bunnygrrl wrote:
Does anyone know NASA's reasoning in moving from a verticle arrangement to the side-by-side arrangement of the shuttle? Obviously the shuttle is larger than any of the Apollo capsules, but other than size, was there a basic reason for the design?

Primarily size reasons - the Orbiter is the size that it is due to a combination of payload requirements as specified by the DOD and the aerodynamic configuration required to meeet other DOD requirements for the shuttle dealing with potential landing sites and other various minutae. With the Orbiter's design calling for a specific size, the only practical solution was to look at a side-mounted or piggy-back launch configuration. Engineering a booster large enough to launch the Orbiter in a traditional in-line configuration would be prohibitive, if not impossible with the resources available. When it was decided that the option of using a fly-back booster during launch was too complex, the Orbiter began carrying its own engines and it was attached to the tanks carrying fuel for those engines.

There are some designs that have been floated around over the past decade or so for smaller lifting-body vehicles to be launched in-line, including the proposed Russian Kliper and the cancelled ESA Hermes. These are much smaller craft, designed to transport crews to the ISS or other orbital facility and not large payloads.

RE: Astronauts Cautious and Confident About Shuttle Repair Plan