Автор Salo, 16.09.2008 16:05:48
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ЦитатаNovember 18, Monday11 a.m.-2:30 p.m. - MAVEN Launch Coverage (Launch is scheduled for 1:28 p.m. - There is a two-hour launch window) KSC (All Channels)4 p.m. - MAVEN Post-Launch Press Conference (2.5 hours post-launch) KSC (All Channels)
ЦитатаNASA's MAVEN Spacecraft has been installed atop its Atlas V 401 launch vehicle on Friday to begin final checkouts ahead of launch on November 18, 2013.After pre-launch processing of the MAVEN spacecraft was complete, the spacecraft was closed out ahead of its encapsulation in the Atlas V payload fairing. The fairing itself underwent inspections and cleaning inside the Payload Hazardous Servicing Facility at the Kennedy Space Center. On Friday, November 1, MAVEN was installed atop its Payload Adapter that is used to attach the spacecraft to the Atlas V rocket. Over the weekend, teams started the installation of the fairing, getting the first half installed around the spacecraft. The second fairing half was moved in place on Monday and installation was completed as planned. Tuesday featured a number of closeouts so that the encapsulated spacecraft could be hoisted atop the Payload Transporter on Wednesday. Later, teams discovered a leak in a gaseous purge line that is part of the ground support system. The purge line was replaced and MAVEN's rollout was pushed back by 24 hours. Starting at 12:33 a.m. local time on Friday, the spacecraft was rolled from the Kennedy Space Center to Space Launch Complex 41 at Cape Canaveral Air Force Station. MAVEN arrived at SLC-41 at 2:59 a.m. local time.After teams completed setup tasks, the fairing was hoisted above the Atlas V 401 rocket and was precisely lowered onto the launch vehicle for installation. The spacecraft was soft-mated at 7:45 a.m. and teams started to firmly attach the stack. When all structural attachments are made, electrical and data lines will be connected.The installation of the MAVEN spacecraft atop the Atlas V marks the start of extensive integrated testing of the combined system to make sure all sub-systems are connected properly and can receive commands. The Atlas V integrated systems test will be performed on Monday. Also, the vehicle will undergo a number of countdown and launch simulations to ensure all commands are sent at the appropriate times. Final activities for the MAVEN spacecraft include health checks and battery charging that is completed ahead of the launch countdown. Currently, operations are on track for an on-time launch of MAVEN on November 18, 2013 during a two-hour launch window opening at 18:28 UTC.------Spaceflight101 | November 8, 2013
ЦитатаMAVEN affixed to Atlas 5 rocket for Nov. 18 launchBY STEPHEN CLARKSPACEFLIGHT NOWPosted: November 8, 201 NASA's MAVEN spacecraft, the centerpiece of a $671 million mission to study the atmosphere of Mars, reached its penultimate stop before liftoff when technicians transported the delicate probe to the Atlas 5 rocket's seaside launch complex Friday. Encapsulated inside its payload fairing, MAVEN is hoisted inside the Vertical Integration Facility for attachment to the Atlas 5 rocket. Credit: NASA/Kim Shiflett The milestone move marks one of the final visible steps ahead of the mission's launch, which is on schedule for Nov. 18 at 1:28 p.m. EST (1828 GMT).Technicians began transferring the 2.8-ton spacecraft from its clean room at the Payload Hazardous Servicing Facility at 12:33 a.m. EST aboard a specialized transporter. The road trip across Kennedy Space Center took about two-and-a-half hours, and NASA says MAVEN arrived at the launch pad at 2:59 a.m. EST.MAVEN was already enshrouded inside the nose cone of its Atlas 5 rocket. The cone-shaped fairing shields the payload from contaminants and airflow during ground preparations and the first phase of launch.United Launch Alliance hooked up a crane to the top of MAVEN's payload fairing and hoisted the spacecraft inside the Atlas 5's Vertical Integration Facility, and technicians completed the initial attachment of MAVEN to its launch vehicle at 7:45 a.m. EST, according to NASA.Mechanical and electrical connections were expected to be completed later Friday, followed by a spacecraft power-up Saturday to check MAVEN's health after the trip across Kennedy Space Center.An integrated systems test is on tap for Monday to ensure MAVEN and the 189-foot-tall Atlas 5 are working together, according to NASA.Friday's movement to the launch pad was delayed a day to repair a faulty purge system inside the Atlas 5's integration building.The Atlas 5 has finished its standalone testing after ULA workers propped up the rocket's first stage booster and Centaur stage inside the 29-story VIF in early October. The ULA launch team put the Atlas 5 through a full countdown rehearsal Oct. 29, including loading of the rocket with kerosene, liquid hydrogen and liquid oxygen propellants. Credit: ULA The Atlas 5 assigned to MAVEN's launch features no solid rocket boosters, a four-meter payload fairing and a single-engine Centaur upper stage. This is known as the "401" configuration in the Atlas 5 nomenclature.The two-stage rocket will be rolled out to the launch pad at Cape Canaveral's Complex 41 at 10 a.m. EST on Nov. 16, making the 1,800-foot trip from its assembly building in about a half-hour under the power of specially-designed "trackmobiles" to push the launcher and its mobile platform to the pad.The day before launch, Nov. 17, is a day off for launch crews before the countdown begins at dawn Nov. 18, leading to the opening of a two-hour launch window at 1:28 p.m. EST.The Mars Atmosphere and Volatile Evolution, or MAVEN, mission will separate from the Atlas 5's Centaur upper stage about 52 minutes after liftoff, deploy its electricity-generating solar panels and begin its interplanetary cruise to Mars.Arrival in orbit around the red planet is set for Sept. 22, 2014, if the launch occurs Nov. 18.Follow Stephen Clark on Twitter: @StephenClark1.
ЦитатаNASA's next Mars mission buttoned up for launch Technicians with Lockheed Martin and United Launch Alliance encapsulated NASA's Mars-bound MAVEN spacecraft on Nov. 2 inside a four-meter diameter payload fairing. Workers installed the fairing in two halves before latching the shroud together and installing the nose cone's separation system. MAVEN will use the Atlas 5's "large payload fairing" option, which measures about 14 feet in diameter and 39 feet tall. Built at ULA's facility in Harlingen, Texas, the fairing is made of aluminum skin and stringers with vertical split-line longerons. The payload fairing protects MAVEN during its stay at the launch pad and shields the sensitive spacecraft during the Atlas 5's initial phase of flight through the lower atmosphere. The fairing will be jettisoned about four-and-a-half minutes after liftoff Nov. 18. Credit: NASA/Kim Shiflett
ЦитатаAtlas 5/MAVEN launch timelineBY SPACEFLIGHT NOWPosted: November 8, 2013T-0:00:02.7 Engine StartThe Russian-designed RD-180 main engine is ignited and undergoes checkout prior to launch.T+0:00:01.1 LiftoffThe Atlas 5 vehicle, designated AV-085, lifts off and begins a vertical rise away from Space Launch Complex 41 at Cape Canaveral Air Force Station, Fla.T+00:17.3 Begin Pitch/Roll/Yaw ManeuverThe 188-foot-tall Atlas 5 begins to maneuver itself on the proper trajectory east of Complex 41 on an azimuth of 94 degrees.T+01:30.9 Max-QThe Atlas 5 rocket passes the region of flight known as maximum dynamic pressure, or Max-Q.T+0:04:02 Main Engine CutoffThe RD-180 main engine completes its firing after consuming its kerosene and liquid oxygen fuel supply in the Atlas first stage.T+0:04:08 Stage SeparationThe Common Core Booster first stage of the Atlas 5 rocket separates from the Centaur upper stage. Over the next few seconds, the Centaur engine liquid hydrogen and liquid oxygen systems are readied for ignition.T+0:04:18 Centaur Ignition 1The Centaur RL10 engine ignites for the longer of the two upper stage firings. This burn will inject the Centaur stage and MAVEN spacecraft into a parking orbit.T+0:04:26 Nose Cone JettisonThe payload fairing that protected the MAVEN spacecraft during the climb through the atmosphere is no longer needed and is separated.T+0:13:48 Centaur Cutoff 1The Centaur engine shuts down after arriving in a planned parking orbit. The vehicle enters a lengthy coast period lasting nearly 28 minutes before arriving at the required location in space for the second burn.T+0:41:24 Centaur Ignition 2The Centaur re-ignites to propel the payload into the desired Earth escape trajectory from the parking achieved earlier in the launch sequence.T+0:46:53 Centaur Cutoff 2At the conclusion of its second firing, the Centaur will have delivered the MAVEN spacecraft on a hyperbolic escape trajectory toward Mars.T+0:52:42 Spacecraft SeparationNASA's Mars Atmosphere and Volatile Evolution, or MAVEN, spacecraft is released from the Centaur upper stage to complete the AV-038 launch.Data source: United Launch Alliance
ЦитатаAtlas launch ground trackThis map illustrates the ground track that the Atlas 5 rocket will follow during launch. Credit: ULA
ЦитатаMAVEN launch windowsBY STEPHEN CLARKSPACEFLIGHT NOWPosted: November 11, 2013Editor's Note: The daily launch window for the Atlas 5 rocket carrying NASA's Mars Atmosphere and Volatile Evolution (MAVEN) mission extends 2 hours in duration for liftoff from Cape Canaveral's Complex 41.All times are Eastern.DATE.........WINDOW OPEN......WINDOW CLOSENOV. 18......1:28 p.m.........3:28 p.m. ESTNOV. 19......1:22 p.m.........3:22 p.m. ESTNOV. 20......1:15 p.m.........3:15 p.m. ESTNOV. 21......1:07 p.m.........3:07 p.m. ESTNOV. 22......12:59 p.m........2:59 p.m. ESTNOV. 23......12:53 p.m........2:53 p.m. ESTNOV. 24......12:46 p.m........2:46 p.m. ESTNOV. 25......12:36 p.m........2:36 p.m. ESTNOV. 26......12:26 p.m........2:26 p.m. ESTNOV. 27......12:19 p.m........2:19 p.m. ESTNOV. 28......12:08 p.m........2:08 p.m. ESTNOV. 29......11:57 a.m........1:57 p.m. ESTNOV. 30......11:45 a.m........1:45 p.m. ESTDEC. 1.......11:32 a.m........1:32 p.m. ESTDEC. 2.......11:22 a.m........1:22 p.m. ESTDEC. 3.......11:07 a.m........1:07 p.m. ESTDEC. 4.......10:51 a.m........12:51 p.m. ESTDEC. 5.......10:33 a.m........12:33 p.m. ESTDEC. 6.......10:13 a.m........12:13 p.m. ESTDEC. 7.......9:57 a.m.........11:57 a.m. ESTDEC. 8.......9:32 a.m.........11:32 a.m. ESTDEC. 9.......9:15 a.m.........11:15 a.m. ESTDEC. 10......8:57 a.m.........10:57 a.m. EST
ЦитатаFRIDAY, NOVEMBER 15, 2013This morning's launch readiness review gave a "go" to continue launch preparations for Monday's liftoff of a NASA spacecraft destined to probe the upper atmosphere of Mars.The review concluded there were no technical issues standing in the way of Monday's launch at 1:28 p.m. EST (1828 GMT) at the opening of a two-hour window.The decision clears the way for the 1,800-foot move of the Atlas 5 rocket from its Vertical Integration Facility to the launch pad at Cape Canaveral's Complex 41 on Saturday. The half-hour rollout should begin at 10 a.m. EST (1500 GMT).Once on the pad, the Atlas 5 and its mobile launch platform will be connected to the facility's fluid and electrical supplies Saturday afternoon. Sunday is scheduled to be a crew rest day before the countdown begins early Monday.The weather forecast issued this morning by Air Force meteorologists hasn't changed much from the outlook released yesterday.There continues to be a 60 percent chance of favorable weather for launch Monday, but conditions worsen Tuesday and Wednesday with only a 40 percent and 30 percent probability of acceptable weather those days.The main worries Monday are still cumulus clouds, disturbed weather and thick clouds.THURSDAY, NOVEMBER 14, 2013Weather forecasters expect to be watching rain showers and thick clouds during Monday's countdown to launch NASA's MAVEN mission to Mars, meteorologists reported Thursday.The forecast for Monday calls for a 40 percent chance of violating the Atlas 5 rocket's weather constraints, with the primary threat coming from cumulus clouds, thick clouds and disturbed weather associated with rain showers, according to meteorologists with the U.S. Air Force's 45th Weather Squadron.The Atlas 5's two-hour launch window opens at 1:28 p.m. EST (1828 GMT)."On launch day, high pressure migrates east into the western Atlantic in advance of the next cold front along the Eastern seaboard and extending into the Florida panhandle," forecasters wrote in a weather synopsis. "Moisture increases through the day with isolated showers developing in the morning and increasing through the afternoon. The bulk of the weather associated with the advancing cold front is expected to remain just to the north with a shower threat over Central Florida."There is a low lightning threat during the count. Winds are expected from the south with gusts in the mid to upper teens [at 230 feet]. The primary concerns for launch day are cumulus clouds, disturbed weather associated with showers, and thick clouds with the quite moist atmosphere."The outlook calls for scattered clouds at 2,500 feet, broken clouds at 10,000 feet and an overcast cloud deck at 24,000 feet with isolated showers in the area. Winds will be out of the south at 12 to 16 knots, temperatures are forecast to be around 76 degrees Fahrenheit, and visibility is predicted to be 7 miles.Forecasters expect the weather to deteriorate over Central Florida on Tuesday and Wednesday, with a 60 percent chance of exceeding weather rules Tuesday and a 70 percent chance Wednesday."In the event of a 24-hour delay, the aforementioned cold front advances into Central Florida during the count and becomes near stationary in the Central Florida vicinity. Showers are likely during the count with a small thunderstorm threat."In the event of a 48-hour delay, the cold front remains near stationary just to the south with a disturbed weather pattern over Central Florida. The pressure gradient tightens Tuesday evening with gusty winds for the 48 hour delay," the forecast says.Conditions are expected to be favorable for Saturday's rollout of the 189-foot-tall Atlas 5 to the launch pad at Cape Canaveral's Complex 41. The rollout is scheduled to begin at 10 a.m. EST (1500 GMT) and will take about a half-hour to complete.A launch readiness review is on tap Friday to give final approval for the rollout.
Цитата1530 GMT (10:30 a.m. EST)Topped with NASA's next Mars mission, the first devoted to study of the Martian atmosphere, the United Launch Alliance Atlas 5 rocket has arrived at its launch pad after completing the first one-third of a mile of the journey to the red planet.The voyage resumes Monday at 1:28 p.m. EST (1828 GMT) with liftoff of the two-stage Atlas 5 rocket. Monday's launch window extends for two hours.The countdown will begin at 6:28 a.m. EST Tuesday (1128 GMT), leading to activation of the rocket, final testing and system preps. Fueling operations start at 11:35 a.m. EST (1635 GMT)."United Launch Alliance is proud to provide NASA's ride to Mars for this very critical science mission," said Jim Sponnick, ULA's vice president of Atlas and Delta programs. "Over the last decade, ULA launch systems have successfully launched all of NASA's missions to the red planet, including the Spirit and Opportunity rovers and most recently the Mars Science Lab mission with the Curiosity rover."The weather forecast from the Air Force's 45th Weather Squardon calls for 40 percent chance of violating launch constraints.The outlook predicts scattered, broken and overcast cloud decks at 2,500, 10,000 and 24,000 feet with showers and isolated rainshower activity. Winds will be out of the southwest at 10 to 15 knots with a temperature of approximately 77 degrees Fahrenheit.The primary concerns for Wednesday morning are violating the thick cloud, disturbed weather and the cumulus cloud rules.If the launch gets pushed back to Tuesday or Wednesday, a cold front pushes into the area, bringing a chance for thunderstorms and windier conditions. The chance of violating weather rules Tuesday and Wednesday is 60 percent and 70 percent, respectively.Watch this page for live updates throughout the countdown and flight, plus live streaming video.We will also be tweeting updates during the countdown, so sign up for our Twitter feed to keep up with the Atlas 5/AEHF 3 mission and all the latest space news. U.S. readers can also receive test messages on your cellphone by texting "follow spaceflightnow" to 40404. (Standard text messaging charges apply.)1525 GMT (10:25 a.m. EST)The Atlas 5 rocket is nearing its destination at Complex 41.1501 GMT (10:01 a.m. EST)The United Launch Alliance Atlas 5 rocket's rollout to the pad is underway!This slow, half-hour drive from the 30-story Vertical Integration Facility to Cape Canaveral's Complex 41 pad uses a pair of specially-made "trackmobiles" to carry the rocket's 1.4-million pound mobile launching platform along rail tracks for the 1,800-foot trip.The 188-foot-tall satellite booster is moving to Cape Canaveral's Complex 41 for the launch of MAVEN, NASA's next Mars orbiter.The two-stage rocket and the MAVEN spacecraft were put together inside the assembly building over the past 36 days in preparation for this rollout event. The Atlas 5 is designed to spend minimal time at the launch pad, which does not include a service gantry like other sites.1455 GMT (9:55 a.m. EST)It is rollout morning for the Atlas 5 rocket, which is about to emerge from its 30-story Vertical Integration Facility for a quick trip to the launch pad.1435 GMT (9:35 a.m. EST)A United Launch Alliance Atlas 5 rocket will roll to its oceanfront launch pad at Cape Canaveral Air Force Station on Saturday morning for blastoff Monday with a $671 million Mars orbiter dedicated to atmospheric research.Rollout is due to begin at 10 a.m. EST (1500 GMT), with the Atlas 5 rocket riding on rails from the 30-story Vertical Integration Facility to the launch pad at Complex 41. The journey should take about a half-hour to complete.The rollout begins the final day-and-a-half of launch preparations for the Atlas 5, which is making its 41st flight since debuting in August 2002 with the launch of a commercial communications satellite for Eutelsat. It also marks the 76th rocket flight conducted under the auspices of United Launch Alliance since 2006.Affixed to this Atlas 5 launcher is NASA's MAVEN spacecraft, a 5,420-pound platform equipped with instruments to sniff the contents of the Martian upper atmosphere and monitor the planet's response to solar storms.The goal is to learn how Mars transformed from a warmer, wetter planet into the barren world of today.Monday's launch is scheduled for a two-hour window opening at 1:28 p.m. EST (1828 GMT).The 188-foot-tall Atlas 5 is flying in the "401" configuration with a four-meter payload fairing manufactured at ULA's facility in Harlingen, Texas, no solid-fueled boosters provided and a single RL10 upper stage engine provided by Aerojet Rocketdyne.Built by Lockheed Martin Corp., MAVEN is embarking on a 10-month cruise to the red planet, with arrival set for Sept. 22, 2014, if the launch occurs Monday.Monday's rollout comes after 36 days of assembly and testing of the Atlas 5 rocket inside the Vertical Integration Facility.Stacking of the Atlas 5 rocket began with the standing up of the launcher's first stage inside the VIF on Oct. 11. Technicians hoisted the rocket's Centaur upper stage into position Oct. 14.The MAVEN spacecraft, encapsulated inside the Atlas 5's payload fairing, topped off the rocket Nov. 8.
ЦитатаAtlas 5 journeys to Cape Canaveral launch pad A United Launch Alliance Atlas 5 rocket rolled its seaside launch pad Saturday ahead of the launch of NASA's MAVEN spacecraft heading for Mars. Riding along rails and powered by a pair of specially-made "trackmobiles," the Atlas 5 and its mobile launch platform completed the 1,800-foot rollout from its 30-story Vertical Integration Facility in about 30 minutes, arriving atop the launch deck at about 10:30 a.m. EST (1530 GMT) Saturday. Workers planned to connect the rocket with ground electrical, fluid and pneumatic supplies, then take the day off Sunday before coming on console early Monday to begin the countdown. Liftoff from Cape Canaveral's Complex 41 is set for 1:28 p.m. EST (1828 GMT) at the opening of a two-hour launch window. Credit: NASA/Kim Shiflett Credit: NASA/Kim Shiflett Credit: United Launch Alliance Credit: NASA/Bill Ingalls Credit: United Launch Alliance Credit: United Launch Alliance Credit: United Launch Alliance Credit: NASA/Kim Shiflett Credit: United Launch Alliance Credit: NASA/Kim Shiflett Credit: NASA/Kim Shiflett Credit: NASA/Kim Shiflett Credit: NASA/Bill Ingalls Credit: Justin Ray/Spaceflight Now Credit: Justin Ray/Spaceflight Now[/B]
ЦитатаMars orbiter set for launch on atmospheric research missionBY STEPHEN CLARKSPACEFLIGHT NOWPosted: November 17, 2013 An Atlas 5 rocket is geared up for launch fr om Cape Canaveral on Monday with a NASA spacecraft dreamed up a decade ago to help solve the puzzle of how Mars cooled off and dried up sometime long ago, likely killing off any life that may have existed there. Artist's concept of MAVEN at Mars. Credit: NASA/Goddard The Mars Atmosphere and Volatile Evolution, or MAVEN, mission carries a suite of instruments built by scientists across the United States to sample the red planet's upper atmosphere and gauge its composition, dynamics and response to a stream of radioactive particles fr om the sun.Scientists do not know how Mars transformed fr om a world with lakes, rivers and potential life into a barren planet without any sign of life today."We're trying to understand why the climate changed on Mars - why Mars appears to have gone from an environment that was habitable, to microorganisms at least, to one that is the cold, dry, uninhabitable environment we see today," said Bruce Jakosky, MAVEN's principal investigator from the University of Colorado at Boulder's Laboratory for Atmospheric and Space Physics.Data from ongoing Mars missions, including NASA's Curiosity rover, have convinced scientists Mars once had ample moisture and harbored warmer temperatures, giving it all the ingredients necessary to support life at some point in its 4.6-billion-year history."We don't just launch missions to Mars one at a time," said John Grunsfeld, head of NASA's science division. "We have an integrated program of Mars exploration. We've been following a path of looking for water on Mars, looking for current water and past water. We've now confirmed that ... We're transitioning into the search for biosignatures, past evidence that life could have started on Mars. And we don't have that answer yet. That's part of the quest trying to answer, are we alone in the universe, in a broader sense."Despite an onslaught of missions over the past decade-and-a-half, including four rovers, a stationary lander, and four orbiters, there is scant evidence for how and when Mars lost its thick atmosphere, leaving a thin blanket of gas just above the surface.Scientists posed that question when developing the proposal for the $671 million MAVEN mission in 2003, Jakosky said."One of the big questions has been what happened to the climate? Why did it change? What we're trying to do is answer that question of wh ere did the water go? Wh ere did the [carbon dioxide] from the early thick atmosphere go? There are two places it can go," Jakosky said. "It can go down into the crust and be locked up there, or it can go up and be lost to space. We have evidence that both of those happened, but we don't see reservoirs of [carbon dioxide] in the crust that could explain what happened to the early thick atmosphere. We're trying to explain the role of loss to space."Asked if he felt anxious, nervous or excited on the eve of launch, Jakosky replied: "All of the above."MAVEN is the first mission dedicated to surveying the Martian upper atmosphere, and the probe also hosts an Electra radio to join NASA and European orbiters providing communications relay between Earth and the rovers on the surface."By looking at the nature of the upper atmosphere today, we learn about the processes that control the atmopshere, and we're going to have a good understanding of what the history of the atmosphere has been," Jakosky said.Fitted with eight instruments, MAVEN is set to blast off from Cape Canaveral, Fla., at 1:28 p.m. EST (1828 GMT) Monday aboard a United Launch Alliance Atlas 5 rocket.Powered by a Russian-built RD-180 engine, the Atlas 5 will ascend from the Florida coastline, break the sound barrier about 78 seconds into flight and rocket into the upper atmosphere in four minutes before releasing its kerosene-fueled first stage to fall back into the Atlantic Ocean. The Atlas 5 rocket is poised on the launch pad after rollout Saturday. Credit: NASA/Kim Shiflett An RL10 engine on the Atlas 5's Centaur upper stage will ignite two times, first to put MAVEN in a parking orbit around Earth, then to shoot the 5,420-pound spacecraft toward Mars. Deployment of MAVEN is expected about an hour after launch.MAVEN is programmed to radio its status to a pair of ground stations in Australia moments later, and its two wings of power-generating solar panels should be unfurled within 15 minutes of spacecraft separation, according to David Mitchell, MAVEN's project manager at NASA's Goddard Space Flight Center in Maryland.The solar arrays stretch 37.5 feet tip-to-tip, about the length of a school bus. Filled with propellant, MAVEN weighs about the same as a fully-loaded SUV, according to NASA.The trip to Mars will take 10 months, and MAVEN is due to put itself into orbit there with a make-or-break 38-minute braking burn scheduled for Sept. 22, 2014, assuming the launch occurs as planned Monday. "There's quite an interest in this mission," said Omar Baez, NASA's launch director for the MAVEN mission. "You wouldn't think so in that it's not as sexy as the rovers going over the planet, but this is kind of like a weather satellite for mars, and it's providing relay. It's real science."Several more engine firings next fall will put MAVEN into its operational orbit, which will take the probe as close as 93 miles to Mars and as far as 3,860 miles, completing lap of the planet every four-and-a-half hours."Every orbit, we're dipping down below the altitude from which gas is lost, so we sample that column directly on every orbit," Jakosky said.The probe has to extend several instrument booms once it arrives at Mars, allowing MAVEN's sensors to be far enough away from the spacecraft to avoid interference and collect pristine measurements. One of the deployable platforms holds three instruments, allowing those sensors to pivot and point toward Mars while the craft's solar arrays are aimed the sun to charge its batteries.By early November 2014, MAVEN should be ready to begin its science campaign, which will last at least one Earth year. MAVEN's science instruments come from institutions across the United States and France. Some of the payloads will track the sun's influence on Mars. Diagram of MAVEN and its instrument package. Credit: NASA/Goddard "Mars is responding in various ways, literally bristling with loss processes," said Janet Luhmann, MAVEN's deputy principal investigator from the University of California at Berkeley. "MAVEN is instrumented specifically to be able to measure what's coming in and what's going out."Unlike other Mars missions, MAVEN does not carry a camera. As a cost-saving measure, Jakosky said he decided to lim it MAVEN's expenditures to those focused on its prime science mission.Other sensors will identify the gases, ions and elements making up the tenuous outer reaches of the Martian atmosphere."This will allow us to estimate over long time periods, on the order of billions of years ... how long Mars has been exposed to this loss process and, therefore, how much atmosphere has been removed in this way," Luhmann said.One way MAVEN will try to quantify how much of the atmosphere was lost to space is measuring concentrations of heavy and lighter isotopes of gases. Scientists think Mars should hold a greater number of heavy isotopes because lighter atoms would have been easier to strip away with the solar wind, a stream of charged particles coming from the sun."Over billions and billions of years, you leave more of the heavy stuff in the atmosphere," said Paul Mahaffy, lead scientist for one of MAVEN's instruments."What got me into this were the measurements of isotopes of the noble gases in the atmosphere," Jakosky said. "The key one that got me excited about this was the ratio of argon-38 to argon-36 because on Mars, it's been measured through Martian meteorites and now confirmed with [the Curiosity rover], that the ratio of argon-38 to argon-36 is about 20-to-30 percent greater than on Earth, and the only thing that can explain that is loss to space, so to me that's a direct measurement proving that atmospheric loss to space was an important process."Earth's strong magnetic field makes it more resistant to atmospheric decay from the solar wind, but Mars does not have the global magnetism required to hold on to air over billions of years."We think that escape to space has been responsible for removing a lot of gas from the atmosphere, and we designed this mission to try to understand how those processes work, and see if we can measure things that will tell us how much gas has escaped over time," Jakosky said.MAVEN will get to Mars just after the peak of the sun's 11-year solar cycle, so scientists hope to get a front-row seat on how a strong solar wind impacts the planet's atmosphere."What we're really getting at is understanding the history of the climate, the history of the volatile inventory, and I think the understanding of the history of the habitability of Mars by microbes," Jakosky said. "I see it as a geology mission, or an astrobiology mission, because that's what we're getting at by studying the top of the atmosphere and its interactions with the sun."Follow Stephen Clark on Twitter: @StephenClark1.