SpaceX says rocket accident probe focussing on fuelling system flaw

By Irene Klotz CAPE CANAVERAL, Fla. (Reuters) - SpaceX said on Friday a fuelling system problem is the most likely cause of a Sept. 1 launch pad explosion that destroyed a Falcon 9 rocket, a finding that takes the company a step closer to resuming flights that were grounded after the accident. The space launch company led by billionaire Elon Musk said it has not confirmed the cause of a failure in the fuelling system. However, the company said in a statement that testing at a facility in Texas had shown that a helium canister inside the rocket could burst depending on how it was filled. SpaceX halted flights while it investigated the cause of the accident. The company, which has a backlog of more than 70 missions worth over $10 billion, said it was working on developing new techniques to load helium into its rockets and hoped to be back flying before the end of the year. Helium is used to pressurize the liquid oxygen system. Accident investigators suspect that a canister of helium inside the liquid oxygen tank burst. “These conditions are mainly affected by the temperature and pressure of the helium being loaded,” SpaceX said in a statement. The Falcon 9 rocket was being filled with fuel at its Cape Canaveral Air Force Station launch pad for a routine, preflight engine test when a fireball burst out from around the booster’s upper-stage liquid oxygen tank. The blast destroyed a $200 million communications satellite owned by Israel’s Space Communication Ltd. The investigation is continuing, led by SpaceX with oversight from the Federal Aviation Administration’s space transportation office. SpaceX said NASA, the US Air Force and industry experts are also working to "investigate all plausible causes." (Reporting By Irene Klotz; Editing by Chris Reese and Andrew Hay)