Planned debris recovery satellite

[MeunierParticipant @meunier]

[MeunierParticipant @meunier]

Watching news reports of the planned launch of a new satellite to recover space debris by 'netting' and 'harpooning' I idly wondered if the satellite would qualify as a 'vacuum cleaner' ?
DaveD

[Neil WyattModerator @neilwyatt]

[Barnaby WildeParticipant @barnabywilde70941]

I'm wondering if it isn't all just nonsense, like the moon landings.

I'm not a math genius, but I couldn't even begin to work out what path it would need to take to catch all that debris.

Is this yet another lesson in appeasing the masses? Are we that worried about space trash? More so than what's in our local oceans?

[BazyleParticipant @bazyle]

Hey, I made some of that trash

[MeunierParticipant @meunier]

Posted by Mick Charity on 30/11/2017 21:34:16:

snip Are we that worried about space trash? More so than what's in our local oceans? snip

While the debris in our oceans is disgusting, many folk would be more than disappointed if an Astra sat were to be destroyed and they lost SKY/FreeSat, etc.
DaveD

[Grizzly bearParticipant @grizzlybear]

I guess it wouldn't be powered by diesel.

[Carl Wilson 4Participant @carlwilson4]

Hold on a minute. The moon landings? Nonsense?

[Chris TriceParticipant @christrice43267]

Posted by Mick Charity on 30/11/2017 21:34:16:

I'm wondering if it isn't all just nonsense, like the moon landings.

I'm not a math genius, but I couldn't even begin to work out what path it would need to take to catch all that debris.

Is this yet another lesson in appeasing the masses? Are we that worried about space trash? More so than what's in our local oceans?

If you're suggesting the moon landings didn't happen then I think I have to keep the discussion junior school simple. Space debris is increasingly a potential problem because even the tiniest particle can do a lot of damage because of the velocity it's travelling at. All that kinetic energy is converted into heat on impact and a grain of sand sized particle can punch a hole in a ship or person the size of a bullet. There are no gentle impacts in space unless they are planned. The bigger pieces, which is generally what the man made stuff is, would destroy anything they came into contact with. There are something like 20,000 objects currently orbiting the Earth bigger than 4" being tracked, some natural, some man made and an estimated half a million smaller than 4". Given that any one of them is pretty much lethal to a satellite or human, a tidy up is wise because sooner or later as traffic up there increases, there will be a problem.

[Clive HartlandParticipant @clivehartland94829]

The speed of the objects are somewhere about 17000 mph. how in hell do you target them? I did read that they may ram them in a direction likely to cause re-entry and a burn up.

Re- firing a harpoon, in space every action has a reaction so how will they stop the launch pad flying away at an equal speed?

[SamsarandaParticipant @samsaranda]

I remember when I was working at a radar tracking site back in the 80's that they kept track of objects in space, at that time one object that was orbiting the Earth was a Hasselblad camera that one of the American astronauts had accidentally let go of, as far as I know it is still up there, wonder if it is worth salvaging?

Dave W

[Brian Sweeting 2Participant @briansweeting2]

Aren't most of the bits all travelling at the same speed, at their particular altitude, otherwise they would fall out of orbit.

If that's right then they will only impact something in a lower orbit when they themselves start decaying.

My head's beginning to hurt now. 

[Chris TriceParticipant @christrice43267]

Posted by Clive Hartland on 30/11/2017 22:38:59:

The speed of the objects are somewhere about 17000 mph. how in hell do you target them? I did read that they may ram them in a direction likely to cause re-entry and a burn up.

Re- firing a harpoon, in space every action has a reaction so how will they stop the launch pad flying away at an equal speed?

It would only recoil at equal speed if the launch platform had equal mass. if it had ten times the mass, it would recoil at a tenth of the speed. If the harpoon were self propelled by rocket, no such recoil would occur. However, the idea of harpooning anything but the very largest of objects is a bit of a non starter. If you match the speed and position (rendezvous) with the object, you could either grab it or redirect it. Despite the sheer number of objects in Earth orbit, it would be like seeking out and dealing with half a million tennis balls spread over the surface of the earth.

[Chris TriceParticipant @christrice43267]

Try this: https://www.youtube.com/watch?v=juQPE-v28es

[Ady1Participant @ady1]

might be easier to use magnets to reroute junk into a different trajectory away from earth

Even non ferrous metals can be induced to change direction via lenz law stuff, they do it in recycling works

[Chris TriceParticipant @christrice43267]

Unfortunately, without a substantial direction change, it just transforms a circular orbit into an elliptical one. Decreasing their velocity will have their orbit decay back into Earth's atmosphere and subsequent burn up. To leave Earth orbit completely never to return, their speed would have to be accelerated to beyond escape velocity. The velocity of the Apollo spacecraft was carefully calculated so that although it's initial speed slowly decayed because of Earth's gravity pulling them back, it reached a point where the Moon's gravity took over and accelerated them forward again for minimal use of fuel.

[Ady1Participant @ady1]

slingshot theory, interesting stuff

Edited By Ady1 on 01/12/2017 01:30:15

[Sam Longley 1Participant @samlongley1]

deleted

Edited By Sam Longley 1 on 01/12/2017 08:09:41

[Sam Longley 1Participant @samlongley1]

Posted by Meunier on 30/11/2017 20:43:20:

Watching news reports of the planned launch of a new satellite to recover space debris by 'netting' and 'harpooning' I idly wondered if the satellite would qualify as a 'vacuum cleaner' ?
DaveD

Well if it does make sure that it has a lady driver otherwise my wife might start getting ideas about letting men drive vacuum cleaners & that is one scenario I do not want

[Barnaby WildeParticipant @barnabywilde70941]

Posted by Chris Trice on 30/11/2017 22:26:52:

If you're suggesting the moon landings didn't happen then I think I have to keep the discussion junior school simple. Space debris is increasingly a potential problem because even the tiniest particle can do a lot of damage because of the velocity it's travelling at. All that kinetic energy is converted into heat on impact and a grain of sand sized particle can punch a hole in a ship or person the size of a bullet. There are no gentle impacts in space unless they are planned. The bigger pieces, which is generally what the man made stuff is, would destroy anything they came into contact with. There are something like 20,000 objects currently orbiting the Earth bigger than 4" being tracked, some natural, some man made and an estimated half a million smaller than 4". Given that any one of them is pretty much lethal to a satellite or human, a tidy up is wise because sooner or later as traffic up there increases, there will be a problem.

Have they finalised what cracked the ISS window yet?

Were they tracking it?

[Martin KyteParticipant @martinkyte99762]

It's getting really crowded up there.

This site is quite interesting

**LINK**

The issue is to come up with a way of reducing the risk of serious damage to sattelites before the usefull orbits become untenable. Can you imagine a world without sttelite communication these days. No satnavs, much of telecomms gone, reduced weather monitoring, loss of all sattelite data gathering for earth sciences. Not to mention space telescopes.

regards Martin

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Mick Charity on 01/12/2017 08:36:25:

Have they finalised what cracked the ISS window yet?

.

Despite being widely reported as a crack … I would suggest that 'chip' is a more realistic description.

MichaelG.

http://www.esa.int/spaceinimages/Images/2016/05/Impact_chip

Edited By Michael Gilligan on 01/12/2017 09:11:00

[Martin DowingParticipant @martindowing58466]

Have red sometime ago about planned weaponry meant to vandalize space with millions and millions of 1-2mm diameter tungsten balls. Few cargos would be good enough to render low orbits useless for decades for *any* craft, including all military surveilance. Similar vandalism of geostationary orbit would be for all practical purpose permanent.

Martin

Edited By Martin Dowing on 01/12/2017 09:14:05

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Martin Dowing on 01/12/2017 09:11:05:

Have red sometime ago about planned weaponry meant to vandalize space with millions and millions of 0.5mm diameter tungsten balls. Few cargos would be good enough to render low orbits useless for decades for *any* craft, including all military surveilance. Similar vandalism of geostationary orbit would be for all practical purpose permanent.

Martin

.

That's a plan by extra-terrestrials … to safeguard Space from Mankind, they want to cage us in.

MichaelG.

.

Edit: I note that the specified diameter has changed since I quoted Martin's post.

Edited By Michael Gilligan on 01/12/2017 09:38:05

[Martin KyteParticipant @martinkyte99762]

Posted by Martin Dowing on 01/12/2017 09:11:05:

Have red sometime ago about planned weaponry meant to vandalize space with millions and millions of 1-2mm diameter tungsten balls. Few cargos would be good enough to render low orbits useless for decades for *any* craft, including all military surveilance. Similar vandalism of geostationary orbit would be for all practical purpose permanent.

Martin

Edited By Martin Dowing on 01/12/2017 09:14:05

Why premanent?

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