The Orbital ATK [OA] Minotaur IV rocket that will launch the Air Force Operationally Responsive Space 5 (ORS-5) space-tracking satellite is also carrying two secondary payloads from Special Operations Command (SOCOM) and one from the Defense Advanced Research Projects Agency (DARPA), government and industry officials said Aug. 24.

The Minotaur, whose lower stages use three motors from decommissioned Peacekeeper intercontinental ballistic missiles, will release the secondary payloads after burning the first of two Orion 38 upper-stage motors, said Phil Joyce, vice president of space launch programs at Orbital ATK. ORS-5 will be released after burning the second Orion.

Orbital ATK's Minotaur IV launch vehicle. Photo: Air Force.
Orbital ATK’s Minotaur IV launch vehicle. Photo: Air Force.

DARPA spokesman Jared Adams said that his agency’s payload, the Space-Based High Frequency Testbed, is a prototype cubesat that will use space-based radio-frequency measurements to improve the performance of over-the-horizon radar.

The SOCOM payloads, also cubesats, “are part of a technology demonstration” for communication, command spokesman Ken McGraw said. “USSOCOM will use the information obtained to determine whether or not the capability will transition to operational use, requires additional development, or warrants further investment.”

The Minotaur is scheduled to lift off late Aug. 25 from Cape Canaveral Air Force Station in Florida (Defense Daily, Aug. 18). Orbital ATK said it is in “final preparations” for the launch. The four-hour launch window opens at 11:15 p.m. Eastern time. The launch’s backup date is Aug. 26.

ORS-5, also called SensorSat, will operate in low Earth orbit to help the military scan for other satellites and debris in geosynchronous orbit. The Massachusetts Institute of Technology’s Lincoln Laboratory built ORS-5.

The launch will be the 26th flight for Orbital ATK’s Minotaur product line and the sixth flight of the Minotaur IV configuration. It will be the Minotaur’s first launch from Florida. Previous launches have occurred from Alaska, California and Virginia.