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Comment: Re:Figures (Score 1) 66

I agree that the Israelis would only use the bomb as a last resort - just don't see how they could do that and still keep their strip of land.

Well, if the US has all the ICBMs only for defense, why have them when they won't have their strip of land either after an attack regardless of whether they use them or not? Same logic.

Comment: Re:Common Knowledge (Score 1) 66

Read up a little basic physics and you will see that the top of the building fell faster than it would if it were free falling in a vacuum

Yes, the secret government conspiracy equipped the building with an alien gravity booster. Only then, it brainwashed a dozen or so of dedicated terrorists who already hated the USA (and wanted to attack it) to hate the USA (and attack it). :-p

Comment: Re:Not sure about the recovery test (Score 1) 75

If I got the numbers correct, "4% of the total fuel mass" of an F9 v1.1 is something like 18 tons. 18 tons also happens to be almost exactly the dry weight of the F9 v1.1 first stage. Combined with the fuel's Isp, that projects to something like 2 km/s delta V. That happens to be precisely the projected separation speed for the reusable first stage, so you'd have just enough fuel to decelerate from an undesirable velocity vector to zero. Let's say that the atmosphere has somehow helped you - saved a bit of fuel to leave you with a few seconds of burst for a soft landing. First, congratulations, you've managed to land, but not anywhere near the launch pad since you had no fuel left to cover the rather considerable downrange distance. Second, you're effectively claiming that those ~20 tons of fuel make a 1,4 km/s difference at separation speed (the separation speed for the non-reusable flight profile is somewhere around 3,4 km/s), even at the final mass of ~100 tons for the dry first stage plus fully fueled upper stage. That must be some wonder fuel they got there! I'm sorry, but that still doesn't add up for me. Still missing the real numbers.

Comment: Re:Not sure about the recovery test (Score 1) 75

The rocket (1st stage) when empty needs almost no fuel (about 4% of the total fuel at launch) to return to the launch site and land.

That seems unbelievable, given its hypersonic speed and considerable downrange distance at the point of first stage separation. Any real numbers on that?

Comment: Re:Not sure about the recovery test (Score 1) 75

Was it an actual soft landing, though? Water seems much more problematic than dry land to me for this feat since rockets tend to be brittle and moving around such masses at single-meters-per-second levels of speed in the vicinity of other heavy masses (like water) without having control over pressure points (like landing gear) and impact impulses (in the presence of changing terrain contours, like water has) is going to break something. Rockets aren't designed to handle random dynamic stresses like that, they're designed for minimum dry mass (and some sustained axial stress), sometimes at extreme costs (look up the thickness of Atlas fuel tanks, up to but not including Atlas III).

Comment: Re:Frist pots (Score 1) 229

by K. S. Kyosuke (#46793897) Attached to: I expect to retire ...
First, I don't see what it has to do with ethics, as opposed to basic principles of economy and productivity. Second, I'm pretty sure quite a lot of people around the world (atheists, Buddhists, Muslims etc.) who are simply working their asses off (that's an religiously neutral technical term) would be profoundly offended if some American A-hole were to smile at them and tell them "Ah, I see you too have Calvinist work ethic!" That would piss me off to no end if anyone did that to me.

Comment: Re:Pilots crash planes (Score 1) 55

by K. S. Kyosuke (#46793887) Attached to: DARPA Developing the Ultimate Auto-Pilot Software
When I was playing with the Microsoft Flight Simulator 3.0 back then, I came away with the impression that I'm a total screw-up at flying and I should probably never sit in a cockpit, but the one thing I've learned is that you don't pull the stick when you're not sure your airspeed and AoA allows for it.

Administration: An ingenious abstraction in politics, designed to receive the kicks and cuffs due to the premier or president. -- Ambrose Bierce

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