SpaceX returns to space on Sunday as investigation closes

What should have been a glorious end to SpaceX's 2016 ended up in a blaze when, on 1st September, its Falcon 9 exploded even before it could get off the ground, taking Facebook's first satellite down with it. Now four months later, SpaceX is closing the books on its joint investigation with government agencies and industry experts. Having traced down the cause of that failed attempt, SpaceX will once again try its luck on 8th January in an attempt to start the year right.

The investigation, which involved not just SpaceX but also an alphabet soup of government agencies such as FAA, USAF, NTSB, and, of course, NASA, concluded that the accident was, indeed, caused by a rare but obviously fatal interplay of helium, liquid oxygen, aluminum, and carbon materials. Cold helium is used to main the pressure in the liquid oxygen tanks and this helium is stored in containers with aluminum inner liners and carbon overwraps.

At launch, helium is heated and released to maintain pressure in the tanks, but, in this case, the helium may have actually been colder than the oxygen, causing the oxygen to solidify in gaps between the aluminum liner and carbon overwrap. This created a volatile chemical soup that would have been easily excited by even the smallest friction, like movement from buckles supporting the liners. Such may have been the case with the ill-fated Falcon 9 launch in September.

With the case practically closed, SpaceX has implemented measures to prevent another "rare" accident, and just in time, too. Iridium Communications, SpaceX's next customer, is probably growing impatient. The mission, which should have launched in mid-December, would replace some of the company's aging satellites. For the sake of safety and completeness, SpaceX pushed the launch date back to early January. Now it seems confident enough that it won't with pie in its face a second time in six months.