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Comment by stuff4ben | Hacker News Reader

I thought the same thing. One of the Youtube commentswas pretty insightful in that it mentioned that when you do a parachute landing into the ocean, it's landing in salt water. Therefore the craft has to be taken apart inspected, cleaned, and put back together. So I'm assuming they've done the cost benefits and figured it's cheaper this way.

I wonder if a combination parachute/thruster landing would be more feasible though? Sort of like the Mars Science Lab without the sky-crane.

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Perhaps on Mars, unlikely on Earth. With our dense atmosphere a vehicle like a mostly empty Falcon 9 first stage is going to have a fairly low terminal velocity, in the low hundreds of km/s range. Slowing down from that speed to a controlled hover/landing is pretty easy. The cost/benefit on Mars might be different though, since the atmosphere is thinner.

> in the low hundreds of km/s range

I think you might mean m/s? low hundreds of km/s is very supersonic. ;)

What am I, a physicist? Jeez, boffing a few orders of magnitude like that is pretty bad, and it's too late to edit.

I meant kph, which was HOPEFULLY obvious from context.

I'll just leave this here: http://www.smbc-comics.com/?id=2679

Not to mention the operational costs of a small navy to recover the rocket and transport it to a launch site.

I believe the "small navy" was a political and technological requirement and not something you'd need today. A single ship ought to do now.

Political, because it was the Space Race, and a lot of it was about shows of force. And hey, why not? You have a bunch of carrier battle groups just waiting around for a hot war, and you need to have them out training anyway, so why not use them to pick up spacecraft from time to time?

Technological, because guidance wasn't necessarily very accurate. It's interesting to look at the miss distances here:

http://en.wikipedia.org/wiki/Splashdown_(spacecraft_landing)...

Some of these landed hundreds of miles from their target. However, by the time Apollo came around, they were all very close. You definitely want a big recovery fleet to cover a lot of area when you can't be sure it'll land on target, but that's not so much of an issue these days.

I remember reading about the issue in a book called "This New Ocean" apparently by the time Apollo was on the go NASA had to ask the military to position the ships off to the side of the splashdown zone - the guidance improved so dramatically they were afraid of hitting the carrier directly

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