Dec. 7 (UPI) -- United Launch Alliance was forced to scrub its Delta 4-Heavy rocket launch as a result of a communications error.
Prior to liftoff, engineers discovered a "redundant communication link between the control center and the launch site," according to a statement released by ULA.
The company's most powerful rocket was scheduled to carry a spy satellite into space on Friday, but the mission has been delayed until Saturday evening. Liftoff from California's Vandenberg Air Force Base is scheduled for 11:06 p.m. ET, 8:19 p.m. local time.
"The forecast shows a 60 percent chance of favorable weather conditions for launch," ULA announced on its blog.
ULA will stream a live broadcast of Saturday's launch.
The satellite belongs to the National Reconnaissance Office, of the U.S. government's five major intelligence agencies. Friday's mission will be ULA's 132nd and the 71st for NRO.
Per usual, little information about the payload for Saturday evening's mission has been shared with the public.
According to new site SpaceFlight 101: "NROL-71 is most likely a heavy Keyhole KH-11 image reconnaissance satellite."
Such satellites are capable of capturing high-resolution images useful to American military and intelligence agencies.
"We are proud to launch this critical payload in support of our nation's national security mission," Gary Wentz, vice president of government and commercial programs at ULA, said in a news release. "As the nation's premiere launch provider, the teams have worked diligently to ensure continued mission success, delivering our customer's payloads to the precise orbits requested."
The Delta 4-Heavy is one of the most powerful American rockets currently in operation. It can carry up to 14,000 pounds into geosynchronous orbit, 28,000 pounds into geo-transfer orbit and 53,000 pounds into low Earth orbit. The rocket's power is derived from a trio of boosters, each featuring liquid hydrogen-liquid oxygen engines. Together, the three engines produce 2.1 million pounds of thrust.