Debris.

[LupusDei]

https://cdn.arstechnica.net/wp-content/uploads/2021/11/FEXO5lmXsAUPYao-980x871.png

USA DoD says they track about 1500 trackable pieces, meaning above 2 inches in size. Smaller, there might be many more, possibly in tens of thousands. Ah, yes, at the orbital speeds anything blows up on impact. ISS armor and shields are rated for up to 1cm (~2/5 inch) impacts, but many satellite have none, and 400km-500km range is popular and rather congested space.

I just can't wrap my head around why. As if there wasn't better ways to do the damn test if they had to. This hooliganism is deliberate, but doesn't make sense.

 

[pecksniff]

Is there any way to scoop it up with nets?

 

[LupusDei]

Nets, not quite... well, you will have to chase each piece to match orbit and speed, and "dock" with it. There's some experiments with magnetic manipulation too. Anyway, you're sending a thug after each piece, as of now, single use thug, likely. Expensive fun.

But that's the largest pieces anyway. The little, the shrapnel... a powerful laser could perhaps fire in a way to burn propulsive jet out of the piece, pushing to deorbit. But space laser of such energy would probably freak everyone out on its own.

 

[bodysong]

New images and analyses reveal extent of (Russian satellite) Cosmos 1408
debris cloud

- Ars Technica

7 hours ago

Ars Technica ✓
Twitter › arstechnica

Bill Gates’ nuclear power company selects a site for its first reactor
(link) science… by @j_timmer

1 hour ago

 

[pecksniff]

Ars Technica ✓
Twitter › arstechnica

Bill Gates’ nuclear power company selects a site for its first reactor
(link) science… by @j_timmer

1 hour ago

In space? Aren't there treaties against that?

 

[LukSkyFokker]

Cool show, bummed they canceled it.

https://static.next-episode.net/tv-shows-images/huge/debris.jpg

 

[LupusDei]

Cool show, bummed they canceled it.

This show will go on for some time.

 

[jomar]

Is there any way to scoop it up with nets?

Space nets is a thought. Get space debris folk together with ocean trash folk and maybe they’ll be inspired.

 

[LupusDei]

Space nets is a thought. Get space debris folk together with ocean trash folk and maybe they’ll be inspired.

There actually was a plan to try and catch a small asteroid in a bag, then bring to moon orbit. Bag, as they wasn't sure how solid the thing was, it might be just tight pile of gravel.

 

[butters]

https://cdn.arstechnica.net/wp-content/uploads/2021/11/FEXO5lmXsAUPYao-980x871.png

USA DoD says they track about 1500 trackable pieces, meaning above 2 inches in size. Smaller, there might be many more, possibly in tens of thousands. Ah, yes, at the orbital speeds anything blows up on impact. ISS armor and shields are rated for up to 1cm (~2/5 inch) impacts, but many satellite have none, and 400km-500km range is popular and rather congested space.

I just can't wrap my head around why. As if there wasn't better ways to do the damn test if they had to. This hooliganism is deliberate, but doesn't make sense.

whose satellites are most at risk? would this move reduce the capacity of other nations way more than any russian collateral damage? a show of russian potential to fuck up other countries if it wants, even if it means harming the i.s.s?

 

[LupusDei]

whose satellites are most at risk? would this move reduce the capacity of other nations way more than any russian collateral damage? a show of russian potential to fuck up other countries if it wants, even if it means harming the i.s.s?

Not quite something I could answer, but about anyone who has assets at around 500km.

How it works, orbits are straight lines on a surface of a sphere. Thus, everything at the same altitude cross paths with everything else on the same altitude (unless directly sharing an orbit like pearls on a string). Overall collision probability goes on proportional to the number of objects squared.

How the debris behaves in those collisions, it will eventually form a fuzzy ring in an orbit derived from the original. Worst case scenario, a certain range of altitudes is denied to anyone.

What's most of risk is the tiny debris that's effectively invisible until it hits something. As time goes on, the debris is getting catalogued and the orbits of the new objects calculated forward with ever increasing accuracy, thus the real risk diminishes and avoidance becomes possible. Everyone, including the ISS, can dodge if forced to, but need advance warning to do so.

Then, for everything but the station dodging debris is expensive. It expends fuel, thus reducing the useful life of the satellite, because you need it for station keeping too -- to compensate for atmospheric drag, solar wind, gravity anomalies and distant bodies interactions, etc tiny forces that add over time --, and it's a finite resource, they launch with a full tank and when it's spent the vehicle is written off, and it starts slowly descend due to those outside forces, until it burns in upper atmosphere (along with ~15,000 tons of meteors yearly).

The Russian derelict was in polar orbit, ~82° inclination currently at ~485km and was hit from behind with a kinetic impactor ascending almost directly in plane. It added energy, kicking debris to orbits with higher apogee. It's looking like there's quite a lot of eccentricity added too, and perhaps that's some wisdom in the madness, as thus most of it should deorbit rather soon, as in, within years not decades, and won't quite block anything completely, just make life stressful for even more broader range.

ISS is at 51.6° in a slightly eccentric orbit ~460 at apogee, thus a little under the source orbit. It crosses (projection of) the debris orbit every 93 minutes.

Starlink with 1,844 satellites launched (1,454 operational, >100 in transfer, a dozen abandoned test articles, I don't know how the rest break between failes and spares) is probably the largest compound surface of any single system already, perhaps times over. Almost all of the operational fleet are at 550km orbits at 53° inclination, slightly above most of the Russian mess.

Those are busy altitudes, because below 400km you have to boost frequently thus it's expensive or short lived, but surface observation stuff wants to be as low as possible for better visibility. Remember, the Hubble is a repurposed slightly modified spy Keyhole, those were made in series at one point (and since replaced with better). Btw, Hubble is on 28.5° at ~545km.

 

[LupusDei]

There's total around 7,500 active satellites in low Earth orbit (~2700 launched in last two years).

Total numbers of debris? Something like 30k uncontrollable objects between two inches in size and up and over several tonnes in mass are tracked (including the ~1500 new from this), the simulations of anything smaller, between 1 and 5 centimeters are closer to a million, and pieces under 1cm are estimated in tens of millions.

Yet, collisions so far had been rare. It's expected to change. In March 18 this year a Chinese military satellite launched in 2019 was hit by a shard of a Russian rocket (probably between 4 inches and 20 inches wide) launched in 1996. The satellite shed some 27 new pieces of debris but apoarently continued to transmit afterwards, how functional it could be is unknown though. Previous known collision was February 2009, when the defunct Russian military spacecraft Kosmos-2251 slammed into Iridium 33, an operational communications satellite.

 

[butters]

thankyou, lupusdei, for that detailed information. appreciated.