Future
Designers look to more economical and reliable launch systems for the future, with lower maintenance and operational costs. One approach is Single Stage To Orbit (SSTO), which would be 100% reusable and use a single stage. NASA evaluated several concepts in the 1990s, and selected the X-33, which would eventually have been the VentureStar. During design that program increased in complexity and development cost, encountered problems and was finally cancelled.
A variant of SSTO is a hypersonic, scramjet-powered, airbreathing vehicle. This would be launched and landed horizontally like an airliner. It would achieve much of orbital velocity while still within the upper atmosphere. It was originally investigated by the U.S. Department of Defense, but passenger-carrying civilian versions were planned. The official name was the Rockwell X-30. Like the X-33, the X-30 development encountered major technical difficulties, primarily due to the system complexity and materials required for hypersonic flight, and was also canceled.
Another approach is lower-cost expendable launch vehicles. NASA currently uses commercial ELVs for unmanned launches, and could use commercial ELVs for future manned launches. This would fit with NASA's mandate to promote commercial access to and use of space. The Commercial Orbital Transportation Services program began in 2006 with the purpose of creating commercially operated unmanned cargo vehicles to service the ISS. The SpaceX Dragon became operational upon launching and docking with the ISS in May 2012. The Orbital Sciences' Cygnus is expected to become operational in 2012. The Commercial Crew Development (CCDev) program was initiated in 2010 with the purpose of creating commercially operated manned spacecraft capable of delivering at least four crew members to the ISS, to stay docked for 180 days and then return them back to Earth. These spacecraft are expected to become fully operational in the mid-2010s. In August 2012, NASA announced funding agreements with three firms, SpaceX, Boeing and Sierra Nevada Corporation, for development of crew delivery capability.
Read more about this topic: Criticism Of The Space Shuttle Program
Famous quotes containing the word future:
“Whoever influences the child’s life ought to try to give him a positive view of himself and of his world. The child’s future happiness and his ability to cope with life and relate to others will depend on it.”
—Bruno Bettelheim (20th century)
“I imagine, on the benches of an assembly, the most intrepid of thinkers, a brilliant mind, one of those men who, when they ascend the tribune, feel it beneath them like the tripod of the oracle, suddenly grow in stature and become colossal, surpass by a head the massive appearances that mask reality, and see clearly the future over the high, frowning wall of the present.”
—Victor Hugo (1802–1885)
“The future is built on brains, not prom court, as most people can tell you after attending their high school reunion. But you’d never know it by talking to kids or listening to the messages they get from the culture and even from their schools.”
—Anna Quindlen (b. 1953)