NASA and several partner firms have been working on the X-57 Maxwell electric propulsion demonstrator for the past several years. It hasn’t been as easy as it looked at first. Encouragingly, NASA is sharing some of the hard lessons it has learned in the process, much like Elon Musk sharing many of his patents with the world. One of the hardest lessons involved the multiple battery packs, originally planned to be off-the-shelf units. A December 2016 test resulted in a thermal runaway, a situation in which one cell that overheats can self-destruct and cause adjacent cells to follow suit. This, as we’ve seen in Dreamliner incidents, can be dangerous and potentially deadly. Such fires are exceedingly well reported, with any Tesla …
