Space / Space Flight

Long before the Columbia disaster, NASA began worrying about its dependence on a fleet of aging, expensive, and fragile space shuttles. In May 2001, the agency consolidated its plans into a program to develop a next-generation shuttle by 2020. That timetable now looks absurdly sluggish, so NASA is focusing on what was, until a few months ago, a secondary part of its manned space strategy: the multibillion-dollar Orbital Space Plane. "It will be a lifeboat for the International Space Station and a transport system that supports a four-man crew on the station," says Dennis Smith of the Marshall Space Flight Center, the program manager for the project.

In mid-February, NASA released a set of design requirements calling for a four-passenger vehicle that would be cheaper, more maneuverable, and safer than the shuttle. Three contractor teams are developing proposals, most of which broadly resemble the original shuttle concepts. The Orbital Sciences Corporation of Dulles, Virginia, and Northrop Grumman of El Segundo, California, are working on a craft that resembles the HL-20 "lifting body," a stubby-winged concept rejected by NASA in the early 1990s. The Boeing Company's Phantom Works in St. Louis will probably modify and scale up the design of the X-37, a 27.5-foot-long winged test vehicle capable of Mach 25 speeds. The Lockheed Martin Corporation of Denver, meanwhile, is considering both an aircraft-type vehicle and a capsule akin to Russia's workhorse Soyuz.

The space plane is still no quick fix. NASA does not expect it to carry a crew before 2012. Meanwhile, the agency urgently needs to get the shuttle flying so it can replace the space station's crew and provide boosts that prevent the station's orbit from decaying. The space plane also does little to rebut critics of the manned space program [see "Letter From Discover," page 33]. Bruce Murray of Caltech, a former director of the Jet Propulsion Laboratory, notes that NASA's spending on human spaceflight far outstrips that for automated probes and even exceeds the budget of the National Science Foundation. "By anybody's standards, the shuttle's science is much less useful than that of NSF," he says. "Exploration is a valid activity, but how well are we doing that? We've been in Earth orbit for 40 years now. Going around in orbit is not exploration."