Smoke Trails With Momentum

[psychotix]

I was reading The Last Man On The Moon where Gene Cernan describes the trail of fire, left behind by the rocket, overtaking the capsule from the expansion of gasses when stages seperate. I think it would be a cool addon if somebody would be able to embody this in orbiter.

 

[Hielor]

The problem is that although that's a neat visual image, it's extremely unrealistic. Rocket exhaust is expelled at several thousand m/s backwards, so in order for it to catch up to the capsule at stage separation (which typically isn't until very high altitude anyway, when there's no visible smoke anyway) either the smoke would need to be accelerating past the rocket (not possible) or the capsule would need to be slowing down (which doesn't happen).

 

[Urwumpe]

I think he means the retro rockets. These should be pretty visible, at least for the S-IC stage.

 

[psychotix]

No. I read word for word about the launch of Gemini 9, "...bam, shutdown. We were thrown forward against our straps and lost enough momentum so that the gigantic fireball that had been tailing us, and still had motion of its own, wrapped the spacecraft in a black-ringed cloud of orange and red, roiling and writhing flames with pulsing smoke, like some kind of deadly Halloween horror. All I could see was fire..."

 

[Hielor]

No. I read word for word about the launch of Gemini 9, "...bam, shutdown. We were thrown forward against our straps and lost enough momentum so that the gigantic fireball that had been tailing us, and still had motion of its own, wrapped the spacecraft in a black-ringed cloud of orange and red, roiling and writhing flames with pulsing smoke, like some kind of deadly Halloween horror. All I could see was fire..."

That doesn't make any sense. How did the capsule *lose* momentum?

 

[Urwumpe]

That doesn't make any sense. How did the capsule *lose* momentum?

Exactly. It makes no sense. Unless the description describes retro rockets on the Gemini second stage (which is likely, as it is a ICBM).

Vernier engine operation could last for about 20 seconds. At sustainer shutdown, the guidance set sent a signal to ignite the verniers. They operated only until the guidance system verified final trajectory corrections and terminal velocity-then guidance generated a shutdown signal. Vernier thrust buildup required 0.2 second and complete thrust decay occurs within 0.5 second. When vernier thrust ended, powered flight was over. The R/V was then separated and the accessory rockets began their work. After R/V separation, the guidance set generated a signal to fire the pitch rockets. The pitch rockets back Stage II away from the R/V and moved it to a nearly vertical position relative to the earth. This movement was stopped by thrust from the depitch rockets, which were also fired by a guidance signal. The translation rockets were then fired to send Stage II toward the ground. The translation rockets thrust was terminated by jettisoning them in response to the final guidance discrete signal. To insure continuous operation of the liquid propellant rocket engines, the propellants must be provided at a steady continuous rate. The missile tank pressurization systems helped maintain this steady rate of flow.