Getting Into Space on a Budget
Recently approved by NASA, the X-33's design is a leap forward in the quest to cut costs.
BOSTON — Inside a cavernous hangar in Palmdale, Calif., technicians are piecing together an experimental spacecraft that could turn the faded promise of quick, cheap access to space into a reality.
Roughly the size of a Boeing 737, Lockheed Martin's X-33 has the look of an oversized nose cone that's been run through a wringer. The design, however, represents one of several technologies - from unique "aerospike" engines to heat-resistant skin - that engineers hope to build into a full-scale version by 2004.
The goal is a craft that uses only one stage from launch to orbit and back; can be reloaded, refueled, and relaunched in two to seven days; and requires a ground crew of only 50 people. Known as the VentureStar, the full-scale space plane could become the Clydesdale in America's stable of launch vehicles, hauling heavy cargoes to the international space station and launching heavy satellites into orbit.
Since the craft's design received thumbs-up from the National Aeronautics and Space Administration (NASA) on Oct. 31, the X-33's unique engine has taken its first test ride atop an SR-71 Blackbird jet, major structural parts have started to appear at the Palmdale facility, and officials have broken ground on a 25-acre launch and processing facility at Edwards Air Force Base.
The $1 billion project is the largest of several aerospace-industry efforts to design and fly completely reusable rockets. Their aim is to dramatically increase the pace and cut the cost of putting satellites and other cargoes into space.
Crafts designed by other projects, with cost estimates ranging from $100 million to nearly $500 million, would launch payloads ranging from 400 to 11,000 pounds.
Lockheed-Martin's VentureStar craft, by contrast, would loft payloads as heavy as 125,000 pounds to the space station, says Dennis Smith, assistant manager of the Space Transportation Systems Office at the Marshall Space Flight Center in Huntsville, Ala. Moreover, it's designed for what he calls "the sweet spot" of the commercial satellite market - medium and heavy communication satellites destined for geostationary orbit.
The X-33 is one of the most visible symbols of NASA's push to shed its role as spacecraft owner-operator and return to its roots.
"The whole idea behind NASA is to do science and exploration," Mr. Smith says, not maintain and operate a fleet of spacecraft. "Getting to space is a necessity to do science and exploration. But we've got to get the costs down."
If costs don't fall markedly, the outlook for the agency's exploration and science programs looks grim. Construction on the international space station is set to begin late next year. Once built, it will need to be supplied with some 375,000 pounds of material a year, notes Jerry Rissing, a vice president at Lockheed Martin and program manager for the X-33 project. At today's $10,000 a pound to launch a payload, that works out to $3.75 billion a year - nearly 30 percent of NASA's current budget.
Jumps in technology
To drive launch costs to a more palatable $1,000 a pound, "you have to drive the weight down, and that requires huge jumps in technology," says Gary Payton, director of space transportation at NASA.
To help drive weight down, X-33 designers are exploiting strong, light composite materials for everything from ribs and beams to fuel tanks. One result: The entire craft is reusable, unlike the current fleet of shuttles, which require a new set of external tanks with each launch.
Yet the craft also is taking advantage of concepts that have been around for years, yet only now can be exploited to their full advantage, according to Paul Landry, the X-33's chief engineer.
One is the X-33's "lift-body" design, a marked difference from the current space shuttles.
"The space shuttle is a tube with wings," he says, noting that the X-33's body contains the curvatures and camber to generate lift for its shuttle-like glide back to Earth. This approach gives the craft the look of a thick, rounded spearhead with stubby stabilizers and tails.
In addition, designers have tapped a 25-year-old engine design that, until now, has never been used in the air. Known as a linear aerospike engine, the power plant sheds bulky bell-shaped exhaust nozzles and their steering gear and uses air flowing past the rocket to shape the exhaust plume to get the most efficiency out of the motor.