Coming Online

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.