Geosynchronous Space Situational Awareness Program (GSSAP) or Hornet is a class of United States spy satellites.
The first two GSSAP spacecraft were launched in 2014, and a further two was launched on 19 August 2016 (USA-270 and USA-271). The first two were built by Orbital Sciences Corporation; their capabilities and development and construction budgets are classified. They operate in "near-geosynchronous orbit",[1][2] The first launch was scheduled for 23 July 2014 aboard a United Launch AllianceDelta IVlaunch vehicle.[3]
Even during the testing process these satellites were pressed into early service to fulfill critical needs.[4]
On 12 September 2017, the third and fourth satellites were declared operational.[5]
Two more satellites (GSSAP-5 and GSSAP-6) have been successfully launched on 21 January 2022 by a Atlas Vlaunch vehicle.[6] USA-270 approached two Chinese satellites in GEO to examine them more closely.[7] In 2023, Chinese researchers reported having observed 13 other instances where US satellites approached Chinese ones.[8]
In August 2023 the Space Systems Command announced the retirement of the GSSAP-2 satellite, the first of the constellation to be decommissioned, and its subsequent transfer into a graveyard orbit. Moreover, it revealed that two more satellites have been ordered to Northrop Grumman to keep up with the demand for GSSAP assets.[9] The launches of the new satellites are planned for 2024 and 2027 respectively, with the spacecraft being the first of the constellation not to be launched in pairs.[10]
^Neighborhood watch in space, Aviation Week and Space Technology, 4 August 2014, p.12