DSP 23 in Trouble

According to a Dec. 3 report on MSNBC.com, the last Defense Support Program missile warning satellite to join the highly classified DSP constellation that’s been in operation since the 1970s, is malfunctioning and potentially could pose a problem for other spacecraft. The Russian International Scientific Optical Network has tracked the satellite, launched in November 2007, and discovered that it had ceased making station-keeping maneuvers a couple of months ago and appeared to be drifting out of its orbit. A Reuters new service Nov. 24 report notes that experts say the six to 10 DSP satellites still functioning are “about double the number needed to watch the entire Earth at once,” so there is little concern for an immediate gap in missile warning. The satellites have been known for their reliability, normally far exceeding their design lives. Prime contractor Northrop Grumman noted in an October release that the DSP sats had provided “an extra 173 satellite years” on orbit. The Air Force plans to replace the DSP constellation with the Space Based Infrared System, clearing the first highly elliptical orbit sat for operational service last month.