AFSPC-11, EAGLE (ESPA Augmented Geostationary Laboratory Experiment): HTI-SpX, MYCROFT, CEASE-III-RR, ISAL, ARMOR - Atlas V 551 (AV-079) - CCAFS SLC-41 - 22:00 14.04.2018 - 02:41 15.04.2018 (UTC)

[Старый]

Apollo13 пишет: 
Возможно ещё NROL-67 был.

Всё, NROL-67 отменяется. Центавр остался на орбите 7957 x 39139 x 11.44 градуса.
Так что видимо текущий запуск будет первым. Самое время РД-181 подвести.  

[tnt22]

https://www.ulalaunch.com/missions/next-launch-Atlas-V-AFSPC-11

[/li]
• Launch Date: Saturday, April 14, 2018
  
• Launch Time: 7:13 p.m. EDT
  
• Launch Broadcast: Live launch coverage will begin at 6:53 p.m. EDT
  

23:13 UTC (02:13 2018-04-15 ДМВ). Трансляция начнётся за 20 мин до пуска

[tnt22]

James Dean‏Подлинная учетная запись @flatoday_jdean 36 мин. назад

Atlas V targeting 7:13pm ET Saturday launch of AFSPC-11 from Cape Canaveral AFS. Full window not specified. Weather looks good Saturday evening, bad Sunday if backup date needed.

[tnt22]

Прогноз погоды L-2 

AV-079 AFSPC-11 L-2 Forecast

80% GO 
Резервный день: ↓↓ 20%

[tnt22]

Atlas V AFSPC-11 Mission Profile

United Launch Alliance

Опубликовано: 12 апр. 2018 г.

 (1:50)

[tnt22]

http://www.losangeles.af.mil/News/Article-Display/Article/1491135/afpsc-11-mission-set-to-launch/

AFPSC-11 Mission Set to Launch
SMC Public Affairs Office / Published April 12, 2018



CAPE CANAVERAL AIR FORCE STATION, Fla. --
The AFSPC-11 mission is set to launch aboard a United Launch Alliance Atlas V rocket from Cape Canaveral Air Force Station, Florida, April 14.

A live feed will begin 20 minutes prior to the launch at 6:53 p.m. EDT and concluding approximately 45 minutes following launch. The launch broadcast can be viewed at http://www.ulalaunch.com/site/pages/multimedia_webcast.shtml.

Спойлер

The AFSPC-11 mission team is led by the Air Force's Space and Missile Systems Center's Launch Systems Enterprise Directorate, located at Los Angeles Air Force Base, California.

The Air Force Space Command's Space and Missile Systems Center, located at the Los Angeles Air Force Base, Calif., is the U.S. Air Force's center of excellence for acquiring and developing military space systems. Its portfolio includes the Global Positioning System, military satellite communications, defense meteorological satellites, space launch and range systems, satellite control networks, space based infrared systems, and space situational awareness capabilities.

[свернуть]

[tnt22]

Tory Bruno‏Подлинная учетная запись @torybruno 9 мин. назад

#AFSPC11

[tnt22]

Tory Bruno‏Подлинная учетная запись @torybruno 6 мин. назад

Planning to roll a couple million pounds out to the pad today. Think good weather thoughts. #AFSPC11

[tnt22]

Прогноз погоды L-1 

AV-079 AFSPC-11 L-1 Forecast

80% GO 
Резервный день: 20%, шторм

[tnt22]

Tory Bruno‏Подлинная учетная запись @torybruno 6 мин. назад

The bird and payload are prep'ed and configured for roll. Weather looks good. #AFSPC11

[tnt22]

Spaceflight Now‏ @SpaceflightNow 7 мин. назад

A @ulalaunch Atlas 5 has started its journey from the Vertical Integration Facility to launch pad 41 at Cape Canaveral, in advance of liftoff Saturday evening on a satellite delivery mission for the US Air Force. https://spaceflightnow.com/2018/04/13/av-079-mission-status-center/ ...

[tnt22]

Upd ated: 04/13/2018 16:35 Stephen Clark

On the eve of launch with two U.S. Air Force satellites, a United Launch Alliance Atlas 5 rocket set for rollout to its launch pad this morning at Cape Canaveral.

The rocket will make the 1,800-foot journey from ULA's Vertical Integration Facility to the Complex 41 launch pad beginning around 10 a.m. EDT (1400 GMT).

The 197-foot-tall Atlas 5 will make the trip on top of a mobile launch platform pushed by locomotives along rail tracks leading to the launch pad. The transfer should take less than an hour to complete.

The Atlas 5 is se t for liftoff during a launch window that opens at 7:13 p.m. EDT (2313 GMT) Saturday and closes at 9:11 p.m. EDT (0111 GMT Sunday).

The rocket will carry the Air Force's Continuous Broadcast Augmenting SATCOM, or CBAS, spacecraft in the upper position inside the payload shroud. The Evolved Expendable Launch Vehicle (EELV) Secondary Payload Adapter (ESPA) Augmented Geosynchronous Laboratory Experiment satellite -- better known as EAGLE -- rides in the lower berth.

The CBAS satellite will "provide communications relay capabilities to support our senior leaders and combatant commanders," the Air Force said in a statement. "The mission of CBAS is to augment existing military satellite communications capabilities and broadcast military data continuously through space-based, satellite communications relay links."

EAGLE is host to several military experiments.

[tnt22]

ULA‏Подлинная учетная запись @ulalaunch 3 мин. назад

Rollin rollin rollin. #AtlasV is rollin. See that rocket rollin, let's go! @AFSpace @AF_SMC @usairforce

[tnt22]

04/13/2018 17:50 Stephen Clark

The Atlas 5 is nearing its destination at pad 41, approaching the facility's Crew Access Tower, which will be used for astronauts boarding Boeing's CST-100 Starliner capsule when it begins flying people in late 2018 or early 2019. Photo credit: Steven Young/Spaceflight Now

[tnt22]

04/13/2018 17:58 Stephen Clark

The Atlas 5 rocket has arrived at Complex 41 after a trip from the Vertical Integration Facility. The Atlas 5's mobile platform followed rail tracks leading to the pad as two "trackmobile" vehicles pushed the stack.

Спойлер

Automatic couplers will connect the Atlas 5 to the launch pad's ground systems, and the Atlas 5 team will complete inspections, checkouts and other activities this afternoon. The agenda today also includes filling of the first stage with RP-1 kerosene fuel.

Liquid oxygen will be loaded in the first stage during the countdown tomorrow evening, along with liquid hydrogen and liquid hydrogen for the Atlas 5's Centaur upper stage.

The latest forecast issued this morning indicates an 80 percent chance of favorable weather conditions during tomorrow's launch window, which opens at 7:13 p.m. EDT (2313 GMT).

"On launch day, high pressure continues to migrate east as the aforementioned cold front advances into the Gulf Coast states in the morning and near the Florida Panhandle during the window," the Air Force wrote in an outlook issued Friday morning. "Moisture is limited early in the count trending up gradually by the evening hours with the warm southerly winds. Diurnal heating will aid in developing limited isolated showers over Central Florida. No thunderstorms are expected."

Forecasters predict gusty southeast winds Saturday evening, partly cloudy skies and isolated rain showers in the vicinity of Cape Canaveral. The temperature during the launch window will be around 77 degrees Fahrenheit, and the main weather concern for liftoff will be cumulus clouds.

If the launch is pushed back to Sunday, there is only a 20 percent chance of favorable weather, with widespread showers and thunderstorms in the forecast.

[свернуть]

[tnt22]

[tnt22]

Emre Kelly‏Подлинная учетная запись @EmreKelly 55 мин. назад

Update: Launch window for #AtlasV #AFSPC11 now runs from 1913 to 2111 ET (2313 to 0111 UTC).

[tnt22]

https://spaceflightnow.com/2018/04/13/atlas-5-rocket-readied-for-high-altitude-dual-satellite-flight-saturday/

Atlas 5 rocket readied for high-altitude dual-satellite flight Saturday
April 13, 2018 | Stephen Clark


The Atlas 5 rocket rolls out to pad 41 Friday. Credit: ULA

United Launch Alliance crews at Cape Canaveral are finishing final preparations for an Atlas 5 rocket launch Saturday evening to dispatch two U.S. military satellites directly to an orbital perch more than 20,000 miles over the equator.

Set for blastoff at 7:13 p.m. EDT (2313 GMT) Saturday, the Atlas 5 rocket will fly in its most powerful configuration, helped off Cape Canaveral's Complex 41 launch pad with five Aerojet Rocketdyne-built solid rocket boosters and a Russian-made RD-180 main engine producing a combined 2.6 million pounds of thrust.

A military communications payload and a free-flying spacecraft hosting multiple Pentagon-funded experiments will ride the Atlas 5 rocket on a marathon six-hour mission to an altitude near geostationary orbit, the region over the equator where objects take advantage of orbital dynamics to hover over a fixed position on Earth.

Спойлер

The geostationary belt is populated by numerous data relay, missile warning and surveillance satellites operated by militaries and commercial companies.

Saturday's launch window extends until 9:11 p.m. EDT (0111 GMT Sunday), according to an Air Force spokesperson, and there is an 80 percent chance of acceptable conditions for liftoff in the official launch forecast issued by the U.S. Air Force's 45th Weather Squadron.

An approaching cold front will worsen weather conditions over Florida's Space Coast on Sunday.

"On launch day, high pressure continues to migrate east as the aforementioned cold front advances into the Gulf Coast states in the morning and near the Florida Panhandle during the window," the Air Force wrote in an outlook issued Friday morning. "Moisture is limited early in the count trending up gradually by the evening hours with the warm southerly winds. Diurnal heating will aid in developing limited isolated showers over Central Florida. No thunderstorms are expected."

Forecasters predict gusty southeast winds Saturday evening, partly cloudy skies and isolated rain showers in the vicinity of Cape Canaveral. The temperature during the launch window will be around 77 degrees Fahrenheit, and the main weather concern for liftoff will be cumulus clouds.

If the launch is pushed back to Sunday, there is only a 20 percent chance of favorable weather, with widespread showers and thunderstorms in the forecast.

Ground teams transferred the Atlas 5 rocket to its launch pad Friday morning. The 197-foot-tall (60-meter) rocket rode a mobile launch platform fr om the Vertical Integration Facility to the Complex 41 launch pad, pushed by locomotives along rail tracks for the 1,800-foot (500-meter) journey.

Once firmly on the launch pad, the Atlas 5 and its mobile platform were scheduled to be plugged into ground propellant and electrical supplies. Workers planned to load RP-1 kerosene fuel in the Atlas 5's first stage Friday afternoon in advance of Saturday's countdown, which will kick off shortly after 12 p.m. EDT (1600 GMT).

The ULA launch team will power up the Atlas 5 rocket, test its telemetry transmitters, guidance system and range safety mechanisms, and fill the launcher's Centaur upper stage with a cryogenic mixture of liquid hydrogen and liquid oxygen. The first stage will also receive its supply of liquid oxygen, to be consumed with RP-1 fuel by the Atlas 5's RD-180 main engine.

The countdown will have two built-in holds, and the final pre-planned pause at T-minus 4 minutes will give engineers time to catch up on last-minute troubleshooting and complete a poll of the launch team for approval to enter the terminal countdown sequence.

In the final four minutes of the countdown, the Atlas 5 will switch to internal power and pressurize its propellant tanks. A final status check is planned in the last 30 seconds before liftoff.

The rocket's RD-180 main engine will ignite at T-minus 2.7 seconds, throttling up to 860,000 pounds of thrust before the Atlas 5's five strap-on solid rocket boosters fire to send the launcher into the sky.

Heading nearly due east, the Atlas 5 will surpass the speed of sound in 34 seconds. The rocket's five strap-on motors will empty their propellant casings and jettison in two groups beginning at T+plus 1 minute, 47 seconds.

The Atlas 5's Swiss-made nose cone and a load-bearing structure around the rocket's Centaur upper stage will separate around three-and-a-half minutes after liftoff. In the final phase of its burn, the RD-180 main engine will throttle back to lim it acceleration on the Atlas 5's satellite payloads, then switch off at T+plus 4 minutes, 33 seconds, in preparation for stage separation.

The Centaur stage's RL10C-1 main engine will ignite at T+plus 4 minutes, 49 seconds, for a six-minute firing to reach a preliminary low-altitude parking orbit. Two more RL10 burns are planned, with the second maneuver starting at T+plus 22 minutes, 57 seconds, followed by a lengthy five-hour coast before the Centaur stage reignites to maneuver into a circular orbit slightly above geostationary altitude.

The rocket's guidance computer will aim to reach an orbit approximately 24,200 miles (39,000 kilometers) over the equator, according to mission data released by ULA.

The Atlas 5's two satellite passengers — the Continuous Broadband Augmented SATCOM spacecraft and a satellite known by the acronym EAGLE — will deploy from the Centaur upper stage approximately six hours after liftoff.

Saturday evening's flight is the first time an unclassified Atlas 5 mission has placed geostationary payloads so close to their final orbital positions. Details of top secret missions for the National Reconnaissance Office, the U.S. government's spy satellite agency, have not been disclosed.

The high-altitude deployment is in contrast to the mission profile for most satellites heading to geostationary orbit. In those cases, launchers release their payloads in an elliptical transfer orbit, and the spacecraft must use it own propellant to raise its altitude and null out its inclination to arrive on station over the equator.

A direct trip to geostationary orbit requires a long-duration coast and an engine restart after six hours in space, a capability used by ULA on multiple Delta 4 rocket flights.

Saturday's flight, codenamed AFSPC 11, will be ULA's fourth of 2018, and the third by an Atlas 5 rocket, which has logged 76 missions since 2002. It will be the eighth launch from Cape Canaveral since Jan. 1, including launches by ULA's Atlas 5 and SpaceX's Falcon rocket families.

AFSPC 11 is the 28th Atlas 5 mission for a branch of the U.S. military, and the 46th Atlas 5 launch with a U.S. national security payload. It is the eighth time an Atlas 5 rocket has flown in the launcher family's most capable "551" version with five boosters, a five-meter fairing and a single-engine Centaur upper stage.


The mission patch for the AFSPC-11 mission set for launch on a United Launch Alliance Atlas 5 rocket Saturday. " The dial is turned to 11 to capture the spirit of the AFSPC-11 government launch team and its mission: maximizing efforts to meet Department of Defense requirements to support our senior leaders and combatant commanders with war-winning space capabilities, on time and on schedule," the Air Force says regarding the mission logo. Credit: U.S. Air Force

Two satellites are fastened inside the Atlas 5's nose cone for Saturday's launch

The upper payload is a military communications satellite named CBAS, short for Continuous Broadcast Augmenting SATCOM.

"CBAS is a military satellite communications spacecraft destined for geosynchronous orbit to provide communications relay capabilities to support senior leaders and combatant commanders," the Air Force's Space and Missile Systems Center said in a statement. "CBAS will augment existing military satellite communications capabilities and broadcast military data continuously through space-based, satellite communications relay links."

The Air Force kept the identity of the main payload on Saturday's launch secret until April 6. An Air Force spokesperson declined to identify the contractor that built the CBAS satellite (pronounced "sea bass"), and the military released no further details on the mission.

"The Air Force issued the contract per standard Department of Defense acquisition practices in cooperation with defense industry partners," the spokesperson said. "Per Department of Defense acquisition practices, details of the spacecraft source selection are not releasable."

The lower passenger is the Evolved Expendable Launch Vehicle (EELV) Secondary Payload Adapter (ESPA) Augmented Geosynchronous Laboratory Experiment satellite. The Air Force calls the nested acronym EAGLE for short.

Orbital ATK developed the EAGLE spacecraft by outfitting a structural adapter often used to connect small satellites to their launchers, adding solar panels, computers, rocket thrusters and instrumentation. The Air Force says EAGLE will a pathfinder for future missions, demonstrating a maneuverable satellite design that could help the military launch new capabilities at less cost.

Managed by the Air Force Research Laboratory's space vehicles directorate at Kirtland Air Force Base, New Mexico, the EAGLE mission "hosts experiments designed to detect, identify, and attribute threatening behavior as well as enhance Space Situational Awareness," the Air Force said in a statement.

One of the experiments is a separating daughter satellite named Mycroft, apparently named for the older brother of the fictional sleuth Sherlock Holmes. In one Sir Arthur Conan Doyle's short stories, Sherlock Holmes says Mycroft possesses observational and deductive abilities greater than his own.

The Air Force describes Mycroft as a "fourth-generation space situational awareness experiment." The service said the satellite will test technology that could be used by future missions to survey, catalog and inspect objects in geostationary orbit.

The Mycroft satellite, also built by Orbital ATK, "will explore ways to enhance space object characterization and navigation capabilities, it will investigate control mechansms used for flight safety, and it will explore the designs and data processing methods for enhancing space situational awareness," the Air Force wrote in a fact sheet on the mission.

Mycroft is a follow-up to the Air Force's ANGELS satellite, which launched into an orbit just above the geostationary belt in 2014 and ended its mission in November. ANGELS inspected the upper stage of its Delta 4 rocket soon after launch, then tested in-orbit surveillance, navigation and rendezvous operations for the rest of its mission.

According to the Air Force fact sheet, Mycroft will fly to a distance of around 21 miles (35 kilometers) from EAGLE, then re-approach the mother satellite to a range of about a kilometer, or 3,300 feet.

Mycroft will evaluate the region around the EAGLE satellite with an on-board camera, the Air Force said, and use its sensors and software to perform advanced guidance, navigation and control functions.

"The space domain is crucial today and will only increase in value moving into the future," said Maj. Gen. William Cooley, commander of the Air Force Research Laboratory. "If the Air Force is to truly embrace space superiority then improving our ability to protect and defend vital space interests is of paramount importance."

The Air Force said engineers have completed "rigorous research and development" to ensure Mycroft can safely fly through the congested geostationary orbit region.

Mycroft weighs a few hundred pounds, and its main body is no bigger than a mini-refrigerator, with a deployable solar panel out the side.

The EAGLE satellite is scheduled to operate at last one year, and the Mycroft mission is expected to last 12 to 18 months, the Air Force said.

"Other experiments hosted on the EAGLE will detect, identify and analyze system threats such as man-made disturbances, space weather events or collisions with small meteorites," the Air Force wrote in a fact sheet released Friday. "Together, EAGLE and Mycroft help train operators and development of tactics, techniques and procedures during exercises or experiments to improve space warfighting."

[свернуть]

The launch team at Cape Canaveral planned to send the CBAS and EAGLE mission skyward April 12, but last week delayed the flight to Saturday to replace a valve.

[tnt22]

http://spaceflight101.com/atlas-v-afspc-11-preview/

Five-Booster Atlas V Rolls out for Direct-to-GEO Launch with CBAS & EAGLE
 April 13, 2018

Photo: United Launch Alliance

The most powerful version of ULA's Atlas V rocket rolled to its Florida launch pad on Friday to set the stage for liftoff in the early evening on Saturday on a direct climb into Geostationary Orbit to dispatch a pair of payloads for the United States Air Force.

Designated AFSPC-11, the mission features two stacked payloads under the rocket's five-meter payload fairing – the CBAS military communications satellite rides in the top position to deliver secure communications to combatant leaders while the EAGLE experimental platform in the lower slot sets out to release a small satellite and test new technologies for Space Situational Awareness and resilient satellite missions of the future.

Atlas V – sporting five Solid Rocket Boosters for maximum liftoff power – is targeting launch at 23:13 UTC on Saturday, 7:13 p.m. local time at Cape Canaveral Air Force Station. The direct-to-GEO mission will take nearly seven hours and require three upper stage burns, aiming for a drift orbit over Earth's equator from where the two payloads will maneuver to their classified operational locations. Weather is expected to be favorable for Saturday's 58-minute launch window before conditions deteriorate on Sunday and a range conflict looms on Monday with a Falcon 9 rocket set to launch NASA's TESS exoplanet telescope.

Спойлер

Depiction of CBAS in ULA's Mission Booklet for AFSPC 11 – Credit: United Launch Alliance

Saturday's launch will be the 77th flight of the Atlas V rocket since its debut in 2002 and only the eighth of the 551 version which comes into play for high-performance missions, having sent the New Horizons and Juno probes to explore Pluto and Jupiter, and doing some heavy-lifting on five deliveries for the Multi-User Objective System of the U.S. Navy, one of three primary communications architectures operated by the U.S. military in Geostationary Orbit.

The primary purpose of the CBAS satellite launching on Saturday appears to be augmentation of the three existing systems, though not much is known about the spacecraft. The identity of the primary payload of the AFSPC-11 mission was only revealed earlier this month when the U.S. Air Force announced that the CBAS satellite had finished launch base testing ahead of launch atop an Atlas V rocket.

CBAS stands for "Continuous Broadcast Augmenting SATCOM" and is a geostationary communications satellite designed for communications relay capabilities to support senior leaders and combatant commanders. "The mission of CBAS is to augment existing military satellite communications capabilities and broadcast military data continuously through space-based, satellite communications relay links," the Air Force said when announcing CBAS as primary AFSPC-11 payload.


EAGLE in Space – Image: Orbital ATK

Neither the satellite's manufacturer nor any operational details like its payload, operating frequencies and desired position in Geostationary Orbit were disclosed to the public in the run-up to launch.

Affixed between Atlas V's Centaur upper stage and CBAS is EAGLE – a multi-purpose platform designed as a high-performance system for technology demonstration and operational missions in the form of hosted payloads and separable satellites. Built by Orbital ATK and hosting at least five Air Force Research Lab-sponsored payloads, EAGLE stands for "Evolved Expendable Launch Vehicle (EELV) Secondary Payload Adapter (ESPA) Augmented Geosynchronous Laboratory Experiment (EAGLE)."

Orbital ATK's ESPAStar platform takes the ESPA adapter system as a basis and adds power generation, propulsion, attitude control, data storage and communications infrastructure that can be shared by up to six hosted payloads installed around the ESPA ring. EAGLE, to public knowledge, hosts one separable satellite and four attached payloads primarily dedicated to the evaluation of systems for Space Situational Awareness – an area of focused development due to efforts underway by multiple countries to come up with the technology to study and potentially manipulate resident objects in orbit.


ESPASat Platform (MYCROFT likely similar) – Image: Orbital ATK

To be deployed from EAGLE is the MYCROFT satellite, understood to be a follow-on mission to the 2014 ANGELS demonstration of an agile satellite capable of flying up to another object in space and collecting information on it using different sensors. The payloads to remain attached to EAGLE include a Hypertemporal Imaging Experiment tasked with blending imagery obtained of targets in different wavelength bands over a period of time to extract a maximum of information; an Inverse Synthetic Aperture Ladar will demonstrate the use of this technology to produce ultra-high resolution imagery of other objects in space to eventually replace electro-optical imaging systems used on today's inspection satellites.

EAGLE also hosts a small-sized space weather monitoring package designed to measure all primary space environment effects that impact the operation of a satellite while another demonstration evaluates the components of a "resilient" spacecraft platform for a future tamper-proof satellite.


AFSPC 11 Mission Insignia – Credit: U.S. Air Force

Currently the most powerful in ULA's Atlas V arsenal, the 551 version offers a total payload upmass of 3,812 Kilograms for a direct Geostationary Injection. EAGLE weighs at most 1,848 Kilograms, leaving between 1,960 and 3,100 Kilograms for CBAS. Both payloads and any separable satellites will likely receive USA designations and amateur satellite trackers are expected to be the only source of information on their orbital activities.

Meteorologists expect generally favorable conditions for Saturday's launch window with an 80% chance of acceptable weather, cumulus clouds being the only concern. For Sunday's backup slot, odds worsen significantly to only a 20% chance of favorable conditions as a cold front will push from the Florida Panhandle into Central Florida by late Sunday evening, bringing the potential for strong thunderstorms, gusty winds and clouds. Skies are expected to clear rapidly after the frontal boundary passes and conditions on Monday/Tuesday are expected to be very favorable for launching rockets. Atlas V is booked on the range for Saturday and Sunday while Falcon 9/TESS has the range on Monday and Tuesday.

Having gone through clean readiness reviews earlier in the week, the AFSPC-11 mission was cleared to the launch pad and Atlas V emerged from its integration facility around 10 a.m. local time on Friday to move to the pad at Cape Canaveral's SLC-41 for the typical one-day on-pad campaign. Teams expect to load the first stage booster with Rocket Propellant 1 later on Friday before buttoning up the launch facility for the start of a lengthy countdown operation on Saturday.
 

Atlas V Countdown & Flight Profile

Photo: United Launch Alliance

Atlas V countdown operations begin around seven hours before the opening of the day's launch window when the launch team reports to console at the Atlas Spaceflight Operations Center for the activation of the two-stage rocket for a multi-hour checkout operation to ensure all systems are ready to support the mission. Approaching L-4 hours, the Launch Team puts the Atlas V through a series of communication checks on its S- and C-Band Systems and also goes through Flight Termination System testing before applying the purge flow to the vehicle in advance of propellant loading.

Coming out of a planned hold at T-2 hours, Atlas V enters the complex procedure to load the two stages with cryogenic propellants. Over the course of an hour and a half, 185,500 liters of Liquid Oxygen will be pumped into the Common Core Booster first stage while the upper stage receives 15,700 liters of the -183°C oxidizer plus 48,100 liters of -253°C Liquid Hydrogen. The first stage receives its dose of Rocket Propellant 1 before the countdown.

>> Atlas V Countdown Timeline

When clocks reach T-4 Minutes, the countdown enters its second built-in hold for final polling of the launch team prior to pressing into Terminal Count. This hold can be extended in case of technical issues or uncooperative weather, taking advantage of the mission's 58-minute launch window.

As clocks start ticking down from T-4 Minutes, final vehicle configurations such as ordnance arming, flight termination system arming, propellant tank pressurization, transfer to internal power, and flight control system reconfigurations will be made as part of the Automated Sequence to place the vehicle in its launch configuration.

Standing over 60 meters tall, Atlas V will come to life at T-2.7 seconds when its two-chamber RD-180 engine will soar to a launch thrust of 390 metric ton-force. As the five boosters ignite, Atlas V will jump off the pad with a liftoff thrust of 1.25 Million Kilogram-force creating an initial thrust to weight ratio of 2.15. Less than four seconds after liftoff, Atlas V will start its roll and pitch program to align itself with its precise ascent path to the east.

>> Atlas V 551 Launch Vehicle Overview


Photo: ULA (MUOS 2)

The five Aerojet-Rocketdyne Solid Rocket Boosters will push Atlas V beyond the speed of sound by T+35 seconds and the vehicle will encounter Maximum Dynamic Pressure 46 seconds into the flight; RD-180 will be operating at reduced thrust during this phase of the flight.

Each burning 41 metric tons of packed propellant, the five SRBs will tail off at the 94-second mark, though Atlas will keep holding onto them for another 13 seconds to ensure they separate in favorable aerodynamic conditions and impact at a safe distance to the coast.

The boosters will separate in two groups, spaced by 1.5 seconds, and Atlas V will continue onward relying on the RD-180 engine alone. Thrust on the engine will climb to 422 metric ton-force as the vehicle escapes the dense atmosphere and the five-meter payload fairing will drop away three minutes and 31 seconds into the mission to reveal the dual-payload stack.

Passing the four-minute mark, RD-180 will gradually reduce thrust to keep the acceleration acting on the structure at manageable levels before shutting down at T+4:33.5.


Image: United Launch Alliance

Six seconds later, pyrotechnics will cut the structural connection between the stages and retrorockets will fire to discard the spent first stage while Centaur readies for ignition. Assuming control of the flight, Centaur will be tasked with a three-burn mission profile – first lifting the stack into a Low Earth Parking Orbit, re-starting over the equator to raise the high point of the orbit to the desired injection altitude and then coasting all the way to the apogee of the orbit for the critical circularization burn.

Firing up its 10,400-Kilogram-force RL-10C engine, Centaur will complete a six minute and one-second burn to inject the stack into a preliminary parking orbit for a coast phase of twelve minutes. While coasting, Centaur will traverse the Atlantic Ocean and arrive over West Africa when re-lighting on the mission's second burn at T+22 minutes and 57 seconds. This five-minute and 49-second burn is designed to lift the apogee of the resulting orbit to an altitude of over 35,000 Kilometers and position it over the equator on the opposite side of the planet.

>> Launch Profile


Image: ULA

Centaur will then settle in for an extended coast phase of five hours and six minutes designed to allow the upper stage to climb all the way to the high point of the transfer orbit so that the third burn could act as circularization and inclination-reduction maneuver. This burn is planned to start at T+5 hours, 34 minutes and 46 seconds and last two minutes and 36 seconds to lift the stack into a perfectly circular orbit and reduce the orbital inclination to zero in order to place the two satellites into a drift orbit near the Geostationary Belt.

The two satellites are expected to separate from the Centaur upper stage before T+6 hours and 57 minutes – the exact timing is not being disclosed to the public due to the semi-classified nature of the AFSPC-11 mission, though separation some 35,300 Kilometers above Borneo would not be visible with conventional means anyway. Mission success will be confirmed by ULA or the U.S. Air Force before CBAS and EAGLE head into obscurity to carry out their missions out of public view.

[свернуть]

[tnt22]

https://spaceflightnow.com/2018/04/13/photos-atlas-5-rolled-out-for-air-force-mission/

Photos: Atlas 5 rolled out for Air Force mission
April 13, 2018 | Stephen Clark

A United Launch Alliance arrived at Cape Canaveral's Complex 41 launch pad Friday morning after rolling out of its vertical hangar with three U.S. Air Force satellites designed to provide communications to military leaders and test new in-orbit inspection and surveillance technology.

These photos show the 197-foot-tall (60-meter) rocket emerging from the Vertical Integration Facility on top of its mobile launch platform. Special locomotives called "trackmobiles" pushed the rocket along tracks toward the launch pad.

Спойлер

The 1,800-foot (550-meter) journey took less than an hour, and ground crews planned to connect the Atlas 5 to the launch pad's electrical and fluid supplies, then load the rocket's first stage with RP-1 kerosene fuel Friday afternoon.

Liftoff on the AFSPC 11 mission is set for 7:13 p.m. EDT (2313 GMT) Saturday. The launch window extends to 9:11 p.m. EDT (0111 GMT Sunday).

Read our full story for details on the mission.


Credit: United Launch Alliance


Credit: United Launch Alliance


Credit: United Launch Alliance


Credit: United Launch Alliance


Credit: United Launch Alliance

[свернуть]