A spacecraft launched nearly a month ago in an ambitious attempt to raise the orbit of a NASA astrophysics satellite is facing serious attitude control issues that could derail its mission. The Link spacecraft, which was launched on July 3, is currently spinning in multiple directions due to problems with its attitude control system. The company behind the mission, Katalyst Space Technologies, reported that two of the three reaction wheels on the spacecraft are not working properly. In addition to the wheel issues, some of the thrusters used for attitude control are only partially functional.
The Link spacecraft was sent into low Earth orbit on a Pegasus XL rocket with the goal of docking with NASA’s Neil Gehrels Swift Observatory. The Swift satellite is currently in a decaying orbit and will reenter Earth’s atmosphere later this year or early next year unless its path is altered. NASA awarded Katalyst a $30 million contract last September to carry out the reboost mission.
The company has not provided many updates since launch, though it did confirm in early July that initial checks were complete and the spacecraft had entered a stable attitude. During those early tests, engineers noted some problems with both attitude control and communications during flight operations.
By July 24, the company reported that it had begun testing electric thrusters and successfully raised the spacecraft’s altitude by about two kilometers. Other systems on Link, including communication, propulsion, and robotics needed for docking with Swift, are still operating as expected. The team plans to use gimbaled electric thrusters to reduce the spinning motion and stabilize the spacecraft over the coming days. After stabilization, engineers will update the guidance and control systems to match the current state of the spacecraft. Once that is done, the mission team will begin approaching Swift with the goal of docking and performing the orbit boost.
The company remains optimistic that the mission can still succeed despite these setbacks. NASA had previously warned that Swift’s orbit must be raised before it drops below 300 kilometers. The satellite is currently at about 350 kilometers, and NASA estimated it would reach the critical altitude in October.
The rescue mission is not only about saving Swift, but also serves as a test for the commercial satellite servicing industry. NASA sees this effort as an opportunity to evaluate how well private companies can handle complex orbital tasks. The timeline for building and launching the Link spacecraft was unusually tight, with only nine months given to complete the mission. Katalyst accepted the challenge and delivered the spacecraft for launch in early June.
The launch was delayed due to weather conditions and a technical issue with the rocket. Regardless of whether the Swift mission succeeds, NASA officials said they were already pleased with what has been accomplished so far. The agency’s astrophysics division director noted that simply attempting the mission was a success from a programmatic standpoint.
The Link spacecraft is still generating enough power to communicate with ground teams, which gives engineers time to work on solutions. Katalyst’s principal investigator had discussed possible problems like these before the launch. He mentioned that past missions had faced issues with power systems and communications, so some risks were expected.
After confirming the spacecraft’s status and stabilizing its attitude, engineers will update the guidance systems to match the current configuration. This step is necessary to prepare for the approach and eventual docking with Swift.
IMAGE: NASA / JSC