In an update released by SpaceX itself, the aerospace manufacturer says it spent thousands of hours analyzing flight data and matching it against rocket systems to come up with what it’s calling a “preliminary assessment.” Though SpaceX plans to continue the investigation, it feels confident the flawed strut which blew during the rocket’s ascension is the main cause for the explosion. It also reports that several hundred struts fly on each mission, with each designed to brace for up to 10,000 lbs of force. Unfortunately for the CRS-7, the failed strut blew at just 2,000 lbs of force.
What makes this strut so much more important than others aboard the CRS-7 is the fact it braced a container of helium within the second-stage liquid oxygen tank. When it eventually blew — at approximately 139 seconds into the flight — the helium bottle began releasing its contents into the oxygen, rapidly increasing the pressure of the tank. The pressure increased so quickly that just 0.893 seconds elapsed between the initial signal of trouble, to when the rocket completely exploded.
During a recent telephone news conference, Musk himself deemed the accident a likely product of company complacency, citing continued success — before CRS-7 obviously — as the reason why. Until last month’s failure, SpaceX saw essentially 18 consecutive successful launches dating back to June of 2010. Musk also added during the call the team plans to continue assessing all aspects of the launch to make sure the strut was the only part of the rocket responsible for CRS-7’s demise.
Despite the explosion seeming like an obvious setback even for a company like SpaceX, the company says it expects to return to flights by this coming fall and intends to fulfill each launch for its list of customers in 2015. Musk and company also feel the explosion gives SpaceX an opportunity to manufacture safer launch vehicles, and remains confident in the program’s safety as it preps for the opportunity to take astronauts to the International Space Station in 2017.
