Atlas Rocket Family

General Dynamics / Convair / Lockheed Martin / ULA

The Atlas rockets were a Convair development of the SM-65 Atlas missile, which was first tested on December 17, 1957. Having no inherent structural stability, the core sustainer stage needed to be pressurized when vertical.

It launched John Glenn on the first US orbital flight, carried different upper stages, including the Agena and Centaur, and launched a wide array of satellites and probes.

Evolution of the Atlas family concluded with the development of the Atlas-V, soon to be replaced by the Vulcan rocket family.

Atlas A, B, C & D

Early Atlas Rockets

The Atlas-A, B and C rockets were boosted by the Rocketdyne MA-1 stage-and-a-half engine system. The central sustainer stage and jettisonable side boosters used LR43 engines, while the verniers were LR101s. Atlas-A however did not yet have the central sustainer engine.

These early Atlas vehicles were mostly used for R&D, but flight 10B carried the SCORE communication experiment within its side pods. Further Atlas-C and Ds were combined with Able second and Altair upper stages for the launch of Pioneer lunar probes.

Atlas D

OV1, Mercury, Antares 2, Burner 2 & the 'Angry Alligator'

When storable solid-fueled ICBMs took over and Atlas became obsolete, the rocket system was repurposed as a Space Launch Vehicle and used for human and satellite launches.

John Glenn launched the first American orbital human space-flight atop an Atlas LV-3B with Mercury capsule, and Atlas started to get paired with new upper stages like Antares 2 and Burner 2.

The Atlas-D MA-2 upgraded to the LR105 sustainer and LR89 sidebooster engines.

Atlas LV-3 with Agena

Spy Sats & Space Probes

One of the upper stages Atlas was paired with was the Agena. This combination launched Ranger and Mariner probes, flew the Gemini GATV docking targets for orbital docking practice, the OAO and OGO observatories, and a whole slew of reconnaissance and intelligence satellites.

The Agena upper stages were powered by the Bell 80XX series of engines. Agena-A used the 8048, Agena-B the 8081 and the Agena-D the 8096.

Atlas SLV-3 Agena D

More Spy Sats & Space Probes

The upgraded SLV-3 was a standardized Atlas launch vehicle. It flew the Agena-D upper stage, with the OGO-3 flight being the only SLV-3 launch using an Agena-B upper stage. Like LV-3 it launched probes, observatories and spysats.

The SLV-3A and -3B revisions both had elongated sustainer stages, with SLV-3B being the only flight with and encapsulated Agena-D upper stage.

Atlas E/F & H

Ex-ICBMs With New Upper Stages

The Atlas-E and F were decommissioned ICBMs. After refurbishment the rockets launched a multitude of upper stages, including Burner 2, PTS, OIS, Altair, MSD, and STAR. Payloads included GPS, OV1, scientific and meteorological satellites.

Atlas-H was a further development of the Atlas first stage called SLV-3B with MSD upper stages powerd by an FW-4D motor, primarily used to launch GPS satellites. SLV-3B was also the first stage on Atlas-G and Atlas I which used the Centaur upper stage.

Atlas Centaur

The First Liquid Hydrogen Upper Stage

During its entire lifetime, the Atlas rocket was paired with the continuously upgrading Centaur, which was the first liquid hydrogen upper stage. Starting in 1962 with Centaurs A, B and C, he later Centaur D would become the standard. Further evolutions Centaur 1, 2 and 3 would fly on Atlas 1, 2 and 3.

Sustainer tank sizes would gradually increase with Atlas 2 using RS-56 engines for boosters and sustainer, Atlas 2AS sporting Castor 4A side-boosters, and Atlas 3 switching to RD-180 main engines. Atlas 3 would be the last Atlas rocket to share technologie with the SM-65 ICBM.

Atlas V

New First Stage & SRBs

Keeping the new RD-180 engines but completely redesigning the Common Core Booster (CCB) first stage and upgrading the upper Centaur stage, Atlas V was Lockheed Martin's entry into the Evolved Expendable Launch Vehicle (EELV) program.

The modular rocket system builds around its CCB and Centaur III stages with up to 5 Aerojet Rocketdyne AJ-60A boosters with a choice of a 4 or 5 meter diameter fairing, with the later encapsulating the Centaur stage. The N22 variant (no fairing, 2 boosters, Dual Engine Centaur) was used to launch the Boeing CST-100 Starliner test flights.

In 2020 the AJ-60A boosters were replaced by the Northrop Grumman GEM 63. Dependency of the Russian RD-180 engine and market pressure from new reusable rocket systems have forced ULA to phase out the Atlas rocket family in favor of the newly designed Vulcan.