Charismatic billionaire Richard Branson’s Virgin Galactic space tourism company was under acute stress well before last Friday’s mid-air disintegration of its sole commercial suborbital passenger craft the VSS Enterprise. Key safety and standards executives had left the company for whatever reasons, and founder Branson started making absurd, and to some observers, desperate statements that the start of space joy-flights would happen by the end of this year.
But the Enterprise, a SpaceShipTwo model designed and built by former business partner Scaled Composites, was to be powered by a new hybrid solid-liquid fuel in which grains of nylon plastic would be fed into a stream of nitrous oxide and burned in the combustion chamber. As of last Friday afternoon, the new fuel had not been burned in VSS Enterprise.
There are various reports that the test flight crew, co-pilot commander Peter Siebold and co-pilot Michael Alsbury had been concerned about the temperature of the stored high-pressure, liquefied nitrous oxide prior to departure. Whether those recent reports are correct or not, there were earlier reports of concerns about this problem dating back to a ground fuel test using nitrous oxide in 2007 which killed three engineers. The oxidiser is considered dangerously unstable as it reaches temperatures where the liquid form turns to gas.
Enterprise was lifted by another special craft to 50,000 feet and dropped, as intended prior to engine ignition. Several seconds after the rocket fired up the flame appeared to go out, and shortly after that a cloud of unburned fuel appeared to surround the suddenly tumbling space craft, which broke up, with some evidence of flame seen through the mist that enveloped the by-then wingless fuselage. Peter Siebold parachuted to safety but was seriously injured. Michael Alsbury was found dead amid the wreckage.
Virgin Galactic, set up in 2004, had initially promised to start its paid thrill rides in 2007 using a fleet of five SpaceShipTwos. The only such vehicle built for it by Scaled Composites has now been destroyed, performing an experimental flight that was supposed to help clear the same craft to carry up to six passengers at US$250,000 each by year’s end.
The second such space ship, the VSS Voyager, won’t be ready until at least 2016, and it is now being built solely by Virgin Galactic, after its construction and design joint venture with Scaled Composites ended in 2012.
The results of the accident investigation by America’s National Transportation Safety Board will take at least a year. It has the power to recommend changes to the design and the fuel system, which could take many years and hundreds of millions of dollars to implement, a task made even more difficult for a Virgin Galactic that no longer has its spaceship designer or its skill base on board, and may not have its claimed 800 customers ready to pay up and board either.
There is no doubt in the space industry that mass space tourism will come to pass — eventually. But it doesn’t look like it will happen the Virgin way.