ISS maneuver test with Cygnus spacecraft did not go as planned

The Cygnus space cargo ship approaches the ISS on February 21, 2022.

The Cygnus space cargo ship approaches the ISS on February 21, 2022.
Photo: Nasa

NASA is currently evaluating the ability of the docked Cygnus spacecraft to serve as boosters for the International Space Station, but a recent test of the concept was quickly shut down, for reasons that are still unclear.

Northrop Grumman’s Cygnus NG CRS-17 spacecraft engine firing began at 11:20 a.m. ET on Monday, June 20, and it was supposed to last exactly 5 minutes and 1 second, but NASA called it off after just 5 seconds. . , according to an agency Press release. Cygnus mission officials said “the cause of the abortion is understood and being investigated“, NASA added, but without providing further details. In an email to Gizmodo, a NASA spokesperson said the agency will be to bring After updates on his space station blog later this week.

The purpose of the test was to assess the ability of docked Cygnus spacecraft to serve as functional thrusters of the ISS. The space station is equipped with its own propulsion system, but this is often insufficient to make significant position adjustments. The ISS, orbiting some 260 miles (418 km) above the surface, has to move at times, whether for operational reasons or when it has to dodge other satellites or potentially hazardous space debris.

The configuration of the ISS as it appeared on June 3, showing the location of Cygnus-17 and Progress 81.

The configuration of the ISS as it appeared on June 3, showing the location of Cygnus-17 and Progress 81.
Image: Nasa

This was the case a few days ago. On June 16, a docked Russian Progress 81 spacecraft fired its thrusters for 4 minutes and 34 seconds, in a procedure that provided additional distance from the predicted trajectory of space junk, namely a fragment of the ancient satellite Russian Cosmos 1408, which Russia deliberately destroyed earlier this year during a cheeky test of anti-satellite weapons. The crew was apparently “never in danger”, but without the orbital adjustment, “it was predicted that the fragment could have passed within about half a mile of the station”, according to a NASA report. Press release.

With so many satellites orbiting Earth, and with so much unnecessary junk and debris up there, these maneuvers are now commonplace. The problem is, Russia threatened to leave the ISS (potentially as early as 2025), and given that Progress vehicles are typically used as ISS boosters, this poses a problem for NASA. Hence the test with the Cygnus.

Failing the test with Cygnus doesn’t mean the spacecraft isn’t up to the task, but it would be nice to know what went wrong. That said, NASA is planning a resumption on Saturday, June 25, when the agency will turn on Cygnus’ engines again. If the test works, it will be the first time a commercial spacecraft has been used to boost the ISS (at least to my knowledge). By the way, SpaceX CEO Elon Musk has suggests that his company’s Dragon should also be able to perform reinforcement tasks if called upon.

This planned new test is still unofficial, as NASA needs to discuss the new plan with its ISS partners, according to the press release. Assuming all goes well, the Cygnus expendable vehicle will leave the station with its load of junk on June 28 and burn up in Earth’s atmosphere.

Related: ISS lost control after Russian module misfires, new details reveal.

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