View Full Version : Extremely OT: rocket launches

06-07-2004, 07:17 AM
I had no place to ask this question and since this is such a nice community, I decided to post my question here. Mods, feel free to move it/remove it.

A few days ago I watched some footages from apollo missions.
I've seen rocket launches on tv before and a particular kind of thing always seems to happen. Please explain it to me.. if possible.

Q1a: What the hell are those things falling down from the rocket during the first seconds of the ascend? It looks like ice cover breaking up or something. Is it getting cold enough in Florida to form ice? Maybe the rocked body is cold?

Q1b: There is a lot of smoke too, obviously, but where are those small puffs of smoke or vapor that are suddenly forming all over the rocket coming from? Is it water that evaporates or something else?

06-07-2004, 10:21 AM
I attached reference quicktimes I have found. Please excuse poor quality. I could not find better.

Apo14a.mov: At 18 seconds on the top-left part you can see pieces of "stuff" falling down. At 24 seconds, top-left and at 27 bottom left you can see some more.

Apo15a.mov: from 10th second to approx. 20th you can see puffs of vapor coming from the rocket as well as the launch tower.

06-07-2004, 10:55 AM
It's mostly condensation. Just like the water that forms on the outside of ice cold soda. Except this is forming on tanks of liquid oxygen and therfore sub zero temperatures, so you get ice. I'm pretty sure the "puffs" are the support umbilical lines separating at liftoff.

06-07-2004, 08:05 PM
The white "stuff" that is falling down is ice as mentioned by 'hunter'.

The puffs coming from the rocket are from the same ice as mentioned above, dislodged from the rocket falling then super heated to gas from the heat of the rocket blast.

As for the tower there appears to be piping running up the outside of the tower probably for pumping the liquid o2 into the shuttle. This will also form condensation as with the rocket, with the same dislodgement and superheating as above.

Note: I'm not a rocket scientist :) so i can not say that the above is 100% accurate, but it would seem to be appropriate.

I'm sure if you asked at a website related to nasa and or space travel you may get more technically correct answers.

06-10-2004, 03:29 PM
A related factoid:

If you've ever seen the large nozzles of the rocket engines you'll notice the ridged texture. This is actually a tube that coils around the nozzle, the liquid oxygen is fed to the engine through this tube. Since the liquid oxygen is pretty damn cold (it boils at -183 C) it serves a dual role of coolant and propellant. Damn elegant. Hats off to those German engineers. Now if only the Brits would share their Cavorite.;)