Shuttle-C

The Shuttle-C was a NASA proposal to turn the Space Shuttle launch stack into a dedicated unmanned cargo launcher. This would use the Space Shuttle external tank and Space Shuttle Solid Rocket Boosters (SRBs), combined with a cargo module that would attach to Shuttle hardpoints (the bipod, etc) and include the Space shuttle main engines. Various Shuttle-C concepts were investigated between 1984 and 1995 [http://www.globalsecurity.org/space/systems/sts-c.htm] .

The Shuttle-C concept would theoretically cut development costs for a heavy launch vehicle by re-using technology developed for the shuttle program. The proposal involved using, at various times, existing spaceframes, Space Shuttle Main Engines that had reached maintenance lifetime limits, and spare navigation computers. One proposal even involved converting the "Columbia" or "Enterprise" into a single-use cargo launcher. NASA had expected over 14 shuttle flights a year after the Challenger incident. They soon realized that this launch rate would not be achievable considering the time each orbiter spends in the Orbiter Processing Facility after each flight. With the Shuttle-C, it was thought that the lower maintenance and safety requirements for the unmanned vehicle would allow a higher flight rate.

There were two development phases planned. The first consisted of deciding the shape and size of the cargo carrier. NASA studies showed that a small but functional carrier would be most efficient for launches.

In the early 1990's, NASA engineers planning a manned mission to Mars, included a Shuttle-C design to launch six non reusable 80 ton segments to create two Mars Ships in Earth orbit. The alternative would be to use 4 Saturn V launch vehicles. However, after President George W. Bush called for the end of the Space Shuttle by 2010, these proposed configurations were put aside.

NASA has recently resurrected the idea of the Shuttle-C concept in the form of the Shuttle Derived Launch Vehicle, currently known as SDLV. As of June 2005 the proposal is reportedly finalizing into the form of a 120 metric tonne payload with an in-line design, now known (July 2006) as Ares V. If chosen, this will be significantly different from the original Shuttle-C reference layout. Shuttle-C comes in various configurations: one variant has three Orbiter main engines, while the other has two. Only one known mock-up of Shuttle-C exists, created by Boeing for engineering development tests in 1989.

External links

* [http://www.globalsecurity.org/space/systems/sts-c.htm More Info at GlobalSecurity]
* [http://www.astronautix.com/lvs/shuttlec.htm Encyclopedia Astronautica link on the Shuttle-C]