Engineering topics
Publications and source records attributed to Marshall, W. R..
The roles of the Space Station, as an R&D facility, as part of an industrial system which support space industralization, and as a transportation node for space operations are considered. Industrial opportunities relative to these roles are identified and space station concepts responsive to these roles are discussed.
A three stage rocket vehicle has a large forward propellant tank and a small aft propellant tank axially aligned. Secured to the rear end of the aft propellant tank is an engine mount structure carrying rocket engines. Offset and secured to the propellant tanks is a payload structure. The propellants from the large forward tank are fed into the aft propellant tank. This arrangement enables the vehicle to parallel stage its use of engines and components and results in significant payload capability. The design and components fully utilize existing space shuttle elements and tooling.
Vehicles capable of lifting very large and heavy payloads into low earth orbit (LEO) will be needed to support certain large-scale space missions being considered for the late 1990-2000 time period. These missions include the support of strategic national commitments, large space power systems, and interplanetary and lunar exploration. Nearer term missions will utilize the Space Shuttle and its direct derivatives, the Shuttle-Derived Vehicles (SDV), currently being defined under NASA and DOD sponsored studies. A conceptual design of a Heavy Lift Launch Vehicle (HLLV) that will lift a half million pounds to low earth orbit is presented. Design alternatives and key system design problems and issues are discussed. The new developments required, such as a new large liquid booster engine and Space Shuttle Main Engine (SSME) modifications, are identified. New candidate launch locations and launch facility requirements are also discussed. The commonality and utilization of the booster stage 'elements' as a liquid booster for a 'growth' Space Shuttle are conceptually defined.
Shuttle improvements and Shuttle-derived vehicles which could answer projected launch system demands for the 1990s are explored. Traffic volume is suggested to be at levels exceeding the STS ability to deliver, thereby necessitating use of unmanned launch vehicles. Some payload delivery increase is possible using an Aft Cargo Carrier attached to the bottom of the external tank. This configuration would handle cargo with a diameter larger than the 15 ft allowable in the Orbiter bay. Various configurations of solid rocket booster cargo rockets are described, together with use of a module containing the Shuttle main engines and avionics as a recoverable part of a system able to place cargo 30 ft in diam and 90-100 ft tall in orbit. Using liquid reusable boosters would permit an increase of cargo capacity by the Shuttle of 50%, while a side-mount cargo vehicle (unmanned) offers a payload capacity of 165-200 klb. It is predicted that launch vehicles in the beginning of the 21st century will be of a fully reusable design.
Approaches to payload definition, design, and planning adopted in the Space Shuttle Program are described. The Space Shuttle offers many new modes of operation featuring reuse of spacecraft, on-orbit checkout and maintenance, sortie experiment missions, and opportunities to trade launch weight and volume for cost savings. In order to take advantage of these new approaches and to accommodate the varying missions, new payload elements have been identified, and new low-cost design approaches are being developed to utilize standardized components and modularized subassemblies that reduce spacecraft buildup and maintenance costs. A new payload planning technique makes use of the computer to provide large-scale planning, scheduling, and costing required for various program options.