Monday, August 01, 2005
SpaceRef - Your Space Reference "Cargo vehicle studies using Space Shuttle ET and SRB hardware focused on two major variants: so-called "side-mounted" and "in-line". Side-mount designs hang cargo and/or crew off the side of a large external fuel tank as is currently done with the space shuttle. In-line designs place the cargo (or crew) directly atop a lower first stage as did Saturn launch vehicles. Budget pressures have intensified due to the grounding of the shuttle fleet after last week's foam and debris shedding. This grounding and a possible hiatus before flights resume could lead to increased pressure to develop a side-mounted shuttle-derived heavy lifter similar in overall concept to the Shuttle-C launch vehicle proposed in the 1990s. This side-mounted launcher would allow many existing shuttle facilities to be used either unmodified or with slight modification since the shuttle orbiter would be replaced with a cargo carrier and use the same 'footprint' as does the current space shuttle. The costs required to transition to such a new system would be less, and current cargoes (ISS components) could be integrated in a fashion nearly identical with how they are launched in shuttle orbiter cargo bays. The larger, more capable in-line shuttle-derived systems that have been studied would require substantial modifications to launch pads and ground support infrastructure."