MA-5A
| Manufacturer | Lockheed Martin | 
|---|---|
| Country of origin | United States | 
| Used on | Atlas II | 
| General characteristics | |
| Height | 3.43 metres (11.3 ft) | 
| Diameter | 3.05 metres (10.0 ft) | 
| Gross mass | 4,187 kilograms (9,231 lb) | 
| Derived from | MA-5 | 
| MA-5A | |
| Powered by | 2 RS-56-OBA | 
| Maximum thrust | 2,100 kN (470,000 lbf) | 
| Specific impulse | 296 seconds (2.90 km/s) | 
| Propellant | LOX/RP-1 | 
| Launch history | |
| Status | Retired | 
MA-5A was an American liquid fueled rocket stage. It was manufactured by Lockheed Martin for use on the Atlas II rocket, derived from the MA-5 used on the Atlas I.