Author Topic: Falcon 9 Core Stage Ocean Landing CGI Animation Video Effort  (Read 63998 times)

Offline Lars-J

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Yes, I wouldn't bother with including the F9R either. And as much as we like the CG rendering, I would just end it on two shots... The chase plane view and the restored CRS3 footage.

Offline Llian Rhydderch

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You are doing great work here, Greg.

My recommendation:  get input from the many smart and thoughtful folks on NSF, think on it and consider it, but then take the pride of video-authorship and make the video that you think needs to be made from all these potentially cool piece-parts.  You are the director, and the producer, as well as video editor, of the final cut!"  8)

We're all going to really love your finished product.

Enjoy!
Re arguments from authority on NSF:  "no one is exempt from error, and errors of authority are usually the worst kind.  Taking your word for things without question is no different than a bracket design not being tested because the designer was an old hand."
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Offline GregA

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Damn... this is what happens when you rush.
Agreeing that the beginning was entirely unnecessary - I made the shorter end video, checked it, hit upload.... waited.... and quick copy and paste into the post above. And ran off to do other family things.

There was no opening takeoff etc... but something strange has happened. Have just worked out (human error unfortunately!)

On another note some more good feedback. I agree too much happening and now have some ideas in how to approach this another way. Will do a couple of tests on the observer plane shots lining up too

In a sec I'll post what was meant to go up 12 hours ago.



Offline GregA

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Just to get it right... Here's the video from last night. New draft coming.


Offline Chris Bergin

Great work again! When the final version is complete, please give me a heads up and I'll get it off to SpaceX's folks.
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Offline RanulfC

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Ok, major question here from the video and if its L2 let me know and I'll slink away but...

The vid shows a segment titled "Reentry Burn" that looks unlike a de-orbit burn and VERY much like a "run-an-engine-and-use-the-exhaust-as-a-heat-shield" maneuver. Is this correct? Because if it is a WHOLE lot of speculation just got trashed....

Randy
From The Amazing Catstronaut on the Black Arrow LV:
British physics, old chap. It's undignified to belch flames and effluvia all over the pad, what. A true gentlemen's orbital conveyance lifts itself into the air unostentatiously, with the minimum of spectacle and a modicum of grace. Not like our American cousins' launch vehicles, eh?

Offline S.Paulissen

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The first stage is not orbital so there isn't a de-orbiting burn, so it doesn't look like one. 

[opinion] It isn't using the exhaust as a heat shield either as heating isn't the issue with first stage reentry.  It's  and speed for aerodynamic pressures and downrange distance for boostback (the goal but not in practice here). [/opinion]
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Offline RanulfC

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The first stage is not orbital so there isn't a de-orbiting burn, so it doesn't look like one. 

[opinion] It isn't using the exhaust as a heat shield either as heating isn't the issue with first stage reentry.  It's  and speed for aerodynamic pressures and downrange distance for boostback (the goal but not in practice here). [/opinion]
Currently there's no "boost-back" either and the way it looks the stage is reaching atmospheric interface which has been "assumed" to involve taking the reentry heating on the forward stage TPS. With all that entails. IF as would be shown in the video, the stage is going to "enter" engines first then that changes a lot of the base assumptions that have been circulated on the operational recovery sequence.

If, once the stage rotates to engines down position it remains that way for the entire recovery sequence that's differenet than what most folks were assuming in other words.

Randy
From The Amazing Catstronaut on the Black Arrow LV:
British physics, old chap. It's undignified to belch flames and effluvia all over the pad, what. A true gentlemen's orbital conveyance lifts itself into the air unostentatiously, with the minimum of spectacle and a modicum of grace. Not like our American cousins' launch vehicles, eh?

Offline sheltonjr

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Currently there's no "boost-back" either and the way it looks the stage is reaching atmospheric interface which has been "assumed" to involve taking the reentry heating on the forward stage TPS. With all that entails. IF as would be shown in the video, the stage is going to "enter" engines first then that changes a lot of the base assumptions that have been circulated on the operational recovery sequence.

If, once the stage rotates to engines down position it remains that way for the entire recovery sequence that's differenet than what most folks were assuming in other words.

Randy

I have always "assumed" that the atmospheric interface was always going to be engine first as depicted in their CGI re-entry video. This is backed up by the Orbcomm F9 First Stage return video showing the re-entry burn from 15:23:45 to at least 15:24:17 (32 sec burn) before SpaceX jumps to the landing burn at 15:25:40, 83 seconds later.

I thought the engine first re-entry burn was obvious, Am I miss-reading your statement above?

Offline somepitch

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Currently there's no "boost-back" either and the way it looks the stage is reaching atmospheric interface which has been "assumed" to involve taking the reentry heating on the forward stage TPS. With all that entails. IF as would be shown in the video, the stage is going to "enter" engines first then that changes a lot of the base assumptions that have been circulated on the operational recovery sequence.

If, once the stage rotates to engines down position it remains that way for the entire recovery sequence that's differenet than what most folks were assuming in other words.

Randy

I have always "assumed" that the atmospheric interface was always going to be engine first as depicted in their CGI re-entry video. This is backed up by the Orbcomm F9 First Stage return video showing the re-entry burn from 15:23:45 to at least 15:24:17 (32 sec burn) before SpaceX jumps to the landing burn at 15:25:40, 83 seconds later.

I thought the engine first re-entry burn was obvious, Am I miss-reading your statement above?

I'm confused too - it's definitely engines first... and what "forward stage TPS"? do you mean?

Offline Lars-J

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The first stage is not orbital so there isn't a de-orbiting burn, so it doesn't look like one. 

[opinion] It isn't using the exhaust as a heat shield either as heating isn't the issue with first stage reentry.  It's  and speed for aerodynamic pressures and downrange distance for boostback (the goal but not in practice here). [/opinion]
Currently there's no "boost-back" either and the way it looks the stage is reaching atmospheric interface which has been "assumed" to involve taking the reentry heating on the forward stage TPS. With all that entails. IF as would be shown in the video, the stage is going to "enter" engines first then that changes a lot of the base assumptions that have been circulated on the operational recovery sequence.

If, once the stage rotates to engines down position it remains that way for the entire recovery sequence that's differenet than what most folks were assuming in other words.

No, that may be different from *your* perception, but not most people. The first stage enters engines first. It always has in all promotional materials.

Offline JasonAW3

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Vids are looking great!

Anyone know when the next landing attempt will be?
My God!  It's full of universes!

Offline RanulfC

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I have always "assumed" that the atmospheric interface was always going to be engine first as depicted in their CGI re-entry video. This is backed up by the Orbcomm F9 First Stage return video showing the re-entry burn from 15:23:45 to at least 15:24:17 (32 sec burn) before SpaceX jumps to the landing burn at 15:25:40, 83 seconds later.

I thought the engine first re-entry burn was obvious, Am I miss-reading your statement above?

The former is the "boost-back" burn (reuse CGI) while I'd not previously SEEN the Orbcomm "reentry burn" video :) SpaceX hadn't "said" as much but when the original idea of reentring "engines first" was discussed Musk (IIRC) tweeted that no one had ever SAID the stage would enter that way and speculation drifted to "top" first reentry since we were aware that there was TPS there. (More I suspect to protect the upper tank dome from damage when the US fired but that's the ONLY thing that made sense at the time and was reinforced when there was the issue of "tumbling" on entry which suggested an aerodynamically unstable entry angle was being used.)

Combined with the obvious (CGI again) reentry of the upper stage "forward" tank first it had become assumed the the first stage did the same thing.

The main point of contention has been if the engines could handle the heating load but after to above tweet it was figured that they simply didn't bother and were using some sort of active control to hold the stage "top" first for reentry. As I pointed out, confirmed "engine first" entry is something new to the non-L2 discussions :)
I'm confused too - it's definitely engines first... and what "forward stage TPS"? do you mean?

The direction hasn't been obvious for the above reasons though it makes all sorts of sense it was NOT something that was clear. There was mention of beefing up the forward tank TPS at one point and this was "assumed" to be for reentry purposes though I now suspect it was to reduce damage from the upper stage seperation and engine firing. And you, (again) have the CGI example of the second stage reentry so it seemed that SpaceX was "comfortable" with that entry position.

No it doesn't make a lot of "sense" to try reentring with the engines NOT facing "forward" because of the aerodynamic forces involved and the extra stress' generated in doing so. Which is why I argued that no matter what "eventually" SpaceX was going to have to do it that way. But I was under the impression given the rather "vehment" denial noted above and the question of whether the engines would be damaged during entry in that position that they had decided to attempt it with the engines-aft and do a turn over prior to the landing burn. The video shows this not to be the case so at the very least MY arguments need to be reconsidered :)

Randy
From The Amazing Catstronaut on the Black Arrow LV:
British physics, old chap. It's undignified to belch flames and effluvia all over the pad, what. A true gentlemen's orbital conveyance lifts itself into the air unostentatiously, with the minimum of spectacle and a modicum of grace. Not like our American cousins' launch vehicles, eh?

Offline bubbagret

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I have always "assumed" that the atmospheric interface was always going to be engine first as depicted in their CGI re-entry video. This is backed up by the Orbcomm F9 First Stage return video showing the re-entry burn from 15:23:45 to at least 15:24:17 (32 sec burn) before SpaceX jumps to the landing burn at 15:25:40, 83 seconds later.

I thought the engine first re-entry burn was obvious, Am I miss-reading your statement above?

The former is the "boost-back" burn (reuse CGI) while I'd not previously SEEN the Orbcomm "reentry burn" video :) SpaceX hadn't "said" as much but when the original idea of reentring "engines first" was discussed Musk (IIRC) tweeted that no one had ever SAID the stage would enter that way and speculation drifted to "top" first reentry since we were aware that there was TPS there. (More I suspect to protect the upper tank dome from damage when the US fired but that's the ONLY thing that made sense at the time and was reinforced when there was the issue of "tumbling" on entry which suggested an aerodynamically unstable entry angle was being used.)

Combined with the obvious (CGI again) reentry of the upper stage "forward" tank first it had become assumed the the first stage did the same thing.

The main point of contention has been if the engines could handle the heating load but after to above tweet it was figured that they simply didn't bother and were using some sort of active control to hold the stage "top" first for reentry. As I pointed out, confirmed "engine first" entry is something new to the non-L2 discussions :)
I'm confused too - it's definitely engines first... and what "forward stage TPS"? do you mean?

The direction hasn't been obvious for the above reasons though it makes all sorts of sense it was NOT something that was clear. There was mention of beefing up the forward tank TPS at one point and this was "assumed" to be for reentry purposes though I now suspect it was to reduce damage from the upper stage seperation and engine firing. And you, (again) have the CGI example of the second stage reentry so it seemed that SpaceX was "comfortable" with that entry position.

No it doesn't make a lot of "sense" to try reentring with the engines NOT facing "forward" because of the aerodynamic forces involved and the extra stress' generated in doing so. Which is why I argued that no matter what "eventually" SpaceX was going to have to do it that way. But I was under the impression given the rather "vehment" denial noted above and the question of whether the engines would be damaged during entry in that position that they had decided to attempt it with the engines-aft and do a turn over prior to the landing burn. The video shows this not to be the case so at the very least MY arguments need to be reconsidered :)

Randy
Launch and acceleration out of the atmosphere.
MECO and stage separation.
180 degree maneuver to engine first attitude while still outside of the atmosphere.
Ballistic coast.
Braking/entry burn at atmospheric interface.
Unpowered drag deceleration to lower atmosphere.
Landing deceleration burn.

If such a long and lightweight aluminum stage attempted an end over end flip while at high mach within even the high, thin atmosphere, it would be instantly shredded by aerodynamic forces.

The second stage is much shorter and conversely, should be better able to take the stress of an inter atmospheric "flip" at (what I would assume will be) very low mach. That should be a fun one to watch! Also, the second stage will enter the atmosphere at much greater velocity and the aerothermal environment would quickly destroy the engine/stage without additional protection.

I will assume that they will have to add in an additional boost back burn before the ballistic coast and then a second flip maneuver before braking when they do attempt an actual 1st stage recovery.

Offline RanulfC

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Launch and acceleration out of the atmosphere.
MECO and stage separation.
180 degree maneuver to engine first attitude while still outside of the atmosphere.
Ballistic coast.
(Added in: {In-Real-use} Boost-Back-Burn to return Booster To Launch Site Just thought I'd keep that in everyones mind as THE goal :) )
Braking/entry burn at atmospheric interface.
Unpowered drag deceleration to lower atmosphere.
Landing deceleration burn.

If such a long and lightweight aluminum stage attempted an end over end flip while at high mach within even the high, thin atmosphere, it would be instantly shredded by aerodynamic forces.

Yes but, when I first brought up that issue I was "informed" here that the stage, specifically the V1.1 was DESIGNED To handle the stress and SpaceX knew what they were doing. Since a stage had not as of then been operationally recovered.... :)

Your also assuming that the stage was "rotated" at high mach speed and then go on to assume the second stage would not be. Again I was informed that this was pefectly "doable" once the first stage reached terminal velocity during return flight. Nothing was suggested differently at any time to me so why should I argue a point that seemed to be decided? :)

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The second stage is much shorter and conversely, should be better able to take the stress of an inter atmospheric "flip" at (what I would assume will be) very low mach. That should be a fun one to watch! Also, the second stage will enter the atmosphere at much greater velocity and the aerothermal environment would quickly destroy the engine/stage without additional protection.

Y'all seem to think I have issues with these conclusions and I don't. It was and is the first stage entry which is DIFFERENT that what had been "given" as the method that was going to be used is all I'm pointing out.

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I will assume that they will have to add in an additional boost back burn before the ballistic coast and then a second flip maneuver before braking when they do attempt an actual 1st stage recovery.

Just to be complete I added that to your description above :) All we had to go with was the CGI originally and it never showed the second "flip" or how the first stage reentered so I let the matter go despite having reservations on the "assumed" manner it was done. Now I see that I was right :)

Rand
From The Amazing Catstronaut on the Black Arrow LV:
British physics, old chap. It's undignified to belch flames and effluvia all over the pad, what. A true gentlemen's orbital conveyance lifts itself into the air unostentatiously, with the minimum of spectacle and a modicum of grace. Not like our American cousins' launch vehicles, eh?

Offline RanulfC

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No, that may be different from *your* perception, but not most people. The first stage enters engines first. It always has in all promotional materials.

Oh yes? Please show me WHERE that might have been :)

The CGI never shows first stage entry and no prior "work" does either. If its so "obvious" why was I informed that wasn't the way it was done on several threads here when I pointed out that the booster WANTS to come in "engines first"? No it's not been "obvious" to everyone though I've maintained that was the only way it COULD work in the end. Now I know so I'll dump all the previous speculation attempting to "fit" into the other method.

Randy
From The Amazing Catstronaut on the Black Arrow LV:
British physics, old chap. It's undignified to belch flames and effluvia all over the pad, what. A true gentlemen's orbital conveyance lifts itself into the air unostentatiously, with the minimum of spectacle and a modicum of grace. Not like our American cousins' launch vehicles, eh?

Offline Lars-J

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Who is this informer that "informed you" otherwise? Stop being obtuse. If you claim that you were right originally but everyone else convinced you that you had to be wrong, then you have a *very* unique recollection of the F9 reusable speculation threads.

(And now you are pulling the same stunt on the second stage reuse thread, missing the forest for the trees)

Yes, the animation didn't show everything, but the gist of it was there in plain sight. How else did you imagine it would work, with the giant air scoop of a trunk attached? How was that possibly going to work?
« Last Edit: 09/29/2014 06:56 pm by Lars-J »

Offline Dudely

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I read a lot of the re-entry threads. No one ever thought they were going to perform any part of the reentry with the engines at the rear.


You are missing one absolutely enormous and completely obvious reason why:

Boost back. Reusability has always targeted landing close the the original launch pad so the stages can be reused without moving them very far. Otherwise, there is no point. Elon has always talked like this. Landing on a barge has just come up recently, and seems to be related to the fact that the pad in NM is still not done so they have not been able to prove to the FAA they have the chops to bring it home.

Offline RanulfC

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Who is this informer that "informed you" otherwise? Stop being obtuse. If you claim that you were right originally but everyone else convinced you that you had to be wrong, then you have a *very* unique recollection of the F9 reusable speculation threads.

As I noted I seem to recall it was Musk who said that "engine-first" was never mentioned or implied...

And I'm NOTHING if not "unique" as we've discussed before but I'll point out that IF I was "incorrect" no one ever pointed out the obvious either :)
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(And now you are pulling the same stunt on the second stage reuse thread, missing the forest for the trees)
Have at thee sir, the thread IS open :)

Quote
Yes, the animation didn't show everything, but the gist of it was there in plain sight. How else did you imagine it would work, with the giant air scoop of a trunk attached? How was that possibly going to work?
Trunk? Interstage? If you look at the CGI it didn't look like that was in place after seperation it looked just like the "bare" forward dome section.
I read a lot of the re-entry threads. No one ever thought they were going to perform any part of the reentry with the engines at the rear.

Wasn't the impression I got during some of the more heated discussions. Not really an "issue" at this point since it is what it is :)
Quote
You are missing one absolutely enormous and completely obvious reason why:

Boost back. Reusability has always targeted landing close the the original launch pad so the stages can be reused without moving them very far. Otherwise, there is no point. Elon has always talked like this. Landing on a barge has just come up recently, and seems to be related to the fact that the pad in NM is still not done so they have not been able to prove to the FAA they have the chops to bring it home.

Not sure how that applies at all unless you were expecting the first recovery to "down-range" from Vandenbugh? Otherwise how are you "showing" your chops by NOT flying a full flight profile? New Mexico is going to take some doing to be an issue...

The barge idea is, I suspect something that would allow recovery without boost-back (allowing more performance from the first stage) and to show that pin-point landing can take place in a down-range location rather than a regular ocean landing. The fact that SpaceX is taking the effort to challenge the BO patents tells me they may be looking at it as an operational as well as practice procedure. (Though the whole barge idea may just be misinterpretation and they are more interested in the aerodynamic pointers/decellerators part :)

Randy
From The Amazing Catstronaut on the Black Arrow LV:
British physics, old chap. It's undignified to belch flames and effluvia all over the pad, what. A true gentlemen's orbital conveyance lifts itself into the air unostentatiously, with the minimum of spectacle and a modicum of grace. Not like our American cousins' launch vehicles, eh?

Offline oiorionsbelt

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MECO and stage separation.
180 degree maneuver to engine first attitude while still outside of the atmosphere.
Ballistic coast.
Braking/entry burn at atmospheric interface.
Unpowered drag deceleration to lower atmosphere.
Landing deceleration burn.
.
Edit:  during the ballistic coast there has to be another 180 degree flip to return to engines first orientation for the breaking/entry and landing burns
« Last Edit: 09/29/2014 09:44 pm by oiorionsbelt »

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