NASA astronaut Terry Virts making the repairs to one of two NanoRacks' cubesat deployers on the ISS. Credit: NASA

WASHINGTON — Astronauts on the International Space Station have made repairs to a set of small satellite deployers that malfunctioned several months ago, a move that the company that provided them calls a milestone for commercial activities there.

The deployer system, used to eject cubesat-sized spacecraft from the ISS, broke down in August, failing to release satellites when commanded. During the troubleshooting process in September, two satellites were inadvertently released. The deployers were returned inside the ISS through the airlock in the Japanese Kibo module in mid-September.

While NanoRacks, the Houston-based company that provided the deployers, has built new deployers to correct the problem, it worked with NASA and other ISS partners to also attempt to repair the deployers currently on the station. “After several months of hard work, we made adjustments to the deployers,” said Jeffrey Manber, managing director of NanoRacks, in an interview Feb. 17.

The problems with the deployers were traced to screws that were not tightened correctly, he said, as well as issues with a power feed. “It was a couple of different things, and we think we’ve corrected it,” he said.

The repair work, Manber said, included installation of a new electronics system for the deployer and latches to prevent the premature deployment of the satellites. A SpaceX Dragon cargo spacecraft delivered the repair hardware to the ISS in January. The station’s crew made the repairs and successfully tested the latches on Feb. 17, and planned to attempt satellite deployments the week of Feb. 23.

Those repair plans took several months of coordination with NASA, Roscosmos, the Japanese space agency JAXA, and the Aerospace Corp., who NanoRacks had brought in to support the investigation of the deployer problem. “We had to go through a review process” with those space agencies, he said. “There was some questioning about whether we should attempt this on-orbit repair, but NASA has been very supportive.”

One of NanoRacks' cubesat dispensers after repair. Credit: NanoRacks
One of NanoRacks’ cubesat dispensers after repair. Credit: NASA
One of NanoRacks’ cubesat dispensers after repair. Credit: NASA

Manber said the company went through the time and effort of the repair process, instead of waiting to ship new deployers to the station, to demonstrate that the ISS is a “robust” platform for commercialization. “We could have brought the payloads down and thrown them away,” he said. “This is to try and fix something that didn’t work, with the same satellites on it.”

He cautioned that there’s no guarantee that the repairs will fix the problems with the deployers, but that the addition of the latches, specifically requested by JAXA, should eliminate any risk to the station from an accidental deployment of satellites. “These are the deployers that did not work last time, so they may not work this time,” he said. “We think we’ve fixed it, but we know we’ve made it safe.”

In addition to the repaired deployers on the station and new ones of a similar design slated to go to the station later this year, NanoRacks has been developing a new small satellite deployment system called Kaber. That system will be able to support launching both cubesat-class spacecraft as well as larger microsatellites weighing up to 50 kilograms.

The hardware for Kaber is being built now, NanoRacks external payloads manager Kirk Woellert said at an ISS utilization workshop the company held here Feb. 17. Kaber will be delivered to the ISS this summer on the seventh SpaceX Dragon cargo mission, with the first microsatellite deployments using it expected by the end of the year.

Even if the repaired deployers don’t work, Manber said that the effort that went into attempting the repair was worthwhile. “It involved astronauts, multiple agencies, NanoRacks, everybody working together,” he said. “It’s a major step forward, using the space station for commercial on-orbit repair.”

Jeff Foust writes about space policy, commercial space, and related topics for SpaceNews. He earned a Ph.D. in planetary sciences from the Massachusetts Institute of Technology and a bachelor’s degree with honors in geophysics and planetary science...