Requiring de-orbiting at EOL would destroy their business no? Also EOL de-orbiting works great for low-altitude orbits, but becomes exponentially more difficult with higher orbits. It is pretty much impossible with the very valuable geostationary orbital slots.
I am by no means a rocket scientist, but wouldn't a de-orbiting requirement be as simple as including a few small chemical thrusters with a dedicated fuel source reserved for de-orbiting?
I have no idea how much force it takes to actually move a given amount of mass out of orbit, and I assume it is different depending on the height of that orbit. So maybe doing this would simply add too much weight in the form of fuel storage to be feasible. In my head though, orbits are fragile and it shouldn't take a lot to nudge something into a death spiral towards the atmosphere.
This works great for a small-subset of the space-debris problem: satellites in low-earth orbit that have reached their end-of-life. For example, Starlink satellites maintain a small reserve propellant for their maneuvering thrusters to be executed at EOL. This activity will likely be mandated by regulatory bodies in the coming years (and definitely should be). However performing this task becomes much more difficult to do as orbits get higher. The higher the orbit, the more fuel is required to perform a de-orbit, and the more fuel is required to lift THAT fuel into the orbit in the first place. Propellant requirements scale exponentially with increased mass. Beyond a certain orbital altitude, it becomes prohibitively expensive.
In addition, the bulk of the space-junk problem is not defunct satellites, but fragments from previous collisions, and stage-separations (screws, scraps, paint-chips, etc). Satellites (even defunct ones) are easily trackable, and have known trajectories. Random 10 cm pieces of metal are not.
While mandating EOL maneuvers for low-earth satellites is definitely a solution to part of the problem, it is not the full solution.
It takes a ton (possibly literally) of propellant to change your orbit from a circle in GEO to an ellipse that intercepts the atmosphere. If you don't have enough, you've not put it in a deorbiting spiral, simply an oval that will stay up for about as long as the original satellite's circular orbit.
Rocket scientists work in terms of 'delta V', meaning an amount of energy gives you a particular change in velocity. GEO to LEO takes on the order of 6 km/s (oversimplifying because orbital mechanics are complicated), meaning you need a rocket engine that's capable of accelerating your satellite from 0 to 13,400 miles per hour.
How valuable are geostationary slots these days? LEO swarms have eaten some of the GEO lunch. What are the niches where LEO swarms aren't a workable replacement?
Communications over a specific geographic region and budget for only one bird and/or only one launch.
That's pretty much most of the world's nations' telecommunication needs. SpaceX has put up at least half a dozen satellites for small nations meeting these very common requirements.
Ah, that makes sense: if sovereignty is a driving requirement you can't just piggyback on the big LEO swarm deployments, but a single geostationary satellite covers exactly the territory that you care about. Now I understand. Thanks.
I’m guessing they be planning on offering their services to carry out said de-orbit.
Lobbying for regulation mandating a service you provide is a pretty tried and tested business model. Every company IT audit I’ve ever had the pleasure of participating in works the same way.
The most efficient way to de-orbit the satellite is to design it with de-orbit capability built in. Satellites already have maneuvering thrusters with propellant and/or "kicker" stages to maneuver them in their destination orbit. De-orbiting capability is just some extra delta-v onboard, and a de-orbit maneuver coded into the flight computer.
"Space-tug" like services from a third-party would be vastly more expensive. The only use case would to de-orbit a satellite that for some reason failed to de-orbit itself.
> De-orbiting capability is just some extra delta-v onboard, and a de-orbit maneuver coded into the flight computer.
It's not "just" some delta-v, it's the same amount of delta-v as the original perigee kick. Most satellites get their perigee kick from a booster stage from their launch vehicle that separates from the satellite and de-orbits.
Every gram of mass of fuel and engine on a satellite is a gram less of payload.
Yes, and it is still vastly more efficient to bring that delta-v with you than to use an entire other vehicle to come up to you provided by a third-party to de-orbit for you. Which is the case I was comparing and contrasting with in response to the parent comment. Evidently this is the case knowing that de-orbiting capabilities are built-in to many low-earth orbit satellites, although it (and any de-orbiting method) is prohibitively expensive for higher orbits
If you require the company to perform a service, one that they may not want to perform or be very good at, it's possible they will subcontract the work.
