FCC Approves 5 Year Satellite Deorbiting Rule(payloadspace.com)
payloadspace.com
FCC Approves 5 Year Satellite Deorbiting Rule
https://payloadspace.com/fcc-approves-5-year-satellite-deorbiting-rule/
118 comments
How high can the debris loft after a particularly nasty collision?
Two satellites hitting at an acute angle should produce a cone of debris in front of them, of which about a third deorbits and a third goes up into a higher orbit that's an average of the two.
Two satellites that hit at an obtuse angle, well, they pancake and produce a donut of debris. The stuff headed straight up is on a parabolic orbit that will hit the atmosphere on the way back down, but in the meantime any other satellite that crosses paths with it is effectively hitting a wall of stationary debris, creating a new cone that ladders up higher. Is there enough space that the ladder stops, or does it just keep building?
Two satellites hitting at an acute angle should produce a cone of debris in front of them, of which about a third deorbits and a third goes up into a higher orbit that's an average of the two.
Two satellites that hit at an obtuse angle, well, they pancake and produce a donut of debris. The stuff headed straight up is on a parabolic orbit that will hit the atmosphere on the way back down, but in the meantime any other satellite that crosses paths with it is effectively hitting a wall of stationary debris, creating a new cone that ladders up higher. Is there enough space that the ladder stops, or does it just keep building?
After a collision, the periapsis is at most as high as the point of collision, and the apoapsis is at least as high as the point of collision. In plain English, if two satellites collide with each other at an altitude of 450km, it doesn't matter what the original orbits were; 100% of the debris will have a low point in their orbit at or below 450km, and 100% of the debris will have a high point in their orbit at or above 450km.
One of the quirks of debris deorbiting is that drag is exponentially higher the lower you are in orbit, and any drag that the debris experiences at any point along its orbit will manifest in a reduction of altitude 180 degrees along is orbit on the other side. So if you have a piece of debris with an eccentric orbit, let's say 300km at periapsis and 1,000km at apoapsis, after a fairly brief amount of time you'd expect the debris to have a periapsis of 299.9km and an apoapsis of 500km. Then perhaps 299km periapsis and a 350km apoapsis. etc. I'm making these numbers up but you get the idea: the high point in an orbit is the part that drops the quickest.
Even if you were to launch 100,000,000 full sized satellites into orbit at 400km altitude and deliberately orchestrated Kessler syndrome, space would be unusable for a few years, but would be 100% back to normal after 5 years.
The dangerous orbits are those in the 500-2,000km range. Satellites whose orbits never bring them low enough to experience significant atmospheric drag. Those are the satellites this new rule is targeting.
One of the quirks of debris deorbiting is that drag is exponentially higher the lower you are in orbit, and any drag that the debris experiences at any point along its orbit will manifest in a reduction of altitude 180 degrees along is orbit on the other side. So if you have a piece of debris with an eccentric orbit, let's say 300km at periapsis and 1,000km at apoapsis, after a fairly brief amount of time you'd expect the debris to have a periapsis of 299.9km and an apoapsis of 500km. Then perhaps 299km periapsis and a 350km apoapsis. etc. I'm making these numbers up but you get the idea: the high point in an orbit is the part that drops the quickest.
Even if you were to launch 100,000,000 full sized satellites into orbit at 400km altitude and deliberately orchestrated Kessler syndrome, space would be unusable for a few years, but would be 100% back to normal after 5 years.
The dangerous orbits are those in the 500-2,000km range. Satellites whose orbits never bring them low enough to experience significant atmospheric drag. Those are the satellites this new rule is targeting.
I don't think debris 'going higher' isn't much of a problem. Whenever this happens the orbit is going to be more eccentric - meaning a lower periapsis, and consequentially lots of drag that will cause a rapid deorbit.
On the second point about parabolic orbits I also find that probably relatively low risk because we are only talking about a fraction of an orbit for a collision to occur so unless the debris field was massive the chance of another collision is probably still low. Remember when we are modelling orbit collisions normally we are often talking over 25+ years - 100,000 + orbits.
I think the main problem is busy orbits (e.g. sun-synchronous polar orbits at popular altitudes) where most of the debris remains roughly in the same orbit following an acute collision but has a lot of other potential collision targets. Also as satellites are disabled by a collision they lose the ability to avoid other objects already in the same crowded orbit - i.e. the fraction of objects able to take avoidance decreases increasing the chance that future collisions are from 2 incapacitated satellites, removing the possibility of avoidance.
On the second point about parabolic orbits I also find that probably relatively low risk because we are only talking about a fraction of an orbit for a collision to occur so unless the debris field was massive the chance of another collision is probably still low. Remember when we are modelling orbit collisions normally we are often talking over 25+ years - 100,000 + orbits.
I think the main problem is busy orbits (e.g. sun-synchronous polar orbits at popular altitudes) where most of the debris remains roughly in the same orbit following an acute collision but has a lot of other potential collision targets. Also as satellites are disabled by a collision they lose the ability to avoid other objects already in the same crowded orbit - i.e. the fraction of objects able to take avoidance decreases increasing the chance that future collisions are from 2 incapacitated satellites, removing the possibility of avoidance.
Angular momentum is subject to a conservation law.
What does angular momentum have to do with Kessler syndrome?
> Debris don't really accumulate dangerously in this zone and collision avoidance is a well-studied problem with a lot of people doing great work.
I think this line of thinking is dangerously incorrect. Sure it’s not a problem right now but we’re poised to have a lot more stuff in orbit than we’ve ever had before. Plastic waste didn’t initially “accumulate dangerously” either but once it became more widely used (and did accumulate dangerously) it was much more difficult to try to reign it back.
I think this line of thinking is dangerously incorrect. Sure it’s not a problem right now but we’re poised to have a lot more stuff in orbit than we’ve ever had before. Plastic waste didn’t initially “accumulate dangerously” either but once it became more widely used (and did accumulate dangerously) it was much more difficult to try to reign it back.
In this case it's policy reflecting Little's Law:
I am worried though, do we really build satellites that are expected to only work for 5 years? Are we disincentivizing people from building 20 year satellites this way?
population = arrival rate X duration of visit
I am worried though, do we really build satellites that are expected to only work for 5 years? Are we disincentivizing people from building 20 year satellites this way?
The article says "5 years after completing their mission", not 5 years after launch.
I assume it means deorbit within 5 years after the satellite is decommissioned.
https://www.youtube.com/watch?v=mQT5aMa_7iI
"Gabbard Diagram for Low Earth Orbit 1959-2021"
See how the stuff in the lower left corner speeds up towards the lower left corner? That's low flying debris falling out of space.
"Gabbard Diagram for Low Earth Orbit 1959-2021"
See how the stuff in the lower left corner speeds up towards the lower left corner? That's low flying debris falling out of space.
Everybody interested in the topic should watch this video (it's just an animated graph, no music). You will get a better intuition for the lifetime of orbital debris, and the impact of various incidents, in a few minutes than in hours of reading.
Wow, what a beautiful video. I really enjoyed trying to figure out what events and phenomena the different shapes/patterns in the diagram represent.
I am generally allergic to video, but that was fascinating to watch. Thanks for sharing it.
I didn't mean to imply orbit debris isn't a real problem. But for the low end of LEO:
- Most debris deorbits naturally in a few years. Any debris causing events or accumulation naturally clears out in a reasonable time frame. It's not like debris at 800-2000km which is the real "Kessler Syndrome" concern where it takes decades or centuries.
- Debris mitigation efforts that are already in place are effective. Limiting debris release during launch and deployments has had a huge positive impact over the last few decades.
- "Traffic control" is a lot easier at these altitudes and debris in this range is well tracked. Obviously this doesn't extend to small stuff (<5cm), but due to active mitigation and natural decay this is less of an issue. Also ground radars are getting better and can actually see a lot of these objects now.
- Most debris deorbits naturally in a few years. Any debris causing events or accumulation naturally clears out in a reasonable time frame. It's not like debris at 800-2000km which is the real "Kessler Syndrome" concern where it takes decades or centuries.
- Debris mitigation efforts that are already in place are effective. Limiting debris release during launch and deployments has had a huge positive impact over the last few decades.
- "Traffic control" is a lot easier at these altitudes and debris in this range is well tracked. Obviously this doesn't extend to small stuff (<5cm), but due to active mitigation and natural decay this is less of an issue. Also ground radars are getting better and can actually see a lot of these objects now.
Debris does not accumulate in LEO, it reenters naturally. This isn't like plastic waste, it's more like organic waste that naturally decays. Sometimes the law says you have to clean up organic waste, but sometimes it's better to let it rot on its own.
The timeframe varies widely based on the shape of the object and the altitude. There are something like 5 orders of magnitude pressure difference between an object at 100km and one at 500km which is the difference between deorbiting in days vs years.
There's probably more than 5 orders of magnitude difference between throwing an apple core into the woods and a city's worth of sewage, but both are organic waste. I think the analogy is fairly sound.
While true, there’s also an asymmetry here in that a city can expand their landfill or sewer system capacity- orbital space has a fixed capacity
That's not really true. The "capacity" such as it is is defined by current technological ability to track the assets and respond to changes quickly. There's a whole ton of work to be done there as satellite operators only update their position every few days usually. It should be at least daily and ideally hourly or even by the minute.
WTF? Space is incomprehendibly big. The number of potential landfill locations are very limited.
Isn't this thread discussing a very specific orbital range? The 450k-800k range is big, but I'm not sure I'd classify it as "incomprehensibly big".
Anything orders of magnitude larger than the Pacific Ocean deserves that title IMO.
It’s at least bigger than the surface of the earth :)
Landfills can go underground though! Although I agree that it's unlike we can dig several hundred thousand kilometers :)
Huge constellations with stable orbits under active control are irrelevant. It’s really the a pair of uncontrolled satellites colliding that’s a meaningful risk, and that risk grows exponentially with age. To the point where the difference between 1 day and 1 year is effectively meaningless while the difference between 5 years and 50 years is huge.
The risk grows quadratically in decay time, not exponentially.
Actually less than that, as orbits with more decay time have more vertical space.
Actually less than that, as orbits with more decay time have more vertical space.
It seems like it should be quadratic in that double the satellites should get 4x the number of collisions, but satellite orbits don’t start out random. Without stationkeeping initially clear orbits become chaotic in that slight differences in initial position and velocity result in wildly different orbits. That transition results in an exponential increase in risk.
This is most obvious with geostationary orbit. Over a single year you could have say 10,000 satellites in geostationary orbit with essentially zero risk of collision, but without station keeping risk continues to grow every year those 10,000 satellites drift around.
This is most obvious with geostationary orbit. Over a single year you could have say 10,000 satellites in geostationary orbit with essentially zero risk of collision, but without station keeping risk continues to grow every year those 10,000 satellites drift around.
I see your point that it’s not random but an exponential increase wouldn’t result from chaotic changes in orbit. That randomizes, making it quadratic.
It looks like inactive geostationary satellites will drift to the same longitudes, and tilt their axis away from the pole. If you have a set of geostationary satellites in that situation, the risk of collision is still quadratic in growth.
The risk is the sum of the pairwise probabilities of collision. So the only way you get super quadratic is if incrementally added satellites have increased pairwise risk with other satellites. It is possible that could be the case, because if you have to pack satellites more tightly, then maybe each satellite has higher pairwise risk with its direct neighbors.
That would still be sub-exponential, unless the collision risk between two satellites got exponentially higher as they get more closely packed. For example, suppose you have a ring of satellites, and you double the number. Then immediately neighboring satellites are twice as close. By basic inequalities you can show that considering the non-neighbor pairs of satellites, they have less than quadrupled the total risk of a collision. So by the master theorem we know the risk of collision would only grow exponentially if there were an exponentially higher risk of collision between two neighboring satellites in terms of the reciprocal of their distance. But that is not the case, is it? You’d expect it to be polynomial. Fewer orbits before the satellite drifts past its neighbor, a smaller expected distance to the neighbor as it drifts past… as with most physics problems these are linear components, multiplied together.
It looks like inactive geostationary satellites will drift to the same longitudes, and tilt their axis away from the pole. If you have a set of geostationary satellites in that situation, the risk of collision is still quadratic in growth.
The risk is the sum of the pairwise probabilities of collision. So the only way you get super quadratic is if incrementally added satellites have increased pairwise risk with other satellites. It is possible that could be the case, because if you have to pack satellites more tightly, then maybe each satellite has higher pairwise risk with its direct neighbors.
That would still be sub-exponential, unless the collision risk between two satellites got exponentially higher as they get more closely packed. For example, suppose you have a ring of satellites, and you double the number. Then immediately neighboring satellites are twice as close. By basic inequalities you can show that considering the non-neighbor pairs of satellites, they have less than quadrupled the total risk of a collision. So by the master theorem we know the risk of collision would only grow exponentially if there were an exponentially higher risk of collision between two neighboring satellites in terms of the reciprocal of their distance. But that is not the case, is it? You’d expect it to be polynomial. Fewer orbits before the satellite drifts past its neighbor, a smaller expected distance to the neighbor as it drifts past… as with most physics problems these are linear components, multiplied together.
Thinking about it more, it could probably be modeled by the intersection of random walks that are initially unable to come into contact. I was thinking that was exponential but it’s presumably some polynomial function with a large exponent that’s eventually bound by a different quadratic function for sufficient values of time.
It would seem to be exponential after the first collision, at least.
If we're launching 15k satellites per year as some people expect, the difference between 1 day deorbit and 5 years deorbit is something like 75,000 satellites.
If the risk of collisions in both scenarios is sub 0.0001%, is it a meaningful difference? Very quickly the risk is dominated by being launched into the wrong orbit.
yes, but if deorbiting in years is sufficient, the difference in time is not relevant.
What? Starlink eventually wants 40,000 satellites - with 5 year lifetimes that'll be 8,000 per year... there are numerous other planned constellations, so figure something like 15,000 LEO per year within a few decades.
15k satellites per year with a 5 year lifespan and a 1-year decay means you'll be stable at 75k satellites. 5 year lifespan with a 3-year decay means you'll eventually be stable at over 100k satellites in orbit with 30,000 of them 'dead' and decaying. That's a massive difference in collision risk.
15k satellites per year with a 5 year lifespan and a 1-year decay means you'll be stable at 75k satellites. 5 year lifespan with a 3-year decay means you'll eventually be stable at over 100k satellites in orbit with 30,000 of them 'dead' and decaying. That's a massive difference in collision risk.
>That's a massive difference in collision risk.
Is it? It's a big difference in absolute numbers but that doesn't mean it's a meaningful difference in Risk.
If both numbers are quite small relative to the level of concern, the difference can still be irrelevant.
My point is that it takes more than just looking at the number of satilites to understand risk. You need to do the work to show how the collision chance compares to what an acceptable limit might be. Both cases could be very acceptable (or both cases could be unacceptable).
Is it? It's a big difference in absolute numbers but that doesn't mean it's a meaningful difference in Risk.
If both numbers are quite small relative to the level of concern, the difference can still be irrelevant.
My point is that it takes more than just looking at the number of satilites to understand risk. You need to do the work to show how the collision chance compares to what an acceptable limit might be. Both cases could be very acceptable (or both cases could be unacceptable).
The rule is 5 years. You've given 2 examples under 5 years. If everything is going to re-enter within 5 years without boosting then your point is moot, because even in your "massively more collision risky" example, it still abides by the rules.
If something was going to deorbit within 1 minute, or was going to deorbit within 4 years, 6 months... It doesn't matter to the creator, because they don't have to change their design at all to meet the rules.
If something was going to deorbit within 8 years (because they previously had a 25 year allowed limit), they now have to rework the design.
There's plenty of room for debate about if 5 years is adequate, but as it stands, _most_ things (under 500km) will naturally deorbit within the legal time frame anyway even without special consideration.
If something was going to deorbit within 1 minute, or was going to deorbit within 4 years, 6 months... It doesn't matter to the creator, because they don't have to change their design at all to meet the rules.
If something was going to deorbit within 8 years (because they previously had a 25 year allowed limit), they now have to rework the design.
There's plenty of room for debate about if 5 years is adequate, but as it stands, _most_ things (under 500km) will naturally deorbit within the legal time frame anyway even without special consideration.
Just responding to a comment that said "If deorbiting in years is sufficient, the difference in time is not relevant" where it's obviously relevant.. this doesn't seem remotely controversial.
You're arguing a different thing. The topic was satellite design for satellites under 450km.
If deorbiting in years is sufficient, the difference in 1 minute vs 4 years is NOT relevant -> to a satellite builder worried about the law.
If everything deorbits within 5 years, the only way for more things to accumulate is to launch things faster. But that's a separate discussion. If everything launched today is deorbited within 5 years, then in 5 years, all satellites will be new satellites launched after today. If everything launched today is deorbited within 5 months, then in 5 years, all satellites will be new satellites launched after today. Deorbit speed under a threshold has no bearing on accumulation beyond that threshold.
If SpaceX launches a trillion Starlink satellites, and they all deorbit within a year, then yes. it's going to be a very crowded year, and we'll have to drastically rethink how much stuff we have in LEO, but at the same time SpaceX would not be in violation of the 5 year deorbit window, so the issue is about how much stuff we're sending up, and not how fast it de-orbits.
"Amount of junk below 450km, total" and "Amount of junk below 450km, that hasn't deorbited after 5 years" are very different things. You're making points about total, while the original point was about deorbit speed.
If deorbiting in years is sufficient, the difference in 1 minute vs 4 years is NOT relevant -> to a satellite builder worried about the law.
If everything deorbits within 5 years, the only way for more things to accumulate is to launch things faster. But that's a separate discussion. If everything launched today is deorbited within 5 years, then in 5 years, all satellites will be new satellites launched after today. If everything launched today is deorbited within 5 months, then in 5 years, all satellites will be new satellites launched after today. Deorbit speed under a threshold has no bearing on accumulation beyond that threshold.
If SpaceX launches a trillion Starlink satellites, and they all deorbit within a year, then yes. it's going to be a very crowded year, and we'll have to drastically rethink how much stuff we have in LEO, but at the same time SpaceX would not be in violation of the 5 year deorbit window, so the issue is about how much stuff we're sending up, and not how fast it de-orbits.
"Amount of junk below 450km, total" and "Amount of junk below 450km, that hasn't deorbited after 5 years" are very different things. You're making points about total, while the original point was about deorbit speed.
Let me put this another way, if I use my computer to send emails, it doesn't matter to me if my ping is 10 milliseconds or 10 femtoseconds.
One time is 10^12 times longer, but the difference does not matter to me. My emails are still sent and received faster than I can possibly perceived.
One time is 10^12 times longer, but the difference does not matter to me. My emails are still sent and received faster than I can possibly perceived.
Several companies have been developing deorbit add-on modules, and I hope this requirement spurs on this growing industry. I would love it if it became the norm that satellites have a passive failsafe deorbit system that activates at after a set amount of time or if ground communications fail for a set duration.
https://www.nasa.gov/smallsat-institute/sst-soa/deorbit-syst...
https://www.nasa.gov/smallsat-institute/sst-soa/deorbit-syst...
I wanted to know if this affects "graveyard orbits". Seems like this applies only to satellites in LEO, while MEO/GEO are exempt.
> The Report and Order adopted today requires satellites ending their mission in or passing through the low-Earth orbit region (below 2,000 kilometers altitude) to deorbit as soon as practicable but no later than five years after mission completion.
> The Report and Order adopted today requires satellites ending their mission in or passing through the low-Earth orbit region (below 2,000 kilometers altitude) to deorbit as soon as practicable but no later than five years after mission completion.
> The rule shortens the time required for satellite operators to deorbit LEO satellites to no more than 5 years after completing their mission, from 25 years.
De-orbiting faster means reserving more propellant for the final de-orbit burn. Since the lifespan of satellites is already generally determined by how much propellant they have, this new rule effectively reduces the lifespan of any satellite high enough to require a de-orbit burn.
Companies that use very low satellites are impacted less, since atmospheric drag does more of the work.
De-orbiting faster means reserving more propellant for the final de-orbit burn. Since the lifespan of satellites is already generally determined by how much propellant they have, this new rule effectively reduces the lifespan of any satellite high enough to require a de-orbit burn.
Companies that use very low satellites are impacted less, since atmospheric drag does more of the work.
To be honest, this seems quite reasonable. Space is obviously a unique environment, but to use an imperfect analogy: we don't let cars that break down just sit in the middle of the road, and we don't let dilapidated buildings sit unattended until they collapse.
There's an externality to leaving a EOL'd satellite in LEO, now these new rules require that externality be priced in. Either through the cost of reserving enough propellant for a de-orbit burn, or perhaps, one day, for more expensive satellites, a new industry could emerge for refueling/boosting/servicing to extend the sat's life.
This regulation seems like a good sign that the commercial space industry is starting to mature in a healthy way.
There's an externality to leaving a EOL'd satellite in LEO, now these new rules require that externality be priced in. Either through the cost of reserving enough propellant for a de-orbit burn, or perhaps, one day, for more expensive satellites, a new industry could emerge for refueling/boosting/servicing to extend the sat's life.
This regulation seems like a good sign that the commercial space industry is starting to mature in a healthy way.
The future is here! I know of at least one company, Orbit Fab, who already has signed contracts for their in-orbit refueling service. It's a bit early to see how successful or profitable this will be though.
If rules didn't cause inconvenience to someone, they wouldn't have to be written.
I was thinking more along the line of the new rule giving another commercial advantage to SpaceX. Starlink will be effected, their satellites already deorbit faster than 5 years. But many other satellite operators will have to launch more frequently, and SpaceX is positioned to meet that growing demand.
> But many other satellite operators will have to launch more frequently, and SpaceX is positioned to meet that growing demand.
Read the article. It's about deorbiting after mission is finished.
If you have enough fuel on board you're free to keep your satellite for 50 years on the orbit. You just have to deorbit it within 5 after you stopped using it.
Read the article. It's about deorbiting after mission is finished.
If you have enough fuel on board you're free to keep your satellite for 50 years on the orbit. You just have to deorbit it within 5 after you stopped using it.
I don't really see it as "giving" a commercial advantage to anyone if the new rule's purpose is to prevent something harmful and someone happens to benefit because they're already not doing that harmful thing.
In my view it's really a separate issue if SpaceX has too many advantages and that levelling the playing field somehow would be useful; allowing companies to grow too powerful does cause problems, and I don't think there's a moral requirement for regulators to be "fair" when dealing with corporations. They are not humans.
The need for that sort of intervention should not keep us from instating otherwise beneficial rules, though.
In my view it's really a separate issue if SpaceX has too many advantages and that levelling the playing field somehow would be useful; allowing companies to grow too powerful does cause problems, and I don't think there's a moral requirement for regulators to be "fair" when dealing with corporations. They are not humans.
The need for that sort of intervention should not keep us from instating otherwise beneficial rules, though.
> In my view it's really a separate issue if SpaceX has too many advantages
That's not what I was saying. I was offering an observation, not a critique. I think this new rule is good.
That's not what I was saying. I was offering an observation, not a critique. I think this new rule is good.
Oh, I didn't really read it as a critique; mostly just the phrasing of "giving another commercial advantage" made me want to comment since it can be read as if that's the (or even just a) purpose of the rule.
How does this FFC rule work in an international market?
I assume it applies for US companies with US based launches.
Does it apply to US satellite companies with ex-US launches?
Are US companies free to purchase service/bandwidth from ex-US launched satellites which are not compliant?
Does it apply to US satellite companies with ex-US launches?
Are US companies free to purchase service/bandwidth from ex-US launched satellites which are not compliant?
US companies launching satellites with foreign launch providers still need to get a license from the FCC if their satellite uses radio communications.
How about foreign satellites on foreign launch systems that wish to communicate with ground stations in the US? I assume they also need an FCC license.
The EU is talking about imposing much the same rule, if they haven't already (link is from 2019): https://spacenews.com/eu-space-envoy-calls-for-satellites-to...
Yes, satellites communicating with ground stations in the US need licenses from the FCC, regardless of where they're launched or where the owner is based. US satellites that exclusively communicate with ground stations outside of the US might not, but I'm not sure about that. Satellites launched by other US government agencies (NRO, etc) might also be exempt.
> De-orbiting faster means reserving more propellant for the final de-orbit burn.
One new technology is releasing a sail to increase drag.
Example: http://www.parabolicarc.com/2021/08/23/millennium-space-syst...
One new technology is releasing a sail to increase drag.
Example: http://www.parabolicarc.com/2021/08/23/millennium-space-syst...
I'm no rocket scientist, but could there be a service which knocks satellites out of orbit for people? I wonder how cost effective such a service could get. Could one mission knock 10 satellites out of orbit?
Astroscale is trying to push a standardized docking adapter for that purpose and Northrop Grumman has a vehicle that was able to dock to the engine of another satellite to serve as a life extension vehicle, so assuming that can be easily adapted to other satellites, they too can provide a deorbiting service.
Clearing out several satellites with one vehicle is not practical though, would need too much fuel. At best one might launch several such vehicles on one launch, or if orbital fuel depots really take off soon, it may be possible to have depots in convenient locations such that deorbiting vehicles can always make a relatively cheap visit to a depot to refuel and wait for another deorbiting target. In such a setup the deorbiter would just lower one end of the orbit to speed up decay rather than dragging it all the way down to Earth.
Clearing out several satellites with one vehicle is not practical though, would need too much fuel. At best one might launch several such vehicles on one launch, or if orbital fuel depots really take off soon, it may be possible to have depots in convenient locations such that deorbiting vehicles can always make a relatively cheap visit to a depot to refuel and wait for another deorbiting target. In such a setup the deorbiter would just lower one end of the orbit to speed up decay rather than dragging it all the way down to Earth.
I'm aware of Astroscale (https://astroscale.com/). They're a Japanese company with a presence in the US and UK that's commercializing this sort of service. I'm not sure if they have plans for multi-satellite de-orbit services, but they do have single-satellite plans.
Among other things, they're promoting a standardized docking adapter (https://astroscale.com/docking-plate/) to give satellite operators a path to either life extension (refueling and/or orbit raising) or de-orbit.
Among other things, they're promoting a standardized docking adapter (https://astroscale.com/docking-plate/) to give satellite operators a path to either life extension (refueling and/or orbit raising) or de-orbit.
With a vehicle, probably not. Moving form one satellite's orbit to another is extremely fuel-intensive (you'd typically need ~thousands of km/h of velocity change to do it), so it's not really practical to have a single vehicle up there moving from satellite to satellite.
But maybe there'd be some other way to do it? There have been proposals for de-orbiting little pieces of debris from the ground with lasers, and I suppose it's possible that those approaches would scale to bigger objects (or maybe you could do it with lasers from other satellites whose orbits were fixed, or something).
But maybe there'd be some other way to do it? There have been proposals for de-orbiting little pieces of debris from the ground with lasers, and I suppose it's possible that those approaches would scale to bigger objects (or maybe you could do it with lasers from other satellites whose orbits were fixed, or something).
A set of satellites that could do laser ablation of debris or EOL sats would be great, but would need safeguards to not become a weapon of economics or war.
Avoiding splash-over or collateral damage to other sats in or near the line-of-sight would be an issue, especially if any of those other sats might have capabilities that their nation/owner might want to keep secret. Perhaps an arrangement of vetos over particular ablation shots would suffice. Countries wanting to hide their interests in some sats could veto N times as many shots as needed, making uncovering which sats are special more difficult.
In any case, laser ablation would need much less delta-V than the usual imagery of plucky space-cowboys chasing errant sats with a net, or some such. Who knew that _Planetes_ would have such a strong effect on our collective imagination.
Avoiding splash-over or collateral damage to other sats in or near the line-of-sight would be an issue, especially if any of those other sats might have capabilities that their nation/owner might want to keep secret. Perhaps an arrangement of vetos over particular ablation shots would suffice. Countries wanting to hide their interests in some sats could veto N times as many shots as needed, making uncovering which sats are special more difficult.
In any case, laser ablation would need much less delta-V than the usual imagery of plucky space-cowboys chasing errant sats with a net, or some such. Who knew that _Planetes_ would have such a strong effect on our collective imagination.
In the far future, perhaps orbit-cleaners could eat dead satellites and space debris, atomizing the debris and turning it into reaction mass.
Going from travelling at Mach 25 in one direction to travelling at Mach 25 in a different direction takes an amount of energy comparable to going from 0 to Mach 25. Being outside of atmosphere helps a lot, and being able to use the less powerful but more efficient electric ion propulsion engines helps a lot, but 10 satellites per mission is usually not feasible. 3 per mission is the number I've heard.
Some companies approaching this problem are hoping to utilize refueling depots. It adds another expensive rendezvous but it does help.
Some companies approaching this problem are hoping to utilize refueling depots. It adds another expensive rendezvous but it does help.
Designing the satellites to self de-orbit would be massively more efficient, but this technology is being developed to de-orbit older sats and other debris without that capability. It could also be useful to remove satellites that fail or who's de-orbit system fails. There was a recent test of a grapple system that harpoons a target sat, but it's early days in the development of such systems for arbitrary sats, rather than recovery missions designed for a particular target sat.
Woz seems to think so.
https://www.cnn.com/2022/03/01/tech/space-junk-steve-wozniak...
https://www.cnn.com/2022/03/01/tech/space-junk-steve-wozniak...
Given Woz's post-Apple track record, that's not a good sign..
Doing better than Jobs!
It would be most likely far more expensive than just adding few kg to your payload to allow for faster deorbit.
It would cost more than reserving some propellant.
I wonder if they could do a "debris offset credits" type thing, where you could extend the life of your satellite by clearing out existing debris. So if you wanted a 25-year orbit, you could clear out maybe 5-10x the cross-sectional area, or mass, or whatever the relevant number is.
The new rule is 5 years after mission completion, so this already allows for a 25-year orbit (as long as you're still operating).
Does this actually have any impact on Space? In other words, FCC can regulate what American companies have to do, but Papua New Guinea would come out and launch 50k satellites tomorrow, and it would be out of FCC control.
If that's the case, then space junk removal is just a financial obstacle that will make it more prohibitive to launch new sats, and cause the business to move to other counties.
If anyone knows the specifics of how this would work, could you enlighten? Thanks!
If that's the case, then space junk removal is just a financial obstacle that will make it more prohibitive to launch new sats, and cause the business to move to other counties.
If anyone knows the specifics of how this would work, could you enlighten? Thanks!
If you're interested in the US market you have to play by these rules. And almost everyone is.
If you're willing to forgo the US market you can jurisdiction shop... though I'd expect the Europeans won't be too far behind.
It's also not a really high bar. Most sats are in a regime where this happens naturally or already have propulsion. It's mostly going to bother SSO birds, and most of them are government owned anyway.
If you're willing to forgo the US market you can jurisdiction shop... though I'd expect the Europeans won't be too far behind.
It's also not a really high bar. Most sats are in a regime where this happens naturally or already have propulsion. It's mostly going to bother SSO birds, and most of them are government owned anyway.
Got ya. I guess I was thinking of a "Delta-V" (a book) type of scenario, where space exploration becomes conducted in space, and regulation from Earth get circumvented in order to achieve a much bigger outcome in the orbit and beyond.
I guess if indeed it's not a big deal though, then probably not an issue to worry about. Thank you for your answer!
I guess if indeed it's not a big deal though, then probably not an issue to worry about. Thank you for your answer!
I know how small the debris is relative to the earth. But the sheer number. Would that have any effect on the sun reaching earth and it’s heating / cooling?
No.
To have an effect you need to launch multiple orders of magnitude more mass than we have, and that mass would need to be optimized towards having as large as an effect as possible by being very very thin film positioned so that it is consistently between earth and the sun (or you could add on a few more orders of magnitude).
You can look at proposal for doing this intentionally to get a sense for the scale: https://en.wikipedia.org/wiki/Space_sunshade
To have an effect you need to launch multiple orders of magnitude more mass than we have, and that mass would need to be optimized towards having as large as an effect as possible by being very very thin film positioned so that it is consistently between earth and the sun (or you could add on a few more orders of magnitude).
You can look at proposal for doing this intentionally to get a sense for the scale: https://en.wikipedia.org/wiki/Space_sunshade
No, that's like trying to cool your house with a pinch of dust.
Bus = 0.0002 km²
Earth = 510.1 million km²
(Earth / Bus) / 100 = 25,000,000,000 bus sized satellites needed to cover 1% of the sky.
Bus = 0.0002 km²
Earth = 510.1 million km²
(Earth / Bus) / 100 = 25,000,000,000 bus sized satellites needed to cover 1% of the sky.
You're a bit off, you have to calculate the area considering the height of satellites.
[deleted]
Nope
One day we will need to pass laws against celebratory satellite launches on holidays and the urban microphone networks will be calibrated to detect heavy-lift launches by gangstas. New nations will enshrine the right to launch satellites in their constitutions. Elementary schools will go on lockdown when a student is discovered to have built a satellite and fuelled their boosters.
The previous "de-orbing 25 years after mission completion" sound a deliberately unenforceable rule.
I expect that's less about having to reserve fuel or have a specific plan for it, and more that to get approval, you have to be able to plausibly show a model where the device will deorbit on its own within 25 years of no maintenance burns.
It was enforced during licensing. In order to obtain a license from the FCC (which is effectively required to launch a satellite, unless you never want to communicate with it), you had to prove it would either deorbit naturally in < 25 years or that you had a system to do so at the end of the mission. The rule was generally to have a plan and an ability to deorbit after 25 years. A lot of satellites fail in ways that prevent using a propulsion system.
I'm not sure but I think has to do with parking the satellite in a lower orbit such that the atmospheric drag will force it to reenter within 25 years, not that the operator has 25 years to deorbit the satellite at some point.
I think this has to do with the amount of fuel the need to save to reach the disposal orbit.
I think this has to do with the amount of fuel the need to save to reach the disposal orbit.
I'd like to see a breakdown of deorbiting fuel requirements with 25 years vs 5 years vs, say, 30 days.
I'd expect the fuel required is generally the same, but this changes the altitude range for the question "do I need propulsion at all?" Satellites that would decay naturally in 6-10 years due to atmospheric drag would have satisfied the old rule. Now they need to install a propulsion system.
The actual impact is probably small - there aren't that many satellites launching to those altitudes, and most of them probably have a propulsion system anyway. But for a university satellite this could be a big obstacle.
The actual impact is probably small - there aren't that many satellites launching to those altitudes, and most of them probably have a propulsion system anyway. But for a university satellite this could be a big obstacle.
> Now they need to install a propulsion system.
Or just add more drag. Like deploying big sail.
Or just add more drag. Like deploying big sail.
Good improvement. What is China's rules for de-orbiting?
It wouldn't surprise me if they wound up just copying this, making it a de-facto international standard. Space junk is an international problem, nobody wins by it continuously becoming worse.
De-orbiting requirements add costs, but space junk damage and or avoidance systems are even more expensive, so this is the cheap solution in the medium to long term.
De-orbiting requirements add costs, but space junk damage and or avoidance systems are even more expensive, so this is the cheap solution in the medium to long term.
I would expect that they put their own rules in places that are different enough to be annoying if you need to permission from both countries, but for practical purposes the end result is the same. It may or may not be possible to satisfy the letter of both countries rules though.
One way to deorbit a satellite that doesn't require fuel is to deploy a simple sail, which could increase the drag on the satellite by 10x or more.
A system like that has already been used.
I figured someone would tell me it was a dumb idea. I'm glad to be wrong about that!
It seems there is an easy loophole.... Just declare the satellite mission to be super long.
Eg. This spacecraft will act as a Comms satellite for 10 years and will then go into a low power mode where it switches to 'gamma ray burst detection mode' which will be active for 150 years, upon which it will then deorbit within 5 years as regulated.
Eg. This spacecraft will act as a Comms satellite for 10 years and will then go into a low power mode where it switches to 'gamma ray burst detection mode' which will be active for 150 years, upon which it will then deorbit within 5 years as regulated.
Meh, can be blocked from starting at all due to:
1. Pretty easy to detect for most cases, especially as blunt in your (exaggerated, I know) example. Agencies should have a rough idea about realistic time frames for mission times in near earth orbits depending on what the satellite does.
2. They still need to have the propulsion unit integrated in the satellite, as otherwise they cannot guarantee the 5 years after mission time in higher orbits. They'll also need to prove that the propulsion unit used is very likely to actually work after mission time, e.g., your 160 year in radiation ridden space, which may be much more expensive than constructing one for the shorter, actual mission time.
1. Pretty easy to detect for most cases, especially as blunt in your (exaggerated, I know) example. Agencies should have a rough idea about realistic time frames for mission times in near earth orbits depending on what the satellite does.
2. They still need to have the propulsion unit integrated in the satellite, as otherwise they cannot guarantee the 5 years after mission time in higher orbits. They'll also need to prove that the propulsion unit used is very likely to actually work after mission time, e.g., your 160 year in radiation ridden space, which may be much more expensive than constructing one for the shorter, actual mission time.
When exactly did the FCC's jurisdiction extend to the heavens? There should be a lot more concern than there currently is over an agency granting itself powers over private property in space.
Search for terms like "satellite" and "space" in the Communications Act of 1934, as amended:
https://www.fcc.gov/Reports/1934new.pdf
https://www.fcc.gov/Reports/1934new.pdf
FCC approval is required to communicate with a (US-based) satellite in space, so effectively they can apply rules like this one. It's less of a power grab/nefarious plot and more a utilitarian kind of thing - the FCC has historically been the only agency that has authority to exert this pressure, so the work falls on them. It's admittedly odd that it's not the FAA or Space Force, but that's how it is.
If one were to launch satellites over the United States that communicate with transponders set up in Mexico, the Caribbean, Greenland, and Canada, would that be outside scope of the FCC's jurisdiction?
In general those countries have their own rules that while different amount to the same with different details. The smaller countries generally copy what the US does (or possibly what the EU does).
While you might be able to find a country to let you pick your own rules, you will only be able to talk to your satellite which means you can't do much with it. Most satellite are used for communicating to people on the ground and if you can't communicate to the US the satellite is much less valuable.
While you might be able to find a country to let you pick your own rules, you will only be able to talk to your satellite which means you can't do much with it. Most satellite are used for communicating to people on the ground and if you can't communicate to the US the satellite is much less valuable.
They're friends with other people with guns and rockets.
Well, various government agencies have jurisdiction over, say, private cars that drive on public roads, so why couldn't you apply similar logic to the FCC with regards to satellite regulation?
No country has any recognized territorial claims to space. Roads are built within and between territories. I don't know of a road built on unclaimed territory that grants a far away government jurisdiction over every car traveling through the said territory, even if these cars used other paths or went off-trail.
The FCC’s jurisdiction only applies to satellites communicating with US based ground stations.
The FCC derives its powers from the Communications Act of 1934 (before Sputnik) and a few Supreme Court cases, none of which have to do with satellite communication. That the FCC has jurisdiction over terrestrial radio spectra does not give it the right to create additional requirements for communication with orbital satellites even if there are US-based ground stations involved.
> The FCC derives its powers from the Communications Act of 1934 (before Sputnik)
...which has many post-Sputnik amebdments, but specifically the FCC role regarding policy for communication satellites comes from the Communication Satellites Act of 1962.
...which has many post-Sputnik amebdments, but specifically the FCC role regarding policy for communication satellites comes from the Communication Satellites Act of 1962.
Right. The text of the report literally states that the guideline isn't legally binding. They condition their approval of radio operations (Which they do have power over) on planned compliance with the guideline.
https://docs.fcc.gov/public/attachments/FCC-22-74A1.pdf
https://docs.fcc.gov/public/attachments/FCC-22-74A1.pdf
For most satellites below ~450km, this is really a non-issue. Atmospheric drag will generally be sufficient to deorbit the satellite in a few years. For big Earth-observing constellations, Starlink and friends, and many small missions, this doesn't change anything. Debris don't really accumulate dangerously in this zone and collision avoidance is a well-studied problem with a lot of people doing great work. The 18th SDS with the US Space Force, LeoLabs, Starlink/SpaceX, and a lot of other constellation operators take this very seriously and do a good job.
For satellites in the 800km+ range, this is also not a meaningful change. The 25-year rule meant that these satellites needed a deorbit plan anyway. 800km is a rough estimate, in real life it depends on the satellite mass + geometry and the solar cycle.
For satellites in the 450-800km range (again - hand waving here) this is actually a big deal. Satellites that would decay naturally between 5 and 25 years now need an active deorbit plan or need to launch lower and keep themselves up with propellant. Small satellite propulsion is becoming cheaper and more available, so this isn't that onerous for commercial operators. But I do worry a little about educational and non-profit launchers of satellites. They'd be excluded from using launches to this orbital range unless the FCC allows waivers (which I'm hopeful they will).
Overall I don't think this has a particularly big impact. It's a sensible revision of an old rule that was a little too lax. But there aren't that many satellites launching at the high end of the 450-800km range without propulsion. The 1000km-2000km area is a more important area for debris mitigation and that was really already covered.
As for the FCC having this jurisdiction vs. the FAA or the USSF, as Spock would say - "it is not logical, but it is true."