Would the FCC have jurisdiction over satellites or junk without radio comms?
FCC Approves 5 Year Satellite Deorbiting Rule
101–110 of 119 posts
Re: FCC Approves 5 Year Satellite Deorbiting Rule
#102Earlier quoted context omitted.
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.
Re: FCC Approves 5 Year Satellite Deorbiting Rule
#103It 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.
Re: FCC Approves 5 Year Satellite Deorbiting Rule
#104Earlier quoted context omitted.
> 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…
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.
Wow, what a beautiful video. I really enjoyed trying to figure out what events and phenomena the different shapes/patterns in the diagram represent.
Re: FCC Approves 5 Year Satellite Deorbiting Rule
#105Earlier quoted context omitted.
The article says "5 years after completing their mission", not 5 years after launch.
time to assign 25 year missions to satellites built to last 10 years!
Every mission has to pass FCC approval, and we're just discussing a super high level gloss of the rules. Thee's no way that would pass, so that's really not an issue.
Re: FCC Approves 5 Year Satellite Deorbiting Rule
#106> 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 req…
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?
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.
Re: FCC Approves 5 Year Satellite Deorbiting Rule
#107Would the FCC have jurisdiction over satellites or junk without radio comms?
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Re: FCC Approves 5 Year Satellite Deorbiting Rule
#108One 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.
Re: FCC Approves 5 Year Satellite Deorbiting Rule
#109It's a bit weird the FCC is ruling on this... not really a space agency... but regardless, it's a good move!
They have jurisdiction over any device providing telecoms service to US territory, which happens to include satellites.
Re: FCC Approves 5 Year Satellite Deorbiting Rule
#110Earlier quoted context omitted.
The risk grows quadratically in decay time, not exponentially. 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…
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.