A Delta IV Medium Plus rocket, strapped with a highly classified spy satellite, will launch from Vandenberg Air Force Base at 4:12 p.m. today. Watch it live right here.
The launch was originally scheduled for last Thursday, but an issue with one of the rocket’s upper engines required additional safety inspections. The National Reconnaissance Office, which develops and oversees the county’s fleet of spy satellites, has not publicly disclosed the the payload’s exact specifications or function.