Request Meco effect

[Interceptor]

Hey Guys you know it would be really cool if somebody could make a meco effect, for the space shuttle or shuttle fleet. The kind where when main engine cuttoff happens you roll foward in the cockpit like in the scene from Apollo 13. I wonder if it could be done. Ok orbiter design gurus lets here what you have to say.Thanks

 

[garyw]

You mean where the crew go from 3.5g's pushing them back to 0g?

I'm no addon developer and I don't know how easy it would be to change the VC in the shuttle but what would be point of such an add on?

 

[Interceptor]

I don't know garyw. I just think it would be kind of a neat effect. When I was at the Kennedy Space center last week. While I was visiting my Father he and I went on the space shuttle simulater, and it had the meco 3.5gs to 0gs and it was kind of an exciting feeling. I just think it would be kind of cool for orbiter. Thanks

 

[Orbinaut Pete]

You're best option would probably be to make an effect that shoots the camera forward at MECO, with a bit of added shake.

 

[tblaxland]

I went on the space shuttle simulater, and it had the meco 3.5gs to 0gs and it was kind of an exciting feeling.

I don't doubt that it would be exciting to go from 3.5g to 0g, but how exactly did you get that sensation in the space shuttle simulator?

About the closest I ever got to a 3.5g acceleration with my Dad was when he kicked me in the a***!

You're best option would probably be to make an effect that shoots the camera forward at MECO, with a bit of added shake.

That would be doable, even in generic form, but MECO detection (as opposed to detecting OMS shutdown, for example) would be more reliable if it was done in vessel. Some vessels simulate camera shake, so it could be an extension of that effect.

 

[FordPrefect]

Once again, I yet fail to see how this "thrown forward effect" at MECO should be realistic. In my mind, the requested effect of the OP is nothing but a movie effect. Not that there is something wrong with that, but just to clarify.

Can somebody enlighten me, which force actually will kick the astronauts forward at MECO? I shall stand corrected if my ideas about this are wrong.

I think the scene in Apollo 13 for example was totally exaggerated. The astronauts are thrown forward into their straps and are pressed forward "hanging in there" almost helplessly, however, this implies that the booster was decelerating with at least 1G right after engine cut-off of the S-1C stage and before ignition of the second stage. I seriously doubt that. The only thing that could cause a slight jolt forward would be the back-pressure of the seat backs (having been under tension during acceleration). And that and only that may apply to the Shuttle seats as well.
Perhaps not the best example, but watch

getting flung off a carrier deck. The forward acceleration is around 3G's during the cat-shot, yet after leaving the deck, the pilots body or head are far from being nudged or even kicked forward.

Better yet: Watch this video, at 10:22 minutes you will see how much the astronauts are thrown forward during MECO! Not at all.

 

[Urwumpe]

The Apollo 13 depiction of the engine cut-off was right, but you have to remember something else to explain it: The seats. The seats in Apollo have their own shock dampers for allowing even land landings, which release the 290 kg tension at engine cut-off. The Shuttle seats don't, the shuttle lands horizontally and the landing gear has it's own shock dampers.

In the shuttle, you only have a slow release of the tension of the MS seats, but the pilots for example are not thrown forward at all.

 

[Orbinaut Pete]

Real MECO effect on the Shuttle is not that you are "thrown forward" as such, just that you return to normal - the SSME's were pushing you back, but then they stop, and you jerk forward.

So I think that for MECO, maybe the seats moving forward + the camera with them would do.

Maybe someone could create a camera shake plugin just for SSU, that included launch effects, MECO, OMS burns etc?

 

[Urwumpe]

Maybe someone could create a camera shake plugin just for SSU, that included launch effects, MECO, OMS burns etc?

If at all, such things (manipulation of the VC) would be handled internally, and are not planned for a while.

 

[T.Neo]

I think the scene in Apollo 13 for example was totally exaggerated.

I think I saw an interview of an Apollo astronaut where he said that the crew was "pushed forward", as the stage seperated, then back again as the second stage took hold.

I dunno. Maybe this particular instance has to do with staging, not MECO.

 

[Interceptor]

Yeah they probably could simulate with cameshake1.1. Oh and TBLAXLAND I really don't know how they simulated but It was cool nuff said. Thanks

 

[Urwumpe]

Yeah they probably could simulate with cameshake1.1. Oh and TBLAXLAND I really don't know how they simulated but It was cool nuff said. Thanks

Camshake does not work well with SSU, we have a small list of bugs caused by it.

 

[T.Neo]

Camshake does not work well with SSU, we have a small list of bugs caused by it.

What bugs?

 

[Urwumpe]

For example staging making the camera view end in the middle of nowhere.

 

[T.Neo]

Ah.

 

[Interceptor]

Yeah! Camshake won't work in Gazzas STS Payloads V2 either causes CTD all the time.

 

[Urwumpe]

Yes. But I am sure I will add such a function during one of the next versions. It is just not planned to have it and I don't want to add a new function soon.

 

[movieman]

The Apollo 13 depiction of the engine cut-off was right, but you have to remember something else to explain it: The seats. The seats in Apollo have their own shock dampers for allowing even land landings, which release the 290 kg tension at engine cut-off.

I've read that the shock absorbers were locked during launch, but I'm not certain of that; I'm not sure how they'd handle an abort if that was true.

Two other issues are that the force of five F-1 engines going through the stack actually compresses it by a few inches while they're firing, and in the Apollo 13 case I believe the retros on the SIc stage fired before it separated, which would have given the stack a small rearward acceleration (they're not big enough to give it a real hard push). In addition, aren't they still low enough at that point to have a noticeable deceleration due to drag?

I do agree though that the sequence in the movie was probably exaggerated for effect.

 

[Urwumpe]

I've read that the shock absorbers were locked during launch, but I'm not certain of that; I'm not sure how they'd handle an abort if that was true.

I am not sure if the absorber had been unlocked before lift-off. In case of a pad abort, you would need to unlock them quickly anyway.

Two other issues are that the force of five F-1 engines going through the stack actually compresses it by a few inches while they're firing, and in the Apollo 13 case I believe the retros on the SIc stage fired before it separated, which would have given the stack a small rearward acceleration (they're not big enough to give it a real hard push). In addition, aren't they still low enough at that point to have a noticeable deceleration due to drag?

Possible. but the retros should not create that much acceleration. These 8 rockets are pretty weak.

I do agree though that the sequence in the movie was probably exaggerated for effect.

We will never know for sure, unless we launch a Saturn V. But I, for my own part, think it was in the worst case, only slightly exaggerated and that most likely not intentionally, but from the dramatic accounts of the astronauts.

The acceleration plots of the Saturn V rocket are tough enough for making it realistic.

 

[astrosammy]

It's not exaggerated:

Suddenly, the rocket cut off. The primer cord sheared off the first stage. Instantaneously, some retro rockets fired. It felt like I was being catapulted right through the instrument panel. Ok - so I threw my hand up. About the time my hand got up here, the second stage cut in - whack! So I looked up and I had my face, my helmet on and here was this gash across my helmet and I thought "oh gosh, you know, when the big boys see this, you know, it's gonna, just, you know, justify the rookie position." Well, we made it into orbit and somewhere along the line, I collected the helmets and I noticed the other two guys each had a slash.

source: Apollo 8 video here: http://www.nasa.gov/externalflash/apollo40/