NASA Moves Forward With Mission Using Spy Satellite Telescope (spaceflightnow.com)
NASA has formally approved plans -- a year ahead of schedule -- for an infrared space telescope launching around 2024 to record unique wide-angle views of the cosmos, seeking answers to questions about mysterious dark energy and searching for habitable worlds around other stars, the space agency announced Thursday. The Wide-Field Infrared Survey Telescope is projected to cost approximately $2.3 billion and should operate for at least six years. WFIRST's centerpiece is a 7.9-foot (2.4-meter) telescope originally built to allow U.S. intelligence officials to spy on adversaries. Instead of turning the powerful telescope toward Earth for a clandestine surveillance mission, NASA plans to repurpose the hardware for cosmic research.
Basically they had this device laying around on a shell and decided to give it to nasa because they don't need it anymore. They have enough of those in orbit already.
Think about that. For Nasa it is a big thing to have a Hubble-class telescope in orbit. The intelligence agencies have them lying on a shell as a leftover..