"filth" falling off rockets after lift-off

[MmPMSFmM]

Take a random launch, any launch is OK. Take a look at the rocket right after lift-off and you see these pieces of (... stuff?) flying off. I took an random image of a falcon-9 launch off the internet, and edited it a bit. This clearly shows stuff falling off the rocket right after lift-off.

Sooo... I was wondering what this stuff is, and why it falls off. And fun fact here, it's one of the few things, of which you just need to know what it is, to look up what it is. (Or of course, it really is not on the internet... Meh, probably just hard to find.)

[Paprika]

Is it ice?

[trvtannenberg]

It's probably ice, but i'm not sure.

Edited August 1, 2013 by trvtannenberg
grammar

[Awaras]

It's ice.

The rockets use liquid hydrogen and liquid oxygen as fuel. They are very, very cold. The water vapor in the air condenses on the rocket and freezes.

[Flixxbeatz]

Looks like ice to me, probably due to the propellants, since Proton doesn't have one...

[Apotheosist]

I believe it's ice forming from the moisture in the air. The falcon 9 has ice on it because it uses liquid oxygen as an oxidizer, which is very cold (about minus 180 degrees Celsius), cold enough to form ice on the outside of the liquid oxygen tanks. This ice is falls off during liftoff because of the vibration and movement of the rocket. There is no ice on the kerosene tank as the kerosene is at ambient temperature. This ice only forms on rockets with cryogenic (very cold) propellants. The proton rocket doesent have ice on it because it uses dinitrogen tetroxide, not liquid oxygen.

However, not all rockets using cryogenic propellants have ice on them at liftoff. Rockets with liquid hydrogen don't usually have ice forming on the outside of the tanks, because they are usually well insulated. Liquid hydrogen tanks have to be well insulated because it is cold enough to liquify, even freeze the oxygen in the air. Having frozen oxygen on the outside of your tanks is much more dangerous than just frozen water.

Take a look at the space shuttle external tank, you don't see ice falling off that at liftoff. That is because it has that orange/brown foam insulation around it. Having ice falling off that tank would be VERY dangerous as it could hit the shuttle orbiter. For other rockets that don't have their payload latched on to the side, but on top, like the Falcon 9 or Saturn V, It's ok to let the ice fall off. Adding insulation would just be extra weight.

[Redjoker]

For many rockets it can be foam insulation. For example this was a common occurrence for the space shuttle, where it would return with small pieces of its heat tiles damaged from foam and the Columbia accident was caused by an abnormally large piece of this foam hitting the wing at 530mph.

[Kryten]

Do we have any idea about this one?

Seems to be routine for this launcher model. Room-temperature propellants like Proton, so no ice and no insulation; and there seems to be a heck of a lot of whatever it is.

[Bobiii11121]

From what i remember they use something like plastic to hold the rocket, and its very easy to break it, so it just breakes while they start.

Correct me if im wrong

[Tiberion]

The SpaceX shot is definitely Ice. If you watch it on the pad during fuel up you can actually see the tank frosting over and the blue text disappearing under the ice layer.

[CtrlAltEL1TE]

Do we have any idea about this one?

Seems to be routine for this launcher model. Room-temperature propellants like Proton, so no ice and no insulation; and there seems to be a heck of a lot of whatever it is.

"Made in China"

[sojourner]

Do we have any idea about this one?

Seems to be routine for this launcher model. Room-temperature propellants like Proton, so no ice and no insulation; and there seems to be a heck of a lot of whatever it is.

While all of these rockets use Rp-1 at room temperature for propellant, they also use liquid oxygen as oxidizer. Hence the ice. The reason the Proton has little to no ice is down to climate at the launch site. If there's low humidity, then there is no moisture in the air to condense into ice.

Falcon 9 to date has launched from Canaveral Airforce Station in Florida. Florida has very high humidity most of the year resulting in icy stages.

[rdfox]

Er, no. Proton doesn't use RP-1 or LOX at all; it uses hypergolics--specifically, unsymmetrical dimethyl hydrazine fuel and nitrogen tetroxide oxidizer. These are both room-temperature chemicals.

You're right, however, that any rocket using RP-1 will still generate ice due to the LOX oxidizer, and that you'll get a hell of a lot more ice formation in a humid climate like CCAFS than an arid one like Baikonur...

[sojourner]

Ah, my bad on the Proton. And on further research, that appears to be a Long March in the image above which also use hypergolics. So no idea what that debris is as it would be neither ice nor insulation.

The Falcon 9 is definitely ice.

[Apotheosist]

I think with the Chinese one it's stuff falling off from the structure between the stages. If you look at the sequence of photos, when the rocket is closer to the ground, you can not see the open structure. You can only see the open structure later on, after the white debris has fallen off. This open structure between stages is typical in Russian rockets like the Proton and Soyuz. So yeah my bet is it's just thin material used to cover up the open structure, to stop any debris getting in there during assembly, transportation, on the pad etc.

[Motokid600]

For many rockets it can be foam insulation. For example this was a common occurrence for the space shuttle, where it would return with small pieces of its heat tiles damaged from foam and the Columbia accident was caused by an abnormally large piece of this foam hitting the wing at 530mph.

I remember watching the test. They fired the foam out of an air cannon. It went right through the heat shield like tin foil. Not a lot of words were said afterwards. I remember sitting there with my mouth open thinking oh..my..god. That sucked something fierce. So stupid. Those people suffered the most horrific death..because of a piece if f****ing foam.

[Mr Shifty]

Take a look at the space shuttle external tank, you don't see ice falling off that at liftoff.

There were scheduled countdown holds during Shuttle launches to inspect for ice:

http://www.universetoday.com/65394/first-ever-video-of-nasas-ice-team/

[Sickle]

Oxidizer and Coolant are Very cold liquids, they are kept inside the rockets with minimal Insulation, but sufficient to keep them from Evaporating, the Air on the outside of the Rocket then freezes onto the side of the Fuselage. Take an Ice-pop for example the plastic has ice on the outside of it. This is why on Tower Cameras during liftoff stages you get the water all over the lens.

[magnemoe]

I think with the Chinese one it's stuff falling off from the structure between the stages. If you look at the sequence of photos, when the rocket is closer to the ground, you can not see the open structure. You can only see the open structure later on, after the white debris has fallen off. This open structure between stages is typical in Russian rockets like the Proton and Soyuz. So yeah my bet is it's just thin material used to cover up the open structure, to stop any debris getting in there during assembly, transportation, on the pad etc.

Make me wonder why they keep the open structure instead of covering during launch if as it must create drag?

[Sma]

There were scheduled countdown holds during Shuttle launches to inspect for ice:

http://www.universetoday.com/65394/first-ever-video-of-nasas-ice-team/

Yep, and to add they had what they called the "Ice team" I believe. (just saw the link for the video ) In the case of the shuttle, the ice usually formed around the vents on I THINK to some extent the fuel transfer lines between the ET and shuttle. Also with the shuttle, they had tyvec covers over the thruster ports, that usually blew off during launch.

Make me wonder why they keep the open structure instead of covering during launch if as it must create drag?

I've wondered that too, though I don't think the Chinese are the only ones that have that. Not sure what the reasoning for this is, unless they're being lazy and letting excess gas escape that way, or something lol. Of course I could google it, but meh.

[NASAFanboy]

Ice or blowout panels.

Most likely ice

[xenomorph555]

Do we have any idea about this one?

http://news.xinhuanet.com/english/sci/2013-07/15/132543262_11n.jpg

Seems to be routine for this launcher model. Room-temperature propellants like Proton, so no ice and no insulation; and there seems to be a heck of a lot of whatever it is.

The chinese DONT use cold fuel like lox or lh, they use room tempreture fuels like hydrazine.

It has nothing to do with drag or structure, merely no ice or plastic to fall off.

[J.Random]

Even with hypergolics, shouldn't there be a small tank with neutral gas, like helium, to "fill the void" made by spent fuel in fuel tanks? Probably, also liquid and cold?

[xenomorph555]

Even with hypergolics, shouldn't there be a small tank with neutral gas, like helium, to "fill the void" made by spent fuel in fuel tanks? Probably, also liquid and cold?

I don't think it's cold enough to make ice, just compact it.

[softweir]

Even with hypergolics, shouldn't there be a small tank with neutral gas, like helium, to "fill the void" made by spent fuel in fuel tanks? Probably, also liquid and cold?

No, just highly compressed. The tank will get chilly as the gas is bled out of it, but it won't get down to freezing until the rocket is quite high up, by which time there will be very little atmospheric moisture available for any freezing.