The Air Force’s newest on-orbit GPS satellite is now fully operational. Spacecraft manufacturer Lockheed Martin announced Jan. 16 that the modernized GPS Block IIR satellite, designated IIR-18M and launched on Dec. 20, 2007, went through on-orbit checkout in a record-setting three days and was declared mission ready on Jan. 2. Lockheed Martin technicians worked with Air Force Space Command’s 2nd Space Operations Squadron, which oversees the GPS constellation, to clear the satellite for use. The new spacecraft joins the 30-spacecraft GPS constellation, which includes four additional IIR-M satellites as well as 12 Block IIR satellites and units of earlier configurations.
The Pentagon agency charged with building and operating U.S. spy satellites recently declassified some details about a Cold War-era surveillance program called Jumpseat—a revelation it says sheds light on the importance of satellite imaging technology and how it has advanced in the decades since.


