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Space X CR6 First stage landing

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Re: Space X CR6 First stage landing

#81
post #76
post #56

Elon says it's in slow motion too "High resolution, color corrected, slow motion rocket landing video https://youtu.be/BhMSzC1crr0" https://twitter.com/elonmusk/status/588463193070022656

If it's slow motion, I suggest changing the YouTube setting to 1.25x and watching it at that speed. It seems quite natural actually. Edit: Or maybe 1.5 or 2x! I don't know..

I can't figure it out either. It's really difficult to determine the speed because of the scale involved here.

Re: Space X CR6 First stage landing

#84
post #76
post #56

Elon says it's in slow motion too "High resolution, color corrected, slow motion rocket landing video https://youtu.be/BhMSzC1crr0" https://twitter.com/elonmusk/status/588463193070022656

If it's slow motion, I suggest changing the YouTube setting to 1.25x and watching it at that speed. It seems quite natural actually. Edit: Or maybe 1.5 or 2x! I don't know..

I replied to Elon's tweet asking for full-speed video.

Fingers crossed :)

Re: Space X CR6 First stage landing

#85
post #42

I almost think it would be easier to let it do what this video shows, and build a giant metal net to just prevent it from sinking. Or is that harder than landing on a small platform?

My thoughts too, but I guess any ingress of sea water makes it necessary to junk the engines. Also, once you've solved the 'landing problem' once, presumably the method can be reused on each and every subsequent landing; if you are looking at many such landings it becomes worth doing it 'once' and properly.

> if you are looking at many such landings it becomes worth doing it 'once' and properly.

Yup; the point is, SpaceX is not trying to just recover the first stage, they're trying to solve the vertical-landing of rockets for rapid reusability - which is vital not only for cost reduction, but for their plans to go to Mars. Because if they solve landing here, they can use the very same technique to land on Moon, Mars and other planets.

Re: Space X CR6 First stage landing

#86

This is an "unpublished video" on a non-SpaceX YouTube channel. Who uploaded this?

From reading the comments over on /r/spacex, this looks to originally have been an unlisted video in SpaceX's youtube channel, and shortly after appearing on reddit it was made private. Not before several people had made copies, however, and re-uploaded it (one of those people has the same reddit username as the youtube channel linked here). That said, impressive video. This shows how close they are truly getting. Un…

One great thing about being a government contractor: Public opinion isn't something you need to worry about.

Re: Space X CR6 First stage landing

#87
post #56

Elon says it's in slow motion too "High resolution, color corrected, slow motion rocket landing video https://youtu.be/BhMSzC1crr0" https://twitter.com/elonmusk/status/588463193070022656

How high did it get? Does it burn the whole way down (I assume it uses those little X-wings to 'fly down?) When does it start the descent burn? How fast is it going at this point? How much does it weigh, what sort of forces are we talking about? How hard is landing this puppy in terms of human achievement? Top 10% of tricky things humans have so far achieved? [edit] wouldn't it be easier to hover it a few meters abov…

It burns three times after the second stage detaches. The first is to get the landing zone closer to the takeoff, the second slows it down from 1300 m/s to about 250 m/s, the third slows it to (hopefully) 0 m/s on the landing pad. Here's a diagram: http://media2.s-nbcnews.com/i/newscms/2014_51/812491/141217-...

If the 'x-wings' are what I think you're referring to, they're the landing legs. They are shaped like that to have as minimal impact on the air resistance of the ascending rocket as is possible. They open just before landing.

It can't hover. Even just using a single one of the nine engines, the engine can't be throttled down enough for the rocket to hover. The landing method relies on what they call a 'hover-slam', where they fire the engine during landing to slow it down just before it touches.

Landing this is extremely impressive. It is going four times faster than the speed of sound, and they are landing it on a pad smaller than a football field. Vertical landing of a returning rocket has never been done. It's also the key step in the process of dramatically lowering the cost of spaceflight which could usher in a new era of technology around earth, and on other planets.

Re: Space X CR6 First stage landing

#88

Why did it explode in such a dramatic fashion? I thought the booster was almost entirely empty when it returns to the barge.

Yep, it's almost empty. It shows how much stored energy rockets deal with and how hard it is to get out of this gravity well we call home.

Re: Space X CR6 First stage landing

#90
post #56

Elon says it's in slow motion too "High resolution, color corrected, slow motion rocket landing video https://youtu.be/BhMSzC1crr0" https://twitter.com/elonmusk/status/588463193070022656

How high did it get? Does it burn the whole way down (I assume it uses those little X-wings to 'fly down?) When does it start the descent burn? How fast is it going at this point? How much does it weigh, what sort of forces are we talking about? How hard is landing this puppy in terms of human achievement? Top 10% of tricky things humans have so far achieved? [edit] wouldn't it be easier to hover it a few meters abov…

According to http://www.spaceflight101.com/falcon-9-v11.html, the first stage has an empty weight of about 20 metric tons.
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