SpaceDaily has an essay today (it actually was posted late last night) by Jeffrey Bell titled “Rocket Plane Roulette”. In it, Bell argues that rocket-powered winged vehicles are inherently unsafe (based on their track record), and that they are likely to be involved in accident(s) shortly after their introduction as space tourism vehicles, which will, in turn, result in lawsuits and regulation that will kill the industry. Not exactly a feel-good article.
I will leave it to other more technically competent to pick apart Prof. Bell’s arguments (IANAAE - I am not an aerospace engineer) but I do see some flaws in his arguments. Much of his belief that rocketplanes are inherently unsafe is based on his examination of “the safety history of research rocketplanes in the US and UK”. Well, there’s a problem right there: experimental vehicles are going to have a much higher failure rate than operational commercial vehicles, because they’re pushing the envelope in terms of speed, altitude, and the like. Bell even concedes this: after going through the history of X-15 and rocketplane failures, he concludes, “Are these safety statistics relevant to the 21st-century commercial operators? Probably not.”
Prof. Bell later argues that “It is unlikely that any tourist rocket operator will be able to afford a comprehensive test program.” But what is a comprehensive test program? He hints at something approaching the much larger number of test flights needed for FAA aircraft certification, but doesn’t spell out the specifics. I will point readers to an article I published Monday in The Space Review that includes a section on when such vehicles will be safe enough for passengers, based on a session at the FAA Commercial Space Transportation Conference last month. These developers are very conscious of safety issues, and none showed any signs of rushing through testing to put vehicles in service. A sample quote from Jeff Greason of XCOR Aerospace: “Simple economic self-interest is going to force us to do our very, very best to get the vehicle that safe, and to do enough tests to convince ourselves that it is that safe.”
There are some other flaws in the article that suggest a lack of familiarity by Prof. Bell about the industry: at one point he lumps the DC-X in with various rocketplane designs, something the developers of the VTVL wingless DC-X would likely take umbrage with; he also claims that “SpaceShip1 [sic] suffered serious problems on all of its flights above 100km”, even though there were no signs of any serious problems on at least SpaceShipOne’s final flight on 2004 October 4. Prof. Bell is correct that safety is a critical issue for the emerging personal spaceflight industry, whether it’s done by rocketplanes or other vehicles. What’s not so certain is that the future is as dire as Bell makes it out to be.