The 'Atlas V'
rocket is an
expendable launch vehicle formerly built by
Lockheed Martin and now built by the Lockheed Martin-
Boeing joint venture
United Launch Alliance.
Aerojet develops and manufactures the Atlas V boosters. The rocket, built in
Decatur, Alabama, consists of a
first stage powered by kerosene and liquid oxygen, which uses a
Russian made
RD-180 engine, and a liquid hydrogen–liquid oxygen powered
Centaur upper stage. Some configurations also use strap-on
booster rockets. Together these components are referred to as the Atlas
launch vehicle.
On
June 15,
2007, the engine in the Centaur upper stage of an Atlas V shut down early, leaving its payload -- a pair of
NRO L-30 ocean
surveillance satellites -- in a lower than intended orbit.
[2] The cause of the anomaly was traced to a leaky valve. Replacing the valve led to a delay in an upcoming Atlas V launch.
Faulty valve pushes back Atlas 5 launch History
The Atlas V is the newest member of the
Atlas family, and is a direct descendant of the previous
Atlas II and especially the
Atlas III vehicles. Most propulsion, avionic and structural elements are either identical to or straightforward derivations of those used on the previous vehicles.
The most obvious external change is to the first stage tanks, which no longer use 10 foot diameter, stainless steel monocoque, common intermediate bulkhead "balloon" construction nor the '1.5 staging' technique which jettisoned two engines in mid-flight but left a third burning all the way from the ground to orbit, but instead use a 12.5 foot diameter welded aluminum alloy construction first stage much like that of the
Titan family of vehicles or the
Space Shuttle external tank.
The Atlas V was developed by Lockheed Martin Commercial Launch Services as part of the US Air Force
Evolved Expendable Launch Vehicle (EELV) program. The term ''expendable launch vehicle'' means it is only used once. Launches are from
Space Launch Complex 41 at
Cape Canaveral Air Force Station. In addition, Space Launch Complex 3 East at
Vandenberg Air Force Base is being prepared for future
polar launches.
The first Atlas V was launched on August 21, 2002. Nine Atlas V launches to date have been completly successful, one was rated partial failure. The Atlas V family uses a single-stage Atlas main engine, the Russian
RD-180 and the newly developed
Common Core Booster (CCB) with up to five Aerojet made strap-on
solid rocket boosters. The CCB is 12.5 ft (3.8 m) in diameter by 106.6 ft (32.5 m) long and uses 627,105 lb (284,450 kg) of liquid oxygen and
RP-1 rocket fuel propellants. The booster operates for about four minutes, providing about 4
meganewtons (860,000 lbf) of thrust at start.
The Centaur upper stage uses a pressure stabilized propellant tank design and cryogenic propellants. The Centaur stage for Atlas V is stretched 5.5 ft (1.68 m) and is powered by either one or two
Pratt & Whitney RL10A-4-2 engines, each engine developing a thrust of 99.2 kN (22,300 lbf). Operational and reliability upgrades are enabled with the RL10A-4-2 engine configuration. The
inertial navigation unit (INU) located on the Centaur provides guidance and navigation for both Atlas and Centaur, and controls both Atlas and Centaur tank pressures and propellant use. The Centaur engines are capable of multiple in-space starts, making possible insertion into low-earth parking orbit, followed by a coast period and then insertion into GTO. A subsequent third burn following a multi-hour coast can permit direct injection of payloads into geostationary orbit. The Centaur vehicle has the highest proportion of burnable propellant relative to total mass of any modern upper stage and hence can deliver substantial payloads to a high energy state.
Many systems on the Atlas V have been the subject of upgrade and enhancement both prior to the first Atlas V flight and since that time. An upgrade to a Fault Tolerant INU (FTINU) was recently made to enhance mission reliability for Atlas vehicles.
Future developments
The Atlas V-Heavy or HLV configuration is available 30 months from order. It would use three CCB stages strapped together to provide the capability necessary to lift the heaviest spacecraft. Approximately 95% of the hardware required for the Atlas HLV has already been flown on the Atlas V single core vehicles.
The Atlas V has two general
payload fairing sizes. The classic 4-meter fairing, used since the
Atlas II, comes in regular and slightly stretched versions (see AV-004/Inmarsat 4-F1 launch), and Lockheed Martin introduced a 5-meter (4.57 meters usable) payload fairing developed and built by Contraves Space (now Oerlikon Space
[1]) in
Switzerland. The Contraves fairing is a composite design and is based on flight proven hardware. Three configurations will be manufactured to support Atlas V. The short and medium length configurations will be used on the Atlas V 500 series. The long configuration will be used on the Atlas V-Heavy. The classic fairing covers only the payload, leaving the Centaur stage exposed to open air. With the Contraves fairing, the Centaur is enclosed within the fairing as well as the payload.
Versions
Core stage of an Atlas V being raised to a vertical position.
Each Atlas booster has a three digit version designation that is determined by the features of the rocket. The first digit is the diameter (in
meters) of the nosecone fairing, and is always either four or five. The second digit is the number of solid rocket boosters attached to the base of the rocket, and can number anywhere from zero through three with the 4-m fairing and zero through five with the 5-m fairing. The third digit is the number of engines on the Centaur stage, either one or two. Single-engine Centaurs are typically used for satellites going to
geostationary transfer orbit or reaching
escape velocity. Dual engine Centaurs are typically used for satellites reaching
low Earth orbit.
For example, if the Atlas V version is ''552'', this means that the fairing is five meters, has five solid rocket boosters, and has two Centaur engines.
If the Atlas V version is ''431'', this means that the fairing is four meters, has three solid rocket boosters, and has a single Centaur engine.
'Comparable rockets:'
Delta IV -
Ariane 5 -
Chang Zheng 5 -
Angara -
Proton -
Falcon 9
An agreement between Lockheed and
Bigelow Aerospace in September 2006 could lead to a
human-rated version of the Atlas V to tap into the potential
space tourism market.
[3]
'Versions:'
The
MRO spacecraft lauches on August the 12. 2005 at 11:43 UTC to the Planet Mars onboard an Atlas V 401 Launch Vehicle.
List Date:
June 16 2007
| Version | Booster | Upper stage | Fairing | Payload to LEO | Payload to GTO | Launches to date |
|---|
| 401 | - | SEC | 4 m | - | 4951 kg | 5 |
| 402 | - | DEC | 4 m | 12500 kg | - | 0 |
| 411 | 1 | SEC | 4 m | - | 5951 kg | 1 |
| 421 | 2 | SEC | 4 m | - | 6832 kg | 0 |
| 431 | 3 | SEC | 4 m | - | 7642 kg | 1 |
| 501 | - | SEC | 5 m | - | 3971 kg | 0 |
| 502 | - | DEC | 5 m | 10300 kg | - | 0 |
| 511 | 1 | SEC | 5 m | - | 5271 kg | 0 |
| 512 | 1 | DEC | 5 m | 12050 kg | - | 0 |
| 521 | 2 | SEC | 5 m | - | 6287 kg | 2 |
| 522 | 2 | DEC | 5 m | 13950 kg | - | 0 |
| 531 | 3 | SEC | 5 m | - | 7202 kg | 0 |
| 532 | 3 | DEC | 5 m | 17250 kg | - | 0 |
| 541 | 4 | SEC | 5 m | - | 7982 kg | 0 |
| 542 | 4 | DEC | 5 m | 18750 kg | - | 0 |
| 551 | 5 | SEC | 5 m | - | 8672 kg | 1 |
| 552 | 5 | DEC | 5 m | 20050 kg | - | 0 |
| Heavy (HLV (5H1)) | 2 CCB | SEC | 5 m | - | 13605 kg | 0 |
| Heavy (HLV DEC (5H2)) | 2 CCB | DEC | 5 m | 25000 kg | - | 0 |
Atlas V Launches
Past launches
List Date:
June 2007
Planned launches
List Date:
August 1 2007
References
★
Atlas V at Lockheed Martin
★
Atlas - Yesterday, Today and Tomorrow
★ http://www.astronautix.com/lvs/atlasv.htm
1. Gunter's Space Page - Atlas V (401)
2.
NRO Shortfall May Delay Upcoming ULA Missions
3.
Human Rated Atlas V for Bigelow Space Station details emerge Braddock Gaskill
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