AFSPC-4 (GSSAP 1 & 2)

The Autonomous Nanosatellite Guardian for Evaluating Local Space (ANGELS) project is an Air Force Research Laboratory project to develop a small satellite which can orbit close to a larger spacecraft and monitor the local space environment.

GSSAP (Geosynchronous Space Situational Awareness Program) or Hornet is a series of space surveillance satellites developed covertly by the Air Force and Orbital Sciences to provide a space-based capability operating in the near-geosynchronous orbit regime supporting U.S. Strategic Command space surveillance operations as a dedicated Space Surveillance Network (SSN) sensor.