we need traffic lights for satellites

[sandalcandal]

About 3% of Starlink satellites have failed so far: https://phys.org/news/2020-10-starlink-satellites.html

I was interested in getting actual numbers but couldn't find anything.

Cited (hobbyist?) reports here: https://planet4589.org/space/jsr/back/
The only thing I found was "As of Oct 7 [2020], 775 Starlinks have been launched and 728 remain in orbit.", 47 lost out of 775 which is a 6% loss at most compared to 8% in the phys.org article and doesn't mention 3% failures to respond. This also contradicts the phys.org article's statement "To date, the company has launched over 800 satellites..." maybe if you include non-starlink satellites? another 120 have been launched between the quote from Jonathan's Space Report No. 784 and the phys.org article.

Also 39 of the no longer in orbit were deorbited prototype systems:

Starlink retirements
--------------------

SpaceX is retiring the V0.9 constellation of 60 prototype satellites launched in May 2019.
As of Oct 7, 39 of the 60 satellites have reentered.

This is a new kind of reentry: it's not a normal impulsive deorbit and
not a normal orbital decay, but something inbetween. The Starlink
satellites are, apparently,  retired by continuously lowering their
orbit with electric propulsion. Reentry occurs in a way similar to
uncontrolled reentry - eventually the satellite is low enough and the
ambient density is high enough that the vehicle heats, breaks up and is
destroyed. The crucial point here is that the *location* of the breakup
on the Earth is unpredictable and uncontrolled, in contrast to an
impulsive deorbit where the rapid elliptical-orbit descent from a
relatively high apogee means that reentry location is determined
relatively precisely by the orbital parameters. These Starlink
retirements should perhaps be termed `propulsion-assisted orbital decay'
- they are more like normal uncontrolled orbital decay but speeded up by
the thrusters.

[madires]

Good news:
OneWeb reduces constellation plans from 47,884 to 6,372 satellites: https://www.oneweb.world/media-center/oneweb-streamlines-constellation

Bad news:
Darkened SpaceX Satellites Can Still Disrupt Astronomy, New Research Suggests: https://gizmodo.com/darkened-spacex-satellites-can-still-disrupt-astronomy-1846066403

[Gyro]

Richard Branson has just sent up another 10 small low orbit satellites from a Boeing 747.

https://www.bbc.co.uk/news/science-environment-55699262

[madires]

Direct competition?
OneWeb, SpaceX satellites dodged a potential collision in orbit: https://www.theverge.com/2021/4/9/22374262/oneweb-spacex-satellites-dodged-potential-collision-orbit-space-force

[GlennSprigg]

Maybe my 'mind' is too simplistic and/or naive, but I can't help thinking that all we need is better communication between Countries, and
work more together towards common goals/needs in space now. I would 'like' to think that GONE are the Cold-War days of secretive developments
and deployments, and to a certain degree it is happening now between certain Countries & Companies!   

I remember reading a book by the very knowledgeable & talented Carl Sagan, (who has sadly passed), who wrote a book called 'Contact'.
It was a work of fiction, but I'm sure it was his dream about how he would love something like this to really come to fruition!!  For the un-
initiated, it is about some remote Alien lifeforms finally actually making contact with us... Containing complex instructions about how to 1st
interpret their information/data, and then instructions about how to 'build' a massively complex machine, to travel back to them!!!   

The upshot of it all, was that it was so huge, complex & expensive technological project, that literally the whole World had to get together
to fabricate all the components, and to actually build it!!  I'm sure he desired 'us' all working together some day!!   

[madires]

SpaceX Starlink satellites responsible for over half of close encounters in orbit, scientist says: https://www.space.com/spacex-starlink-satellite-collision-alerts-on-the-rise (includes autoplay video )

[SiliconWizard]

And this is just the beginning...

[SiliconWizard]

Maybe my 'mind' is too simplistic and/or naive, but I can't help thinking that all we need is better communication between Countries, and
work more together towards common goals/needs in space now.

This sounds nice, but what exactly would be those common goals and who is going to define them? Who is going to make sure they'll be good for people and the future of humankind? At this point, it looks like a lot of what we have done has been pretty disastrous on a large scale, and those disastrous decisions are usually the ones that are the most well shared among countries. In other words, if there's something we seem to easily agree on worldwide, it's doing a lot of shit. This doesn't bode well.

I would 'like' to think that GONE are the Cold-War days of secretive developments
and deployments, and to a certain degree it is happening now between certain Countries & Companies!   

Oh really. It doesn't appear to be the case. The current situation is a lot worse than during the cold war IMHO, and the world a lot more unstable.

[james_s]

I still find it hard to believe in a three dimensional space (spherical skin with depth of x meters or kms) the size of the earths diameter plus a tiny bit - that satellites really get that close to each other - ever! Unless they are programmed to do so (conspiracy theory time!).

Am I wrong? Please help my old grey matter understand if so. I just dont see it happening. Sure, space debris, but that is many many magnitudes higher density.

It's one of those things where if you tried to aim a satellite so it would collide with another it would probably never happen, but chance collisions do happen. It's similar with aircraft, the sky is really big, airplanes are relatively thin, yet aircraft still collide now and then.

[ejeffrey]

Also just like aircraft certain orbits are much more popular than others, such a sun synchronous polar orbits and geostationary equitorial orbits.

Also the threshold for corrective action is extremely conservative.  The vast majority of events would not result in a collision without correction but they move anyway.

[rdl]

Starlink satellites are in a fairly regularly spaced network. They are widely spread over a range of inclinations. They are at low enough altitudes that they will naturally de-orbit in a matter of years due to atmospheric drag. Seems like the biggest danger is running into one on the way up to somewhere else.

[antenna]

I've been using Starlink internet since January and it has been absolutely amazing. I went from 25kb tether as an only option to downloading several GB in minutes.  I hope people keep their satellites out of Starlink's way, because I really like my internet!  Someone needs to build a satellite with enough maneuver fuel and a big dust pan to fly around and scoop up the trash like dish network, direct tv and hughesnet, the old satcoms used by pirates, broken noaa imaging sats etc and toss it all in the pacific lol. Get rid of the junk, know your altitude, and maybe we wouldn't need traffic lights in space. Stop and go takes thrust. You cannot sustain that kind of solution.

[james_s]

The problem with trying to scoop up the junk is that it tends to be moving at thousands of miles per hour with random trajectories and if you do have a collision you end up with a whole bunch more debris flying at high speed in random directions.

[madires]

Yep, a single collision event can cause an avalanche, especially when happening in a popular orbit. Another point often ignored is that satellites don't have a precise track they follow. They wobble around and need corrections from time to time. We're talking about a few 100 meters. The next point is about launch windows for rockets. With much more LEO satellites swirling around launches become complex as your rocket needs to avoid whatever is orbiting our planet. It's a 3D space with many objects moving around with different speeds in different orbits.

[nuclearcat]

Stupid idea (because i didnt thought a lot about it), what is we deploy one big amount of substance like polyurethane foam that will expand after "cleaner satellite" reach orbit, as it expand, it take large space and work as trap. All objects will be stuck inside it and it wont go pieces, similar what sand and water does to bullets.
Plus attached to the metal mesh net and some kind of engine that can deorbit it, when it gets full or too unstable (too many impacts).

[m98]

Stupid idea (because i didnt thought a lot about it), what is we deploy one big amount of substance like polyurethane foam that will expand after "cleaner satellite" reach orbit, as it expand, it take large space and work as trap. All objects will be stuck inside it and it wont go pieces, similar what sand and water does to bullets.
Plus attached to the metal mesh net and some kind of engine that can deorbit it, when it gets full or too unstable (too many impacts).

Space is big. Imagine trying to stop global traffic violations by deploying two police officers to the Gobi desert.

[nuclearcat]

Stupid idea (because i didnt thought a lot about it), what is we deploy one big amount of substance like polyurethane foam that will expand after "cleaner satellite" reach orbit, as it expand, it take large space and work as trap. All objects will be stuck inside it and it wont go pieces, similar what sand and water does to bullets.
Plus attached to the metal mesh net and some kind of engine that can deorbit it, when it gets full or too unstable (too many impacts).

Space is big. Imagine trying to stop global traffic violations by deploying two police officers to the Gobi desert.

Since it have thruster it can be directed on collision path with debris, to adsorb them. Its big in size, but mass is low, so it wont require lot of fuel.

[wraper]

Stupid idea (because i didnt thought a lot about it), what is we deploy one big amount of substance like polyurethane foam that will expand after "cleaner satellite" reach orbit, as it expand, it take large space and work as trap. All objects will be stuck inside it and it wont go pieces, similar what sand and water does to bullets.
Plus attached to the metal mesh net and some kind of engine that can deorbit it, when it gets full or too unstable (too many impacts).

You will need a lot of very durable foam to capture something that travels at ~30000 km/h velocity. And as that foam need to stay in orbit as well, up to ~60000 km/h equivalent of hitting stationary object. And then it needs to be able to deorbit itself, otherwise you only create more junk in orbit.

Since it have thruster it can be directed on collision path with debris, to adsorb them. Its big in size, but mass is low, so it wont require lot of fuel.

You cannot simply steer it. Changing direction even slightly takes a huge amount of energy. 

[nuclearcat]

Stupid idea (because i didnt thought a lot about it), what is we deploy one big amount of substance like polyurethane foam that will expand after "cleaner satellite" reach orbit, as it expand, it take large space and work as trap. All objects will be stuck inside it and it wont go pieces, similar what sand and water does to bullets.
Plus attached to the metal mesh net and some kind of engine that can deorbit it, when it gets full or too unstable (too many impacts).

You will need a lot of very durable foam to capture something that travels at ~30000 km/h velocity. And as that foam need to stay in orbit as well, up to ~60000 km/h equivalent of hitting stationary object. And then it needs to be able to deorbit itself, otherwise you only create more junk in orbit.

Since it have thruster it can be directed on collision path with debris, to adsorb them. Its big in size, but mass is low, so it wont require lot of fuel.

You cannot simply steer it. Changing direction even slightly takes a huge amount of energy.

Might be possible, if this foam are in cells, and foam itself is non-newtonian. But sure its not easy.
And not only durable, most likely on impact all this will begin to spin, i.e. it will be difficult to compensate for the kinetic energy from the impact and stabilize such "cleaner satellite" (and it needs to be stabilized, so RF links and solar panels can work properly).
Some minor manoeuvres can be done, but for sure you need to launch such satellites on specific orbits, targeting largest or most problematic debris.

My idea is not original or new: https://www.forbes.com/sites/jamiecartereurope/2020/06/16/well-clean-up-space-junk-using-sticky-foam-spiderwebs-in-orbit-says-russian-space-start-up/

[iMo]

Small debris could be swept out with a strong laser gun.
Something like 10MWatt continuous laser beam would do the job, imho..
 

[wraper]

My idea is not original or new: https://www.forbes.com/sites/jamiecartereurope/2020/06/16/well-clean-up-space-junk-using-sticky-foam-spiderwebs-in-orbit-says-russian-space-start-up/

That is quite different from what you proposed.

[sandalcandal]

Small debris could be swept out with a strong laser gun.
Something like 10MWatt continuous laser beam would do the job, imho..
 

I was actually involved in a project using lasers to perturb space debris out of orbit during undergrad.
https://www.flightglobal.com/eos-to-build-system-to-clear-up-space-debris-/55033.article
Project seems to still be alive and going (same supervisor too)
https://www.universetoday.com/150896/ground-based-lasers-could-push-space-debris-off-collision-course-orbits/

Edit: I'll add it was definitely a real serious project with real hardware and money being implemented. However, the laser pushing function seemed like a side benefit to the "primary" utility which was the star guide star function for Astronomy AO, most of the systems being used were interchangeable so the laser pushing concept was a major idea being explored.

[iMo]

Small debris could be swept out with a strong laser gun.
Something like 10MWatt continuous laser beam would do the job, imho..
 

I was actually involved in a project using lasers to perturb space debris out of orbit during undergrad.
https://www.flightglobal.com/eos-to-build-system-to-clear-up-space-debris-/55033.article
Project seems to still be alive and going (same supervisor too)
https://www.universetoday.com/150896/ground-based-lasers-could-push-space-debris-off-collision-course-orbits/

Edit: I'll add it was definitely a real serious project with real hardware and money being implemented. However, the laser pushing function seemed like a side benefit to the "primary" utility which was the star guide star function for Astronomy AO, most of the systems being used were interchangeable so the laser pushing concept was a major idea being explored.

That would certainly work provided you have got a pretty powerful laser handy.
Today's best military lasers are around 100kW max. That is not enough for working with LEO debris, imho.

[SiliconWizard]

Let's send all our trash into orbit and then play with lasers. The 21st century is going to be a lot of fun!

[sandalcandal]

That would certainly work provided you have got a pretty powerful laser handy.
Today's best military lasers are around 100kW max. That is not enough for working with LEO debris, imho.

Can't remember the exact figures but the laser power was much lower than that I think. I recall the idea isn't to obliterate the debris but get the (presumably small) debris to deorbit through ablation/differential heating by shooting them as they are approaching (from appearing at the horizon till overhead-ish) to give negative acceleration. I was just doing some system engineering for some of the support infrastructure so I didn't do any numbers on how efficient the system was likely to be. They still seem to be going if that's any indication of being feasible still or just milking funding. The main commercial partner for the project, EOS, is a defence contractor.

Edit: Found a conference paper from the same research group on the project here https://openresearch-repository.anu.edu.au/bitstream/1885/196466/2/01_Lingham_Adaptive_optics_tracking_and_2018.pdf Looks like the planned operational power of the manoeuvring laser was 10kW.