SpaceX And/Or Rocketry In General

Mike Hewson
Mike Hewson
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What can one say ???

What can one say ??? :_))))

A hole in one !

Cheers, Mike.

I have made this letter longer than usual because I lack the time to make it shorter ...

... and my other CPU is a Ryzen 5950X :-) Blaise Pascal

archae86
archae86
Joined: 6 Dec 05
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Nailed it.

Nailed it.

Mike Hewson
Mike Hewson
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You up and about Peter ?

You up and about Peter ? :-)

Given that GSTO insertion is the hardest task for SpaceX at current configurations then this is an exceptional achievement ! I want to know how many litres were left in the tank at shutdown on Of Course I Still Love You.

Cheers, Mike.

I have made this letter longer than usual because I lack the time to make it shorter ...

... and my other CPU is a Ryzen 5950X :-) Blaise Pascal

archae86
archae86
Joined: 6 Dec 05
Posts: 3157
Credit: 7225354931
RAC: 1041031

RE: You up and about Peter

Quote:

You up and about Peter ? :-)


Yes.

We got home from singing in the chorus for a performance of Mahler's second Symphony, and I realized this was before midnight local time, so got to watch a bit.

Anonymous

I just watched the video

I just watched the video replay. Quite an amazing performance. Now will someone please run out there and blow out that lingering flame. I am sure there are other videos to come. Or at least I hope there are.

archae86
archae86
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Credit: 7225354931
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Someone on the

Someone on the NASASpaceflight forum just posted the link to some images SpaceX posted to flickr which show this mission's stage on the barge in daylight. (there are two more which you can get to by clicking the right arrow on the first).

To my casual eye it seems intact, and to have come to rest quite near the center of the target. Since I posted concern about wind I should say that later forecasts had the wind getting down to the low teens by landing time, so this try did not demonstrate success at nearly so high a wind as they would wish.

Someone thought they heard a SpaceX person announcing the cutoff of two of the engines a bit before landing, suggesting that they chose to waste a bit of fuel to get a more controllable situation.

(I suspect that with three engines burning at the nearly fully depleted fuel level, the lowest thrust to which the Merlin engines will throttle would still produce appreciable positive G--not a good proposition from a control authority point of view).

Anonymous

RE: Someone on the

Quote:
Someone on the NASASpaceflight forum just posted the link to some images SpaceX posted to flickr which show this mission's stage on the barge in daylight. (there are two more which you can get to by clicking the right arrow on the first).

tried the above link but it failed with 404. Do you have an update?

archae86
archae86
Joined: 6 Dec 05
Posts: 3157
Credit: 7225354931
RAC: 1041031

RE: RE: Someone on the

Quote:
Quote:
Someone on the NASASpaceflight forum just posted the link to some images SpaceX posted to flickr which show this mission's stage on the barge in daylight. (there are two more which you can get to by clicking the right arrow on the first).

tried the above link but it failed with 404. Do you have an update?


It is 404 for me now also, but I tested at the time I posted, so something changed.

Here are links to the three specific photos of interest, as they were posted as attachments to a thread at NASASpaceflight.com. Possibly these won't work either if you are not a member, but I tried them in another browser which had never logged in there, and at the moment of posting they worked.

Image 1
Image 2
Image 3

I'm posting from a PC under construction, and checking that in "another browser" was the very first time I launched Micrsoft Edge.

archae86
archae86
Joined: 6 Dec 05
Posts: 3157
Credit: 7225354931
RAC: 1041031

RE: Someone thought they

Quote:

Someone thought they heard a SpaceX person announcing the cutoff of two of the engines a bit before landing, suggesting that they chose to waste a bit of fuel to get a more controllable situation.

(I suspect that with three engines burning at the nearly fully depleted fuel level, the lowest thrust to which the Merlin engines will throttle would still produce appreciable positive G--not a good proposition from a control authority point of view).


Elon himself settled this point, replying to someone on his Twitter account thus:

Quote:
Max is just 3X Merlin thrust and min is ~40% of 1 Merlin. Two outer engines shut off before the center does.
Mike Hewson
Mike Hewson
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Joined: 1 Dec 05
Posts: 6588
Credit: 318096427
RAC: 399640

There's quite alot more burn

There's quite alot more burn on this one, especially in the top image near the paddles. The peak heating goes like the cube of the speed. Again I will say : this is a big rocket to be doing this sort of thing. A long way from the grasshoppers. :-)

Cheers, Mike.

( edit ) Another shot I've taken from the video ( remember rowvid folks ? ) just moments after shutdown on the barge :

I guess the hot central Merlin is producing all the residual flame etc ....

I have made this letter longer than usual because I lack the time to make it shorter ...

... and my other CPU is a Ryzen 5950X :-) Blaise Pascal

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