United Launch Alliance Atlas 5 rocket launches NROL-55 mission. Credit: ULA

WASHINGTON — A United Launch Alliance Atlas 5 rocket lifted off Oct. 8 from Vandenberg Air Force Base in California carrying a classified payload for the U.S. National Reconnaissance Office.

Liftoff of the NROL-55 mission occurred at 5:49 a.m. local time. Almost all missions for the NRO, which buys and operates U.S. spy satellites, are classified, meaning few details are released. However, the West Coast launch site suggests that the satellite or satellites were destined for a high-inclination orbit, which is ideal for imaging and other missions that require synoptic global coverage.

The NRO did say the launch included an auxiliary payload known as the Government Rideshare Advanced Concepts Experiment, or GRACE, which carried 13 cubesats. The GRACE carrier was attached to the aft end of the Atlas 5’s Centaur upper-stage engine.

Nine of the cubesats were sponsored by the NRO, with the remaining four sponsored by NASA.

Among the NRO-sponsored cubesats are three experimental communications satellites for the U.S. Army’s Space and Missile Defense Command. The SMDC Nanosatellite Program, or SNaP, cubesats each weigh about 4.5 kilograms and will be used to help develop radios that provide “beyond-line-of-sight communication for disadvantaged users in remote locations,” an NRO fact sheet said.

The other NRO-sponsored cubesats include two from the Aerospace Corp. to demonstrate tracking technologies and laser-optical communications; two from Tyvak to perform ionospheric calibration measurements; and two from SRI International to demonstrate software defined radio communications.

The NASA-sponsored cubesats were developed by the University of Alaska, Fairbanks; Salish Kootenai College; the AMSAT amateur satellite radio organization; and the Jet Propulsion Laboratory.

Mike Gruss covers military space issues, including the U.S. Air Force and Missile Defense Agency, for SpaceNews. He is a graduate of Miami University in Oxford, Ohio.