Experimental NASA Cubesat Suffers Attitude Control Problem


WASHINGTON — An experimental NASA cubesat launched Oct. 8 has an attitude control problem that is preventing its laser communications payload from being tested, the agency said Oct. 13.

In a brief statement, NASA said the Optical Communications and Sensor Demonstration (OCSD) spacecraft, known as OCSD-A or AeroCube-7A, suffered an unspecified problem with its attitude control system. While the spacecraft is in contact with ground controllers by radio, “the attitude control system must function properly in order to demonstrate the optical communications system,” NASA said.

OCSD-A, a joint project of NASA and the Aerospace Corp., launched as a secondary payload on an Atlas 5 rocket from Vandenberg Air Force Base, California. The spacecraft was one of 13 cubesats sponsored by NASA and the National Reconnaissance Office that flew along with the primary payload, a classified mission for the NRO.

The Aerospace Corp. built the satellite, funded by NASA’s Small Satellite Technology Program, to demonstrate the ability to use lasers on very small spacecraft to provide communications at high data rates. The satellite is a 1.5-unit cubesat, measuring 10 by 10 by 15 centimeters, outfitted with a laser capable of transmitting data at rates of 5 to 50 megabits per second to telescopes on the ground.

OCSD-A is designed primarily to test both the laser and an attitude control system in lieu of more traditional ground testing. “Cubesats are relatively inexpensive, and you have a number of launch opportunities each year, so you can actually think about flying something rather than doing extensive ground testing,” Siegfried Janson of the Aerospace Corp. said in an Aug. 11 presentation about the mission during the Conference on Small Satellites at Utah State University.

NASA plans to follow OCSD-A with two similar cubesats, known as OCSD-B and -C or AeroCube-7B and -7C. Those satellites, scheduled for launch in early 2016, will test laser communications at even higher data rates, as well as proximity operations near each other. Those satellites will use a simplified version of the laser flown on OCSD-A, as well as a new thruster system that uses steam for propulsion.