When it comes to heat, plastic is usually a pretty bad idea, which is why it has been advised not to use plastic together with hot things, like boiling soup, drinks, food, and etc. So if plastic isn’t advised for hot food, it probably makes sense that you wouldn’t use plastic for even hotter things, like a rocket motor, right?
However the folks at MIT have done just that (via Engadget) when they decided to cobble together a rocket motor that has been made out of 3D printed plastic parts. You might think that this would be a disaster, but surprisingly enough the plastic casing of the motor survived the initial thrust, although there was a small amount of damage to the motor’s throat, but other than that it wasn’t as if the casing melted or exploded from the heat.
The second test unfortunately did not fare well, although to be fair the researchers at MIT did not intend for it to fire up more than once. As to what is the point of having a rocket motor whose casing is only good for one use? The idea is that this can help to keep costs down since 3D printing metal can be expensive in terms of materials and the machine itself.
It can even be used in events where the rocket might only be needed to be used once, or for relatively short trips.