Designs for the Next Space Shuttle

Feb. 10, 2003 -- When the space shuttle first launched on April 21, 1981, it opened a whole new era in space exploration for NASA. For the first time, the agency — and the world — had a space vehicle that could be recovered and used repeatedly.

Now, the tragic loss of Columbia may speed up the hunt for the next-generation shuttle — a task the aerospace industry has pursued almost since the current shuttle came into existence.

"The overall general consensus is that NASA needs to move forward in a new [launch] system," said Dennis Smith, a program manager involved with looking at next generation space vehicles at NASA's Marshall Center. "But we're early on in the process [of development]," he said during a teleconference with reporters today.

It's been NASA's call for cheaper, more capable, and safer spacecraft that has prompted the effort for a successor shuttle. And while many of the previous designs never got much past the drawing board, the attempts could help lead the industry and the U.S. space program to newer technologies for reaching the stars.

One example of the more recently attempted shuttle replacement efforts was the so-called Reusable Launch Vehicle, or RLV, program. Commissioned under President Clinton in 1994, the project hoped to develop a truly reusable space "plane."

The experimental shuttle design, dubbed the X-33 by Lockheed-Martin, would be a so-called single-stage-to-orbit vehicle. Launched vertically like the current shuttle, the X-33 would reach orbit using its own internal engines and fuel.

Once the mission was completed, it would glide back to land on a runway just like current shuttle. Its single-piece design meant that a working X-33 craft would need less work — and less expense — to prepare it for the next mission.

Technology Setbacks, Cost Overruns

It was hoped that the X-33 could save as much as 90 percent of current shuttle's launch costs.

But to lift the X-33, its payload and internal fuel without external assistance, designers turned to new rockets called aerospike engines that were supposed to propel the craft at up to 18 times the speed of sound. New lightweight, composite materials were supposed to keep the weight of the X-33 down as well.