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Flight control requirements of reusable launch vehicles are reviewed and compared to those of aircraft, current launch vehicles, and spacecraft. Areas are identified in which more work on the flight control system will improve mission performance. Current work in three areas is briefly reviewed - the use of man in the control loop, the development of systems which can accommodate large changes in the flight conditions, and use of the flight control system to reduce wind-induced loading.

This paper deals with a system for the computerized monitoring of manufacturing operations and the methods employed in collecting and analyzing production information. It covers briefly the relationship of the manufacturing system to the balance of the information system. The system employs a special purpose digital computer interfaced with a general purpose computer on a real time basis and various visual and audio controls.

The Titan IIIB recovery experiment is designed to recover the spent Stage I of a Titan IIIB to evaluate the feasibility of refurbishment and reuse. The stage, slowed after reentry by parachute deployment, can be allowed to impact in the water or retrieved via helicopter in midair. In either case, the stage will be returned to land, refurbished, and reused. Cost data will determine the economic feasibility of the program. A preliminary design of the recovery system has been made, the economic factors evaluated, subsystem contractors contacted, and an experiment program defined.

The evolution of space activities based on the use of large ballistic vehicles appears now to have been fortuitous. The delayed start of European programmes necessitates reconsideration of what will be the most profitable line of development. Until men are seen to inhabit space stations for useful purposes and to be transported there and back safely and economically popular support for these activities will be reluctantly given. A re-usable transporter, of whatever type, enlarges man's capability in space. Industrial recommendations for a European space programme accept it as a necessary implement in the long term.

A new concept for land recovery of launch vehicle stages is described. After burn out and separation of a conventional cylindrical booster configuration, the outer tank portions are discarded, leaving a lifting shaped center-body capable of re-entry, pull out, flyback and landing. The essential features are the application of intersecting pressure vessel theory for shaping the tanks and the simple arrangement of hinged tail panels (dive brakes). The panels are used for stabilization and deceleration during the re-entry phase and fold back in sequence during the pull out maneuver and transition into an aerodynamic lifting body configuration of low wing loading. In conclusion, the concept promises the following advantages: 1. No essential weight increase versus expendable stages. 2. Maximum use of existing and proven stage hardware and launch facilities. 3.

A review of current trends in the technology for reusable launch vehicles is an appropriate method of highlighting the pacing technologies to provide a suitable introduction to discussions in specific technical areas. Improvements in both operational capabilities and in economic characteristics can be expected from the advances in the relevant technologies. The attainment of such improvements involves two dilemmas of technical innovation. One is that the greater the desired capabilities, the more significant the technical challenge. The second is that the more complex technical approaches involve significant program investments that are justified only in terms of high levels of utilization. The paper establishes the technical areas of most fundamental importance and provides a resume of each area in terms of its potential contribution to the attainment of low-cost orbita transportation.

With the objective of minimizing structural weight in future large launch vehicles, several applicable advanced structural analysis techniques, materials, and unique approaches to structural design are assessed. Advanced structural design analysis techniques such as pressure coupling effects and higher allowable stresses by use of various biaxial stress field failure theories are considered. Each new technology or approach is individually applied to a representative vehicle. Structural weights with and without the new technology or approach are compared. The results may be used to assess the relative potential of each new technology as applied to possible future large launch vehicles.

The preparation of necessary facilities, the checkout and the launch of an Apollo/Saturn V vehicle is probably one of the most complicated and intricate single operation of our times. It is an orderly outgrowth of the firing many years ago of the first rocket propelled vehicle. But, you must add to this the advances being made in computer technology, communications, and even mechanical design before you have an idea of what is required in a launching of the Saturn V. The Kennedy Space Center has had recent training with the Saturn I and the uprated Saturns but even these are dwarfed by the Apollo/Saturn V. New concepts have been devised such as the mobile concept, computer technologies, and advanced communications which enable a high degree of automation and remote control of the operation. Certain management techniques have been used such as an activation board and a series of facilities tests.

The flight environment of the X-15 research aircraft is similar to that of a first-stage rocket booster. The data obtained during the flight program is, therefore, of interest for reusable space vehicles. Detailed information is presented concerning development, operation, and the economic aspects of the vehicle and facilities, including manpower effort, and calendar time required for refurbishment and turnaround. The effect of component improvements, which have been dictated by failure experience, on operations is examined. These data have been derived from more than 7 years of X-15 operations.

The operating costs of current space systems are examined briefly to determine the distribution of these costs through the major operational elements of the systems. For flight frequencies of between 5-20 flights per year, the system costs associated with recovery and reuse are examined to show where major savings are potentially achievable. The authors then describe the results of a feasibility analysis of a vehicle concept emphasizing recovery and reuse of the spacecraft and the simplification of the expendable elements. The latter is accomplished by incorporating the boost phase steering function in the spacecraft and using solid propellant motor booster stages. A first order cost comparison with other current and projected concepts is then presented to indicate the separate effect on operating costs of launch vehicle propulsion type, spacecraft type, and steering techniques.

Three critical aspects of implementing reusable booster concepts are discussed. These aspects center on requirements for economic justification, establishing the credibility of recurring cost characteristics, and means of minimizing development costs such that these nonrecurring costs are matched with the size of market which must amortize them. The impact of these factors on implementing a reusable booster development program is discussed. Approaches and possible programs are suggested that could make significant progress toward establishing our technological preparedness for reusable booster program implementation.

The space rotor corresponds to a device designed to satisfy the general requirement for a light, maneuvrable, fully reusable reentry system, having a high capability to spot-land, softly, a variety of space vehicles in unprepared areas. Recent feasibility studies carried out for the “Centre de Prospective et d'Evaluation” under French Ministry of Defence contracts have shawn that the space rotor exhibits a number remarkable features, its light weight characteristics, when compared with maneuvrable or ballistic reentry means, being the most striking ones. In general the combined system, space-rotor-vehicle, can be regarded as a hypersonic glider having a L/D ratio of the order of 1.0 to 1.5. However, whatever are the applications envisaged, booster recoveries, orbital recoveries of manned or unmanned vehicles, the weight penalty incurred by this new system is fairly constant and situated well below that of the equivalent, more conventional, means of reentry and recovery.

Performance is examined of a re-usable space launcher system suitable for European development with an air-breathing first stage and rocket-propelled second stage. The merits of ram-rocket and turbo-ramjet propulsion are compared and the research programme required for such a system is discussed. It is concluded that a partly air-breathing re-usable launcher system is likely to emerge as a by-product of air transport development.

This paper presents a summary of an initial phase of a long term study to develop techniques for accurately predicting launch vehicle costs, and is an initial part of a larger research project to develop a computer program cost model for long range planning. Emphasis is on the accuracy or confidence associated with cost estimates calculated by industry launch vehicle cost models. Results are shown of a statistical analysis of the mean and standard deviation of sample model estimates for various cost elements of a liquid and solid launch vehicle program. The variations in the cost estimates are discussed.

Future, potential developments in space transportation systems are reviewed. Consideration is given to spacecraft systems, launch and recovery facilities, and economic justification of future alternatives. It is concluded that requirements for high system utilization rates must be evolved before a fully recoverable, reusable space transportation system can be economically justified. The recovery and refurbishment of current-type systems is suggested as an intermediate alternative which, by reducing cost per mission and increasing space system utilization, will ultimately lead to a valid requirement for advanced reusable systems.

Assuming the delivery with an excess velocity reserve 3.300 ft/sec of a 1 ton. transferable load to a space laboratory orbiting at 200 S.M., the feasibility of a 2 (or 3) stages “horizontal take-off transporter” is considered. Analysis includes the concept of two recoverable vehicles and discusses the configuration, separation, return and propulsion. Design assumes that conventional airports can be used without special facilities, except LOX and LH.

Complete feasibility studies of seven reusable launch systems being carried out by Germany since 1962 are described. Work has reached the early experimental phase (as in the U.S.). The author explains why, at this stage, cooperation between Europe and the U.S. would present substantial economic advantages for both parties. He also suggests how this cooperation could be approached.

With reusability accepted as a means of reducing operating costs, the size of the initial investment (research and development) is likely to determine the choice for the next generation boosters. High volume utilisation lifting bodies propelled by LH/LOX rockets in a vertical take-off mode are shown to be superior to several other concepts. This is largely due to the low manufactured weight without undue complexity or use of exotic materials, leading to low R&D and low unit cost. Even lower costs can be shown for a modular concept (MUSTARD) in which basically identical lifting bodies units are utilised as both boosters and spacecraft. The concept is shown to be feasible, and progress on some aspects of the associated structural analysis is described.

This paper discusses the relative merits of ballistic versus lifting-body and Winged recovery techniques for space launch vehicles in the small-payload category. Costs and operational capabilities of vertical-takeoff vertical-landing (VTOVL) vehicles are compared with two variations of all-rocket, vertical-takeoff horizontal-landing (VTOHL) vehicles: winged first stage, lifting-body second stage and Winged first and second stages. In addition, three baseline configurations are discussed and compared. Problems associated with maximum vehicle versatility are identified and solutions are suggested.

Eight fixed-wing reusable horizontal landing booster point design concepts are presented and compared on the basis of weight, cost, technical difficulty, and availability date. The eight vehicle types considered are all basically two-stage systems with a lifting body reusable second stage, with all vehicles normalized to place 40,000 lbs. payload in orbit. All flight vehicles are fully recoverable and capable of flying back and landing at the launch site. Vehicle types discussed are vertical take-off horizontal landing rockets, sled launched horizontal take-off rockets, runway launched horizontal take-off rockets, air breathing first stages, combined air breathing and rocket first stages, oxidizer collection concepts, supersonic combustion ramjets, and in-flight refueling vehicles. Each of these vehicle types is depicted in the paper and its design and performance characteristics are discussed.