Skip to main content

Engineers get NASA’s CAPSTONE lunar satellite spin back under control

For the past month, NASA’s CAPSTONE satellite has been spinning through space after it suffered an error on its way to an experimental orbit around the moon. But now, engineers have managed to stabilize the satellite, stopping its spin and getting its attitude back under control.

The error occurred on September 8, after a trajectory correction maneuver. The error caused the spacecraft to go into safe mode, and there were concerns about whether it had enough power coming through its solar panels to maintain heat in the propulsion system. On Friday, October 7, team members sent recovery commands to the spacecraft which succeeded in stopping its spin.

Artist's illustration of CAPSTONE approaching the moon.
Artist’s illustration of CAPSTONE approaching the moon. Illustration by NASA/Daniel Rutter

“Initial telemetry from CAPSTONE and observation data points to a successful maneuver, indicating the spacecraft has stopped its spin and regained full 3-axis attitude control, meaning CAPSTONE’s position is controlled without unplanned rotation,” NASA said in an update. That should help with power concerns as the solar panels can now be oriented, the agency said. “CAPSTONE now has oriented its solar arrays to the Sun and adjusted the pointing of its antennas to provide a better data connection to Earth.”

Performing the recovery operation was risky, according to Advanced Space, the company which owns the satellite on behalf of NASA. So the process was tested extensively before the commands were sent, and now the team will continue to monitor the satellite closely to check that everything is operating as it should.

The company also shared information about the underlying cause of the issue, which seems to have a problem with a valve on one of the spacecraft’s thrusters. “Data from the spacecraft suggests the most likely cause was a valve-related issue in one of the spacecraft’s eight thrusters,” NASA said. “The partially open valve meant the thruster produced thrust whenever the propulsion system was pressurized.” This was what caused the spacecraft to spin out of control following the trajectory correction maneuver, in which the thrusters are fired to adjust the course of the spacecraft.

Now, CAPSTONE will continue on its journey to a special orbit around the moon, which is it set to enter on November 13. As it travels, the team will continue to work on possible fixes for the value issue.

Editors' Recommendations

Georgina Torbet
Georgina is the Digital Trends space writer, covering human space exploration, planetary science, and cosmology. She…
Large NASA satellite falls back to Earth after decades in orbit
NASA's ERBS satellite.

A 5,400-pound NASA satellite has fallen safely back to Earth after 38 years in space.

The retired Earth Radiation Budget Satellite (ERBS) entered Earth’s atmosphere over the Bering Sea between Alaska and eastern Russia at 11:04 p.m. ET on Sunday, January 8, NASA confirmed in a tweet.

Read more
Old NASA satellite predicted to reenter the atmosphere tomorrow
NASA’s retired Earth Radiation Budget Satellite (ERBS) is expected to reenter Earth’s atmosphere in early January.

An old NASA satellite is set to reenter the atmosphere tomorrow, Sunday, January 8. Though most of the satellite is expected to burn up in the atmosphere and pose minimal risk, some debris could reach the surface. NASA satellites launched today are designed to deorbit more gracefully and with less risk of creating space debris, but this satellite was launched in 1984 before guidelines were in place.

The current guidelines, updated in November 2019, require that any risk of a deorbiting satellite impacting people on Earth is less than 1 in 10,000. The old satellite doesn't quite meet that requirement as there is marginally more risk from its impact. "NASA expects most of the satellite to burn up as it travels through the atmosphere, but some components are expected to survive the reentry," the agency wrote in a statement. "The risk of harm coming to anyone on Earth is very low – approximately 1 in 9,400."

Read more
See NASA’s newest Earth-monitoring satellite unfurl in space
This illustration shows the SWOT spacecraft with its antenna mast and solar arrays fully deployed.

This month, NASA launched a new Earth-monitoring satellite that will observe fresh water systems across the planet. Now, the satellite has unfurled in space ready to begin science operations, and NASA has shared a video showing the unfolding process.

KaRIn Antennas Deploy on International SWOT Satellite

Read more