Material published on the Serpo site in August 2006 mentions a Project ORION. It allegedly is a fairly recent project that since 2002 tests alien propulsion systems at the Nevada Test Site.
Other sources mention different names for such programme. See Pluto, Redlight and Snowbird.
It is possible however, that Orion would be the more recent name.
A similar programme exists in Canada and is called Magnet.
Project Orion also is the name of a programme in France, developed by the French Ministry of Defense, for the purpose of monitoring, identifying and predicting the passage of satellites over French territory.