PARIS, June 17 (UPI) -- European Space Agency controllers sent a final command to the Herschel satellite Monday, marking the end of operations for the successful space observatory.
Herschel's science mission ended April 29 when the liquid helium that cooled the observatory's instruments close to absolute zero ran out, but the satellite has been kept active since then as an orbiting test bed for control techniques that can't normally be tested in flight, a release from ESA headquarters in Paris said.