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4 hours ago, Motokid600 said:

If i recall correctly there have been successful three engine landings in the past, but not all the way to the deck. Two shutdown a few seconds prior. Was this all the way?

If so, it could explain why it came down so nearly off the deck, and then crushed the legs. A three-engine shutdown could easily have air-launched and ended up dropping from a few meters above the deck.

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7 minutes ago, Spaceception said:

Quickest turnaround is 13 days, what does that mean? I don't recall SpaceX launching a reused rocket that quickly, or is that the time for them to get a recovered stage firing again?

It's just timing between launches, it has nothing at all to do with booster turn around.

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8 hours ago, Motokid600 said:

If i recall correctly there have been successful three engine landings in the past, but not all the way to the deck. Two shutdown a few seconds prior. Was this all the way?

As I understand it based on a single Facebook comment on a moderately trustworthy website, yes. :D

 

?!?

Oh for flarp's flarping sake! How in the great furry flying flarp am I out of likes for the day already?! :mad: I just got up, dagnabbit!

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42 minutes ago, Technical Ben said:

Not all 3 engines shut off at the same time? Waves on the sea?

Elon said it was either a mechanical problem or a very large wind gust.

Asymmetric shutdown could be the mechanical problem. I suppose we could calculate force gradients during engine shutdown from existing videos but it would be a lot of guesswork.

On the subject of the grid fins, Elon stated that the old painted aluminum ones never were so damaged as to lose control authority, but they were always "fragged", i.e., too melty to be reused. The titanium ones provide a little extra control authority (which will help later, with FH) and are completely reusable without refurb.

By this I assume we can conclude that even with the two reused rockets so far, none of the grid fins were original.

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5 hours ago, sevenperforce said:

Whoa, really freaking cool:

34707526913_a9498956db_o_kindlephoto-164

The new Block V titanium grid fins are curved. They're also substantially larger than the original aluminum ones.

Interesting. I thought that the computer would know more or less how the rocket will react when it tilts and twists the grid fins. But, here it looks like they just came in and slapped on some bigger & curvier fins and they still expect the rocket to return no problem. I guess it implies that the computer basically learns how to control the rocket on the fly. It makes sense; so many variables are always changing. I wonder if, for example, half a grid fin got ripped off, would the computer be able to adjust for it?

Edited by Lukaszenko
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8 minutes ago, Lukaszenko said:

Interesting. I thought that the computer would know more or less how the rocket will react to when it tilts and twists the grid fins. But, here it looks like they just came in and slapped on some bigger & curvier fins and they still expect the rocket to return no problem. I guess it implies that the computer basically learns how to control the rocket on the fly...

Or, if we assume this was done by professional engineers rather than monkeys, maybe it could suggest that they've extensively simulated and tested these new grid fins and have updated the software with new parameters? :P

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24 minutes ago, Steel said:

Or, if we assume this was done by professional engineers rather than monkeys, maybe it could suggest that they've extensively simulated and tested these new grid fins and have updated the software with new parameters? :P

WIll assume so, the curving is probably done for some reasons, like distribute stress or heating over the surface.
First I assumed they was curved to follow the rocet diameter but they are curved in the in-out direction not sideways. 
A bit weird they are not covered, think they would add some air resistance even then folded. A simple fiberglass or cheat metal cover should help. 

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10 minutes ago, magnemoe said:

A bit weird they are not covered, think they would add some air resistance even then folded. A simple fiberglass or cheat metal cover should help. 

A bit, but then that's extra parts, throwaway or complex, and weight, probably not worth it the hassle or expense. The curve appears to be for aerodynamics. 

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16 minutes ago, magnemoe said:

WIll assume so, the curving is probably done for some reasons, like distribute stress or heating over the surface.
First I assumed they was curved to follow the rocet diameter but they are curved in the in-out direction not sideways. 
A bit weird they are not covered, think they would add some air resistance even then folded. A simple fiberglass or cheat metal cover should help. 

That might cut into the payload fraction, I mean, an aerodynamic cover with some sort of decoupler, that has to take at least a few hundred kilos off the max payload (Or I'm just overthinking it) and on top of that, it adds something else they have to replace. 

Ninja'd by @StrandedonEarth

Edited by Spaceception
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6 minutes ago, sevenperforce said:

Even sexier pic:

[PICTURE]

6 minutes ago, sevenperforce said:

 

As you can see, they ARE curved around the stage, plus they have awesome leading-edge sharp points to break up airflow.

Now those are some sexy grid fins...

So the new shape is definitely for aerodynamic reasons while ascending.

Edited by Steel
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