4th Space Launch Squadron
The Landsat Data Continuity Mission spacecraft launches aboard an Atlas VEvolved Expendable Launch Vehicle
Active	1994-1998; 2003-2019
Country	United States
Branch	United States Air Force
Role	Space Launch
Part of	Air Force Space Command
Garrison/HQ	Vandenberg AFB, California
Decorations	Air Force Outstanding Unit Award[1]
Insignia
4th Space Launch Squadron emblem(approved 31 March 1995)[1]

TheUnited States Air Force's4th Space Launch Squadron was a space launch unit located atVandenberg 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.

The4th Space Launch Squadron was the Air Force'sEvolved Expendable Launch Vehicle (EELV) launch agency for the West Coast. The EELV system is a liquid-fueled first stageCommon 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.^[2]

Thesquadron was activated atVandenberg Air Force Base, California on 15 April 1994. Until it was inactivated in June 1998, it launched surveillance and meteorological satellites intopolar orbit.^[1]

After reactivation in 2003, the squadron managed operations for EELVs.^[1] The EELV program was intended to develop provide alternatives to older and expensive heavy-lift launch vehicles, such as theTitan IV. EELVs include:

The BoeingDelta IV. There are different configurations for the Delta IV, which can lift payloads from 9,000 lb to over 13,000 lb intoGeosynchronous Orbit.

The Lockheed MartinAtlas V. This system also has different available configurations, and can lift payloads between 10,000 lb and 30,000 lb to Geosynchronous Transfer Orbit.

TheDelta II, a heritage vehicle smaller than the newerDelta IV. The Delta II can have up to nine external rockets strapped to its main stage, increasing lift capability. It can send approximately 4,000 lb into Geosynchronous Transfer Orbit.^[2]

• Constituted as the4th Space Launch Squadron on 29 March 1994

Activated on 15 April 1994

Inactivated on 29 June 1998

Activated on 1 December 2003^[1]

Inactivated on 31 May 2019 (in merger with1st Air and Space Test Squadron as2nd Space Launch Squadron)

• 30th Operations Group, 15 April 1994 – 29 June 1998
• 30th Launch Group, 1 Dec 2003 – 20 July 2018
• 30th Operations Group, 20 July 2018 – 31 May 2019^[1]

• Vandenberg Air Force Base, California, 15 April 1994 – 29 June 1998
• Vandenberg Air Force Base, California, 1 December 2003^[1] – 31 May 2019

Award streamer	Award	Dates	Notes
	Air Force Outstanding Unit Award	1 October 1994 – 30 September 1996	4th Space Launch Squadron[1]
	Air Force Outstanding Unit Award	1 October 1996 – 30 September 1997	4th Space Launch Squadron[1]
	Air Force Outstanding Unit Award	1 January 1997 – 31 December 1997	4th Space Launch Squadron[1]
	Air Force Outstanding Unit Award	1 January 1998 – 29 June 1998	4th Space Launch Squadron[1]
	Air Force Outstanding Unit Award	1 October 2009 – 30 September 2010	4th Space Launch Squadron[1]

• Titan II (1997–1998)
• Titan IV (1995–1997)
• Delta IV (2003–2019)
• Atlas V (2003–2019)

 This article incorporatespublic domain material from the Air Force Historical Research Agency

• Military units and formations in California
• Space squadrons of the United States Air Force

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