In a recent question asked here, it was asked what debris falling from a Rocket Lab Electron Rocket was during launch.


Electron rocket launching, with ice debris falling off the side of the rocket

The answer, was that it was ice that had formed after cryogenic fuel/oxidiser tanks were filled, and that vibrations/other stresses caused it to fall off during launch.

This lead to a comment:

Why don't American and Ariane rockets seem to have the same problem?

Why don't they have this problem? Or do they indeed have the ice problem?

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    $\begingroup$ SpaceX Iridium 7 launch I noticed some ice fall off on the camera feed. It was just a second. Shuttle infamously had icing issues. Delta Heavy sets itself on fire and burns the ice off (Kidding, just like the sets itself on fire joke). Atlas V has ice fall off at launch usually as well. (LOX not RP1 tanks). Falcon soot patterns on reused boosters show where LOX tanks were, since the ice protects from charring/sooting. $\endgroup$ – geoffc Jul 26 '18 at 14:49
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    $\begingroup$ spacex.com/sites/spacex/files/falcon_9_thaicom_engines.jpg shows some ice too $\endgroup$ – jkavalik Jul 26 '18 at 14:52
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    $\begingroup$ If you watch yesterday's Ariane 5 launch you can see ice falling away. $\endgroup$ – Jack Jul 26 '18 at 14:56
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    $\begingroup$ that's not ice shedding, that's covers coming away. $\endgroup$ – Hobbes Jul 26 '18 at 16:06
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    $\begingroup$ @JRCM: for Ariane 5 at least, the premise is not false. $\endgroup$ – Hobbes Jul 26 '18 at 16:26

Ariane 5 does not shed ice at liftoff. The first stage is covered in foam insulation that prevents ice buildup.

enter image description here

In this image, the insulation is the brown stuff. Later Ariane 5 versions switched to light-blue insulation tiles.

The Shuttle had insulation on its External Tank for the same purpose. For the Shuttle, it was critical not to have chunks of ice break off from the ET and strike the (fragile) heat shield tiles of the orbiter.

Other launchers (like the Falcon 9) do without the insulation and accept the ice buildup. This question gives some examples and shows how much ice would build up.

  • $\begingroup$ Really interesting - I always thought the small pieces were from uninsulated areas $\endgroup$ – Jack Jul 26 '18 at 17:54
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    $\begingroup$ Does this mean there is no external icing or that it's significantly reduced? $\endgroup$ – Jack Jul 26 '18 at 18:12
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    $\begingroup$ Any ice is trapped inside the foam, but this is closed-cell foam so should be minimal. The Shuttle ET foam trapped quite a bit of ice. $\endgroup$ – Hobbes Jul 26 '18 at 18:30

They do.

Ariane 5 uses Liquid Oxygen/Liquid Hydrogen for its main stage engine, so ice accumulation on the body also occurs. See this video for a very clear example of it falling away, but on most launches it's still visible.

Editors note: these highlighted panels are NOT ice, they are covers for the SRB attachment points. See this answer.

An Ariane 5 launch showing ice debris

Here's ice falling from a SpaceX vehicle:

Ice falling from a SpaceX Falcon rocket launch

This question gives more examples with images of US-based launches demonstrating the same phenomenon.


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