| Astris | |
| Country Of Origin: | Germany |
| First Date: | 1969-07-31 |
| Last Date: | 1971-11-05 |
| Designer: | ERNO Raumfahrttechnik GmbH |
| Manufacturer: | Snecma |
| Purpose: | Upper stage engine |
| Associated: | Europa (rocket) |
| Status: | Retired |
| Type: | liquid |
| Oxidiser: | N2O4 |
| Fuel: | Aerozine 50 |
| Cycle: | pressure fed |
| Combustion Chamber: | 1 |
| Thrust(Vac): | 23.3kN |
| Thrust(Sl): | 19.6kN |
| Specific Impulse Vacuum: | 310isp |
| Specific Impulse Sea Level: | 260isp |
| Burn Time: | 330 seconds |
| Dry Weight: | 68kg (150lb) |
| Used In: | Astris (rocket stage) |
The Astris was a liquid rocket engine burning the hypergolic propellant combination of Aerozine 50 and N2O4. A single engine powered Astris third stage of the failed Europa rocket.
On November 29, 1968, its inaugural flight, the Astris third stage exploded. On the second attempt on July 1969, the Astris engine failed to start. On the third attempt on June 11, 1970, the stage performed correctly, but the fairing failed to separate. On November 5, 1971, the Europa II launched from CSG ELA-1, had a mishap due to structural failure of the third stage. After this last failure the project was definitely cancelled.