Updates SpaceX Falcon 9 F5 CRS SpX-2 through CRS SpX-12 Updates

RisingFury

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On the road, but here's a link to a video of the "landing" https://twitter.com/spacex/status/556131313905070081

That's actually pretty impressive. I'm guessing they run out of hydraulic fluid about 5 to 10 seconds before the landing.

The velocity is under control, but you can see the rocket is not rotating. No thrust vectoring is going on. They were over target, almost nulled velocity, but could not get the rocket upright.

They'll do it next time. The only thing I thing might go wrong is that the rocket might tip over after landing. But they'll get it.
 

ISProgram

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Interesting position of the grid fins though; they look broadside from the camera's perspective.
 

ISProgram

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They don't matter anymore.

Well yeah, of course! The entire reason the rocket failed to land was because the grid fins failed to do their job (because they ran out of hydraulic fluid), but I just found it interesting that they froze in that position.
 

RisingFury

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Well yeah, of course! The entire reason the rocket failed to land was because the grid fins failed to do their job (because they ran out of hydraulic fluid), but I just found it interesting that they froze in that position.

I don't think so.

The fins don't have any effect at that speed anymore. Having hydraulic fluid or not. I think thrust vectoring stopped working.
 

ISProgram

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I don't think so.

The fins don't have any effect at that speed anymore. Having hydraulic fluid or not. I think thrust vectoring stopped working.

...I know they weren't working down to landing speed, they only work in the high speed regime. Musk said that the reason the landing failed was because the fin failed - or at least that was what I interpreted.

But then again, if the fins failed that high up, the stage shouldn't have landed on the barge anyways.
 

Urwumpe

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...I know they weren't working down to landing speed, they only work in the high speed regime. Musk said that the reason the landing failed was because the fin failed - or at least that was what I interpreted.

But then again, if the fins failed that high up, the stage shouldn't have landed on the barge anyways.

It could also be that the fins failed and the stage simply dropped close enough to the barge for the powered landing autopilot to barely reach it with extreme maneuvers.

Or there was just a partial failure of the fins and some powerpacks of the fins failed (if SpaceX used the hydraulic system style that the british jets loved after WW2, like Vulcan or Concorde, there every control surface had its own pump and hydraulic circuit)
 

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Could it be that the fins and the TVC system share their hydraulic fluid supply, or that in some other way a failure of the fins may also (indirectly) mean a failure of the TVC system?
 

Urwumpe

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Could it be that the fins and the TVC system share their hydraulic fluid supply, or that in some other way a failure of the fins may also (indirectly) mean a failure of the TVC system?

I doubt it - the engines are likely unchanged from the previous flights and thus have their own hydraulic system for the TVC.

The fins could then be plugged into the hydraulic system of one or more engines and be powered by accumulator pressure when the engine pump is not operating. But this would require very long hydraulic lines from one end of the rocket to the other.

possibly the rocket used either small powerpacks for each fin or a separate hydraulic system for the fins.
 

Andy44

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I just love the fact that they released the official video as a Vine. Ah, SpaceX... Darn impressive though.

It's a bit tricky to see, but I can't seem to see any legs deployed.

If you look carefully at this photo it looks like a landing leg extending up to the right away from the base of the rocket where all the glowing gas is:

B7c73oaCQAA7V-j.jpg:large
 

Urwumpe

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That's a sturdy barge.

Yeah, but it also doesn't look like a detonation, more like a tank burst like an inflated balloon after buckling during a hard landing. Most of the damage seems really be "just" from a few tons of metal landing hard.
 

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There's really not much to detonate at that point either.
 

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That's a sturdy barge.

At that point stage is nearly empty and very light. Even if engine failed to ignite for final braking burn and stage fell on the barge at terminal velocity I doubt it would sink. A barge like they use usually have multiple longitudinal and transverse bulkheads making multiple sealed compartments so even if falling stage makes a hole right through the barge it would not sink and could be quickly fixed and put back in service.
 

Galactic Penguin SST

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So the Dragon is leaving port again very soon....

....and as chances go, Dragon may land just 1.5 hours after a F9 1st stage lands! It will be released from the station's SSRMS at around 19:10 UTC on February 10 and splash-down is scheduled at 00:44 UTC the next day. That marks 3 things landing from space in 13 hours..... (the 3rd one is in that separate thread :p) :hmm:
 

Galactic Penguin SST

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While F9 and GoreSat is grounded for another day, the Dragon has left port right at the planned time earlier today: :thumbup:


De-orbit burn will start in 20 minutes time with splashdown at 00:44 UTC (4:44 pm Pacific).
 
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