Space Shuttle: The Next Generation

Aviation experts contend that if NASA alters its business model and improves its understanding of the economics of a new shuttle, the RLV designs now afloat could be built for far less than the $35 billion the agency forecast a new shuttle would cost. For instance, instead of asking for an unrealistically flawless and overly reliable vehicle, which will add hundreds of millions of dollars to the RLV price tag, a better option might be for NASA to accept a much less expensive and easier to maintain computerized crew escape system. This would make the RLV safer than the current shuttle and less costly to build.




The truth is, NASA is preoccupied in the Columbia aftermath and continues to be vague about its intentions regarding the shuttle. The agency says that by next year there will be a decision on a shuttle-replacement schedule. One possibility might be a five-year effort to develop key components like lightweight fuel tanks and more advanced rocket engines. Then, in 2009, NASA could determine whether to go ahead with constructing a full-scale RLV based on those technologies; a replacement shuttle might fly by 2015. Alternatively, if NASA chooses to delay a new RLV for longer, it could spend the interim developing "broad-based, longer-range" technologies, such as improved composite materials and scramjets.




But NASA's long-term hopes to replace whatever reusable spacecraft it has with an air-breathing, scramjet-propelled, single-stage-to-orbit vehicle—a new version of the proposed National Aerospace Plane—won't bear fruit for many years. The agency is still very far away from overcoming critical technological hurdles like sustaining thrust at hypersonic speeds and developing composite materials that can withstand such high-stress applications. Because the scramjet isn't likely to be the next RLV that the space agency builds, or perhaps even the one after that, space experts argue that NASA can't afford to wait and risk being caught empty-handed, without any reusable space plane in its arsenal. "NASA needs to stop having fun," says St. Louis University professor Paul Czysz, who has been designing hypersonic aircraft and space planes since the 1950s, "and build a vehicle."

Bill Sweetman is a contributing editor at Popular Science.