Amateur satellite sleuths believe a U.S. National Reconnaissance Office (NRO) satellite launched from Vandenberg Air Force Base, Calif., Jan. 20 aboard a Delta 4 Heavy rocket is another in the Keyhole series of optical reconnaissance satellites, the website reports.

The satellite is the latest in a long line of Lockheed Martin-built craft that was extended following the failure of the NRO’s Future Imagery Architecture development program, the story says.

      “Built by Lockheed Martin, the telescope-like Keyhole satellites are electro-optical imaging craft that circle the planet in elliptical polar orbits and collect pictures for U.S. national security uses. There have now been 15 such launches since 1976, all but one successfully reaching orbit,” said Ted Molczan, a respected observer who keeps tabs on orbiting spacecraft.

READ IT AT: [Spaceflight Now]