Atlas (rocket family)

Atlas is a family of United States missiles and space launch vehicles. The original Atlas missile was designed in the late 1950s and produced by the Convair Division of General Dynamics,^[2] to be used as an intercontinental ballistic missile (ICBM). It was a liquid-fuel rocket burning liquid oxygen and RP-1 in three engines configured in an unusual "stage-and-a-half" or "Parallel Staging" design: its two outboard booster engines were jettisoned during ascent, while its center sustainer engine, fuel tanks and other structural elements were retained into orbit.

The missiles saw only brief ICBM service, and the last squadron was taken off operational alert in 1965. From 1962 to 1963, Atlas boosters launched the first four American astronauts to orbit the Earth. Various Atlas II models were launched 63 times between 1991 and 2004. There were only six launches of the Atlas III, all between 2000 and 2005. The Atlas V is still in service, with launches planned until 2020.

More than 300 Atlas launches have been conducted from Cape Canaveral Air Force Station in Florida and 285 from Vandenberg Air Force Base in California.

Variants

SM-65 Atlas missile

Launch of an Atlas B intercontinental ballistic missile

Launch of the first American manned orbital space flight

The first successful test launch of an SM-65 Atlas missile was on December 17, 1957.^[1] Approximately 350 Atlas missiles were built. Many were eventually converted to orbital launch vehicles after they were removed from service as missiles.

Early Atlas rockets were also built specifically for non-military uses. On December 18, 1958, an Atlas was used to launch the Signal Communication by Orbiting Relay Equipment (SCORE) satellite, which was, "The first prototype of a communications satellite, and the first test of any satellite for direct practical applications."^[3][4] The satellite broadcast President Eisenhower’s pre-recorded Christmas message around the world.

The Atlas boosters would collapse under their own weight if not kept pressurized with nitrogen gas in the tank, even when not fueled. The Atlas booster was unusual in its use of balloon tanks for holding its fuel. The rockets were made from very thin stainless steel that offered minimal or no rigid support. It was pressure in the tanks that gave the rigidity required for space flight.

The SM-65 Atlas was used as a first stage for satellite launch vehicles for half a century. Many were eventually converted to orbital launch vehicles after they were removed from service as missiles. Missiles converted into Atlas E/F "space boosters" were used to launch the early "Block I" GPS satellites.^[5]

Mercury program

Atlas boosters were also used for the last four manned Project Mercury missions, the first United States manned space program. On February 20, 1962 it launched Friendship 7, which made three earth orbits carrying John Glenn, the first United States astronaut to orbit the Earth. Identical Atlas boosters successfully launched three more manned Mercury orbital missions from 1962 to 1963.

Atlas-Agena

Beginning in 1960, the Agena upper-stage, powered by hypergolic propellant, was used extensively on Atlas launch vehicles. The United States Air Force, NRO and CIA used them to launch SIGINT satellites.^[6] NASA used them in the Ranger program to obtain the first close-up images of the surface of the Moon and for Mariner 2, the first spacecraft to fly by another planet. Each of the Agena target vehicles used for the later space rendezvous practice missions of Gemini was launched on an Atlas rocket.

Atlas-Centaur

The Atlas-Centaur was an expendable launch system derived from the SM-65D Atlas missile.^{[citation needed]} Launches were conducted from two pads of the Launch Complex 36 at Cape Canaveral Air Force Station, Florida. A specially-enhanced version of the Atlas D vehicle for mating with Centaur stages; the Atlas's engines were upgraded and the structure reinforced for the large upper stage, along with elongated fuel tanks.

Beginning in 1963, the liquid hydrogen-fueled Centaur upper stage was also used on dozens of Atlas launches. NASA launched the Surveyor program lunar lander spacecraft and most of the Mars-bound Mariner program spacecraft with Atlas-Centaur launch vehicles.

Launch vehicles based on original Atlas ICBM

Atlas III

The Atlas III was a major revised version from Atlas II, which both dropped balloon tank design, together with the 1.5 stage in previous Altas family. It is the first Atlas rocket that adopted Russian-designed RD-180 engine at the first stage.

Atlas V

2005 Launch of Mars Reconnaissance Orbiter

Launch of an Atlas V 401 carrying the LRO and LCROSS

The newest version of Atlas, the Atlas V, is an Atlas in name alone,^{[citation needed]} as it contains little Atlas technology. It no longer uses balloon tanks nor 1.5 staging, but incorporates a rigid framework for its first stage booster, much like the Titan family of vehicles. The rigid fuselage is heavier, but easier to handle and transport, eliminating the need for constant internal pressure.

The Atlas V is an active expendable launch system in the Atlas rocket family. The Atlas V was developed, as part of the US Air Force Evolved Expendable Launch Vehicle (EELV) program, and formerly operated by Lockheed Martin. It is now operated by the Lockheed Martin-Boeing joint venture United Launch Alliance. The first Atlas V was launched on August 21, 2002 from Cape Canaveral Air Force Station. Launches are from Space Launch Complex 41 at Cape Canaveral Air Force Station and Space Launch Complex 3-E at Vandenberg Air Force Base. The Atlas V family uses a single-stage Atlas main engine, the Russian RD-180, burning kerosene and liquid oxygen, and the newly developed Common Core Booster (CCB) with up to five Aerojet made strap-on solid rocket boosters. A single or dual American Pratt & Whitney Rocketdyne RL10A-4-2 burning liquid hydrogen and liquid oxygen is used to power the Centaur upper stage.^[10]

Lockheed Martin Commercial Launch Services continues to market the Atlas V to commercial customers worldwide.^[11]

The Atlas III and Atlas V use Russian-designed/built NPO Energomash RD-180 engines. These engines are now prepared for production under license by Pratt & Whitney Rocketdyne in the United States. The Atlas V is built in Denver, Colorado by United Launch Alliance, a joint venture of Lockheed Martin and Boeing. Future production will be shifted to Decatur, Alabama.^{[citation needed]}

Proposed future developments

Atlas V Heavy

The Atlas V Heavy would use three Common Core Booster (CCB) stages strapped together to provide the capability necessary to lift 25 tonne payload to low Earth orbit.^{[citation needed]} Approximately 95% of the hardware required for the Atlas HLV has already been flown on the Atlas V single core vehicles.^{[citation needed]}

A report, prepared by RAND Corporation for the Office of the Secretary of Defense in 2006, stated that Lockheed Martin had decided not to develop an Atlas V heavy-lift vehicle (HLV).^[12] The report recommended for the Air Force and the National Reconnaissance Office to "determine the necessity of an EELV heavy-lift variant, including development of an Atlas V Heavy", and to "resolve the RD-180 issue, including coproduction, Stockpile, or U.S. development of an RD-180 replacement."^[13]

The lifting capability of the Atlas V HLV is roughly equivalent to the Delta IV Heavy. The latter utilizes RS-68 engines developed and produced domestically by Pratt & Whitney Rocketdyne.^{[citation needed]}

As of February 2008, the Atlas V HLV configuration was available to customers 30 months from date of order.^[14]

Atlas Phase 2

Since December 2006, with the merger of Boeing and Lockheed-Martin space operations into United Launch Alliance, the Atlas V program gained access to the tooling and processes for 5-meter-diameter stages, used on Delta IV. At 5 meters, a stage can accept dual RD-180 engines.

The conceptual heavy-lift vehicle was called "Atlas Phase 2" or "PH2" in the 2009 Augustine Report report. An Atlas V PH2-Heavy (three 5 m stages in parallel; six RD-180s) along with Shuttle-derived, Ares V and Ares V Lite, were considered as a possible heavy lifter concept for use in future space missions in the Augustine Report.^[15] The Atlas PH2 HLV concept vehicle would have notionally been able to launch a payload mass of approximately 70 metric tons into an orbit of 28.5 degree-inclination.^[15]

SM-65A Atlas missile, 1958

Mercury-Atlas 9 at Launch Complex 14

Atlas-Agena

Atlas-Centaur

See also

• Delta (rocket family)
• Comparison of orbital launchers families

References

Further reading

• Gainor, Christopher, “The Atlas and the Air Force: Reassessing the Beginnings of America’s First Intercontinental Ballistic Missile,” Technology and Culture 54 (April 2013), 346–70.

External links

• Atlas at Encyclopedia Astronautica

v t e Atlas rockets Main articles Atlas family SM-65 Atlas Rockets Prototypes MX-774 Atlas A Atlas B Atlas C Missiles Atlas D Atlas E Atlas F Launch systems Alphabetical Atlas B Atlas D Atlas E/F Atlas G Atlas H Upper stages Atlas-Able Atlas-Agena Atlas-Centaur Numerical Atlas I Atlas II Atlas III Atlas V Other Atlas LV-3B Atlas SLV-3 GX Launch sites Cape Canaveral LC-11 LC-12 LC-13 LC-14 (S)LC-36 SLC-41 Vandenberg LC-576 SLC-3 SLC-4 Bases Altus Dyess Fairchild Forbes Francis E. Warren Lincoln Offutt Plattsburgh Schilling Walker Components Boosters Aerojet SRM Castor 4A MA First stages Common Core Booster Upper stages Able Agena Altair Burner Centaur IABS MSD OIS PTS SGS Star SVS Trident Engines AJ-10 B-8048 B-8081 B-8096 LR-89 LR-105 R-4D RD-180 RL10 RS-56 Corporations Manufacturers Rocket Convair General Dynamics Lockheed Lockheed Martin Engines Aerojet NPO Energomash Pratt & Whitney Rocketdyne Thiokol LSPs International Launch Services United Launch Alliance Launches 1957-1959 1960-1969 1970-1979 1980-1989 1990-1999 2000-2009 2010-2019

v t e Project Mercury General NASA (Organizer) Space race (Political background) Space flight (Scientific background) Contractors McDonnell Aircraft Corporation (Space craft) North American Aviation (Test rocket) Related programs USA Gemini (Mercury Mark II) Apollo (Moon program) Soviet Vostok (Rival in space race) Missions Manned Freedom 7 (First suborbital flight) Liberty Bell 7 Friendship 7 (First orbital flight) Aurora 7 Sigma 7 Faith 7 Freedom 7 II (cancelled) Unmanned LJ-1 Big Joe 1 LJ-6 LJ-1A LJ-2 LJ-1B Beach Abort MA-1 Little Joe 5 MR-1 MR-1A MR-2 MA-2 LJ-5A MR-BD MA-3 LJ-5B MA-4 MS-1 MA-5 Astronauts General Mercury Seven In order of flight (In suborbit:) Alan Shepard Gus Grissom (In orbit:) John Glenn Scott Carpenter Wally Schirra Gordon Cooper (Did not fly:) Deke Slayton Equipment Navy Mark IV (Space suit) Test animals Ham Enos (Background:) Animals in space Subprograms Mercury-Atlas Mercury-Redstone Mercury-Scout Big Joe Mercury-Jupiter (Canceled) Rockets Atlas Redstone Blue Scout II Little Joe Jupiter (Proposed) Launch sites and Control Center Wallops Island / Wallops Flight Facility Cape Canaveral Air Force Station Launch Complex 5 Cape Canaveral Air Force Station Launch Complex 18 Cape Canaveral Air Force Station Launch Complex 14 Mercury Control Center Other Mercury 13 (Non NASA project inspired by Project Mercury)