STSS 2

Spacecraft n°:

US spacecraft n°:

Launch data: Designation  35938 / 09052B Launch date  25 Sep 2009 - 12:20 UT Launch site  CC, SLC-17B Launch vehicle  Delta-7920-10C Mission  Military: Technology Development / Tracking LEO Earth orbit on: Perigee / Apogee  1339 x 1351 km Eccentricity  7.78E-04 Inclination  58 deg Period  112.58 min

Spacecraft data:

Mission details:

• Use sensors on the two spacecraft to track ballistic missiles.
• The STSS (Space Tracking and Surveillance System) Demo launch on Sep 23 placed the two STSS satellites in orbit using a Delta 7920 launch vehicle. STSS 1 and 2 were designated USA 208 and 209 after launch. The satellites were built by Northrop Grumman for the US Missile Defense Agency and will monitor missile flights using infrared sensors. Mass of the spacecraft is around 1000 kg each and they are in a 1350 x 1350 km x 58 deg orbit.
• On Sep 25 at 14:33 UT: First signals received from the STSS SV1 Demonstrator satellite at the Zarya (UK) location, SV2 is transmitting at 2272.5 MHz.
• On Oct 7: The orbit of SVS Demonstrator satellite SV2 is adjusted slightly in order to slow the rate of separation.
• On Nov 11, 2009: The orbit of STSS Demonstrator satellite SV2 is adjusted for a second time and the gap between the two satellites starts reducing. They had reached a point where each was close to the other's visible horizon.