon 1 spacecraft through CRS-20 while Orbital ATK received an order of three additional missions.

Dragon SpX-14 is the third SpaceX cargo mission to fly a re-used spacecraft and the second to employ a "flight-proven" Falcon 9 first stage as part of the company's re-use business model that has taken major steps toward becoming routine over the past year. The SpX-14 mission is re-using the Dragon C110 spacecraft that spent 33 days in orbit in April/May 2016 supporting the Dragon SpX-8 mission, delivering 3,136 Kilograms of cargo to the Space Station including the Bigelow Expandable Activity Module. The Falcon 9 launching this mission will employ Booster #1039 fr om the SpX-12 mission of August 2017.

NASA completed extensive reviews of data on the condition of previously flown Falcon 9 first stages and life-leader experimentation as well as SpaceX's successful re-use missions in 2017 to conclude that the use of flight-proven first stages comes with no to minimal additional risk to the success of the overall CRS mission. Engineering reviews cleared Dragon missions to fly on first stages with no more than one prior Low Earth Orbit mission, excluding first stages that have gone through more rigorous re-entry environments when flying higher energy missions like GTO deliveries. Dragon SpX-13 in late 2017 was the first NASA CRS mission to fly on a previously used Falcon 9.


Image: NASA

All in all, Dragon SpX-14 is delivering 2,647 Kilograms of cargo to the International Space Station, primarily focused on utilization hardware and dozens of science experiments – some of which are to be completed while Dragon is attached to ISS in order to ride back to Earth on the spacecraft. Also aboard the Dragon is the largest satellite to be deployed fr om the Space Station to date.

Dragon takes a unique spot on the Space Station's cargo vehicle roster, given its ability of returning meaningful quantities of cargo to the ground – allowing for the return to performed experiments for laboratory analysis and the return of failed hardware for inspections and/or refurbishment. To that end, Dragon SpX-14 will be tasked with ferrying nearly two metric tons of cargo back to Earth, primarily consisting of science hardware and experiment samples riding back to the ground in laboratory freezers and double cold bags.

[/li]
• Total Cargo: 2,647 Kilograms
• Pressurized Cargo (with packaging): 1,721 Kilograms
• Science Investigations: 1,070 Kilograms
• Satellites: Remove Debris, Overview 1A (?)
  

[/li][li]Vehicle Hardware: 148 Kilograms[/li][li]Crew Supplies: 344 Kilograms[/li][li]Computer Resources: 49 Kilograms[/li][li]Spacewalk Equipment: 99 Kilograms[/li][li]Russian Cargo: 11 Kilograms
[/li][/LIST][/li][li]Unpressurized Cargo: 926 Kilograms

[/li]
• MISSE-FF – Materials on ISS Experiment – Flight Facility
• ASIM – Atmosphere-Space Interactions Monitor
• PFCS – Pump Flow Control Subassembly
  

[/li][/LIST]
[/li][/LIST]

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RemoveDebris Satellite

>> RemoveDebris Satellite Overview

MISSE Flight Facility

>> Detailed MISSE-FF Overview

ASIM – Atmosphere-Space Interactions Monitor

>> ASIM Instrument Overview

PFCS Spare

>> PFCS Overview

NASA Sample Cartridge Assembly

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Liquid phase sintered tungsten alloy – Image: San Diego State University

The MSL SCA-GEDS-German experiment will be run in the Materials Science Laboratory aboard ESA's Columbus module to look into the underlying mechanisms of sintering processes and their ability of creating hardened materials. The Physical Sciences experiment was developed at San Diego State University under Principal Investigator Randall German.

Sintering is the process of compacting and forming a solid mass of material by heat or pressure, typically with the goal of creating a hardened piece of material. Typically, sintering occurs without melting the material to the point of liquefecation, though liquid-phase sintering has been a method used for the fabrication of net-shaped composite materials.

Although sintering has been used for centuries and is a critical element in a large number of industrial branches today, the underlying scientific principles are only poorly understood. The goal of this experiment is to determine the mechanisms driving the density, size, shape, and properties for liquid phase sintered bodies in Earth-gravity and microgravity conditions with special focus on the causes of distortion in the material that appears to be alleviated by the presence of a gravitational force.


Material Science Lab – Image: ESA

During low-temperature sintering, powders can gain strength through interparticle bonding – typically through solid-state surface diffusion, followed by further strengthening at high temperatures driven by densification of the powder material. However, a secondary process occurring at high temperatures causes a softening of the material due to a distortion phenomenon. While conducive for the formation of net-shaped composites it is counterproductive if only densification is desired. Working out the interplay between the various processes may allow for a sintering method to be developed that can accomplish densification without distortion.

Previous studies have shown surprising results as gravity may be playing a beneficial role in reducing distortion – in contrast to a very large number of physical processes wh ere gravity has been identified as a disturbing force. Microgravity liquid-phase sintering experiments performed to date have shown a lesser degree of densification and higher distortion, raising questions on the underlying mechanisms to fully understand the role of gravity to work out routes for minimized distortion.

It has been found that when a liquid phase forms, densification can be accelerated via solid transport within the liquid, capillary forces and liquid lubrication. This, however, only works to a certain degree as long as there are solid bonds or open pores in the sintering body. If the degree of liquefecation outweighs the solid material, substantial weakness is introduced.

Scientists have likened this process to building a sand castle which works poorly when one only has dry sand with no strength and no ability to hold shape or when sand is saturated with water. It works best with an intermediate mix wh ere the liquid pulls the sand grains into contact and gives the greatest strength.


Image: ESA

The MSL SCA-GEDS-German experiment observes phase changes and product formation within solid mixtures undergoing spontaneous reaction in the absence of gravity to find out what causes lower performance, an inability to eliminate pores, and higher distortion. Cartridges with different sample materials will be delivered to ISS by Dragon SpX-14 and fully processed within the Materials Science Laboratory (MSL) Low Gradient Furnace (LGF) followed by return to Earth for sample analysis with the added context of temperature profiles and other sensor data from the furnace.

Knowledge gained by this experiment will be beneficial for sintering processes on Earth as information on the underlying mechanisms of distortion will lead to better protocols to increase densification. For the spacefarers of the future, knowledge on sintering in zero- or reduced gravity environments is of importance as extraterrestrial repair and construction based on freeform fabrication from powders will be a key element of settlements on the Moon, Mars and beyond.

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Nano Racks Microscopes Facility

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Photo: NanoRacks

The NanoRacks Microscope Facility hosts three Commercial Off The Shelf (COTS) microscopes for use on the International Space Station to study in-situ samples in a simplified architecture using plug-and-play USB interfaces to allow the microscopes to be used from any laptop. "The NanoRacks Microscopes are ideally suited for examining specimen slides of yeasts and molds, cultures, plant and animal parts, fibers, bacteria, etc"

The first of the three Microscopes offers objectives for 5x, 10x and 20x magnification, Microscope-2 has the same video head but adds a lighting system and offers 20x to 40x, and 200x digital power magnification as well as a 20x eyepiece for viewing with 4x to 8x, and 50x power. Microscope-3 is a handheld microscope with a 5-megapixel imager, adjustable polarization to set the proper light level and reduce glare, eight LEDs for sample illumination, and 10x to 240x zoom magnification.

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Multi-Use Variable-G Platform

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Image: Techshot

The Multi-Use Variable-G Platform, MVG, is a product of Techshot to expand the Space Station's scientific repertoire by adding a new centrifuge facility capable of producing anything between microgravity and 2 G of artificial gravity. This will open up possibilities for a large number of studies, including commercial exploitation of the novel environment found on the International Space Station. MVG is suitable for a number of sample types, including fruit flies, flatworms, plants, fish, cells, protein crystals and many others.

MVP is a commercially developed, manufactured, owned and operated platform, offering a pair of 39-centimeter carousels that can produce up to 2G of artificial gravity with six experiment modules on each carousel. The facility is designed to allow for easy exchange of sample modules, permitting a large number of experiments to be completed with little crew time requirements. Real-time video and still imagery, including microscopy, can be provided for each sample module per the specific needs of every experiment and the facility provides additional environmental control with a temperature range of 14 to 40 °C and a humidity between 50 ad 80% while data logging is provided for Oxygen and Carbon Dioxide.

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Veggie PONDS

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Veggie Facility – Photo: NASA

Veggie PONDS uses the existing Veggie plant-growth hardware present on the International Space Station as well as knowledge gained through the initial experiment runs to develop a passive nutrient delivery system that could build the basis for the reliable plant production facilities on future long-duration space missions. PONDS, the Passive Orbital Nutrient Delivery System, addresses some of the deficiencies found with the standard plant pillow system employed by the initial Veggie runs and will also expand the facility's envelope by supporting larger leafy vegetables and fruit crops like tomatoes which will be grown as part of the Veg-05 experiment.

The PONDS system is designed to mitigate microgravity effects on water distribution, increase oxygen exchange and provide sufficient room for root zone growth. The initial PONDS experiment has the goal of validating whether improved water and nutrient delivery can produce a more uniform plant growth and increase crop yields.


Lettuce Plants growing inside Veggie Facility – Photo: NASA

The experiment will use 'Outredgeous' red romaine lettuce and mizuna mustard plants, the former has been used for studies Veg-01 through Veg-03 and will allow for comparisons between plant pillows and PONDS. Another aspect will be studying the microbial load of plants grown during the initial Veggie runs and those provided with PONDS technology.

The PONDS architecture was designed at the Kennedy Space Center and involves contributions by TechShot, and commercial partner Tupperware. PONDS retains the arcillite, a calcined clay type, as growth medium which has been sel ected through comparative studies in the earlier Veggie runs and PONDS continues as single-use hardware, only employed for one growth run to manage microbial contamination. Like previous runs, PONDS will use the cut-and-come again harvest technique with four planned harvests or more if plant growth allows.

The crew will be cleared to consume any lettuce that is not needed for analysis on the ground.


Mixed Crops inside Veggie – Photo: NASA

Veg-01 ran in 2014 and provided valuable data in the form of returned water samples and root pads, imagery acquired in orbit of the growth process, and plant samples that were brought back to Earth. This data helped investigators assess the two different growth media with respect to water and root distribution within the different sized particles to chose media for future Veggie missions.

Although the overall Veg-01 experiment was a success, a number of deficiencies with regard to the plant pillows and the water delivery systems were identified leading to modifications made to the pillows and watering procedures that will be tested by Veg-03, also introducing a different crop with different water requirements. In 2015, the Space Station crew got their first taste of home-grown lettuce harvested from the Veggie Plant Growth Unit. Another 2015 study provided the crew with a touch of color when the first flowers grown on ISS were harvested by Astronaut Scott Kelly.


Space-Grown Zinnia Flowers in Veggie Facility – Photo: NASA

Veg-03 A-C tested different crop harvest techniques, showing that cut-and-come again repetitive harvest could be used to double the amount harvested with the same set of starting materials; Veg-03 B and C tested a new crop, Tokyo bekana. The Veg-03 D-F experiments looked into mixed growth of different leafy greens and different harvest schedules.

The Veggie experiment facility provides lighting and nutrient supply and is capable of supporting a variety of plant species that can be cultivated for educational outreach, fresh food and even recreation for crewmembers on long-duration missions. Thermal control is provided fr om ISS in-cabin systems and the carbon dioxide source is the ambient air aboard ISS.

Plants grown in the Veg-03 facility will be observed to determine how plants sense gravity and how they respond to microgravity. Serving as a pathfinder, the plants grown as part of VEGGIE will be harvested and studied before being cleared for consumption by crew members in orbit. The VEGGIE facility is the largest volume available aboard ISS for plant growth, which will allow the study of larger plants that could not be grown in previous experiments.


Photo: ORBITEC

Veggie uses a plant growth chamber using planting pillows and an LED bank to provide lighting. Ground testing of the pillow planting concept led to the selection of growth media and fertilizers, plant species, materials, and protocols. The facility weighs 7.2 Kilograms and measures 53 by 40 centimeters and permits a maximum growth height of 45 centimeters. The root mat has a growing area of 0.16m² with a 2-liter fluid reservoir.

The system draws 115W of peak power and its LED banks can support adjustable wavelengths, light levels and day and night cycles to match the biological needs of the plants. A transparent teflon cover allows viewing of the plants. The plants will be photographed regularly to assess plant growth rates and health. Tissue samples will provide information on possible growth anomalies when being compared to ground controls. Environmental data will be provided by a data logger that measures temperature, humidity and pCO2.

The first studies performed with VEGGIE will also provide microbial samples of the plants and pillows to assess the level of microbial contamination and implement corrective measures if needed. For most species, microbial contamination levels will be well within limits and pose no threat to the crew. Other species that naturally have higher levels of microorganisms may need a sanitation method which must be developed and tested as part of the experiment. Growing plants in space provides crewmembers with fresh foods to supplement their diets, as well as a positive effect on morale and well-being.

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STEMonstrations: Kinetic and Potential Energy

NASA Johnson

Опубликовано: 3 апр. 2018 г.

Watch NASA astronaut Joe Acaba demonstrate kinetic and potential energy on the International Space Station by showing how an object's potential energy changes due to its position. How can potential be converted into kinetic energy?

 (2:49)

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04/04/2018 11:24 Stephen Clark

Closing in on the International Space Station a day-and-a-half after lifting off fr om Cape Canaveral, SpaceX's Dragon cargo capsule is set to arrive at the orbiting research complex at 7 a.m. EDT (1100 GMT) Wednesday, when Japanese astronaut Norishige Kanai will capture the supply ship with the station's robotic arm.

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The unpiloted Dragon supply ship carries more than 5,800 pounds (2,600 kilograms) of hardware, crew provisions and experiments, including a habitat with 12 rodents for a Japanese research investigation, a Danish-developed instrument to study high-altitude electrical discharges from thunderstorms, and a European smallsat aimed at testing technologies that could eliminate space junk.

Kanai will be assisted by NASA flight engineer Scott Tingle during Dragon's approach and capture operations. Astronaut Ricky Arnold will be monitoring communications between the space station and Dragon. The crew will be on standby to manually issue hold or retreat commands to the Dragon spacecraft, which will be flying on autopilot.

Laser navigation sensors and thermal cameras aboard the Dragon capsule will collect data on the range, closure rate and orientation between the supply ship and the space station.

The Dragon capsule lifted off at 4:30 p.m. EDT (2030 GMT) Monday from Cape Canaveral.

Since liftoff, the cargo craft has completed several orbit adjustments using its rocket thrusters to boost itself to the space station's altitude more than 250 miles (400 kilometers) above Earth.

The Dragon will arrive at a hold point 350 meters -- or 1,150 feet -- below the space station around two hours before its scheduled capture by the robotic arm. The spacecraft will conduct a 180-degree yaw maneuver to align its grapple fixture with the position of the station's robotic arm before continuing the approach.

Soon after beginning its final approach sequence, the Dragon spacecraft will halt again at a hold position 250 meters, or 820 feet, below the space station. This brief hold allows ground controllers to assess the status of the rendezvous and issue a "go" for the Dragon to enter the so-called keep-out sphere, an imaginary circle around the space station in which traffic is tightly controlled for safety reasons.

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The Dragon spacecraft should depart the 250-meter hold point around 5:30 a.m. EDT (0930 GMT), heading for a 30-meter hold position before pressing on to a final point about 10 meters, or 33 feet, beneath the space station for capture by the robot arm.

Once in the grasp of the robot arm, Dragon will be maneuvered to a berthing port on the space station's Harmony module, wh ere it will stay until May 2. The supply ship will head back to Earth for a parachute-assisted splashdown in the Pacific Ocean with around two tons of research specimens and other equipment requiring analysis and refurbishment.

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