The Atlas E/F (or SB-1A) was an American

expendable launch system An expendable launch system (or expendable launch vehicle/ELV) is a launch vehicle that can be launched only once, after which its components are either destroyed during reentry or discarded in space. ELVs typically consist of several multistage ...

and

sounding rocket A sounding rocket or rocketsonde, sometimes called a research rocket or a suborbital rocket, is an instrument-carrying rocket designed to take measurements and perform scientific experiments during its sub-orbital flight. The rockets are used to ...

built using parts of decommissioned

SM-65 Atlas The SM-65 Atlas was the first operational intercontinental ballistic missile (ICBM) developed by the United States and the first member of the Atlas rocket family. It was built for the U.S. Air Force by the Convair Division of General Dy ...

missiles. It was a member of the

Atlas An atlas is a collection of maps; it is typically a bundle of maps of Earth or of a region of Earth. Atlases have traditionally been bound into book form, but today many atlases are in multimedia formats. In addition to presenting geogra ...

family of rockets. The first stage was built using parts taken from decommissioned

Atlas-E The SM-65E Atlas, or Atlas-E, was an operational variant of the Atlas missile. It first flew on October 11, 1960, and was deployed as an operational ICBM from September 1961 until April 1966. Following retirement as an ICBM, the Atlas-E, along wi ...

and Atlas-F missiles, with various

solid propellant A propellant (or propellent) is a mass that is expelled or expanded in such a way as to create a thrust or other motive force in accordance with Newton's third law of motion, and "propel" a vehicle, projectile, or fluid payload. In vehicles, the e ...

upper stage A multistage rocket or step rocket is a launch vehicle that uses two or more rocket ''stages'', each of which contains its own engines and propellant. A ''tandem'' or ''serial'' stage is mounted on top of another stage; a ''parallel'' stage is ...

s used depending on the requirements of the payload.Encyclopedia Astronautica - Atlas
/ref> The Atlas E/F was also used without an upper stage for a series of re-entry vehicle tests. On a single launch, an RM-81 Agena liquid-propellant upper stage was used.Gunter's Space Page - Atlas Agena
/ref>

Variants

Atlas E/F

Thirty Atlas E/F rockets were launched without upper stages for ABRES and BMRS re-entry vehicle tests between 1965 and 1974. Three of these launches failed. Five ABRES launches were also conducted while the missiles were still operational, but did not use the Atlas E/F configuration.

Atlas E/F-Agena

An RM-81 Agena upper stage was used on a former Atlas-F, to launch the Seasat satellite on 27 June 1978. This was the final flight of the Atlas-Agena. Previous Atlas-Agena launches were launched on Atlas D or Atlas SLV-3 first stages, but the final Atlas-Agena used an Atlas E/F.

Atlas E/F-Altair

An Atlas E/F with an Altair-3A upper stage was used to launch three Stacksat spacecraft on 11 April 1990. The rocket was capable of placing of payload into

low Earth orbit A low Earth orbit (LEO) is an orbit around Earth with a period of 128 minutes or less (making at least 11.25 orbits per day) and an eccentricity less than 0.25. Most of the artificial objects in outer space are in LEO, with an altitude never m ...

Atlas E/F-Burner

A Burner-2 upper stage was used on an Atlas E/F to launch the Radsat and Radcat satellites on 2 October 1972. The rocket had a payload capacity of to low Earth orbit.

Atlas E/F-MSD

Atlas E/F rockets with MSD upper stages were used for four launches, with NOSS naval reconnaissance satellites between 1976 and 1980. The fourth of these launches failed when one of the booster unit engines shut down early. This configuration had a maximum payload capacity of to LEO.

Atlas E/F-OIS

The OIS upper stage was used for two Atlas E/F launches in 1979 and 1985, with the Solwind and

Geosat The GEOSAT (GEOdetic SATellite) was a U.S. Navy Earth observation satellite, launched on March 12, 1985 into an 800 km, 108° inclination orbit, with a nodal period of about 6040 seconds. The satellite carried a radar altimeter capable of m ...

spacecraft respectively. The rocket could place into low Earth orbit.

Atlas E/F-OV1

The Atlas E/F was used between 1968 and 1971 to launch four groups of OV1 satellites, using OV1 upper stages. Each payload had its own upper stage. Three of the launches carried two OV1 satellites, and one carried three. Two of the launches also carried secondary payloads. In this configuration, the rocket could place into LEO.

Atlas E/F-PTS

The PTS upper stage was used to launch the NTS-1 satellite on 14 July 1974. The upper stage gave the vehicle a payload capacity of to a medium Earth transfer orbit.

Atlas E/F-SGS

The SGS upper stage, which consisted of two series-burning solid rocket motors, was used on twelve Atlas E/F launches, with early GPS satellites. The first eight used the SGS-1, which could place of payload into a medium Earth transfer orbit, whereas the last four used the more powerful SGS-2. The eighth launch failed.

Atlas E/F-Star

The

Star A star is an astronomical object comprising a luminous spheroid of plasma (physics), plasma held together by its gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked ...

was used to propel most of the other upper stages used on the Atlas E/F, however it was also used in its own right on several launches. A Star-17A was used in the launch of the RM-20 spacecraft on 12 April 1975, giving the rocket a LEO payload of , while the Star-37S-ISS was used to launch nineteen Defense Meteorological Satellite Program (DMSP),

National Oceanic and Atmospheric Administration The National Oceanic and Atmospheric Administration (abbreviated as NOAA ) is an United States scientific and regulatory agency within the United States Department of Commerce that forecasts weather, monitors oceanic and atmospheric conditi ...

(NOAA) and

Television Infrared Observation Satellite TIROS, or Television InfraRed Observation Satellite, is a series of early weather satellites launched by the United States, beginning with TIROS-1 in 1960. TIROS was the first satellite that was capable of remote sensing of the Earth, enabli ...

(

TIROS TIROS, or Television InfraRed Observation Satellite, is a series of early weather satellites launched by the United States, beginning with TIROS-1 in 1960. TIROS was the first satellite that was capable of remote sensing of the Earth, enabli ...

)

weather satellite A weather satellite or meteorological satellite is a type of Earth observation satellite that is primarily used to monitor the weather and climate of the Earth. Satellites can be polar orbiting (covering the entire Earth asynchronously), or ...

s between 1978 and 1995. With the Star-37 upper stage, the rocket could place into a

Sun-synchronous orbit A Sun-synchronous orbit (SSO), also called a heliosynchronous orbit, is a nearly polar orbit around a planet, in which the satellite passes over any given point of the planet's surface at the same local mean solar time. More technically, it is ...

(SSO). The RM-20 launch failed due to damage to the first stage, caused by the explosion of residual fuel in the flame trench during launch. Another launch failed due to stage separation occurring at the correct time despite the first stage burn being extended by fifty seconds to resolve an underperformance issue, the end result of which was the upper stage separating and igniting while the first stage was still firing.

Atlas E/F-Trident

The Atlas E/F was used with a

Trident A trident is a three- pronged spear. It is used for spear fishing and historically as a polearm. The trident is the weapon of Poseidon, or Neptune, the God of the Sea in classical mythology. The trident may occasionally be held by other mar ...

upper stage, between 1967 and 1971, for

suborbital A sub-orbital spaceflight is a spaceflight in which the spacecraft reaches outer space, but its trajectory intersects the atmosphere or surface of the gravitating body from which it was launched, so that it will not complete one orbital ...

tests of re-entry vehicles. Nineteen were launched, of which two failed.

References

{{US launch systems Rockets and missiles Atlas (rocket family)