The private space industry suffered a setback last Thursday when an explosion ripped through a rocket-engine test area in the California desert, killing three workers and seriously injuring three others.
The industry's first fatal accident is already becoming a defining event in the history of commercial spaceflight -- it's the private rocketeers' Apollo 1.
In 1967, NASA's first moon ship was swept by fire in a ground test, killing all three astronauts on board and forcing a re-evaluation of the Apollo space-capsule design. Thursday's accident will likely force a similar period of self-reflection for the new industry of commercial space travel.
The workers killed in Thursday's blast had been testing a nitrous-oxide delivery system for a commercial spaceship under construction by Scaled Composites for Richard Branson's Virgin Galactic. And while it's too early to tell what effect Scaled's accident will have on the industry as a whole, it's safe to say it will take more than this to put the commercial spaceflight genie back in its bottle.
Meanwhile, the three men who died -- Eric Blackwell, Todd Ivens and Charles Glen May -- are being remembered by others in the industry as heroes who died for a higher calling.
"We are reaching for the stars, and it is not easy," said space entrepreneur and Space Frontier Foundation co-founder Rick Tumlinson in a press release. "Accidents happen. Good people die. And we move on. We move on to reach the goal they died for, because to do less would be to dishonor them and their sacrifice."
Scaled Composites built and flew the first privately funded manned spacecraft, SpaceShipOne, and sent the first commercial astronauts out of the atmosphere in 2004. The company is still the favorite to win the race to send the first paying passengers on brief, suborbital jaunts with its SpaceShipTwo, though the accident is certain to delay the new ship's first flight. It may also give potential passengers reason to question the safety of travel by rocket.
The cause of the accident, which did not involve the firing of a rocket engine, won't be known until the just-begun investigation is complete. For now, Scaled managers won't publicly speculate on it. A shaken Burt Rutan, Scaled's CEO and the designer of many envelope-pushing air- and spacecraft, could only tell reporters the day of the accident, "We were doing a test we believe was safe. We don't know why it exploded. We just don't know."
Nitrous oxide, also called laughing gas for its intoxicating effects when inhaled, is nonflammable and safe to handle under most conditions. "Nitrous is manageable in the context of dentists, whipped-cream containers, hospitals, race cars, etc.," Tim Pickens, head of Orion Propulsion and one-time propulsion chief for SpaceShipOne told Wired News. "But we still have to respect it and remember that it has the potential to release lots of energy."
A 1974 study by the Air Force concluded that nitrous oxide can be handled safely in just about any conditions, as long as it stays in a supercold, liquid state, but warned that "great hazards exist in the gaseous condition at elevated pressure and/or temperature."
SpaceShipOne used nitrous oxide as an oxidizer to enable the combustion of a synthetic rubber rocket fuel. The nitrous oxide feeding the rocket engine remained liquid through most of the ship's flight, but turned gaseous toward the end of the rocket burn to reach space. SpaceShipTwo will use similar hybrid rocket technology, so-called because of the combination of solid fuel and liquid oxidizer.
While Scaled begins to pick up the pieces in an effort that's likely to take months, other private spaceship companies press onward. The European Aeronautic Defense and Space Company, prime contractor for the European Space Agency and owner of Airbus, announced in June that its EADS Astrium division would build its own tourist spaceship. The planned ship, a spaceplane the size of a business jet, features twin jet engines and a rocket engine powered by methane with liquid oxygen, or lox, as oxidizer.
EADS Astrium hopes to start construction in 2008 for first flights beginning in 2012 with financing from as-yet-unannounced business partners. The design borrows heavily from that of American company Rocketplane Kistler, which hopes to launch a jet-and-rocket hybrid built around a Learjet fuselage by 2009.
Amazon.com CEO Jeff Bezos has been quietly testing subscale versions of his planned New Shepard vertical-takeoff and -landing spaceship away from public view at a specially built launch facility in West Texas. Bezos won't talk to the press, but the website for his space startup, Blue Origin, says he wants to "lower the cost of spaceflight so that ... we humans can better continue exploring the solar system."
PayPal cofounder and head of Space Exploration Technologies, or SpaceX, is heading straight to orbit with his kerosene/lox Falcon rockets. A Falcon 1 test flight reached 200 miles in altitude last March, and SpaceX plans to launch a satellite into orbit later this year.
Musk's ultimate mission is to send people to Mars. Long before then, though, the first commercial space stations will likely open for use by researchers and thrill-seekers by 2012 if the plans of Las Vegas Real Estate developer Robert Bigelow come to fruition. Bigelow's company Bigelow Aerospace launched its second small-scale test satellite July 12 aboard a converted Russian ICBM. Large-scale tests will soon follow.