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My big concern is that we still don't have a solution for https://en.wikipedia.org/wiki/Kessler_syndrome https://en.wikipedia.org/wiki/Kessler_syndrome. Lots a

by btilly 8y ago

My big concern is that we still don't have a solution for https://en.wikipedia.org/wiki/Kessler_syndrome https://en.wikipedia.org/wiki/Kessler_syndrome. Lots and lots of small satellites brings us closer to that potential catastrophe. My big hope is that SpaceX's BFR can potentially launch and maneuver cheaply enough to take dead satellites out of orbit in a cost effective manner. Hopefully they manage to launch, and someone is willing to pay to make it happen...

mistrial9 8y ago
concern ok -- hand-wringing.. not so much.. obstruction and FUD .. you get the idea .. offhand seems like it is a crucial time to get data
gregallan 8y ago
There are other attempts at disposal of dead satellites that don’t rely on a long-shot like the BFR [1]. Besides, maneuvering a big heavy spacecraft like that to match orbits with a bunch of little satellites would be tremendously wasteful in terms of fuel. A much better use would be to remove larger satellites like defunct communications satellites. These are actually a much bigger danger to orbital space as well. See this event for example [2], which generated over 2000 pieces of debris large enough to track and many more of a smaller size. Small satellites are not nearly as dangerous because when they are defunct their low mass causes them to renter faster. (FYI I’m a PhD student in the lab that built the satellite in the article.) [1] https://www.google.com/amp/s/www.theverge.com/platform/amp/2018/9/19/17878218/space-junk-remove-debris-net-harpoon-collisions https://www.google.com/amp/s/www.theverge.com/platform/amp/2... [2] https://en.m.wikipedia.org/wiki/2009_satellite_collision https://en.m.wikipedia.org/wiki/2009_satellite_collision
maxxxxx 8y ago
Most satellites these days have a way to deorbit once they reach the end of their lifetime. I hope this applies to the cubes too.
- mirashii 8y ago
  In LEO, that deorbit mechanism is called drag.
  - maxxxxx 8y ago
    Any ideas how long it takes to deorbit?
    - AngryData 8y ago
      It depends on the altitude/orbital height. Some are made to come down after only 5 years, I think most are restricted to no more than 25 years and head for a 20 year target. Of course just a small amount of on-board propellant could extend the time further boosting it a bit after a few years of drag.
mirashii 8y ago
Cubesats at their typical altitudes have deorbit times ranging from 6 months to 20 years, with regulation (in the USA at least) mandating a deorbit within 25 years to receive a license. The fear of Kessler syndrome is much more relevant to launching large geostationary satellites that may break apart than for cubesats.
- btilly 8y ago
  That is good to know. Thanks.
Gravityloss 8y ago
For small satellites and low orbits, drag brings them down. There is lots of potential for low mass deorbit devices for other satellites. These projects just need funding to iterate them to work.
alliecat 8y ago
Cubesats are disposable; they're launched in a way that their orbit decays towards the end of their usable life, at which point they re-enter the atmosphere.

by btilly 8y ago

mistrial9 8y ago

concern ok -- hand-wringing.. not so much.. obstruction and FUD .. you get the idea .. offhand seems like it is a crucial time to get data

gregallan 8y ago

There are other attempts at disposal of dead satellites that don’t rely on a long-shot like the BFR [1]. Besides, maneuvering a big heavy spacecraft like that to match orbits with a bunch of little satellites would be tremendously wasteful in terms of fuel. A much better use would be to remove larger satellites like defunct communications satellites. These are actually a much bigger danger to orbital space as well. See this event for example [2], which generated over 2000 pieces of debris large enough to track and many more of a smaller size. Small satellites are not nearly as dangerous because when they are defunct their low mass causes them to renter faster. (FYI I’m a PhD student in the lab that built the satellite in the article.) [1] https://www.google.com/amp/s/www.theverge.com/platform/amp/2018/9/19/17878218/space-junk-remove-debris-net-harpoon-collisions https://www.google.com/amp/s/www.theverge.com/platform/amp/2... [2] https://en.m.wikipedia.org/wiki/2009_satellite_collision https://en.m.wikipedia.org/wiki/2009_satellite_collision

maxxxxx 8y ago

Most satellites these days have a way to deorbit once they reach the end of their lifetime. I hope this applies to the cubes too.

mirashii 8y ago
In LEO, that deorbit mechanism is called drag.
- maxxxxx 8y ago
  Any ideas how long it takes to deorbit?
  - AngryData 8y ago
    It depends on the altitude/orbital height. Some are made to come down after only 5 years, I think most are restricted to no more than 25 years and head for a 20 year target. Of course just a small amount of on-board propellant could extend the time further boosting it a bit after a few years of drag.

mirashii 8y ago

Cubesats at their typical altitudes have deorbit times ranging from 6 months to 20 years, with regulation (in the USA at least) mandating a deorbit within 25 years to receive a license. The fear of Kessler syndrome is much more relevant to launching large geostationary satellites that may break apart than for cubesats.

btilly 8y ago
That is good to know. Thanks.

Gravityloss 8y ago

For small satellites and low orbits, drag brings them down. There is lots of potential for low mass deorbit devices for other satellites. These projects just need funding to iterate them to work.

alliecat 8y ago

Cubesats are disposable; they're launched in a way that their orbit decays towards the end of their usable life, at which point they re-enter the atmosphere.