An official investigation into the deadly crash of a Virgin Galactic SpaceShipTwo over California last October finds that a co-pilot unlocked the ship’s braking system too early. The incident, according to the US National Transportation and Safety Board’s report, could have been prevented with better safety procedures.
At 17:19 GMT on October 31st, 2014, a Virgin Galactic SpaceShipTwo—a prototype vehicle designed to ferry tourists to the edge of space and back—took off from the from the Mojave Air and Space Port onboard a carrier aircraft. The test flight marked the first use of a new hybrid type of rocket motor, along with a new, plastic-based fuel.
It was a short-lived attempt. Seconds after separating from its carrier aircraft and igniting its engine, the spacecraft, flown by two civilian pilots from Virgin Galactic partner Space Composites, broke into pieces and fell back to Earth.
Virgin Galactic rocket separating from the carrier aircraft prior to exploding. Image via AP/ Ken Brown
SpaceShipTwo’s explosion in October. Image via AP / Ken Brown.
Secondhand reports at the time indicated that there seemed to be some sort of explosion:
Just talked to Ken Brown. Pictures show Engine fired fine, then there's a white plume. He thinks the nitrous oxide tank blew. #SpaceShipTwo
But according to the NTSB’s official investigation, the breakup was not due to an engine failure. Rather, it was caused by early deployment of the ship’s feathering system by co-pilot Michael Alsbury. CNET reports:
In a normal flight, the ship rockets up and out of the atmosphere and then, momentum exhausted, falls gently back to earth. The wings fold backwards at this point to stabilize the return journey. Those wings are supposed to be locked in place until the ship accelerates through a speed of Mach 1.4 (just over 1,000mph, or 1,700kmph). However, according to the NTSB report, co-pilot Michael Alsbury released those locks early, at just Mach 0.92. Four seconds later, the ship flew into pieces.
Alsbury tragically lost his life in the accident. Pilot Peter Siebold’s seat was thrown clear, allowing him to release his harness and deploy his parachute.
The crash was considered a major setback for the aspiring space tourism company, which has been promising to ferry civilians out of Earth’s atmosphere for over a decade. An earlier accident involving a SpaceShipTwo rocket system claimed the lives of three Scaled Composite employees in 2007.
The NTSB report found that the pilots were properly certified, qualified, and not experiencing fatigue or other medical issues at the time of the incident. However, it does seems that a lack of experience with the SpaceShipTwo’s systems, and the particular challenges of rocket-based flight might have contributed to the failure:
NTSB Finding 3: the copilot was experiencing high workload as a result of recalling tasks from memory while performing under time pressure..
Finding 3: ...and with vibration and loads he is not recently experienced which increase the opportunity for errors.
Another disturbing revelation: In 2013, the FAA issued Scaled Composites a safety waiver for SpaceShipTwo. The waiver, posted on the website parabolicarc.com this morning, essentially gave Virgin Galactic’s partner company license to carry out crewed flight tests without conducting an analysis of “hazards resulting from human and software error.” The FAA apparently issued the waiver “because the SS2 operation will not jeopardize public health and safety or safety of property, national security or foreign policy interests of the United States, and is in the public interest.”
According to the waiver:
A hazard analysis serves to reduce risk to the public by limiting the possibility of a vehicle mishap. Although Scaled did not complete its hazard analysis as required by the regulations, the combination of its training program, incremental approach to flight testing, use of chase planes, and two-pilot model, as well as the limited duration of the permit and thus the waiver, the remoteness of its operating area and its use of a winged vehicle combine to allow the FAA to find that Scaled’s activities will not jeopardize public health and safety or safety of property.
Huh. In hindsight, there might have been a few, er, teensy lapses in judgement on the part of the FAA:
In retrospect, FAA waiver looks ridiculous. Doesn't anticipate any of the things that went wrong actually going wrong http://t.co/d9ehNOIxPi
FAA waiver assumes either ability to recover from problem and glide back to Mojave or that it wouldn't hit anything if it broke up.
The cockpit containing Mike Alsbury nearly hit two truck drivers. http://t.co/Zsf9mcjMS8
FAA's calculations of people per square mile didn't take into account construction projects in the Koehn Dry Lake area.
At the NTSB’s recommendation, Virgin Galactic and Scaled Composites have already implemented several additional safety features, including a mechanical lock that will prevent the SS2’s feathering system from premature deployment, and a change to the checklist and call-outs pilots must go through before unlocking that system.
It remains to be seen when Virgin Galactic will resume testing.
Top image: Debris from the crash sits in the Mohave Desert on Nov.3. Image via Getty / Sandy Huffaker