SpaceX And/Or Rocketry In General

archae86
archae86
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Mike Hewson wrote: It looks

Mike Hewson wrote:
It looks to me like there are some very heavy duty dampers b/w the cores.

There is something that looks sort of pneumatic up at the top as well.  My guess is that both are part of the separation provisions.

There is a very long-lasting thread at at NasaSpaceFlight.com regarding the separation considerations and provisions for getting the side boosters safely away, and then started on their return to launch site.  While people posting in the thread have brought in a lot of knowledge on the Shuttle, the Soviet R7 (whose lineal descendant continues to launch people to the ISS under the Soyuz name), they have offered very nearly nothing actually from SpaceX itself.

Just to share a couple of tidbits form the past: on the Shuttle the residual chamber pressure in the SRB's was monitored.  When it tailed down to 50 psi, separation was initiated, helped along by multiple side-thrusters (basically short-burning rocket engines pointed sideways to assure the solids got away from the main vehicle).  The R7 scheme was very different, and gives rise to riveting video of the four side-pieces very rapidly turning end-over-end as they fall behind the continuing part.  I had never seen this before.

See the Soyuz side boosters depart just after 0:50 in this video

Mike Hewson
Mike Hewson
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archae86 wrote:See the Soyuz

archae86 wrote:
See the Soyuz side boosters depart just after 0:50 in this video

Here's even better views.

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
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archae86 wrote:Mike Hewson

archae86 wrote:
Mike Hewson wrote:
It looks to me like there are some very heavy duty dampers b/w the cores.
There is something that looks sort of pneumatic up at the top as well.  My guess is that both are part of the separation provisions.

I posed this question regarding the components near the engines in the Falcon Heavy Demo discussion thread at NASASpaceflight.com.  One person sent me a PM, and three commented directly in the thread. 

One PM'd "The grayish parts are the brackets that hold on the rotatable processing rings and the black part above is the strut and separation guide for the boosters and retracts upon completion of separation."

One guessed "I'd guess it's a pusher, while the other attachment points just hold it in place. Once they let go these would push the booster away."

One frequent poster said "They are the pneumatic pusher mechanisms. Two for each booster’s octaweb."

One frequent poster, well-known on the site for being in the trade, being terse, and being well-informed said "not dampers.  no need for such.  It is the sep system"

My guess is that the extra bits up at the top are far smaller push power components of the same function.  (the tubes on a funny sort of angle to the main top cross-connection).

 

Mike Hewson
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OK. If we go with the

OK. If we go with the terse-in-the-trade guy, then prior to separation ( including ditto at the top ends of the side boosters ) we have, say, two times four = eight attachments that each & all have to cope with any peak asymmetric thrust b/w cores without the benefit of even momentary jerk* buffering. Otherwise we have a Challenger scenario with bits banging around.

Cheers, Mike.

* Rate of change of acceleration, the third time derivative of position, or if you the like a difference of accelerations per some time interval. This is what rips your spleen from it's internal attachments in a car accident. Or Lady Diana's lungs from her heart. 

( edit ) Unless there's some more substantial attachments to cope with jerk ( probably hidden in plain sight, but not immediately identifiable to us ) snapped with explosive bolts et al. If so then the sequence is to cleave the jerk loaded connections, use pushers to separate hopefully without imparting too much longitudinal spin, or pitch/yaw for that matter, on the side boosters. Each side booster has to return to it's landing zone without colliding with the other. Cripes. Elon knows the worst of this and has hence lowered expectations accordingly.

( edit ) Here's a Kerbal Mars return demo that hilariously shows the exponential nature of fuel requirements of direct missions ie. most fuel present at launch is there to deliver other fuel to some time, place and velocity.

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
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One more guy has commented on

One more guy has commented on Mike's damper, saying:

"id guess the left side is the release mechanism. The right cylinder might be a dampener.  interesting white dots. Might be used to record video of dampener movement?"

Mike Hewson
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White dots. Maybe it is part

White dots. Maybe it is part of an alignment process of the side boosters with respect to the core. This would be done based upon observations during the test firings when upright. A few centimeters either way could be important with such massive power in flight. There is no way each of the three boosters will behave absolutely identically under power however standardised the manufacturing and testing. One couldn't simulate this nor assess adequately while horizontal. What I would have is stress/strain gauges at said attachment points to note asymmetries. Could this warn of a slight alignment adjustment to avoid a later catastrophe ? Goal : the thrust vectors at the centre of masses of each of the three  boosters to be parallel. Oh heck, let's call it a prototype without paradigmatic peer.

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

Mike Hewson
Mike Hewson
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SpaceX have released a drone

SpaceX have released a drone survey of The Beast on the pad. That Tesla Roadster will be the fastest in the world and/or in the most pieces.

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
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The Falcon 9 launch of a

The Falcon 9 launch of a hush-hush payload called Zuma from the Cape, which has slipped repeatedly in recent months, is currently scheduled for just a few hours over 24 hours from now (so late afternoon/early evening local time).  The window opens at 1:00 UTC January 8, accounting for the January 7 (local) to January 8 (UTC) discrepancy.  This one is expected to return the first stage to land at LZ-1 at the Cape.

Here is the youtube URL

https://youtu.be/0PWu3BRxn60

Separately the first Falcon Heavy launch (yes, Elon's red Tesla Roadster as payload), which was for a while strongly suggested to be a mid-January launch target is more recently targeted for right at the turn of the month from January to February (2018).  Sources include both an Elon tweet and the dates on the latest round of member of the press permission slips.  This one is currently expected to land the two side boosters back at the Cape at LZ-1 and the new, smaller LZ-2 (smaller, and shockingly close at 1000 feet to the original LZ-1).  The center booster will burn longer (no crossfeed, but shifted in time by differences in throttling), and is hoped to land on the barge downrange.

 

Anonymous

SpaceX has just launched its

SpaceX has just launched its secret Zuma mission: 2000 hrs.

MAGIC Quantum Mechanic
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Just got done watching the

Just got done watching the last NFL Wildcard game and on to the Zuma FALCON 9 

I have a good friend in Florida that always takes videos for me.

 

http://www.spacex.com/webcast

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