They're experimenting with 3mm steel instead of 4mm steel. A test tank they've built already passed an initial pressure test on 26 Jan. One Starship requires 1

They're experimenting with 3mm steel instead of 4mm steel. A test tank they've built already passed an initial pressure test on 26 Jan. One Starship requires 15 rings, a nosecone, a bottom and tanks. If they would all move from 4mm to 3mm then that would save a lot of weight. About 7-10 tonnes according to [1]. [1]: https://forum.nasaspaceflight.com/index.php?topic=52701.160 https://forum.nasaspaceflight.com/index.php?topic=52701.160