[Rooster61]

> There is just far too much space for 100k objects, let alone 10k to ever run the risk of collission.

No, there isn't. Satellites can and do collide despite the vast amount of space in a given orbit. It is improbable, but likely enough to warrant at least some concern.

> Why don't you hold that same fear for existing satelittes which typically operate at an orbit with far lower decay rate?

I do, as does the FCC. This is evident in the fact that they now require any body wishing to launch a spacecraft guarantee that the craft can be put into a graveyard orbit.

> Your comments just echo the same type of delusions of people who think in their brillance they've found problems others have not foreseen. SpaceX is really just full of amateurs you ought to submit your findings.

I'm genuinely sorry this post made you feel this way. If I already had the brilliance to answer this question as I'm sure many bright minds at SpaceX do, I would not have asked the question and rebutted the responses to begin with.

[ubercore]

> Satellites can and do collide despite the vast amount of space in a given orbit.

Excluding planned collisions, or collisions during failed docking, I found 4 instances of collisions between satellites and space debris. Ever. Now, a couple of things:

* Yes this larger constellation will increase those odds in the future.

* No, a catastrophic doomsday scenario did not occur when those happened.

* SpaceX will have complete control of these satellites through their operational lifespan (excluding collisions or malfunctions).

* Orbital decay for debris at the altitude they're operating at is ~10 years.

Also, have to ask... is all this concern a result of reading Seveneves? :)

[Rooster61]

I'm afraid I haven't heard of Seveneves before today, although it does look like an interesting read.

My concern is just from a general interest in spaceflight. More of a wish to protect a resource rather than a Chicken Little fear of the sky literally falling out.

[PeterisP]

Satellites don't just cross their paths by magic. If their orbits don't intersect, they can't collide. Satellites don't collide with each other, it has never happened.

Satellites do collide with debris, but that's a different issue. Furthermore, they don't need a guarantee that they can be put into a graveyard orbit - the proposed satellites (and even any debris, if they'd explode for whatever reason) will be in a graveyard orbit from day one until they stop being pushed up and deorbit.

[Rooster61]

> Satellites don't collide with each other, it has never happened.

Actually, they do, and it has indeed happened before (https://en.wikipedia.org/wiki/2009_satellite_collision). Far from a Kessler syndrome scenario, but certainly something that should be examined.