It seems somewhat trite to say it but rocket science is hard. Ask anyone who lived near a NASA testing site back in the heydays of the space program and they’ll regale you with stories of numerous rockets thundering skyward only to meet their fate shortly after. There is no universal reason behind rockets exploding as there are so many things in which a failure leads to a rapid, unplanned deconstruction event. The only universal truth behind sending things into orbit atop a giant continuous explosion is that one day one of your rockets will end up blowing itself to bits. Today that has happened to SpaceX.
The CRS-7 mission was SpaceX’s 7th commercial resupply mission to the International Space Station with its primary payload consisting of around 1800kgs of supplies and equipment. The most important piece of cargo it was carrying was the International Docking Adapter (IDA-1) which would have been used to convert one of the current Pressurized Mating Adapters to the new NASA Docking System. This would have allowed resupply craft such as the Dragon capsule to dock directly with the ISS rather than being grappled and attached, which is currently not the preferred method for coupling craft (especially for crew egress in emergency). Other payloads included things like the Meteor Shower Camera which was actually a backup camera as the primary was lost in the Antares rocket explosion of last year.
Elon Musk tweeted shortly after the incident that the cause appears to be an overpressure event in the upper stage LOX tank. Watching the video you can see what he’s alluding to here as shortly after take off there appears to be a rupture in the upper tank which leads to the massive cloud of gas enveloping the rocket. The event happened shortly after the rocket reached max-q, the point at which the aerodynamic stresses on the craft have reached their maximum. It’s possible that the combination of a high pressure event coinciding with max-q was enough to rupture the tank which then led to its demise. SpaceX is still continuing its investigation however and we’ll have a full picture once they conduct a full fault analysis.
A few keen observers have noted that unlike other rocket failures, which usually end in a rather spectacular fireball, it appears that the payload capsule may have survived. The press conference held shortly after made mention of telemetry data being received for some time after the explosion had occurred which would indicate that the capsule did manage to survive. However it’s unlikely that the payload would be retrievable as no one has mentioned seeing parachutes after the explosion happened. It would be a great boon to the few secondary payloads if they were able to be recovered but I’m certain none of them are holding their breath.
This marks the first failed launch out of 18 for SpaceX’s Falcon-9 program, a milestone I’m sure none were hoping they’d mark. Putting that in perspective though this is a 13 year old space company who’s managed to do things that took their competitors decades to do. I’m sure the investigations that are currently underway will identify the cause in short order and future flights will not suffer the same fate. My heart goes out to all the engineers at SpaceX during this time as it cannot be easy picking through the debris of your flagship rocket.