Future space colonists hoping to make structures out of local materials will face a serious construction challenge: metal-rich asteroids are not suited to current welding techniques.

Electron-beam welding has been used in space to join materials such as steel, but it was unknown whether the technique would work on extraterrestrial materials. John Elmer and his colleagues at the Lawrence Livermore National Laboratory in California welded a fragment of the Canyon Diablo meteorite — a 57,000-tonne iron-rich rock that hit Arizona 50,000 years ago — using an electron beam under a vacuum. High levels of phosphorous in the meteorite created cracks as the weld cooled, and the high carbon content made the weld harder than the surrounding material, leading to a weak joint.

Sci. Technol. Weld. Join. http://dx.doi.org/10.1179/1362171813Y.0000000188 (2014)