SDS-3

American military communications satellite, provided data relay services for optical reconnaissance and other military spacecraft. Operational, first launch 2000.12.06. Comsat / Relay, early warning satellite built by for USAF, USA. Launched 1998 - 2014.

Replacement for the SDS-2 satellites, which from Molniya-type orbits, provided data relay services for optical reconnaissance and other military spacecraft. The Atlas-IIAS payload capability indicates they had a mass under 3600 kg, compared to 6000 kg for the SDS-2 series. Therefore they surely had a different payload, and may have had a substantially different mission.