Dec. 8 (UPI) -- Another day, another scrub. United Launch Alliance once again called off the launch of its Delta 4-Heavy rocket, this time with just 7 seconds to go on the countdown.
In an update, ULA said they called off the launch due to an "unexpected condition during terminal count."
The mission delay marks the second scrubbed launch in as many days.
The company's most powerful rocket was originally scheduled to carry a spy satellite into space on Friday, but a communications error forced ULA to delay the liftoff until Saturday evening. ULA hasn't yet announced when attempt three will take place.
During Friday's preflight checks, engineers discovered a "redundant communication link between the control center and the launch site," according to a statement released by ULA.
The rocket's payload belongs to the National Reconnaissance Office, one of the U.S. government's five major intelligence agencies. When the mission finally does launch, it will mark ULA's 132nd -- the 71st for NRO.
NRO and ULA have offered very little information about the satellite being carried into space Saturday.
According to new site SpaceFlight 101: "NROL-71 is most likely a heavy Keyhole KH-11 image reconnaissance satellite."
The telescope-like spy satellites are capable of capturing high-resolution images useful to U.S. 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 U.S. 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.