It's interesting that you have a source giving 750km and one giving a different number of 1100km. It's worth noting that 1100km is actually around 750 miles. Perhaps the Businessweek article got the units mixed up?
“We did it with O3b and we’ll do it again with OneWeb,” Wyler said, stressing that the O3b business of delivering high-throughput to corporate and government users has few overlaps with the lower-speed OneWeb, whose market is centered on individual consumers and airlines.
Here is a comparison of the SpaceX/Musk and OneWeb/Wyler global internet satellite constellations. I'll update it as more information becomes available.FeatureOneWebSpaceXFinancingTotal funding$1.5B - $2B[1], $2B initial sat batch[5]$10B - $15B[2]Initial constellation funding??Initial funding fromVirgin & Qualcomm[4]SpaceX[2].
You can add "cost to launch entire constellation"For Wyler, it is 648 * $10M, or $6.5B For Musk, it is 4025 / <sats-per-launch> * <FH reusable cost>Since we don't know the numbers, using a WAG of 64 planes * 64 satellites, and each FH carrying one plane's worth (plus a dispenser, and maybe spares), so a total of 64 launches at <$80M, or $5.1B.Less if reusability works well.
So if I understand correctly there will only be communication with the ground and not between sats, I don't know how one can achieve across the globe latency of 20ms in such a case (like Musk said).
Quote from: MikeAtkinson on 01/18/2015 09:47 amHere is a comparison of the SpaceX/Musk and OneWeb/Wyler global internet satellite constellations. I'll update it as more information becomes available.FeatureOneWebSpaceXFinancingTotal funding$1.5B - $2B[1], $2B initial sat batch[5]$10B - $15B[2]Initial constellation funding??Initial funding fromVirgin & Qualcomm[4]SpaceX[2].This table fails to reflect the most important difference: The SpaceX operation will be part of a multi-billion dollar company, led by a multi-billionaire. OneWeb is a tiny company. The fact that they've gotten small investments (so small they're too embarrassed to say how big they are) from two larger companies doesn't make up the difference. Many small companies get investments from other companies, particularly companies that are trying to sell them something. It's not a coincidence that Virgin is a company desperate to sell small satellite launch service and Qualcomm is a telecommunications hardware company. Investments by vendors are generally little more than a way to pay a small deposit to get the foot in the door on the off chance that a little company is a success.The SpaceX operation has access to two orders of magnitude more funding.
Quote from: Oli on 01/19/2015 07:54 amSo if I understand correctly there will only be communication with the ground and not between sats, I don't know how one can achieve across the globe latency of 20ms in such a case (like Musk said). As far as I can tell from the statements both networks will have inter-satellite links at least in their eventual configurations. It is possible that initial (test) sats may not have those links or that they are not required to work to give a usable constellation.
I agree that investments in OneWeb are at present small, whether they are embarrassed about them or not is speculation, and I want to avoid speculation here as much as possible.
Let's say you want to communicate from Seattle to South Africa. If you look at the actual path it takes, that's extremely convoluted. It'll follow the outline of the continents. It'll go through 200 routers and repeaters and the latency is extremely bad. Whereas, if you did it with a satellite network, you could actually do it in two or three hops. Well, maybe four hops. It depends on the altitude of the satellites and what the capacity and things are. But basically, let's say, at least an order of magnitude fewer repeaters or routers and then going through space at 50% faster speed of light. So it seems from a physics standpoint inherently better to do the long distance Internet traffic through space - source
Quote from: MikeAtkinson on 01/19/2015 08:31 amQuote from: Oli on 01/19/2015 07:54 amSo if I understand correctly there will only be communication with the ground and not between sats, I don't know how one can achieve across the globe latency of 20ms in such a case (like Musk said). As far as I can tell from the statements both networks will have inter-satellite links at least in their eventual configurations. It is possible that initial (test) sats may not have those links or that they are not required to work to give a usable constellation.Thanks.As I see it the only advantage a MEO or LEO constellation has over GEO sats is the latency. GEO sats can service specific regions with high demand (unless LEO sats which fly over the ocean and uninhabited territory most of the time) and do not need adjustable ground antennas (unless they're on planes and ships).
I would also assume only 2, maybe 3 inclinations to launch into.
FH makes sense since it is cheaper per pound (cost, not price!) in the reusable mode, and since even one plane is heavy enough for it. Of course if they choose to, they can also launch to multiple inclinations, it is just extra dv.
I guess this is the successor thread to "SpaceX - now a satellite vendor?"
I don't think SpaceX has the ability to design a wireless data transmission standard, or implementation.
Quote from: Oli on 01/19/2015 07:54 amSo if I understand correctly there will only be communication with the ground and not between sats, I don't know how one can achieve across the globe latency of 20ms in such a case (like Musk said).I got the exact opposite impression. i.e., he saidQuote from: Elon MuskLet's say you want to communicate from Seattle to South Africa. If you look at the actual path it takes, that's extremely convoluted. It'll follow the outline of the continents. It'll go through 200 routers and repeaters and the latency is extremely bad. Whereas, if you did it with a satellite network, you could actually do it in two or three hops. Well, maybe four hops. It depends on the altitude of the satellites and what the capacity and things are. But basically, let's say, at least an order of magnitude fewer repeaters or routers and then going through space at 50% faster speed of light. So it seems from a physics standpoint inherently better to do the long distance Internet traffic through spaceSounds like space-to-space to me.
Let's say you want to communicate from Seattle to South Africa. If you look at the actual path it takes, that's extremely convoluted. It'll follow the outline of the continents. It'll go through 200 routers and repeaters and the latency is extremely bad. Whereas, if you did it with a satellite network, you could actually do it in two or three hops. Well, maybe four hops. It depends on the altitude of the satellites and what the capacity and things are. But basically, let's say, at least an order of magnitude fewer repeaters or routers and then going through space at 50% faster speed of light. So it seems from a physics standpoint inherently better to do the long distance Internet traffic through space
Quote from: meekGee on 01/19/2015 11:08 amFH makes sense since it is cheaper per pound (cost, not price!) in the reusable mode, and since even one plane is heavy enough for it. Of course if they choose to, they can also launch to multiple inclinations, it is just extra dv.I think that fairing volume will be the limiting factor, possibly 20-30 satellites per launch (which would be 6-9 tonnes for 300 kg satellites).FH payload to LEO when reusing all the 1st stage cores has not been published by SpaceX. The cost and price are unknown for such a large multi-launch order either for F9R for FHR, it is in my opinion unwise to assume that either one or other is cheaper for this application.It is also unwise in my opinion to assume that the satellite division will be charged less than external customers for launches. They could charge the same for many reasons, not least because the satellite division may be spun off into a separate company.