 SpaceX Kestrel | |
| Country of origin | United States |
|---|---|
| First flight | 2006 |
| Last flight | 2009 |
| Designer | Tom Mueller |
| Manufacturer | SpaceX |
| Application | Upper stage boost |
| Liquid-fuel engine | |
| Propellant | LOX / RP-1 |
| Cycle | Pressure fed |
| Performance | |
| Thrust, vacuum | 28 kN (2.9 tf) |
| Thrust-to-weight ratio | 65 |
| Chamber pressure | 9.3 bar (135 psi) |
| Specific impulse, vacuum | 317 seconds (3.11 km/s) |
| Dimensions | |
| Dry weight | 52 kg (115 lb) |
| References | |
| References | [1][2][3] |
The SpaceX Kestrel was an LOX/RP-1 pressure-fed rocket engine. The Kestrel engine was developed in the 2000s by SpaceX for upper stage use on the Falcon 1 rocket. Kestrel is no longer being manufactured; the last flight of Falcon 1 was in 2009.
Kestrel was built around the same pintle architecture as the SpaceX Merlin engine but does not have a turbopump and is fed only by tank pressure.
Kestrel was ablatively cooled in the chamber and throat and radiatively cooled in the nozzle, which was fabricated from a high strength niobium alloy. As a metal, niobium is highly resistant to cracking compared to carbon-carbon. According to SpaceX, an impact from orbital debris or during stage separation might dent the metal but have no meaningful effect on engine performance.[4] Helium pressurant efficiency is substantially increased via a titanium heat exchanger on the ablative/niobium boundary.[5]
Thrust vector control is provided by electro-mechanical actuators on the engine dome for pitch and yaw. Roll control (and attitude control during coast phases) is provided by helium cold gas thrusters.
A TEA-TEB pyrophoric ignition system is used to provide multiple restart capability on the upper stage. In a multi-manifested mission, this design would allow for drop off at different altitudes and inclinations.
