US to launch secret spy satellite Saturday

The mobile service tower rolls back from the United Launch Alliance (ULA) Delta IV Heavy rocket carrying NRO's NROL-71 mission in preparation for launch from Space Launch Complex 6 at Vandenberg Air Force Base in California. Liftoff is targeted for Jan. 19, 2018. (United Launch Alliance)

The United States' newest spy satellite will finally get off the ground this weekend, if all goes according to plan.

The NROL-71 spacecraft is scheduled to launch atop a United Launch Alliance (ULA) Delta IV Heavy rocket from California's Vandenberg Air Force Base on Saturday (Jan. 19) at 2:05 p.m. EST (1905 GMT; 11:05 a.m. local California time), ULA representatives announced yesterday (Jan. 15).

You can watch the launch here at Space.com, courtesy of ULA, or directly via the company.

ULA had originally targeted early December for NROL-71's liftoff, but bad weather and technical issues pushed the launch back multiple times. The most recent attempt, on Dec. 19, was nixed because of a slight hydrogen leak on the Delta IV Heavy — an issue that has taken several weeks to resolve.

"We continue to remedy the technical issues that caused the last scrub of the Delta IV Heavy, and are working with our partners, the National Reconnaissance Office [NRO] and the U.S. Air Force, to ensure that we fly when it is safe to do so," Gary Wentz, ULA's vice president of government and commercial programs, said in a statement on Jan. 5. "We understand that this is a high-priority mission for the nation's war fighters, and we take our commitment to safety and mission assurance seriously."

NROL-71 will be operated by the NRO, which manages the United States' fleet of spy satellites. The activities of such spacecraft are generally classified, and NROL-71 is no different. Government officials have not disclosed details about the satellite's mission, and ULA is expected to end its launch webcast about 6 minutes after liftoff to help preserve secrecy.

Originally published on Space.com.