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Are satellites the size of books required to have a method of self de-orbiting? Or are they in orbits that have limited lifespans?



Usually, a satellite that launches from a country has to abide by that country's regulations.

As a requirement for getting regulatory approval to launch your satellite, I think you have to submit a debris management plan, which can include raising a geostationary satellite to a graveyard orbit after EOL (GEO is really far from earth, it would take a lot of fuel to de-orbit them), or lower a low-earth orbit to an altitude at which it would decay in a few weeks or years.

Generally, I think these small satellites are quite cheap both to launch and manufacture, do not have a great lifespan, and certainly not have lots of fuel. So they are most likely intended for LEO, and a low one with that, where atmospheric drag is small, but could bring a satellite down in a few (~5-7) years. Hopefully smaller than the rate at which the operator renews them.

Picking LEO has many benefits: lower latency, higher bandwidth, smaller antennas, higher resolution for pictures, with a few drawbacks: more earth shadow, faster ground velocity, smaller coverage for earth sensors.


I wonder what regulations would need to be followed if spacex did their launches from a modified oil rig in international waters?


American regulations. Because of ITAR, SpaceX cannot legally export any of their development or manufacturing. This means they are, and will always be, subject to all the other American regulation too.

And there is precedent that even if an American company launches their satellite from somewhere that is not the USA, they still have to follow all the American regulation. See FCC and Swarm Technologies over the SpaceBee 1-4 launch.


Probably the regulations of the country the oil rig is registered in.


The orbits have a 5 year life span and the satellites can deorbit. The satellites actually use propulsion to stay in their orbit!

https://en.m.wikipedia.org/wiki/Starlink


This[1] suggests an orbit of 500-600km can a lifetime anywhere from 10-100 years. That's not short.

[1] https://www.spaceacademy.net.au/watch/debris/orblife.htm

The 5-year lifespan is for them to be intentionally deorbited. If they die, they become debris subject to atmospheric drag and other forces.


Thats a great link

I think it's inportant to note that a traditional 3 ton sattelite and a cubesat will have totally different lifetimes, and that articles appears to assume a larger satellite


Yea, I saw that. It seems the key thing is the ratio of surface area to mass. It seems reasonable for a smaller satellite to have higher surface area to mass, and thus deorbit faster, but I don't have a handy link to that data.


The Planetary Society Lightsail 1 mission was a 3U cubesat and went down really quickly from LEO once it unfurled its solar sail - IIRC it basically multiplied its cross-section 300 times.


Interesting. Spacex says it's 5 years for the 550km orbit without propulsion. Maybe the orbit isn't perfectly circular or something else changes the maths.

wiki citation - https://spacenews.com/starlink-failures-highlight-space-sust...


So like little space drones? But way more subtle I guess. Like a mini blowtorch prodding this little thing along, and in the background, a giant view of Earth, below.

And some clouds. Children love clouds.




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