| Country of origin | United States |
|---|---|
| Manufacturer | SpaceX |
| Purpose | Upper stage boost |
| First date | 2006 |
| Last date | 2009 |
| Designer | Tom Mueller |
| Fuel | RP-1 |
| Oxidiser | LOX |
| Cycle | Pressure fed |
| Thrust(vac) | 28 kN |
| Specific impulse vacuum | 317 isp |
| Chamber pressure | 9.3 bar (135 psi) |
| Thrust to weight | 65 |
| Dry weight | 52 kg (115 lb) |
| 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 restart capability on the upper stage and simplify design.[6] In a multi-manifested mission, this design would allow for drop off at different altitudes and inclinations.
Kestrel 2
Enhancements to the design of the original Kestrel engine were planned, called the Kestrel 2.[7]
The engine design was still pressure-fed, and was supposed to fly on a newly designed second stage that used Aluminium-lithium alloy 2195, rather than the 2014 Aluminum used in the Falcon 1 second stage.[7] Engine changes were to include tighter tolerances to improve consistency, higher Isp, and lighter weight.[8] The Kestrel 2 did not remain in active development after the Falcon 1 was replaced by the much larger Falcon 9 v1.0 which used an improved Merlin 1C for its upper stage.
See also
References
- ^ "Falcon 1 Users Guide". SpaceX. 2008-09-28. Archived from the original on October 1, 2008.
- ^ "SpaceX Falcon Data Sheet". 2015-01-19. Archived from the original on 19 January 2015. Retrieved 2024-12-27.
- ^ Wade, Mark. "Kestrel". Encyclopedia Astronautica. Archived 2025-05-27 at the Wayback Machine. Retrieved 2026-02-04.
- ^ Greg Zsidisin (23 March 2007). "SpaceX Confirms Stage Bump On Demoflight 2". Space Daily. Retrieved 2008-09-30.
- ^ "Falcon 1 Flight Three Press Kit". SpaceX. Archived from the original on 2008-10-01. Retrieved 2008-09-30.
- ^ "Space Exploration Technologies Corporation - Updates Archive". SpaceX. Archived from the original on 2007-11-05. Retrieved 2024-09-13.
- ^ Bjelde, Brian; Max Vozoff; Gwynne Shotwell (August 2007). "The Falcon 1 Launch Vehicle: Demonstration Flights, Status, Manifest, and Upgrade Path". 21st Annual AIAA/USU Conference on Small Satellites. ' (SSC07 - III - 6). Retrieved 2013-12-06.
- ^ Bergin, Chris & Braddock Gaskill (2007-09-24). "Elon Musk Q and A - Updates SpaceX status on Falcon and Dragon". NASAspaceflight.com. Archived from the original on 2008-05-29. Retrieved 2008-06-16.