Atlas V

Infobox rocket

---

caption = Launch of the Mars Reconnaissance Orbiter, 11:43:00 am GMT August 12, 2005 on the first Atlas V rocket used by NASA. The rocket is in the 401 configuration.
name = Atlas V
function = EELV/Medium-heavy launch vehicle
manufacturer = United Launch Alliance
country-origin = United States
height = 58.3 m
alt-height = 191.2 ft
diameter = 3.81 m
alt-diameter = 12.49 ft
mass = 546,700 kg
alt-mass = 1,205,200 lb
stages = 2
LEO-payload = 10,300 - 20,050 kg
alt-LEO =
payload-location = GTO
payload = 4,100 - 8,200 kg
alt-payload =
status = Active
sites = LC-41, CCAFS
SLC-3E, Vandenberg AFB
launches = 14
For breakdown by variant, see text
success = 13
fail =
partial = 1 (401) [ [http://space.skyrocket.de/index_frame.htm?http://space.skyrocket.de/doc_lau_det/atlas-5-401.htm Gunter's Space Page - Atlas V (401)] ]
first=August 21, 2002
last=
payloads = Mars Reconnaissance Orbiter
New Horizons
boosters = 1 to 5 (see text)
diff = Not Heavy
boostername = Aerojet
boosterengines = 1 Solid
boosterthrust = 1,270 kN
alt-boosterthrust = 285,500 lb_f
boostertime = 94 seconds
boosterSI = 275 sec
boosterfuel = Solid
alt-boosters = 2
alt-diff = Atlas V Heavy (5HX)
alt-boostername = Atlas CCB
alt-boosterengines = 1 RD-180
alt-boostersthrust = 4,152 kN
alt-alt-boosterthrust = 933,406 lb_f
alt-boostertime = 253 seconds
alt-boosterSI = 311 sec
alt-boosterfuel = RP-1/LOX
stage1name = Atlas CCB
stage1engines = 1 RD-180
stage1thrust = 4,152 kN
alt-stage1thrust = 933,406 lb_f
stage1time = 253 seconds
stage1SI = 311 sec
stage1fuel = RP-1/LOX
stage2name = Centaur
stage2engines = 1 RL-10A
stage2thrust = 99.2 kN
alt-stage2thrust = 22,290 lb_f
stage2time = 842 seconds
stage2SI = 451 sec
stage2fuel = LH2/LOX
stage2diff = Atlas V XX1
stage2aname = Centaur
stage2aengines = 2 RL-10A
stage2athrust = 147 kN
alt-stage2athrust = 41,592 lb_f
stage2atime = 421 seconds
stage2aSI = 449 sec
stage2afuel = LH2/LOX
stage2adiff = Atlas V XX2The 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 V launch vehicle.

In its 12 launches, from its maiden launch in August 2002 to March 2008, the Atlas V has had a near-perfect success rate. On one flight, NRO L-30 on June 15, 2007, an upper-stage anomaly occurred when the engine in the vehicle's Centaur upper stage shut down early, leaving the payload—a pair of ocean surveillance satellites—in a lower than intended orbit. [cite web |url=http://www.aviationweek.com/aw/generic/story_channel.jsp?channel=defense&id=news/NRO062207.xml |title=NRO Shortfall May Delay Upcoming ULA Missions |publisher=Aviation Week] However, the customer, the National Reconnaissance Office, categorized the mission as a success.fact |date=March 2008 The anomaly was thoroughly investigated.fact |date=March 2008 Atlas V has made four successful flights since the anomaly.

Comparable rockets:
Delta IV —
Proton —
Ariane 5 —
Chang Zheng 5 —
GSLV Mk.III —
Angara —
Falcon 9 —
H-IIA —
H-IIB

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. Twelve Atlas V launches to date have been successful except for the 2007 anomaly. 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 major part of this thrust, 4.152 meganewtons being provided by Russian RD-180 engine.

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.

On April 14, 2008, Atlas V lifted its heaviest payload to date into orbit - a convert|14625|lb|kg|adj=on telecommunications satellite built by Space Systems/Loral of Palo Alto, CA. [ [http://www.foxnews.com/story/0,2933,351292,00.html FOXNews.com - Telecommunication Satellite Launches With Heavy Payload - Science News | Science & Technology | Technology News ] ]

2007 valve anomaly

The only anomalous event in the use of the Atlas V launch system occurred June 15, 2007, when the engine in the Centaur upper stage of an Atlas V shut down early, leaving its payloadndash a pair of NRO L-30 ocean surveillance satellitesndash in a lower than intended orbit. [cite web |url=http://www.aviationweek.com/aw/generic/story_channel.jsp?channel=defense&id=news/NRO062207.xml |title=NRO Shortfall May Delay Upcoming ULA Missions |publisher=Aviation Week] The cause of the anomaly was traced to a leaky valve. Replacing the valve led to a delay in an upcoming Atlas V launch.cite web |url=http://www.floridatoday.com/apps/pbcs.dll/article?AID=/20070902/NEWS02/709020335/1007 |title=Faulty valve pushes back Atlas 5 launch |publisher=Florida Today]

Future developments

The Atlas V-Heavy or HLV configuration is available 30 months from order. [http://www.globalsecurity.org/space/systems/atlas-v.htm Atlas V EELV - Lockheed-Martin Retrieved on 2008-02-08] 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 [http://www.oerlikon.com/space/] ) 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

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 '4' or '5'. The second digit is the number of solid rocket boosters attached to the base of the rocket, and can number anywhere from '0' through '3' with the 4-m fairing and '0' through '5' with the 5-m fairing. The third digit is the number of engines on the Centaur stage, either '1' or '2'. Single-engine Centaurs (SEC) are typically used for satellites going to geostationary transfer orbit or reaching escape velocity. Dual-engine Centaurs (DEC) 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. [cite news
last=Gaskill
first=Braddock
title=Human Rated Atlas V for Bigelow Space Station details emerge
publisher=NASASpaceflight.com
date=2007-01-31
url=http://www.nasaspaceflight.com/content/?cid=5008 ]

Versions:List Date: June 16, 2007

Atlas V Launches

List Date: June 2007

Photo Gallery

See also

* Comparison of heavy lift launch systems

References

* [http://www.ulalaunch.com/index_products_services.html ULA data sheets]
* [http://www.lockheedmartin.com/wms/findPage.do?dsp=fec&ci=17607&rsbci=14917&fti=0&ti=0&sc=400 Atlas - Yesterday, Today and Tomorrow]
* http://www.astronautix.com/lvs/atlasv.htm