Potential collision of space junk

[Prepuce of Doom 21,052]

 

^^^short thread 

I don't know shit about this shit, but this seems like a bad deal. 

Details:

 

[RPM 26,315]

Quote

The combined mass of the objects is about 6,170 lbs. (2,800 kilograms) and they'll be barreling toward each other at a relatively velocity of 32,900 mph (52,950 km/h).

Boop.

[Prepuce of Doom 21,052]

Good news, everyone! 

 

 

[RPM 26,315]

I'm surprised they haven't developed a system to capture and de-orbit large junk. Some sort of drone to match speed, deploy a net and drag it to a fiery death.

[thunderlounge 7,813]

10 hours ago, RPM said:

I'm surprised they haven't developed a system to capture and de-orbit large junk. Some sort of drone to match speed, deploy a net and drag it to a fiery death.

 

You would think! Fuck other stuff but just the impact on space flight is bad enough that they should have done something already, let alone all the other bad things coming from it as well. 
 

Unless you want to get wigged out, don’t dig too much into all the space junk. 
 

Think it’s bad now? Here come all the min/micro satellites and bullshit ramping up too.  Space in space is becoming prime real estate.

 

[RPM 26,315]

Speaking of space junk... Yeah, space is hard. 

AT&T Pushes Back on DirecTV Satellite Disposal Fees

Telecom joins Amazon in complaining about the FCC’s new rules for regulating space junk

 

[Sam Lin 3,550]

On 10/16/2020 at 3:13 AM, RPM said:

I'm surprised they haven't developed a system to capture and de-orbit large junk. Some sort of drone to match speed, deploy a net and drag it to a fiery death.

They have, there are multiple research projects testing concepts for this, some have flown demonstrations already. The difficulty is one of orbital physics - unless you specifically target pieces of junk and match their orbit, A. you never have a chance to come close enough to collect them, and B. anything you hit in a random other orbit is moving so fast relative to you that no material on earth can catch and contain the kinetic energy.

The incident in the OP is a great example of the difficulty - you had 2 objects on near-miss trajectory and A, they still missed, so you would have missed your grab, and B, they were moving at 33000 mph - nothing is going to 'catch' something going that speed.

There is a large amount of awareness now regarding space junk. The focus is on keeping the "junk" satellite in one piece and disposing of it, instead of having it break apart into many uncontrollable pieces. Some projects are focusing on being a "space tug" that can then target each satellite orbit, grab it, and tow it to a graveyard orbit or tow it to deorbit. Most modern satellites have End of Life (EOL) or deorbit as a distinct item in design. Fuel reserves are specifically saved for final EOL maneuvers, either to a graveyard orbit high out of use, or deorbit. If the final plan is deorbit, satellite components are designed to burn away on reentry, no large solid masses are allowed to survive through reentry, or deorbit is controlled enough to put surviving masses into the ocean and not over land.

SpaceX Starlink is designed to burn away completely, and their orbit is low enough that even if the lose control or break apart, their debris will deorbit itself in roughly 5yr. Some of the large commuications or imaging satellites are MUCH higher orbits where there will be no natural deorbit for thousands of years.

Other projects are investigating large deployable 'nets' where you could go to an important orbital lane and "sweep" it to gather up junk. Again the difficulty of closing speeds - you can be in the same orbit but still have too much speed for anything to be caught vs punching holes in the net. And if you fail, you just added pieces of net to the debris field.

 

Finally, any mention of space junk needs to mention this incident. In 2007, China shot one of its own satellites to prove an anti-sat missile system. The resulting debris makes up a full 1/3 of all tracked objects in ISS-risk orbit. A few shotguns of debris like this in common orbital lanes could effectively deny space to everyone if someone were to decide to go 'scorched earth' on space assets:

https://en.wikipedia.org/wiki/2007_Chinese_anti-satellite_missile_test

 

Ultimately keeping orbit clear is going to require everyone be responsibile with their shit in orbit.

 

Edit: Bond figured out safe orbital practice 50yrs ago!

Edited October 20, 2020 by Sam Lin

[RPM 26,315]

18 minutes ago, Sam Lin said:

Bond figured out safe orbital practice 50yrs ago!

That was the sort of "capture" I was thinking of. Slow approach from rear then overfly. I'm aware it would be incredibly difficult and only viable on larger objects.

[Sam Lin 3,550]

This is one company that has actually launched a space tug that can help move satellites that are out of propulsion - in this case the tug will help the satellite remain in useful orbit for 5 additional years, and then will move it to graveyard orbit.

https://phys.org/news/2019-10-life-geosynchronous-satellites.html

 

Edit: A lot more mission detail here, latest updates near bottom, but the relocated satellite was put into service April of this year. MEV-2 has also been launched.

https://directory.eoportal.org/web/eoportal/satellite-missions/m/mev-1

Edited October 20, 2020 by Sam Lin

[RamjetFDO 10,575]

So, this topic is near and dear to my heart for several reasons.  First - it was a part of my job as a Flight Dynamics Officer during the Space Shuttle program, and second - it was the topic of my Master's dissertation.

FDO-wise, we were responsible for maintaining contact with USSPACECOM (US Space Command, formerly NORAD, renamed SPADOC, merged "somewhat" into Space Force - sheesh).  They had a huge database of both classified and unclassified debris with a mainframe predictor that could take any orbiting object and run predictive orbital propagation against that database (which would also be propagated forward) and flag any close "conjunctions", within a certain volume around the original object.  For Shuttle, that was defined in our Flight Rules as a 5NM x 25NM x 5NM (radial x downrange x out-of-plan) box.   That box size was defined after extensive computer runs were done to compute what size we'd need to have a 1-in-10,000 chance of a collision.  Orbital state vector determination, much less long-range propagation, had certain levels of uncertainty.  When you add those uncertainties together and propagate them over time, we were able to define that box and be comfortable with it.  If anything was predicted to enter that "box" over the next 72 hours, USSPACECOM would issue a COMBO (Computation of Miss Between Orbits) alert, and we then would have several options:

1. Send a more precise state vector to USSPACECOM and request them to "re-run" their analysis.  We would normally send a vector every 24 hours, and often times either updated tracking and/or future maneuver planning that we already had on the books would make this COMBO just "go away" because of the now-changed trajectory.
2. If the updated state vector still showed the COMBO within the box, we would ask USSPACECOM to update *their* state vector on the possible debris object.  That could mean looking at the pedigree of the last tracked vector - if it was "very old" and couldn't be found any more, we could often ignore it.  If it was an "active" debris object, they had world-wide tracking stations that they could alert to try to pick it up and provide updated vector info.  They'd then re-run and see if the COMBO still existed.
3. IF IT DID, then we could start looking at avoidance options on our side.  Options could include:
   1. If this was far enough in advance and we weren't actively involved in trajectory station keeping (i.e., currently in rendezvous mode with a target - satellite or station), we could plan an attitude change that would provide "just enough drag" to change our orbit days in advance to push us out of the box (usually in the downrange direction).
   2. If it was closer (in time), we could actually plan a small avoidance maneuver -- depending on the miss direction, a small (1-3 fps) tweak could easily push us out of the box.
   3. The problem, of course, would be if we had trajectory issues we needed to meet as well or if the crew was asleep or if we had payloads that just couldn't handle jet firings (often had microgravity experiments that required us to almost "go silent" with regards to attitude jet firings, much less translational).
4. So - if we did have to come up with "a plan", we'd model it and then send USSPACECOM an updated post-maneuver vector or post attitude change vector propagated by us much closer to the COMBO time.  They'd re-run and let us know if we resolved the issue or if we made it worse.  We were pretty good at resolving it the first time - just based on event approach direction and timing.

As you can imagine, we thought about this a lot.  We would train it during other simulations that might not have had FDO-intensive activities -- usually with the younger FDO trainees.  If we were ever looking to throw multiple activities at a FDO at the same time, a debris COMBO event would always be a possible.  Being a senior FDO, I would often get to "script" certification sims for our guys ... and coming up with creative ways to trip them up.   

In addition, we would always send a post-MECO and post-OMS-2 vector to USSPACECOM to make sure we weren't launching *INTO* a COMBO event.  Sim-wise, we did that a bunch, too - and sometimes that could mean changing the launch time (usually by a second or two would do it).

But - "space is big" and our actually having to do these avoidance maneuvers was EXTREMELY rare during the Shuttle program.  We simmed, trained, and prepped for these for YEARS before ever actually having to do one.  I worked the flight (having an issue remembering the exact one) in the mid-90s when we did the first one -- we tracked and planned this piece of junk for a few shifts before making the recommendation (which was accepted) to actually perform the small maneuver - which actually ended up helping us with deorbit opportunities, too (we were able to make this an overall beneficial event).  The ISS program has had some ~30 events that they've had to maneuver -- but their trajectory is slightly different in that (1) they're a little higher than our average altitude (junk decays out the lower you go), (2) they're a much bigger target than Shuttle was, so their COMBO box is slightly bigger, and (3) there's more stuff now than there was before.

But ~30 events over 20 years of ISS operations for a fairly large target?  That's not horrible ... and they're able to often handle things as part of the normal ISS reboost activities anyway.   

Sorry - lots of words, but a subject I used to have to deal with all the time.

[Pato del Muerto 52,484]

Instead of pulling them into the atmosphere, would it be too difficult to propel them all out of earth’s orbit and into deep space in all directions like breadcrumbs?

[RamjetFDO 10,575]

The problem is that there are essentially "four classes" of orbital debris:

1. ACTIVE satellites/spacecraft (not really debris, but still need to account for them!)  
2. INERT objects - those that are still fully intact, but not performing any useful function - this includes spent rocket/booster bodies that finished their job boosting satellites to higher orbits, but are still hanging around and orbiting the earth.  The Russians and Chinese are guilty of not providing planned deorbit capabilities for most of theirs.  We "used to be" bad about that, but have gotten much better about adding that little bit of fuel budget to nudge our spent boosters into a decaying/re-entering orbit to burn up after they're done.
3. LARGE collision debris - chunks of things from collision events.  This is actually a much smaller number than you might think (see that "space is big" comment above).  There have been a relatively few "collision events" and most of those occurred low enough to where the debris was scattered and ended up deorbiting relatively soon after.
4. REALLY HARD TO TRACK debris - the unclassified tracking limit is roughly softball-sized... the classified limit is obviously much smaller.  I could tell you about it, but then I'd have to kill you.  So, things much smaller than rocket bodies - all the way down to (no kidding) flecks of paint are included in this group (the classified tracking doesn't account for paint flecks). 

The only categories above that we can plan for doing something about are the first two.  And, for our part, the US (and EU... essentially everyone *but* the Russians and Chinese) try to be good stewards of the Low Earth Orbit (LEO) environment with regards debris.

Challenger, on STS-7, noted a debris impact post-flight on one of her windows.  It was a whopping 2.5mm in diameter.  Detailed analysis was able to determine it was from a paint fleck ... and further analysis of the COLOR of the paint fleck (!!!!) indicated that it was the same crappy green color that most Russian boosters were painted.  So ... the Rooskies attacked Challenger with paint.

 

[freyguy 4,258]

11 hours ago, Pato del Muerto said:

Instead of pulling them into the atmosphere, would it be too difficult to propel them all out of earth’s orbit and into deep space in all directions like breadcrumbs?

That would produce way too many Vgers for the future human race to handle.

[Sam Lin 3,550]

On 10/20/2020 at 10:12 PM, Pato del Muerto said:

Instead of pulling them into the atmosphere, would it be too difficult to propel them all out of earth’s orbit and into deep space in all directions like breadcrumbs?

In short, yes. Actually getting out of orbit takes a LOT of energy.

[RamjetFDO 10,575]

9 hours ago, Sam Lin said:

In short, yes. Actually getting out of orbit takes a LOT of energy.

Yup -- it's literally only a little over 1% difference between being "in orbit" and "re-entering" (at least in LEO altitudes, more as you go higher, but it only takes the low/perigee end of the orbit to reduce into the atmosphere to deorbit), so that's much easier to budget for and execute.

[thunderlounge 7,813]

Sure sure, shoot em out into space so we can have a big pile of garbage threaten to take us out 1000 years from now. 

[utee94 15,797]

On 10/22/2020 at 1:26 PM, thunderlounge said:

Sure sure, shoot em out into space so we can have a big pile of garbage threaten to take us out 1000 years from now. 

1000 years from now???

#NotMyProblem

 

[PhillyD 1,257]

Coming to this thread late but the paint fleck and the story of the Chinese blowing up a satellite to account for 1/3 of space junk have always made me think of  how much we must not know is out there.  If they blew up a satellite, there must be a ton of debris that I would think we have no idea is there, say the size of a small wing nut or screw.  Tiny, but 1000 times more massive than a paint fleck that nearly cracked a shuttle window.  I always think we are going to have a day when there is a chain reaction of debris in space crashing into each other knocking out satellite after satellite.

[Sam Lin 3,550]

Just saw this article, mission planned to go grab a junk booster that's sitting in a widely used orbit, and drag it out of orbit to burn up.

 

https://amp.9news.com.au/article/f421dd77-36af-411e-85c7-8c80dd2cb8bd

[Armybrat 40,815]

NSIAP

[jeevsie 3,733]

[Sam Lin 3,550]

Update on the Mission Extension Vehicles, satellites intended to dock to other satellites and extend their usable life by being 'tugboats' for orbital positioning (and also provide additional electrical power!) One has been active a year, the other just docked a week ago. Cool photo of the receiving satellite near the end of the article. This, combined with the decreasing cost of launch driven by SpaceX, has huge potential to spur a fundamental change in satellite design and life planning.

https://arstechnica.com/science/2021/04/the-era-of-reusability-in-space-has-begun/

[beer 3,220]

I came here to watch space porn

[Sam Lin 3,550]

Russia just blasted one of their old satellites, in what appears to be a test of an anti-sat missile, and created yet another massive space debris cloud:

https://arstechnica.com/science/2021/11/debris-from-a-satellite-shot-down-by-the-russians-appears-to-threaten-the-iss/

[Radical Larry 28,539]

They don’t take a dump without a plan.

[NeverMarryAStripper 21,867]

Why don’t we just detonate a few nukes in orbit and vaporize all the junk

Edited November 16, 2021 by NeverMarryAStripper

[RamjetFDO 10,575]

1. Russia plays stupid ASAT games. 
2. Blows up target and creates debris field. (same link as 3 posts above)
3. Debris field scatters and creates potential collision alert with ISS.
4. ISS crew has to "retreat" to docked capsules in case of debris collision. 
5. Russia denies ISS crew was ever in danger.
6. ...
7. Profit?

 

[RamjetFDO 10,575]

This just pisses me off to no end...

 

[Sam Lin 3,550]

Ars has another article with more talk about the debris orbits:

https://arstechnica.com/science/2021/11/new-images-and-analyses-reveal-extent-of-cosmos-1408-debris-cloud/

[RamjetFDO 10,575]

Space junk revealed by University of Texas graph database

Even though this isn't anything ground-breakingly *new*, per se, it's still very cool and good job to the Aerospace Engineering department guys for doing it.  Keep in mind that these are the "unclassified" tracking size elements.  There are many many more objects that are much smaller are are either not able to be tracked (due to size) or aren't represented in this database (to protect the minimum tracking size capabilities by our space assets).

AstriaGraph

 

[Hate 20,106]

Jesus.  That is cool but it also just can't be good.  Isn't there anything that can be done with the inactives?

[Captainant 27,620]

5 hours ago, Hate said:

Jesus.  That is cool but it also just can't be good.  Isn't there anything that can be done with the inactives?

It's a pretty hard problem, and a modern day tragedy of the commons. Orbital debris is a negative externality that you can ignore in a single case, but each collision and poorly designed mission/launch only worsens the problem. The things orbiting are at a high energy state and we don't currently have any scalable mechanisms to remove energy from that system to deorbit the debris.

Maybe some sort of directed energy weapon (read: frikin lazer beams) could be used, but it's not really something that has a solution yet

[thunderlounge 7,813]

This is extremely over simplified, but can’t we take a “net” and cruise up behind shit going just barely faster than the debris, and dunk it to the burn zone?

 

[wild_turkey 3,159]

What about some really big magnets?

[Sbbruin 21,826]

13 hours ago, Captainant said:

Maybe some sort of directed energy weapon (read: frikin lazer beams) could be used, but it's not really something that has a solution yet

On it.

[Captainant 27,620]

3 minutes ago, Sbbruin said:

On it.

Oi vey.

[Sam Lin 3,550]

Where can I order that patch? Asking for a friend...

[Sam Lin 3,550]

Next developments on increasing satellite life by adding refueling or servicing. Testbed missions to repair/refuel existing satellites that were never designed for repair or refuel:

https://arstechnica.com/science/2022/03/orbiting-robots-could-help-fix-and-fuel-satellites-in-space/

 

[thunderlounge 7,813]

Robot gas stations in space?

That’s crazy enough it just might work. 

[RamjetFDO 10,575]

The problem with grand ideas like this is from terrestrial thinking.  People don't realize the amount of energy required to change planes, altitudes, and phase angles to catch even the most obvious "refueling targets".  And, unless the systems were designed with robotic/remote refueling from the beginning, don't expect any sort of commonality or easy access to any refueling ports. 

This isn't a standardized industry where the nozzle on the local gas pump fits EVERY car on the market by design.  Spacecraft designers work with what they have and what they can afford to produce what they're required to produce.  Commonality with someone else's future refueling bot isn't "a thing" yet.

[thunderlounge 7,813]

Damn it, Deborah.

 

[woohorn 1,131]

The problem with grand ideas like this is from terrestrial thinking.  People don't realize the amount of energy required to change planes, altitudes, and phase angles to catch even the most obvious "refueling targets".  And, unless the systems were designed with robotic/remote refueling from the beginning, don't expect any sort of commonality or easy access to any refueling ports. 
This isn't a standardized industry where the nozzle on the local gas pump fits EVERY car on the market by design.  Spacecraft designers work with what they have and what they can afford to produce what they're required to produce.  Commonality with someone else's future refueling bot isn't "a thing" yet.

So it IS rocket science??