Author Topic: SpaceX Falcon-9 - Thaicom-8 - May 27, 2016 - DISCUSSION  (Read 287715 times)

Offline Robotbeat

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Re: SpaceX Falcon-9 - Thaicom-8 - May 27, 2016 - DISCUSSION
« Reply #360 on: 05/28/2016 12:14 am »
@elonmusk
Rocket landing speed was close to design max & used up contingency crush core, hence back & forth motion. Prob ok, but some risk of tipping


Meaning?

Meaning that the first stage ...
No.
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Offline Robotbeat

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Re: SpaceX Falcon-9 - Thaicom-8 - May 27, 2016 - DISCUSSION
« Reply #361 on: 05/28/2016 12:19 am »
This thing is so tall, if they can't secure it, I wonder they will have to shove it overboard before entering the shipping lanes and the port itself.

Anyone know?
No. As long as they depressurize it, it shouldn't be a risk to other structures other than the droneship.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

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Offline rickl

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Re: SpaceX Falcon-9 - Thaicom-8 - May 27, 2016 - DISCUSSION
« Reply #362 on: 05/28/2016 12:33 am »
Is the 91,000 km apogee a record for SpaceX?  I don't recall hearing of one that high before.

If so, it's all the more impressive that they could do that and still land the first stage.
The Space Age is just starting to get interesting.

Offline Robotbeat

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Re: SpaceX Falcon-9 - Thaicom-8 - May 27, 2016 - DISCUSSION
« Reply #363 on: 05/28/2016 12:34 am »
Is the 91,000 km apogee a record for SpaceX?  I don't recall hearing of one that high before.

If so, it's all the more impressive that they could do that and still land the first stage.
DISCOVR higher.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline NovaSilisko

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Re: SpaceX Falcon-9 - Thaicom-8 - May 27, 2016 - DISCUSSION
« Reply #364 on: 05/28/2016 01:02 am »
I think this is a slightly different angle clearer shot (from SpaceX Twitter).  I'll leave it to others to have opinions on leg position.

https://pbs.twimg.com/media/Cjfpe5NVAAE35KP.jpg

[image snipped]

Tweet:

https://twitter.com/SpaceX/status/736313781907685376

It most decidedly is touching the deck. Remember, the little footpad on the bottom of the leg extends a few centimeters below the aerodynamic housing. Any remaining percieved gap is due to that.
« Last Edit: 05/28/2016 01:03 am by NovaSilisko »

Offline Jdeshetler

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Re: SpaceX Falcon-9 - Thaicom-8 - May 27, 2016 - DISCUSSION
« Reply #365 on: 05/28/2016 01:12 am »
The core is swinging a bit....

Can't get around latest Adobe GIF bug so here are mpg & quicktime clips speed up by 3X.
« Last Edit: 05/28/2016 01:23 am by Jdeshetler »

I can't get the gif to activate, but I believe you. In the landing vid, as the smoke is clearing away, the top of the stage is moving relative to a droplet on the camera lens. If both were in stasis, there would be no relative movement. It is rocking.

(starting from 2:23 in this vid: )
« Last Edit: 05/28/2016 01:19 am by MarsInMyLifetime »
--
Don Day

Offline NovaSilisko

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Re: SpaceX Falcon-9 - Thaicom-8 - May 27, 2016 - DISCUSSION
« Reply #367 on: 05/28/2016 01:45 am »
Interestingly, you can see that the leg opposite to the direction of the tilt (the one accused of being aloft) doesn't seem to ever actually lift up, rather the piston extends a little to allow the foot to continue to rest on the deck.

Offline RocketGoBoom

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Re: SpaceX Falcon-9 - Thaicom-8 - May 27, 2016 - DISCUSSION
« Reply #368 on: 05/28/2016 02:17 am »
This makes landing bingo so much easier to figure out the winner !!!

The complete landing from the perspective of the first stage, from grid deployment to the barge...

https://www.instagram.com/p/BF7wQGkF8ZJ/?taken-by=spacex
« Last Edit: 05/28/2016 02:21 am by RocketGoBoom »

Offline JebK

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Re: SpaceX Falcon-9 - Thaicom-8 - May 27, 2016 - DISCUSSION
« Reply #369 on: 05/28/2016 02:19 am »
This makes landing bingo so much easier to figure out the winner !!!

https://www.instagram.com/p/BF7wQGkF8ZJ/?taken-by=spacex

WOW! Amazing video!  Here's hoping they release that at normal speed!

Offline Steven Pietrobon

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Re: SpaceX Falcon-9 - Thaicom-8 - May 27, 2016 - DISCUSSION
« Reply #370 on: 05/28/2016 02:23 am »
I calculated the entry and landing burns to be about 18 seconds each. For the landing burn, the starting point was from the beginning of the callout.

For the supposed camera cracking, that looked like a bit of dirt hitting the camera lens to me.

Update. The landing video shows that the camera did not crack.
« Last Edit: 05/28/2016 02:29 am by Steven Pietrobon »
Akin's Laws of Spacecraft Design #1:  Engineering is done with numbers.  Analysis without numbers is only an opinion.

Offline cscott

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Re: SpaceX Falcon-9 - Thaicom-8 - May 27, 2016 - DISCUSSION
« Reply #371 on: 05/28/2016 02:31 am »
I wonder if the "sped up" nature is due to itar and/or protecting their "special sauce".  They might be able to insert just enough frame rate jitter to obscure the exact duration of various key events.

Or maybe they just thought it looked cooler this way.

Offline Elmar Moelzer

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Re: SpaceX Falcon-9 - Thaicom-8 - May 27, 2016 - DISCUSSION
« Reply #372 on: 05/28/2016 02:38 am »
This makes landing bingo so much easier to figure out the winner !!!

https://www.instagram.com/p/BF7wQGkF8ZJ/?taken-by=spacex

WOW! Amazing video!  Here's hoping they release that at normal speed!
I second that hope! I don't get why they think they had to accelerate it. This is cool enough to watch in real time all the the way down!

Online docmordrid

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Re: SpaceX Falcon-9 - Thaicom-8 - May 27, 2016 - DISCUSSION
« Reply #373 on: 05/28/2016 02:47 am »
DM

Offline arsenal

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Re: SpaceX Falcon-9 - Thaicom-8 - May 27, 2016 - DISCUSSION
« Reply #374 on: 05/28/2016 02:50 am »
I wonder if the "sped up" nature is due to itar and/or protecting their "special sauce".  They might be able to insert just enough frame rate jitter to obscure the exact duration of various key events.

Or maybe they just thought it looked cooler this way.
I highly doubt it. They showed it in normal speed during the webcast, and even though it cutoff while reentering I am sure that if they had a solid connection they would have showed it the whole way in. I watched the hosted webcast after watching the technical one live, and one of the guys even made it sound like they were originally planning on showing it even after reentry. Besides, there is a lot more to it than just the timing of the events.

Offline Space Ghost 1962

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Re: SpaceX Falcon-9 - Thaicom-8 - May 27, 2016 - DISCUSSION
« Reply #375 on: 05/28/2016 02:50 am »
Note the torque on entry burn engine shutdown.

Also, looks like they aim for a near miss off the edge of the barge until braking burn engine starts. Then the redirect to the center of the barge.

You also can note that the grid fins roast after the entry burn before transonic.

Offline Wolfram66

49:56 into technical broadcast, a big chunk of something comes off the MVac right after shutdown. ice, coke or insulation? Any ideas, gang?
« Last Edit: 05/28/2016 03:26 am by Wolfram66 »

Online Herb Schaltegger

I watched the Technical webcast live and then later this evening watched the Hosted webcast through until SECO1 and parking orbit. Did anyone else notice one of the hosts, at about 38:30 in the webcast during the landing burn discussion, mention that they apparently did a 1-3-1 engine landing burn? I watched it twice and that's what it sounded to me like he was saying.

If so, I wonder if Lou can work his calculator magic and come up with some good dV estimates for the landing profile.
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Offline AC in NC

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Re: SpaceX Falcon-9 - Thaicom-8 - May 27, 2016 - DISCUSSION
« Reply #378 on: 05/28/2016 03:02 am »
Also, looks like they aim for a near miss off the edge of the barge until braking burn engine starts. Then the redirect to the center of the barge.

Somewhere there was a diagram that showed just that.  However, I thought it was dramatic how late the move to center was.  Very impressive that they don't need to have the landing point of impact centered earlier than that.

Offline Elmar Moelzer

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Re: SpaceX Falcon-9 - Thaicom-8 - May 27, 2016 - DISCUSSION
« Reply #379 on: 05/28/2016 03:06 am »
Not sure if this has been discussed before, but what about that "tarp"? covering part of the second stage engine? Is that some sort of extra insulation for the restart later, or what is the purpose of it? I don't think I have seen it before.

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