Kryten

20 tons to LEO is not a meaningful figure for commercial space. Proton/Briz and Ariane 5 both do about that much, but Ariane has twice the payload to GTO.

He's aiming to compete directly with fibre backbone on latency grounds.

The FCC application does not mention mobile usage afaict, the only mention of antenna is as wall or roof mounted. Elon has said that the intention for the network is internet backbone, with direct consumer use as a small proportion; and at the same event opined that trying to connect direct to phones was one of Teledesic's major mistakes. He's intending to compete with fibre backbone companies, not making a super-Iridium.

The idea was proposed by Teledesic over twenty years ago, and they won't have been the first. SpaceX have made actual FCC applications and are building test sats, they're not just sitting on ideas and patents.

It will be some kind of phase-array 'tracking' antennae without actual moving parts.

There's not likely to have been much commonality between CST-100 and Boeing CEV capsule except capsule shape and diameter; there was a four year gap betweeen CEV selection and CST-100 reveal, they didn't spend it sitting on their hands. Boeing CEV had a soyuz-style orbital module and giant methalox SM that would need to be developed, and it would need addition of thickened heatshield, BEO comms gear, et.c. et.c. None of this would be trivial.

Altair is not coming back. Far too expensive.

The dual launches on Proton are small comsats that physically connect together, equivalent to the launches SpaceX have done. PSLV has a DLA similar to Ariana's SYLDRA except smaller, and H-2A does dual launches through an odd stacked fairing system; Fairing on right stacks onto fairing at left.

The largest sats have only been launchable by Ariane 5 for a while now, (e.g. the ~ 7 metric ton Terrestar-1 in 2009), so that can't be it.

The GTO communications market is pretty crowded and close to saturation already, you can't just put up twice-as-large (and twice as expensive) sat and expect it to get twice as many subscribers. You have to size for the market, and the market right now isn't too healthy.

China's main deterrent is the heavy hypergolic DF-5, and they've recently been upgraded for MIRV capability so seen to be here to stay.

H2O2 turbopumps are used on the Soyuz rocket, the usage on the Soyuz spacecraft is in monoprop RCS on the return capsule.

A very interesting statement by the head of CASC; CASC is essentially most of China's aerospace industry and space programme, their subsidiaries make all long march series rockets and most Chinese satellites.

They're pretty common in Chinese designs. The latest CZ-2C and -2D variants have small fins at the first stage base, CZ-3C has two larger fins on the first stage, and CZ-3B and -2F have fins on the boosters.

This is going to be a schedule risk thing rather than a technical risk thing. Given that Dragon isn't available, and that HTV has been majorly delayed (Oct to Dec), they need to know that they can get at least this cargo up there on time.

It'd been assumed to have been scrubbed because they'd gone past the window in the airspace closure, they must've put out a last-minute extension.

Launch is scrubbed for today.

Looks like the launch has been pushed back another hour.

Launch has slipped an hour to about 11:00 UTC

Sounds like they put in 10pm UTC instead of 10am.

Launch is still on for the 3rd, time is now confirmed to be at about 10am UTC. While we wait, have a nice vid showing stacking and launch prep;

I can't think of any rocket using 'soft' cryogens like liquid oxygen that has external insulation, the boiloff during flight isn't worth the extra weight. Conversely, rockets using liquid hydrogen always have insulation, both because it boils off much more rapidly and because it creates much higher volumes of gas as it does. There have been cases of hydrolox stages rupturing after insulation issues, despite having pressure relief valves; the boil-off is so rapid it overwhelms the valve.

Plenty of rockets have staging like that, e.g. Titan 3C. Means your assembly building doesn't have to be as large/tall, and that the aerodynamics are easier.

http://www.independent.co.uk/news/science/shooting-for-the-moon-time-called-on-isle-of-man-space-race-10101750.html

Energiya is the only previous example.