SpaceX Tuesday...

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MartG

20,691 posts

205 months

Saturday 10th January 2015
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Previous 1st stage test landing attempts had been within 6 miles of the desired target - they had to bring down the accuracy to 33ft. That part worked.

London424

12,829 posts

176 months

Eric Mc

122,053 posts

266 months

Saturday 10th January 2015
quotequote all
MartG said:
Previous 1st stage test landing attempts had been within 6 miles of the desired target - they had to bring down the accuracy to 33ft. That part worked.
Step by step.

The next time they'll land softly, and it will topple over.

I expect full success after four attempts.

Simpo Two

85,526 posts

266 months

Saturday 10th January 2015
quotequote all
Perhaps it needs the equivalent of arrester wires on a flight deck... in other words, get it to within a few yards and some kind of capture system can do the last, most difficult bit, automatically...?

Eric Mc

122,053 posts

266 months

Saturday 10th January 2015
quotequote all
Like the way Royal Navy Lynxs and Merlins Harpoon themselves to the deck.

That's what I was thinking might work.

Weight and added complexity is always the issue with these things.

MartG

20,691 posts

205 months

Saturday 10th January 2015
quotequote all
Eric Mc said:
Weight and added complexity is always the issue with these things.
Perhaps fit the landing barge with a net raised by arms to support the stage once it touches down - a bit like the way an octopus engulfs its prey ?

Eric Mc

122,053 posts

266 months

Saturday 10th January 2015
quotequote all
Yep - stored in the horizontal position and then spring loaded as soon as the footpads touch the deck to shoot up into the vertical to "cage" and capture the rocket.

Good idea.

In fact, who needs legs with footpads. Just let the rocket topple into the net

anonymous-user

55 months

Saturday 10th January 2015
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Eric Mc said:
MartG said:
"" Ship itself is fine. Some of the support equipment on the deck will need to be replaced... "

-Elon Musk on Twitter"
Hee hee.

Read that as - "the barge is thrashed and will need to be rebuilt" - possibly.
I read that as> "we didn't sink the ship".... ;-) Still, even hitting a very small ship in the middle of a large ocean, even if they were going a bit quick when it got there, is a major achievement!

MartG

20,691 posts

205 months

Saturday 10th January 2015
quotequote all

Simpo Two

85,526 posts

266 months

Saturday 10th January 2015
quotequote all
I liked this response to the Guardian's news item:

'Yes, after you cut the crap, please TRY Guardian to understand what is going on - I know it's difficult for dumb arts graduates who infest our media.' hehe

As for any recovery system, I was thinking more of a large funnel with some kind of damping structure at the bottom. That way, once you get the butt-end of the rocket into the top, it doesn't matter what happens.

As for the current system, I see its landing speed is 2m/s. That's fast - I can see any slight inclination either breaking a leg or making it bounce straight over the opposite side.

There must be an easier way...

Eric Mc

122,053 posts

266 months

Saturday 10th January 2015
quotequote all
A big trampoline?

A huge bucket of marshmallow?

Now that they can find the target.....

London424

12,829 posts

176 months

Saturday 10th January 2015
quotequote all

Eric Mc

122,053 posts

266 months

Saturday 10th January 2015
quotequote all
How?

And what function does the hydraulics play in the final phase of flight?

There is s till a lot I'd like to know about what happened.

Was the rocket in the braking phase or in the hover before it hit the ship or did it plummet in at unabated speed?

Did the landing legs deploy?

Did they lose control of the gimbal mechanism of the engine just before touchdown? That would be the type of thing that might happen with loss of hydraulic pressure.




Eric Mc

122,053 posts

266 months

Saturday 10th January 2015
quotequote all
How?

And what function does the hydraulics play in the final phase of flight?

There is s till a lot I'd like to know about what happened.

Was the rocket in the braking phase or in the hover before it hit the ship or did it plummet in at unabated speed?

Did the landing legs deploy?

Did they lose control of the gimbal mechanism of the engine just before touchdown? That would be the type of thing that might happen with loss of hydraulic pressure.




MartG

20,691 posts

205 months

Saturday 10th January 2015
quotequote all
"The legs and engine gimbal hydraulics are powered by the engines themselves, independently of the system operating the grid fins up in the interstage above the LOX tank. That system is probably a draining, open-loop hydraulic system powered by a pressurizing gas accumulator."

Eric Mc

122,053 posts

266 months

Saturday 10th January 2015
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Just forgot to top it up then smile

Or understimated how much hydraulic fluid was required.

London424

12,829 posts

176 months

MartG

20,691 posts

205 months

Saturday 10th January 2015
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ISS approach and docking due around 11am Monday GMT - will be live on NASA TV etc.

MartG

20,691 posts

205 months

Saturday 10th January 2015
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MartG

20,691 posts

205 months

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