SpaceX and Tesla founder/owner Elon Musk says he believes the lithium-ion batteries installed on the troubled Boeing 787 aircraft are no good, by design. “Unfortunately, the pack architecture supplied to Boeing is inherently unsafe,” Musk says in correspondence with Flightglobal.com. “Large cells without enough space between them to isolate against the cell-to-cell thermal domino effect means it is simply a matter of time before there are more incidents of this nature.”