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Comment by walrus01

2 hours ago

It's not exactly the first, this is the first (unclassified, that we know about) satellite to go up and grapple a satellite in geostationary and provide stationkeeping functions for it, which did so back in 2020:

https://en.wikipedia.org/wiki/Mission_Extension_Vehicle

This is all very novel because in the relatively long history of humans sticking stuff in geostationary orbit, not once until 2020 had any sort of mission gone out to geostationary and intentionally grappled or docked with another satellite.

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walrus01

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notahacker  1 hour ago

The multi-purpose robotic manipulation makes this a bit more advanced and experimental than the dedicated MEV attachment, as useful and performant as the MEV has been. China also demonstrated robotic grappling and towing in GEO in 2021. A few other US and European experimental robotic servicing missions in the pipeline, involving both Active Debris Removal grappling and robotic arms playing with designated payloads and attachment interfaces, but mostly planned for LEO.

There's a tendency for such experimental servicing missions (e.g DARPA Orbital Express) to take place in lower orbits, along with all the crewed space station docking and shuttle servicing missions. LEO is cheaper for servicing demonstrations, more human-friendly and also where the Hubble Space Telescope that took a fair bit of servicing happens to be based. But for the robotics, sufficiently advanced autonomy for the latency not to be a major issue is also important.

  • walrus01  1 hour ago

    The new robot grappler arm definitely seems like an advancement on previous designs. The MEV was, as I recall, designed to mate with only a specific set of models of geostationary satellite bus and, for lack of a better term, ram a probe up its backside to grab onto it.

    the probe ramming: https://www.youtube.com/watch?v=vJZ3xmuom0M

    One of the things that people who don't pay attention to space based infrastructure find odd, if you tell them, is that in the entire history of manned spaceflight no human has ever gone to geostationary orbit.