More info...
Sounds like an optical imagery bird in a typically low orbit.
Lacrosse/Onyx tracking data show ~420 mile orbits.
Here
“Specialists who follow spy satellite operations suspect it is an experimental imagery satellite built by Lockheed Martin and launched from Vandenberg Air Force Base in California in December 2006 aboard a Delta II rocket. Shortly after the satellite reached orbit, ground controllers lost the ability to control it and were never able to regain communication.”