The U.S. Air Force (USAF) continued adding space situational awareness (SSA) satellites to the nation’s operational military SSA satellite inventory during 2016. By the end of the year, seven satellites made up the nation’s unclassified SSA fleet. These were the Automated Navigation and Guidance Experiment for Local Space (ANGELS), Advanced Technology Risk Reduction (ATRR), Space Based Space Surveillance (SBSS) system, and four Geosynchronous Space Situational Awareness Program (GSSAP) satellites.

Launched in 2014, the original mission of the Air Force Research Laboratory’s ANGELS satellite was to monitor the upper stage of the rocket the satellite was launched on using new SSA techniques.¹ During 2016, USAF stated it was still conducting experiments with ANGELS.²

ATRR and SBSS satellites both conducted SSA missions from low Earth orbit during 2016. With the ability to observe objects, such as satellites, in geosynchronous orbits, they provide an object’s orbital position and enhance the USAF’s ability to identify an object in space.³‘⁴ SBSS, considered by the USAF as a pathfinding satellite, is expected to remain operational through 2019.⁵ The first of the planned follow-on SBSS satellites is expected to be launched by 2021.⁶

Two GSSAP satellites were launched in August 2016, doubling the number of GSSAP satellites circling the Earth in geosynchronous drifting orbits. All four GSSAP satellites can view and maneuver around space objects, and the data the satellites provide helps satellite operators determine space object collision avoidance options.⁷ In a different scenario, a U.S. Navy communications satellite launched in 2016 experienced a main engine fault before reaching its orbit. The orbiting GSSAP satellites were requested to provide images of the satellite’s propulsion system for fault diagnosis.⁸

1. Mike Gruss. “Secretive ANGELS satellite part of new space experiments.” SpaceNews.com. April 14, 2016. http://spacenews.com/secretive-angels-satellite-part-of-new-space-experiments/. (accessed December 13, 2016)
2. Mike Gruss. “Secretive ANGELS satellite part of new space experiments.” SpaceNews.com. April 14, 2016. http://spacenews.com/secretive-angels-satellite-part-of-new-space-experiments/. (accessed December 13, 2016)
3. Scott Prater. “SSA enhanced thanks to new 1 SOPS mission.” Schriever Sentinel. March 3, 2011. http://csmng.com/wp-files/schriever-sentinel-weekly-pdfs/sentinel_2011-03-03.pdf. (accessed December 13, 2016)
4. Kevin Williams. “Latest Space Situational Awareness system heading to 1 SOPS.” AFSPC Public Affairs Office. June 10, 2014. http://www.schriever.af.mil/News/Article-Display/Article/735935/latest-space-situational-awareness-system-heading-to-1-sops. (accessed December 13, 2016)
5. Mike Gruss. “U.S., Canada may partner on space surveillance proposal.” SpaceNews.com. September 21, 2016. http://spacenews.com/u-s-canada-may-partner-on-space-surveillance-proposal/. (accessed December 13, 2016)
6. Staff Writers. “US Air Force to Introduce Space Based Surveillance System in 2021.” SpaceWar.com. August 2, 2016. http://www.spacewar.com/reports/US_Air_Force_to_Introduce_Space_Based_Surveillance_System_in_2021_999.html. (accessed December 13, 2016)
7. Air Force Space Command Public Affairs Office. “Fact Sheet: GEOSYNCHRONOUS SPACE SITUATIONAL AWARENESS PROGRAM (GSSAP).” USAF. April 15, 2015. http://www.afspc.af.mil/About-Us/Fact-Sheets/Article/730802/geosynchronous-space-situational-awareness-program-gssap. (accessed December 13, 2016)
8. Jennifer Thibault. “’Neighborhood Watch’ supports Navy operations.” 50^th Space Wing Public Affairs Office. August 17, 2016. http://www.schriever.af.mil/News/Article-Display/Article/917972/neighborhood-watch-supports-navy-operations. (accessed December 13, 2016)