Earlier this week, the International Space Station was forced to adjust its orbit to avoid an encroaching commercial satellite. The object is likely one of many Earth-observing satellites that are falling into and aligning with the space station’s orbital path, according to experts.
On Monday, the Progress 83 resupply ship that’s docked to the space station fired its engines for just over six minutes, slightly raising the orbit of the ISS in order to avoid an approaching satellite, NASA wrote in a blog post. The space agency did not identify the object, except to say that it was an “Earth observation satellite.”
However, there is speculation that the satellite in question may be Argentina’s Nusat-17, one of 10 commercial Earth observation satellites form the Aleph-1 constellation operated by Satellogic. Jonathan McDowell, an astrophysicist at the Harvard-Smithsonian Centre for Astrophysics, wrote on Twitter that the orbits of the Satellogic constellation has been gradually decaying and the satellites are now crossing the orbit of the ISS.
Orbital decay: the Satellogic constellation is only one of a number of Earth observing constellations with multiple satellites entering the ISS orbital height regime. Im magenta, Nusat-17 which was the cause of yesterday’s ISS dodge manuever pic.twitter.com/OM0mcToe0p
— Jonathan McDowell (@planet4589) March 7, 2023
The latest ISS manoeuvre points to a larger issue of the growing number of satellites, both defunct and operational, and debris that pose a threat to orbiting spacecraft. More than 27,000 pieces of orbital debris are currently being tracked by the Department of Defence’s global Space Surveillance Network, with lots of smaller pieces also floating around undetected.
In December 2022, the ISS conducted a similar manoeuvre to avoid a collision with a Russian Fregat-SB upper stage fragment that threatened to come within less than a quarter mile of the space station. In fact, the space station has had to carry out 32 collision avoidance manoeuvres since 1999. These orbital swerves have not impacted the astronauts on board the ISS so far. NASA stated that the most recent manoeuvre won’t impact the imminent Crew-5 departure from the space station.
The four astronauts of the Crew-6 mission arrived at the ISS on March 3, while Crew-5 astronauts are set to return home aboard the docked SpaceX Endurance spacecraft as soon as March 9. However, Cosmonauts Sergey Prokopyev and Dmitry Petelin, and NASA astronaut Frank Rubio, will stay aboard the ISS until September.
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