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
External links
References
- Falcon 1 Users Guide SpaceX, 2008-09-28^
- SpaceX Falcon Data Sheet 2015-01-19, retrieved 2024-12-27^
- Mark Wade. Kestrel Encyclopedia Astronautica, retrieved 2026-02-04^
- Greg Zsidisin. SpaceX Confirms Stage Bump On Demoflight 2 Space Daily, 23 March 2007, retrieved 2008-09-30^
- Falcon 1 Flight Three Press Kit SpaceX, retrieved 2008-09-30^
- Space Exploration Technologies Corporation - Updates Archive SpaceX, retrieved 2024-09-13^
- Brian Bjelde. The Falcon 1 Launch Vehicle: Demonstration Flights, Status, Manifest, and Upgrade Path 21st Annual AIAA/USU Conference on Small Satellites, August 2007, retrieved 2013-12-06^
- Chris Bergin. Elon Musk Q and A - Updates SpaceX status on Falcon and Dragon NASAspaceflight.com, 2007-09-24, retrieved 2008-06-16^