CAPSTONE attitude control restored

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WASHINGTON — Engineers have restored normal attitude control of a cubesat bound for the moon nearly a month after suffering a problem during a maneuver.

Advanced Space, the company that owns the Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment (CAPSTONE) spacecraft, said Oct. 7 that it was able to restore normal three-axis attitude control of the spacecraft earlier that day. The spacecraft had been in a spin-stabilized state since going into a safe mode during a trajectory correction maneuver Sept. 8.

According to the company, engineers isolated the problem to a valve with one of the spacecraft’s eight thrusters. “The partially open valve resulted in thrust from the associated thruster whenever the propulsion system was pressurized,” Advanced Space said in a statement.

After what the company described as extensive testing and simulation, controllers uploaded commands to the spacecraft Oct. 6 to restore normal three-axis attitude control. “Initial telemetry and observation data after the recovery attempt points to a successful recovery of the system which has now regained 3-axis attitude control,” the company stated.

Advanced Space said that, assuming the spacecraft remains in its normal attitude, it will work on changes to other spacecraft procedures for subsequent maneuvers that incorporate the effects of the partially open valve.

The attitude control problem was the second major issue for CAPSTONE since it was launched in June. Shortly after its deployment from Rocket Lab’s Lunar Photon kick stage July 4, the spacecraft lost contact with controllers. That contact was restored about a day later, and the company said a series of events that included an “improperly formatted command” caused the communications outage.

CAPSTONE, funded by NASA to test the stability of the near-rectilinear halo orbit that will be used by future Artemis missions, remains on track to enter orbit around the moon on Nov. 13.