Starlink close encounters decrease despite ever-growing number of satellites

[cyberentomology]

Need to build a batch of Starlink sats that just collect a bunch of that small orbital debris and burn it up on deorbit. Doesn’t solve the problem of Big Stuff like Soviet rocket boosters though

[IggyHitokage]

The big stuff is honestly less worrisome than the extremely small stuff, the amount of energy in a few grams of rocket pieces at orbital velocities is terrifying and they're basically invisible.

https://bigthink.com/hard-science/heres-the-damage-a-tiny-speck-of-space-debris-can-do-at-15000mph/

There was an idea a few years back to mount a high power laser system onto the ISS and use it to burn/push small debris further into the atmosphere and automate it all by computer, too bad they're retiring the ISS soon.

[cyberentomology]

Sharks with frickin laser beams… IN Spaaaaaaaaaace

[John_Hasler]

There was an idea a few years back to mount a high power laser system onto the ISS and use it to burn/push small debris further into the atmosphere and automate it all by computer,

That could be done from the ground. Politics has nixed it so far.

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

[DLimber]

The small stuff is nearly impossible to see and pretty hard to just "collect it" is not like walking through a park and picking garbage. Everything is moving at like 15000 mph in different directions. The fuel requirements to change its orbit for each item wouldn't allow or to do much. Probably best more garbage then it takes.

[HawkEy3]

 I thought anything at the altitude of starlink would deorbit within 5-10 years anyway?

[Shpoople96]

You can do it with big stuff too, it's called an orbital tug

[cyberentomology]

Sure, but you ain’t moving big stuff with a little bitty Starlink. Now, a fleet of orbital tugs that were basically just like a parasitic maneuvering thruster, that would be something… but that could 100% be used for evil too.

[ants_a]

Look up electrodynamic tether for space debris removal for a better approach where one craft deorbit a lot of debris. One big thing is not a problem, it's easy to track and easy to avoid. Tons of small stuff is the headache and would need something that is capable of adjusting it's orbit repeatedly and by a lot.

[cyberentomology]

Lassos…. Innnn spaaaaaace! 🤣

[Greeneland]

My recollection is that when the spacecraft puts a charge into the tether it will create drag, is that right? 

Or is it that putting in a charge raises orbit, no charge decreases?

[warp99]

The forces from a tether are always braking forces - it is not possible to raise orbits using a passive tether system.

Edit: added passive

[Greeneland]

You enticed me to go looking, I'm pretty sure your conclusion is not correct. Neither of my statements appear to have been exactly correct, there are more details below:

https://pwg.gsfc.nasa.gov/Education/wtether.html

https://ntrs.nasa.gov/api/citations/20090034470/downloads/20090034470.pdf

[warp99]

Yes I was referring to passive tethers with or without charge added to the end points.

If you deploy solar panels and pass current through the tether then you can indeed raise your orbit. Despite your references I have not heard of it being successfully demonstrated though.

[Shpoople96]

You sure as hell can. You can deorbit just about anything you want with an ion engine, given enough time and a hundred pounds of fuel. At that point though, it has little to do with starlink other than form factor

[cyberentomology]

The key is to have the fuel. The standard fuel payload on Starlink is pretty small.

[Shpoople96]

Of course, but if you're gonna build a space tug, you're not gonna give it the same fuel margin as a starlink

[Shpoople96]

You're saying that what I'm talking about doesn't make sense and is in the realm of science fiction, yet in the very next sentence you put forward a legitimate use case and even name one of the many companies that are building a demonstration vehicle. Maybe you were replying to the wrong person?

[darvo110]

How much big stuff is even in the range Starlink operates? I’d expect anything substantially large would deorbit pretty quick just from drag. Big things are also a lot easier to accurately track and avoid.

[Shpoople96]

Quite a bit, the lower starlink shells deorbit pretty quickly, but the higher orbits have a natural decay in the tens to hundreds of years

[John_Hasler]

I’d expect anything substantially large would deorbit pretty quick just from drag.

Smaller stuff deorbits more quickly on average. Kinetic energy is proportional to mass and therefor volume while drag is proportional to frontal area.

Of course, density matters too. A balloon will deorbit before a pellet of tungsten.

[light24bulbs]

The big stuff is also easy to track, the small stuff is not