History of Failure
Creating reusable rocket planes should have been NASA’s job. But NASA’s effort-the X-33, an ambitious concept for a reusable rocket plane that by 2005 was supposed to demonstrate technologies that could eventually replace the space shuttle program-became the biggest white elephant ever produced by the U.S. space program. Between 1997 and 2001 almost $1.3 billion was spent on the hydrogen-powered craft, and there’s virtually nothing to show for it. Fatefully, NASA chose a plan that employed a host of technically challenging (read: risky) technologies-including unique rocket engines, fuel tanks, and heat shields-and a complex vehicle design. Each of those technologies would have had to work for the craft to successfully unseat the space shuttle fleet-now more than two decades old-for missions that include ferrying astronauts to the International Space Station and launching scientific payloads such as the Hubble Space Telescope.
But one part, a composite liquid-hydrogen fuel tank built by Lockheed Martin, failed in tests. In 2001 NASA, facing the prospect of waiting another year for a new version, “walked away from the effort and started something new,” says Lori Garver, a former NASA associate administrator. “Every time you do that, you lose ground.” Now, two years after the X-33’s cancellation, NASA’s still largely undefined new effort is not expected to produce a space shuttle replacement earlier than two decades from now. However, there will undoubtedly be pressure post-Columbia to accelerate that timetable.
One result of the X-33 debacle was to put a serious damper on private investment in the field. Conventional wisdom held that if NASA couldn’t build a reusable rocket, no one could, says Collins. But the world lacks a rocket plane “not because it’s difficult to build,” he says. “It’s just that virtually all rocket research has been done by a monopoly government agency.” Buzz Aldrin, who in 1969 became the second man to walk on the moon, says the United States simply lacks a coherent national program for developing affordable launch technology. Although Columbia’s fate could sharpen the focus, Aldrin says that for the time being anyway, “we’re in a mess.”
Into this mess arrive Xcor Aerospace and its competitors. Their vision: to build a new breed of rocket. Unlike every rocket launched so far, this craft would fly into space and return intact. (Some designs call for the rocket initially getting aloft by piggybacking atop a jet.) Even each of the space shuttles, the world’s first and only reusable spacecraft, discards parts of the twin booster rockets and all of the huge external fuel tank with every launch.
Realizing this ambition looks relatively straightforward on paper. Rocket engines are basically combustion chambers with pumps that bring in fuel and oxidizer-oxygen or an oxygen-rich chemical that allows the fuel to burn even in the vacuum of space. They don’t need a jet engine’s high-speed turbofans and compressors, which provide oxygen from the air and account for about 80 percent of the engine’s size, weight, and complexity. And as a result, rockets can fly far higher than jets, which cannot exceed altitudes of 16 kilometers because the air becomes too thin to burn aviation fuel and provide lift to their wings.
No one is saying that such upstarts as Xcor Aerospace can reach space in one step. Reaching orbit means attaining speeds of 27,800 kilometers per hour, carrying enormous amounts of fuel, and withstanding extreme stresses. Meeting these challenges will, by all accounts, take at least a decade. In the meantime, though, a lot can be learned while shooting for a much more modest goal: a rocket-powered craft able to reach the edge of space-an altitude of 100 kilometers-without actually going into orbit. Achieving that altitude requires a speed of about 4,500 kilometers per hour, not much faster than the top speeds of today’s jet fighters, so designers of the rocket craft should be able to adapt the fighters’ relatively tried-and-true systems and engineering procedures.
Xcor Aerospace president Greason says meeting the design goal is possible within the next few years. Six years ago he left the booming microchip industry because he saw the space business as being where computers had been back in the 1970s: a few companies controlled a market for big, expensive, exclusive hardware, and they were oblivious to the sea change being brought about by a few obsessed college dropouts who, working in garages, used off-the-shelf parts to produce amazing new personal computer systems. “It’s very similar to the early days of the PC,” says Peter Diamandis, chairman and founder of the X-Prize Foundation. “Suborbital vehicles that can make thousands of flights a year will create a marketplace by changing the perspective on space: it’s not just for governments, but for the public.”