Discussion of Cleaning up LEO and Beyond

Not a contract yet, but could lead to some contracts:

Plasmos unveils Space Truck

Plasmos Space Truck

spacenews.com

FWIW, unlikely this ever represents a full launch, so unlikely more than a small drop in the revenue bucket.

Bit editorial here, but IMO the various "space tug" type companies out there are going to be fighting a shrinking market with as time moves on. With the progress being made on affordable electric propulsion--not to mention opening up electric propellants beyond the traditional and massively expensive Xe (a lot of the world's supply comes from the Ukraine....), its becoming far more practical and efficient to just have a full-up satellite rather than have a third party solution (and corollary interfaces) to do the lifting.

There's also regulations that are either in place or about to be put in place that require satellites bigger than a ~cubesat to have on board propulsion for COLA, and then there's also similar deorbit-to-reentry (rather than deorbit to graveyard) regulations--including a max timeline--that effectively require many satellites to carry quite a bit of propellant to deorbit to a tenable altitude. At that point it's not a massive <ahem> lift to also carry enough propellant for orbit raising as well.

IMO about the only space that could have some sustainable market is recovery--if there's a dead sat floating around everyone else would greatly prefer it be removed. The current problem we're seeing with that notion is: who is actually responsible. Sure, if it's a megaconstellation, it's probably in their best interest to get the dead satellite out of orbit for their own sake. But if its a smaller entity in much less statistical jeopardy from that dead sat than, say, the megaconstellations, that smaller company doesn't really have a lot of incentive to take action, especially when that action is fairly costly and 0% ROI.

There's also a technical element to recovery that's not a slam dunk. Yeah, if the dead sat is stable (no or very low spin rates) then its reasonable to capture...but once the rates start ramping up--and certainly if the rates are across multiple axes--it gets really REALLY had to capture.

Nevertheless, there's definitely conversations going on regarding this kind of scenario, and at some point we'll likely (hopefully?) see some level of regulation...though without full global compliance (looking at you, Jai-Nuh) its going to be an uphill battle.

Somewhat related, at the big smallest conference last week in Mountain View (as opposed to the big one in Logan that's always in August...) Dankberg actually called for proactive action to mitigate worst case scenarios. In a nutshell his proposal is to limit total mass and satellite area relative to an orbit, with a corollary to limit what would become an explosion in space real estate. Obviously the concept is a shot directly at Starlink (and Kuiper) so there's more than just a Good Samaritan agenda going on, but rising above that it does carry some pretty sound logic.

"SpaceX Dragon 16" by Astro_Alex is licensed under CC BY-SA 2.0.
Admin note: Image added for Blog Feed thumbnail

 

[Grendal]

I copied the previous post from another thread. We've had a number of posts on the subject of the clutter in space and some ideas from different sources on what to do about it. So I think there should be a dedicated thread to highlight the issue and the possible solutions.

Let's discuss.

 

[Ben W]

For stabilizing a spinning dead satellite, a capturing satellite could presumably just aim a small (Draco-size or smaller) thruster at it from a safe distance, and gently "blow" on it off-center with enough force to gradually slow and stop its spin. (Counterbalanced by a thruster firing in the opposite direction to maintain relative position.) Given enough time, even an ion thruster ought to be able to do this. The efficiency would be quite low; maybe only 1% of exhaust momentum would transfer to the dead satellite to slow its spin, but that may still be enough for real-world scenarios. The rotational "delta-v" needed to stabilize the satellite would typically be just a few meters per second, much lower than the linear delta-v subsequently required to deorbit it.

 

[ICUDoc]

Are we talking about de-orbiting or capturing these satellites ?
Deorbiting might be easier- just a push. Does rotation matter in that case?

But capture would be fun- grab it regardless of spin. Capture it in a box then "grab" it with some mechanical device in several (?2) axes.
This will cause the recovery satellite to spin, but slowly, due to its large mass. So one can then correct the slow recovery satellite spin.
Then crush the captured sat into the storage hold, like a garbage truck does.

Rinse and repeat.
Is there enough precious metal and minerals in the sats to make recovery economically viable? I would think not, given that we chuck them out there...

 

[bxr140]

Are we talking about de-orbiting or capturing these satellites ?

Deorbiting for sure--that's what actually removes the risk. Capture just happens to be the first step in the process, and technical difficulty of capture goes plaid pretty quickly as the dead sat's rates come off zero. Certainly we can all imagine fanciful solutions to capturing a tumbling sat (IMO its a trawler), but when the rubber meets the road (or the fuel meets the oxidizer?) its going to be really REALLY impractical to do anything but leave it be and hope real hard everything else gets out of its way, and that will be the MO for quite a long time. Much longer than its going to take to significantly populate (and potentially overpopulate...) LEO. And really, even in the best of scenarios (a to-be-deorbited sat that still has control authority and can stabilize itself), a recovery mission is still a massive undertaking requiring a significant amount of resources such that without punitive measures in place (fines, maybe a cleanup insurance/escrow?) its pretty much financially untenable, and again will be so for a long time. It turns out you can't get around physics.

So...the solution then needs to lean heavily on the proactive philosophy of "the best way to get out of a bad situation is to not get in one in the first place" rather than focusing on [the admittedly fun thought experiment of] Rube Goldberging cleanup. For better or worse, that philosophy is going to require significant global consensus on regulation in order to be effective. Off the top of my head, some potential useful elements of regulation could be:

• Low insertion (and IOT) orbits to quickly drag down DOA or infant failures
• Maximum population in a shell (basically what Dankberg is calling for, which is some maths-up of quantity/mass/size)
• Ps (probability of success) minimums for deorbit
• Early deorbit based on redundancy failures over time (eg, if one of your thrusters fails, perhaps that's grounds to deorbit)
• Concise responsibility heirarchy for COLAs (who's the aggressor and who's the victim, who takes action and who does not, etc.)
• Minimum standards for COLA agility (short turnaround, automation rules, minimum passing distances, etc)
• Use of standardized, open source tools for normalizing deorbit calculations (notably, drag...this is mostly so people don't fudge numbers)
• Maximum passive deorbit altitude and timeline (the in-proposal reg is passive deorbit within 5 years, which is REALLY long and effectively results in a dead satellite dragging down through a bunch of valuable altitudes)

Obviously, all that is easier said than done, and some of these are in work to varying degrees. Pathfinders in this space--notably Starlink--are also implementing some of the above already; what really needs to happen is alignment on how these kinds of regulations come together in such a way that they protect space without impairing space entities...and especially the smaller fish.

Deorbiting might be easier- just a push. Does rotation matter in that case?

Deorbiting needs more than an instantaneous push--there's a significant temporal element to the impulse, and especially given that any kind of recovery/undertaker type mission is going to use low thrust electric propulsion. Non-starter with a tumbling sat.

Is there enough precious metal and minerals in the sats to make recovery economically viable? I would think not, given that we chuck them out there...

Certainly not anything close to offsetting the expended resources used to recover the materials. I think the bigger question is whether we (globally) want to regulate the atomization of the various satellite materials into the atmosphere. It's hard to imagine we're at a place where it currently matters; I'm not smart enough to know if the increase in on orbit mass that's on the horizon will make a material difference. But...case studying lead here, potentially Bad Math using potentially dubious googs results suggest there's billions of naturally occurring kg's of lead in the atmosphere. While that's certainly a LOT of lead that could be better used elsewhere (paint for kids' toys or whatever), atomizing the tens or hundreds of grams in a satellite's various solders--even over thousands or tens of thousands of satellites--doesn't seem like its going to tip any scales.

Flipping recovery a bit, there's of course been plenty of concepts around on-orbit repurposing of materials--notably components--but that's also one of those far-future things that needs a lot of foresight to successfully implement. Theoretically if a sat's batteries and solar arrays (for instance) are easily removable by an automated on-orbit wrecker, they can be reinstalled on another sat. Obviously that saves all the resources required to manufacture and launch the mass of those items; presumably that savings eventually weighs out the complexity overhead of the recovery exercise (and also the fact that those components would likely be degraded by that point). And of course, any corollary concept still starts with capture.

 

[Grendal]

FCC Adopts New '5-Year Rule' for Deorbiting Satellites

News Release (Agenda Item)

www.fcc.gov

Space debris - Wikipedia

en.wikipedia.org

 

[mjwojtukiewicz]

https://www.cnn.com/2021/03/19/business/space-junk-mission-astroscale-scn/index.html#:~:text=ClearSpace%201%2C%20the%20European%20Space%20Agency%E2%80%99s%20mission%20to,the%20first%20successful%20demonstration%20of%20space%20cleanup%20technology.

 

[BigNick]

Some Deep Purple to start off Friday morning: Space Truckin'

 

[mjwojtukiewicz]

There was a movie MANY years ago starring Andy Griffith who ran a space junk business and had to bring some rocket or something back to earth.
Found it: Salvage 1 (TV Series 1979) - IMDb

 

[bxr140]

https://www.cnn.com/2021/03/19/business/space-junk-mission-astroscale-scn/index.html#:~:text=ClearSpace%201%2C%20the%20European%20Space%20Agency%E2%80%99s%20mission%20to,the%20first%20successful%20demonstration%20of%20space%20cleanup%20technology.

They had a successful first recovery but their recovery sat lost half of their thrusters and so couldn't try the long term recovery.

It's a clever idea, but like most cleanup ideas it requires compatibility from the to-be-recovered satellite, in this case a feature compatible with the recovery sat's electromagnet. So...at the risk of stating the obvious, its no good for current sats on orbit or anything near term that's going up without said feature.

IMO, ideally satellites will be regulated to carry some standardized (or at least standardized-enough) feature or set of features such that they can be compatible with a number of different recovery solutions. Right now is super early days on both a) developing technical recovery solutions and also b) codifying demand + need for recovery, but without commonized features every satellite to be recovered is sort of a snowflake and so regardless of progress on a) or b) it makes the whole problem exponentially harder to solve).

Not that there's any particular unique benefit to this product other than the fact that it exists, but Oneweb has the Altius Dog Tag on their sats, and I know others in the industry plan to use it as well.

 

[scaesare]

They had a successful first recovery but their recovery sat lost half of their thrusters and so couldn't try the long term recovery.

It's a clever idea, but like most cleanup ideas it requires compatibility from the to-be-recovered satellite, in this case a feature compatible with the recovery sat's electromagnet. So...at the risk of stating the obvious, its no good for current sats on orbit or anything near term that's going up without said feature.

IMO, ideally satellites will be regulated to carry some standardized (or at least standardized-enough) feature or set of features such that they can be compatible with a number of different recovery solutions. Right now is super early days on both a) developing technical recovery solutions and also b) codifying demand + need for recovery, but without commonized features every satellite to be recovered is sort of a snowflake and so regardless of progress on a) or b) it makes the whole problem exponentially harder to solve).

Not that there's any particular unique benefit to this product other than the fact that it exists, but Oneweb has the Altius Dog Tag on their sats, and I know others in the industry plan to use it as well.

That dog tag is a is cool... seems like a decent general purpose solution to several needs...

 

[Grendal]

NASA study assesses costs and benefits of orbital debris removal

A NASA study concluded that some methods of removing orbital debris could pay for themselves within a decade by reducing operators' costs and risks.

spacenews.com

 

[Bobfitz1]

NASA study assesses costs and benefits of orbital debris removal

A NASA study concluded that some methods of removing orbital debris could pay for themselves within a decade by reducing operators' costs and risks.

spacenews.com

It will be interesting to see what a redo of this NASA cost/benefit analysis in a few years concludes once Starship lowers the cost of payload to LEO to 2 - 3% of what it is now. I'd expect SpaceX to come up with a lowest cost system and convince enough of the entities that stand to reap savings to pay for clean up of those regions where cleanup benefits would be greatest.