|4th Space Launch Squadron
|Branch||United States Air Force|
|Part of||Air Force Space Command|
|Garrison/HQ||Vandenberg AFB, California|
|Decorations||Air Force Outstanding Unit Award|
|4th Space Launch Squadron emblem (approved 31 March 1995)|
The United States Air Force's 4th Space Launch Squadron was a space launch unit located at Vandenberg Air Force Base, California. It was active at Vandenberg from 1994 to 1998 and again from 2003 to 2019. It launched various satellites into orbit from the complex of launch pads at Vandenberg.
The 4th Space Launch Squadron was the Air Force's Evolved Expendable Launch Vehicle (EELV) launch agency for the West Coast. The EELV system is a liquid-fueled first stage Common Booster Core (CBC) that can be used alone, with strap-on solid fuel rocket boosters, or as a configuration of three CBCs acting as a more powerful booster.
The squadron was activated at Vandenberg Air Force Base, California on 15 April 1994. Until it was inactivated in June 1998, it launched surveillance and meteorological satellites into polar orbit.
After reactivation in 2003, the squadron managed operations for EELVs. The EELV program was intended to develop provide alternatives to older and expensive heavy-lift launch vehicles, such as the Titan IV. EELVs include:
|Air Force Outstanding Unit Award||1 October 1994 – 30 September 1996||4th Space Launch Squadron|
|Air Force Outstanding Unit Award||1 October 1996 – 30 September 1997||4th Space Launch Squadron|
|Air Force Outstanding Unit Award||1 January 1997 – 31 December 1997||4th Space Launch Squadron|
|Air Force Outstanding Unit Award||1 January 1998 – 29 June 1998||4th Space Launch Squadron|
|Air Force Outstanding Unit Award||1 October 2009 – 30 September 2010||4th Space Launch Squadron|