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Comment Re:Why do these reaction wheels keep failing? (Score 1) 28

All you're saying is true, but I think we've had enough problems with space-based moving parts (the assorted reaction wheels, Voyager 1 and 2 scan platforms etc.) compared to non-moving parts that finding a reasonable solution to this problem seems like something that everyone could benefit from. If a number of long-distance scientific missions have all the components working with the exception of moving parts, it would appear that moving parts with long lifetimes are the next major problem to solve. Voyagers had problems early on. That made the scientific output from Voyager 2 diminished even before it got to Uranus and Neptune. It's not just about extended missions in some cases.

Comment Re:Why do these reaction wheels keep failing? (Score 1) 28

For these missions, though, it's generally desirable for the vehicle to last as much as you can make it. Surely the average scientific return per day from Opportunity is much, much cheaper now that it's been operating for ten years than it would have been had it only worked for the originally planned ninety days.

Comment Re:Avesome (Score 1) 56

You can't conjure the "kinetic energy of a small nuke" out of thin air - the launch vehicle has to provide it. Even with this rocket, you won't get more than ~40 tons of TNT equivalent per launch. That's a tiny nuke. And that's before accounting for atmospheric losses. And forget ground blasts (or low altitude airbursts), not gonna happen with such small masses. Not to mention how awfully impractical such a weapon would be from an operational perspective (target choice, attack timing etc.)

Comment Re:Sour grapes anyone? (Score 1) 56

You used the word 'ripoff'

I did, because it's an accurate description of Vikas. The US equivalent of Indians adopting Vikas would be the US flying to the Moon with the V-2 engine - which obviously didn't happen. The Indian equivalent of replicating the US post-war engine development would be Indians letting French guys immigrate and develop a much improved new engine on Indian salary - which didn't happen either. That's why I considered the topic digression to post-war US completely inconsequential. Their new CE-20 engine is fully domestic, though - although that's exactly the one that hasn't flown yet. Which is unfortunate, because it seems really nice, I'll give them that. If it's cheap enough, it could become a real workhorse for ISRO.

Comment Re:Sour grapes anyone? (Score 2) 56

Very much incomparable. There was a lot of knowledge transfer from the German engineers, but mostly in the theoretical area, whereas Vikas is a case of virtually identical flight hardware. That wasn't the case in the US beyond some initial experiments with V-2s; all the US hardware had to be developed from the first principles. For example, the German regenerative cooling on V-2 sucked, so it couldn't be used, and even after that problem was solved, nobody in the world - not even Germans - really knew how to build really large engines, so US engineering had to step into an unmapped territory with the F-1. And essentially identical knowledge to what was transferred back then after the war plus a lot of new knowledge is now pretty much textbook material (and has been for a few decades) that you can buy from Amazon - where do you think Elon Musk learned it?

And again, what has that to do with me explaining why the core stage uses toxic fuels? How are Americans or Germans related to the problem of how GLSV Mk III ended up using those fuels?

Comment Re:Sour grapes anyone? (Score 2) 56

http://en.wikipedia.org/wiki/Viking_(rocket)

What are you prattling about? I was clearly talking of the Viking engine . The similarly-named rocket has nothing to do with that.

So, US rockets are just a ripoff of Germans. And Germans just ripped off the Russians.

No, they're not. There's nothing in German rockets that was copied in either American or Russian designs, post-1950. Whereas the Indian engine in question is pretty much identical to Ariane's engine. Furthermore, the reason I've mentioned it is because it explains how hypergolics got into the core stage (not for military reasons). I'm sorry that your reading comprehension sucks so badly. I hope you'll get better.

Comment Re:Weird design (Score 1) 56

Normally that's a sign of military heritage - hypergolic fuels are common in ICBM designs because they're storable at room temperature, and guarantee that the missile will at least launch. Purely civilian designs rarely use such fuels, because they're dangerous as hell

Well, in this case, it's because of Ariane (1-4). The engine is a rip-off of Viking.

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