MA-2 (rocket stage)

MA-2

Manufacturer	Lockheed Martin
Country of origin	United States
Used on	Atlas-D, Atlas-Agena and Atlas LV-3B
General characteristics
Height	3.43 metres (11.3 ft)
Diameter	4.9 metres (16 ft)
Gross mass	3,050 kilograms (6,720 lb)
Associated stages
Derived from	MA-1
Derivatives	MA-3
Launch history
Status	Retired
MA-2
Powered by	2 XLR89-5
Maximum thrust	1,517.42 kN (341,130 lbf)
Specific impulse	282 seconds (2.77 km/s)
Propellant	LOX/RP-1

MA-2 was an American liquid fueled rocket stage, developed by Lockheed Martin for use on the Atlas-D, Atlas-Agena and Atlas LV-3B ). ^{[1] [2] [3] [4]}

Design

MA-2 functioned as the "half stage" in the Atlas's "stage-and-a-half" design, meaning they functioned as a booster attached to a central sustainer core, but did not include their own fuel tanks. ^[2] Instead, fuel was drained out of the tanks of the sustainer core, until partway through the launch the booster segment was jettisoned. Similar to the booster segment on previous Atlas rockets, ^{[5] [3]} MA-2 consisted of a thrust structure with attachment points and fuel lines for two XLR89-5 rocket engines, each contained in a nacelle for aerodynamic reasons. The middle was left empty to accommodate the LR-105-5 engine of the sustainer stage. The two booster engines shared a common gas generator located at one of the engines, but separate turbopumps. ^[2]

See also

• MA-5 rocket stage

References

1. "Atlas MA-2". www.astronautix.com. Retrieved 2025-09-22.
2. "Atlas "stage-and-a-half" drive system". www.b14643.de. Archived from the original on 2016-01-22. Retrieved 2025-09-22.
3. "Atlas Family". Gunter's Space Page. Retrieved 2025-09-22.
4. "CONVAIR LV-3B / SM-65D ATLAS". Official United States Air Force Website.
5. "Atlas MA engine series". www.astronautix.com. Retrieved 2025-09-22.