jccooper

103 ms·

1021.
by jccooper 13y ago
Grasshopper is a test vehicle with the aim of making the first stage of the Falcon 9 reusable. Grasshopper, for example, has one motor, while an F9 first stage will have nine. (Thus the name.) The landing gear is also obviously not streamli
1022.
by jccooper 13y ago
No sane new organization offers pensions. Joint contribution individual accounts (like the 401k) are much more reasonable. Any old org with pensions and half a clue should be scrambling to get out from under them.
1023.
by jccooper 13y ago
Ballistic launch to orbit is... problematic. Getting something going fast enough is tough (G loads, aero loads, material in the launcher, etc) but doable. A really really big light gas gun should do, if the "Slingatron" won't
1024.
by jccooper 13y ago
"The study focused exclusively on male CEOs rather than female CEOs: men account for over 90 percent of the CEOs in the authors’ study and an even larger proportion of the CEOs of large companies around the world,..." Fair enough;
1025.
by jccooper 13y ago
From that video, if it was the batteries, someone moved them, and then set them on fire. The batteries are nowhere near there. They're low on the plane, one set near the wings and one forward. That's maybe the APU, though more for
1026.
by jccooper 13y ago
Why would you size for multiple incidents? One is rare enough, but you have to deal with it. Two guarantees a whole set of people and equipment that will never have a use. Anyway, I suspect the real reason is that an emergency is a dynamic
1027.
by jccooper 13y ago
I think the important thing is what's missing: "software". Apparently, Microsoft, the world's biggest software company, is no longer interested in software. I wouldn't call this a great idea, considering "core
1028.
by jccooper 13y ago
Oh, and I should also point out that Armadillo Aerospace originally considered rocket-only recovery. I don't know if they posted any numbers on the necessary fuel reserves; I did look briefly but didn't see anything, and don'
1029.
by jccooper 13y ago
No one quite knows, as no such system exists yet, though I imagine SpaceX has some internal numbers. You need enough to slow your mostly-empty (and thus fairly light) stage from its terminal velocity to 0, and however many seconds margin yo
1030.
by jccooper 13y ago
Are so many bugs really caused by type problems? I run into type based errors in Python almost never. It is not hard to keep track of dynamic types, and takes the same effort (or less) than static typed programming. In both cases, you have
1031.
by jccooper 13y ago
Yeah, just think of all the lawyers out of work. It's hard enough out there for the poor JDs already!
1032.
by jccooper 14y ago
...perhaps intentionally. Which would be a responsible thing to do.
1033.
by jccooper 14y ago
More realistic numbers (and w/o exemptions and "time saved") and I get $974/mo. for the 60 kWh model. Which is, well, an expensive car; around a BMW 7-series lease cost. But BMW sells plenty of those, and so can Tesla. But telling me it's a
1034.
by jccooper 14y ago
For some other vehicles (Volt) I've heard the leasing company gets the credit if you lease; probably ought to be the same for Tesla. Dunno why they wouldn't be able to pass that along. The residual value guarantee is pretty good though.
1035.
by jccooper 14y ago
SpaceX tried parachute recovery of first stages with earlier launches. Apparently it trashed the stage pretty good every time, so that they consider it a failed technique. (They've never released photos of a recovered part, so far as I know
1036.
by jccooper 14y ago
Details are scant, but I don't think they're talking of a station at L2. Looks more like a plan to stick an Orion there for a little while. It links to http://www.space.com/14518-nasa-moon-deep-space-station-astr... which mentions an Orio
1037.
by jccooper 14y ago
They don't claim all their customers forever will get the privilege. Just customers of this car. For as long as they're making the offer. And that's really not that many people. They're trying to do, what, 3000 a quarter? That's many fewer,
1038.
by jccooper 14y ago
It can't come back down for several reasons. Besides there being no way to bring it down, it's already been released, and is basically on the other side of the planet now. Compare track of ISS vs OrbComm OG2: http://www.n2yo.com/satellite/
1039.
by jccooper 14y ago
Orbital rendezvous with the ISS has a very tight window (2.5-10 minutes), since on-orbit propellant is very limited. They could add more, and make the window a bit bigger, but that subtracts directly from cargo, which is already small: ju
1040.
by jccooper 14y ago
They probably refer to breakaway panel fairings above the engine isolation armor. Space X has an armor "cup"around the dangerous parts of the engine, and put fittings on top of that for some reason; aero probably. Their statement suggests t
1041.
by jccooper 14y ago
Some do, most don't. Saturn V could (and did several times) survive failure of a first-stage motor. STS (Shuttle) theoretically could survive an engine loss under some conditions. The Soviet N1 could well have survived a motor loss (it had
1042.
by jccooper 14y ago
If it costs you more to not use something than to use something, well, what do you think is going to happen? Sounds like a poor incentive structure to me, one which was almost certainly not put into place by the customer.
1043.
by jccooper 15y ago
I do it myself; getting comfortable with graphics isn't a bad thing. You need to try to retain a critical eye, though. It's easy to fall in love with a bad design if its your own.
1044.
by jccooper 15y ago
Seems pretty quick to me. I checked a few times, and the median was about 200ms, though I did see the occasional 2s.