SpaceX Kestrel

{{short description|Family of rocket engines developed by SpaceX for use on its Falcon 1 launch vehicles}}

{{Infobox rocket engine

|image = SpaceX Kestrel engine2.gif

|image_size = 140

|caption = SpaceX Kestrel

|name = SpaceX Kestrel

|country_of_origin= United States

|manufacturer = SpaceX

|purpose = Upper stage boost

|first_date = 2006

|last_date = 2009

|designer = Tom Mueller

|type = liquid

|fuel = RP-1

|oxidiser = LOX

|cycle = Pressure fed

|thrust(Vac) = {{cvt| 28|kN| t-f}}

|specific_impulse_vacuum = {{convert| 317| isp}}

|chamber_pressure = {{cvt| 9.3| bar| psi}}

|thrust_to_weight = 65

|length=

|diameter=

|dry_weight= {{cvt| 52| kg| lb}}

|references={{cite news|url=http://www.spacex.com/Falcon1UsersGuide.pdf |title=Falcon 1 Users Guide |date=2008-09-28 |publisher=SpaceX |url-status=dead |archive-url=https://web.archive.org/web/20081001161902/http://www.spacex.com/Falcon1UsersGuide.pdf |archive-date=October 1, 2008 }}{{Cite web |date=2015-01-19 |title=SpaceX Falcon Data Sheet |url=http://www.spacelaunchreport.com/falcon.html |access-date=2024-12-27 |archive-url=https://web.archive.org/web/20150119203838/http://www.spacelaunchreport.com/falcon.html |archive-date=19 January 2015 }}[http://www.astronautix.com/engines/kestrel.htm astronautix] {{webarchive|url=https://web.archive.org/web/20131216104115/http://www.astronautix.com/engines/kestrel.htm |date=2013-12-16 }}

}}

Image:SpaceX engine test fire.jpg

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.{{cite news |url=http://www.spacedaily.com/reports/SpaceX_Confirms_Stage_Bump_On_Demoflight_2_999.html | title=SpaceX Confirms Stage Bump On Demoflight 2 | author = Greg Zsidisin | date = 23 March 2007 | publisher = Space Daily |access-date=2008-09-30}} Helium pressurant efficiency is substantially increased via a titanium heat exchanger on the ablative/niobium boundary.{{cite web|url=http://www.spacex.com/SpaceX_F1-003_PressKit.pdf |publisher=SpaceX |title=Falcon 1 Flight Three Press Kit |access-date=2008-09-30 |url-status=dead |archive-url=https://web.archive.org/web/20081001161901/http://www.spacex.com/SpaceX_F1-003_PressKit.pdf |archive-date=2008-10-01 }}

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.{{Cite web |date= |title=Space Exploration Technologies Corporation - Updates Archive |url=http://spacex.com/updates_archive.php?page=0205-0505 |url-status=dead |archive-url=https://web.archive.org/web/20071105080852/http://spacex.com/updates_archive.php?page=0205-0505 |archive-date=2007-11-05 |access-date=2024-09-13 |website=SpaceX}} In a multi-manifested mission, this design would allow for drop off at different altitudes and inclinations.