Spy Satellite Launch Delayed

The Vandenberg Air Force Base rocket launch set for Thursday afternoon has been rescheduled for Monday, April 2, after technicians “observed an upper stage engine condition that will require additional time for review,” according to base officials.

The Delta IV Medium Plus rocket will carry a “national security payload” — or more colloquially, a spy satellite — into orbit. The National Reconnaissance Office, which develops and manages the country’s fleet of spy satellites, hasn’t publicly disclosed the payload’s exact specifications or functions.

The launch is scheduled for 4:04 p.m. on Monday.