The shop I was working at in \'03 did a lot of work for a subsidiary of General Dynamics in Redmond Wa. that specialized in gas generators, air bag technology. We ended up machining the canisters and pistons for the high speed, low atmosphere re-entry parachutes for both rovers. Machined them from billet alum. approx. 12
in. dia. by 18in. lg. They ended up weighing next to nothing. One of the coolest projects I made tooling for.
Gary