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SpaceX just got FCC approval to launch 7,518 satellites

fastcompany.com

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Re: SpaceX just got FCC approval to launch 7,518 satellites

#91

Post by Rooster61 »

ubercore wrote: post #87
Rooster61 wrote: post #77

Earlier quoted context omitted.

Thank you for the article, but it really doesn't answer my question. That thread's answers assume that we are talking about the current situation we have around the Earth. We have no precedent for this many satellites orbiting at the same altitude, but at different latitudes/longitudes (which negates the safeguard that they are moving at the same speed, it doesn't matter if they can intersect). The satellites would a…

First, check out the video explaining the orbits: https://www.youtube.com/watch?feature=youtu.be&v=AdKNCBrkZQ4... Doing some quick math, the shell in which they'll be orbiting has a surface area of 373,367,808km. With ~7000 satellites, an even distribution would leave them 533,382 km between satellites. All the satellites have station keeping thrusters to keep them in LEO with drag. Keeping them from running into eac…

Sure, but this assumes nothing ever collides with one and causes debris to be introduced to the web. The web itself will clearly be ok as long as it remains intact, but if something does cause one of these to RUD catastrophically, we now have debris following a similar, but just different enough orbit to be dangerous.

Re: SpaceX just got FCC approval to launch 7,518 satellites

#92

Post by dv_dt »

zaroth wrote: post #11

Too bad the public markets have given Elon such a lashing with Tesla, because I would love to buy into SpaceX. But then, I’m not the only one; “There is an unlimited amount of funding that the company could probably access globally in private markets," Hilmer said, adding that he has personally met many of "a diverse group" interested in SpaceX. Everywhere I travel around the world, investors of all types — individua…

I read that as there is a lot of money that wants to piggyback on the success of SpaceX instead of fundamentally developing anything via their own investments.

Re: SpaceX just got FCC approval to launch 7,518 satellites

#93

Post by soared »

Rooster61 wrote: post #79
zackbloom wrote: post #75

Earlier quoted context omitted.

Think how big the Earth is. How hard it would be to find a Xerox machine in the Amazon or the middle of the Atlantic if someone stuck it there. Space is much, much, bigger.

I'm no stranger to the vast physical space at play here (amateur astronomer, here). I'm aware there is a LOT of room for this stuff to move around, but there is still a threshold, however high, to where the amount of debris would become dangerously numerous.

And you think that we can only fit <10k objects in an area larger than the surface of the earth?

Re: SpaceX just got FCC approval to launch 7,518 satellites

#94

Post by bargl »

reaperducer wrote: post #40
bargl wrote: post #33

This is such a cool problem. We already have a ton of Geo sat which can do this kind of communication but they are super expensive and have a limited bandwidth. These satellites will actually have a ton of limitations in how much data they can send around and how they'll have to balance out their signals. Geo are easier to point to because, well they don't move. But these are going to be moving and changing all the t…

Or you are over the equator in a band that is used strictly for GEO. It's my understanding that this constellation is going to be significantly lower than GEO, so that's not a problem. Also, the dead zones are toward the poles, but those are mitigated in phase two.

There is another constellation system (I forget the name) and they're going to have a partnership with GEO to beam signals for customers as the satellites pass over the equator.

Re: SpaceX just got FCC approval to launch 7,518 satellites

#95

Post by tsuraan »

dr_orpheus wrote: post #81
biaachmonkie wrote: post #69

Earlier quoted context omitted.

Well since it's in LEO and since the sats will have been destroyed or damaged they won't be able to maintain their orbits, so the debris orbit will be decaying from the moment of the incident and should re-enter in a matter of a few months. The scenario I'm sure will be simulated by numerous people/orgs by the time this project is in full swing.

This is not true of the orbit that the SpaceX satellites are going in to. LEO is a bit of a general term that covers altitudes anywhere from 100 km to 2000 km. While it is true that something at 400 km altitude will deorbit in a few months, they will be orbiting at an altitude of 1100-1300 km. At that altitude it will take hundreds of years from them to deorbit. The drag goes down exponentially as you get in to highe…

I believe you're thinking about their initial application. They've updated it [0] to an altitude of 550km, so atmospheric drag should still de-orbit broken satellites fairly promptly.

[0] - " rel="nofollow">https://fcc.report/IBFS/SAT-MOD-20181108-00083>

Re: SpaceX just got FCC approval to launch 7,518 satellites

#96

Post by _ph_ »

dr_orpheus wrote: post #81
biaachmonkie wrote: post #69

Earlier quoted context omitted.

Well since it's in LEO and since the sats will have been destroyed or damaged they won't be able to maintain their orbits, so the debris orbit will be decaying from the moment of the incident and should re-enter in a matter of a few months. The scenario I'm sure will be simulated by numerous people/orgs by the time this project is in full swing.

This is not true of the orbit that the SpaceX satellites are going in to. LEO is a bit of a general term that covers altitudes anywhere from 100 km to 2000 km. While it is true that something at 400 km altitude will deorbit in a few months, they will be orbiting at an altitude of 1100-1300 km. At that altitude it will take hundreds of years from them to deorbit. The drag goes down exponentially as you get in to highe…

SpaceX recently updated their plans to put most satellites between 300 and 400km. That ensures a quick deorbit of the satellites and debris and cuts down the ping times.

Re: SpaceX just got FCC approval to launch 7,518 satellites

#97

Post by dr_orpheus »

tsuraan wrote: post #95
dr_orpheus wrote: post #81

Earlier quoted context omitted.

This is not true of the orbit that the SpaceX satellites are going in to. LEO is a bit of a general term that covers altitudes anywhere from 100 km to 2000 km. While it is true that something at 400 km altitude will deorbit in a few months, they will be orbiting at an altitude of 1100-1300 km. At that altitude it will take hundreds of years from them to deorbit. The drag goes down exponentially as you get in to highe…

I believe you're thinking about their initial application. They've updated it [0] to an altitude of 550km, so atmospheric drag should still de-orbit broken satellites fairly promptly. [0] - " rel="nofollow">https://fcc.report/IBFS/SAT-MOD-20181108-00083>

Thank you, I was thinking about their initial application. Yes, de-orbit times from 550 km are on the order of years to possibly tens of years. The requirement from the FCC is to deorbit your satellite within 25 years after the end of mission.

Edit: Their most recent application only moved the Phase 1 satellites in to the lower orbit. In later phases they are still planning on having more than 1000 satellites at the higher orbital altitude.

Re: SpaceX just got FCC approval to launch 7,518 satellites

#98

Post by Rooster61 »

_ph_ wrote: post #96
dr_orpheus wrote: post #81

Earlier quoted context omitted.

This is not true of the orbit that the SpaceX satellites are going in to. LEO is a bit of a general term that covers altitudes anywhere from 100 km to 2000 km. While it is true that something at 400 km altitude will deorbit in a few months, they will be orbiting at an altitude of 1100-1300 km. At that altitude it will take hundreds of years from them to deorbit. The drag goes down exponentially as you get in to highe…

SpaceX recently updated their plans to put most satellites between 300 and 400km. That ensures a quick deorbit of the satellites and debris and cuts down the ping times.

Interesting. That does make me feel a bit more secure about the whole thing, but it does raise the question of how much they will need to invest in orbital upkeep/replacement of decayed spacecraft. I can see this getting expensive quick.

Re: SpaceX just got FCC approval to launch 7,518 satellites

#99

Post by _ph_ »

CarVac wrote: post #5
zjaffee wrote: post #3

Does anyone have any context on what sort of internet speeds satellite internet has been benchmarked to provide. I can't imagine the latency being anywhere near good enough to do many of the high bandwidth things people use the internet for today.

You're conflating bandwidth and latency. Not much needs both high bandwidth and low latency. The latency has the potential to be better than the current internet backbone when going intercontinental due to straighter paths, but it'll be higher when going to your local AWS, probably. Bandwidth is anyone's guess.

Over long distances, their latency is going to be significant better, as light speed in fiber is over 30% less than through vacuum.

Re: SpaceX just got FCC approval to launch 7,518 satellites

#100

Post by hwillis »

soared wrote: post #93
Rooster61 wrote: post #79

Earlier quoted context omitted.

I'm no stranger to the vast physical space at play here (amateur astronomer, here). I'm aware there is a LOT of room for this stuff to move around, but there is still a threshold, however high, to where the amount of debris would become dangerously numerous.

And you think that we can only fit <10k objects in an area larger than the surface of the earth?

At any one time there are usually <10k airplanes in the sky,and they still hit each other sometimes despite going 23x slower than satellites
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