Amazon Seeks Permission to Launch 3k Internet Satellites • Hacker News Board

Re: Amazon Seeks Permission to Launch 3k Internet Satellites

#201

Post by choonway » Sat, Jul 06, 2019, 7:22 AM UTC

Robotbeat wrote: post #132

Scaevolus wrote: post #61

Earlier quoted context omitted.

A single impact can't put something into a higher circular orbit-- it can create an elliptical orbit with a higher apogee (max distance), but the correspondingly nearer perigee (closest approach) means that it experiences more atmospheric drag and falls out of orbit faster.

I thought so too, but apparently this is not universally true. Some of the debris can be put in an orbit with a longer lifetime than the original satellite. I got into a long twitter argument with experts in this field, and I was proven false: some of the debris can have longer orbital lifetime and go to higher orbit. EDIT: Here: https://twitter.com/SpaceJosh/status/1119721780254371840 Always embarrassing to make a f…

Galilean cannon?

Re: Amazon Seeks Permission to Launch 3k Internet Satellites

#202

Post by coolspot » Sat, Jul 06, 2019, 7:22 AM UTC

regnerba wrote: post #33

djsumdog wrote: post #21

Earlier quoted context omitted.

I've heard that at least with the SpaceX satellites, they have full plans for decommissioning with these satellites re-entering the atmosphere. I do agree that this is a real concern though, and we'd hope there's pretty careful consideration, considering the sheer number of satellites being launched. Still, space is big .. really big, even the space just above our planet. I don't put it past humanity to not fuck up s…

Correct on the decommissioning plans. SpaceX lists out in their FCC filings a number of things including how long it will take them to actively de-orbit satellites, how long for them to de-orbit if they lose contact/control, and also how much of the material will survive re-entry. I have read conflicting things so don't hold me to this, but on article I read said they delayed adding the laser links to the current bat…

What I heard they launched them ASAP because otherwise they would lose spectrum license.

Re: Amazon Seeks Permission to Launch 3k Internet Satellites

#203

Post by AYBABTME » Sat, Jul 06, 2019, 7:26 AM UTC

strikelaserclaw wrote: post #9

Anyone wanna offer me their hypothesis on what Amazon and other tech companies gain from offering internet to people who probably aren't valuable consumers?

Lower latency internet backbone for cross continental links. Latency around the world via satellite is less than via optical fiber, since speed of light in fiber is much less than in a vacuum. For AWS, it's a huge selling point for many customers if they can offer lower global latencies than anyone else! Think of all the algorithmic traders, the canonical example.

Re: Amazon Seeks Permission to Launch 3k Internet Satellites

#204

Post by visarga » Sat, Jul 06, 2019, 7:32 AM UTC

shaklee3 wrote: post #190

regnerba wrote: post #28

Earlier quoted context omitted.

The video in the article you linked is not a good example of the long term impacts. The satellites were at a lower orbit than their final orbit and not oriented the same way they will be once in their operational orbit. Once they reach their final orbit, which most of them have now, they will be far more spread out, higher, and all around much harder to identify. That and SpaceX is actively working with astronomy gro…

There were plenty of studies done by astronomers that showed the effect of the satellites can be detrimental to astrology. No, we shouldn't just build them; that's a red herring. There are plenty of other competitors that have comparable bandwidth and don't light up the sky. Of course, the musk effect makes people ignore those.

Yep, I wouldn't like my daily horoscope be wrong because of these satellites.

Re: Amazon Seeks Permission to Launch 3k Internet Satellites

#205

Post by _8j50 » Sat, Jul 06, 2019, 7:40 AM UTC

mruts wrote: post #176

_8j50 wrote: post #24

Maybe it's time to talk about tech-free preserves established by international treaties. E.g.: sections of each continent and ocean can be declared tech free where modern technology is forbidden on earth,sea or land. This is so we don't lose and forget the nature that forged the present.

Maybe we should each decide what we want to forget or not forget.

How so? It isn't for individuals but for future generations. Ever heard of UNHCR?

Re: Amazon Seeks Permission to Launch 3k Internet Satellites

#206

Post by djaychela » Sat, Jul 06, 2019, 7:41 AM UTC

gexla wrote: post #200

nordsieck wrote: post #144

Earlier quoted context omitted.

> I've heard that at least with the SpaceX satellites, they have full plans for decommissioning with these satellites re-entering the atmosphere. It's not just that they have plans to do so, they're low enough that they'll de-orbit fairly quickly on their own without active control (boost from their ion engines). Something pretty strange would have to happen for them not to eventually burn up.

Isn't the Kessler effect partly about creating further junk from a cascade of collisions? Even if the "junk" were to re-enter the atmosphere eventually, how long would that take? How long would access to space be cut off before the junk were to clear?

I'm not an expert (and expect to be corrected on details here), but I think it depends on the orbit altitude - if it's low enough to suffer significant atmospheric drag, then it'll de-orbit fairly quickly. But if they're at high altitude (geostationary and geosynchronous orbits spring to mind - around 22000-26000 miles), then that's much less likely, although there's a much bigger area to cover at that altitude. But given the damage that even a tiny particle can cause at those velocities, I think it's a real concern with such mass launches.

Re: Amazon Seeks Permission to Launch 3k Internet Satellites

#207

Post by blurbleblurble » Sat, Jul 06, 2019, 8:05 AM UTC

jimmaswell wrote: post #180

mratzloff wrote: post #140

Earlier quoted context omitted.

The bigger issue is all these satellites outnumbering the total number stars visible from Earth. It has astronomers worried. https://www.nytimes.com/2019/06/01/science/starlink-spacex-a...

Astronomy is fine and all but I think this is more important.

I can't tell if you're being sarcastic or not.

Re: Amazon Seeks Permission to Launch 3k Internet Satellites

#208

Post by ehsankia » Sat, Jul 06, 2019, 8:09 AM UTC

shaklee3 wrote: post #189

ehsankia wrote: post #104

Earlier quoted context omitted.

For latency at LEO, we're looking at below 50ms, going as low as 20ms. For bandwidth, it obviously depends on load and usage. SpaceX's satellites each can handle 1 Tbps, so it comes down to how they distribute and price it. At 100Mbps and 3000 satellites, that's roughly 10 million users. Obviously not all users will be using that much data simultaneously.

SpaceX satellites cannot do 1Tbps, and it's irresponsible to keep saying this. See the MIT study. They estimate ~20Tbps of total capacity for 4000 satellites.

Can you attach said MIT study?

Re: Amazon Seeks Permission to Launch 3k Internet Satellites

#209

Post by chillydawg » Sat, Jul 06, 2019, 8:34 AM UTC

jimmaswell wrote: post #180

mratzloff wrote: post #140

Earlier quoted context omitted.

The bigger issue is all these satellites outnumbering the total number stars visible from Earth. It has astronomers worried. https://www.nytimes.com/2019/06/01/science/starlink-spacex-a...

Astronomy is fine and all but I think this is more important.

Without astronomy, this whole enterprise couldn't have happened.

Re: Amazon Seeks Permission to Launch 3k Internet Satellites

#210

Post by usaphp » Sat, Jul 06, 2019, 8:41 AM UTC

throw0101a wrote: post #10

At what point should we start worrying about Kessler Syndrome? > The Kessler syndrome (also called the Kessler effect,[1][2] collisional cascading or ablation cascade), proposed by the NASA scientist Donald J. Kessler in 1978, is a scenario in which the density of objects in low Earth orbit (LEO) is high enough that collisions between objects could cause a cascade in which each collision generates space debris that i…

Think about it in terms of cars. Imagine spread out 3k cars around the surface of the earth. Each car will be thousands of Km away from each other. For example New York has 5 million registered cars. And they manage to use only a fraction of available land dedicated to roads. So I don’t think 3k is anything for a orbit around earth, which is also much bigger than the surface of the earth itself

Edit: I am not saying a collision would not cause the effect that OP referred to. I am saying that 3K satellites in Earth's orbit will be very far apart, so the odds of them colliding in the first place is incredibly low.