Discoverer II

Discoverer II (initially known as STARLITE) was a joint DARPA, Air Force, and National Reconnaissance Office project to build and launch a low Earth orbit (LEO) constellation for space-based radar.

The Discoverer II concept dates back to June 1996, when the Director of Central Intelligence's Small Satellite Review Panel concluded that: "...now is an appropriate time to make a qualitative change in the systems architecture of the nation's reconnaissance assets... We see the opportunity to move towards an operational capability for the country, at least for imagery systems, that consists of an array of smaller, cheaper spacecraft in larger numbers which is at least as useful as those currently planned and to transport them to space with substantially smaller and less costly launch vehicles."

In its January 1998 report, the Task Force recommended that a modified STARLITE program be initiated, as a "Military Space Radar Surveillance Program," in an effort to achieve broad-area, all-weather, near-continuous radar access that could be integrated with military operations.

The constellation would allow for a very rapid revisit rate (about 15 minutes) to most areas of the earth for near-continuous surveillance of terrestrial and maritime vehicles, and could produce Interferometric SAR images for high-resolution terrain mapping.

On February 22, 1999, three contractor teams were selected, led by Lockheed Martin Astronautics, Spectrum Astro, and TRW Defense Systems Division.