Potential improvements to the Shuttle through evolution
A possible series of evolutionary changes in the Space Shuttle are discussed that would increase both safety and performance while simultaneously decreasing the cost of operations. It is argued that major savings in operations costs can be achieved by employing electromechanical actuators in the hydraulic system and by making an architectural change to isolate the critical flight control processing system from other hardware. Minor modifications to existing Orbiters would enable the system to carry about 8000-10,000 more pounds to any given orbit. A more powerful, more reliable, and completely reusable booster should be developed, and reliability and safety improvements should be made. The SSMEs should be removed from the Orbiter and installed in a recoverable pod that would be attached to the rear of the ET.