Engineering topics

Fletcher, J. C.

Publications and source records attributed to Fletcher, J. C..

9 records

NASA NTRS1988

Reusable space systems (Eugen Saenger Lecture, 1987)

The history and current status of reusable launch vehicle (RLV) development are surveyed, with emphases on the contributions of Eugen Saenger and ongoing NASA projects. Topics addressed include the capabilities and achievements of the Space Shuttle, the need to maintain a fleet with both ELVs and RLVs to meet different mission requirements, the X-30 testbed aircraft for the National Aerospace Plane program, current design concepts for Shuttle II (a 1000-ton fully reusable two-stage rocket-powered spacecraft capable of carrying 11,000 kg to Space Station orbit), proposals for dual-fuel-propulsion SSTO RLVs, and the Space Station Orbital Maneuvering Vehicle and Orbital Transfer Vehicle. The importance of RLVs and of international cooperation in establishing the LEO infrastructure needed for planetary exploration missions is stressed.

Fletcher, J. C.↗

NASA NTRS1986

Space Shuttle development

The technical-planning and decision-making processes involved in the initiation of the NASA Space Shuttle program in 1970-1972 are briefly discussed, responding to the critical evaluation of Logsdon (1986). The complex nature of the interactions among White House, OMB, DOD, and NASA; the difficulty of making long-term commitments under the U.S. system; the positive technological achievements of the program; and the need for unemotional evaluation of the policy options available after the loss of the Challenger are stressed. In a reply by Logsdon, it is argued that the structuring of the policy process itself and the presentation of the Shuttle to Congress as a relatively inexpensive routine launch system for virtually all government needs were directly related to its failure to gain continuing full funding from Administrations and Congress. It is suggested that a strong proposal of bold scientific and exploratory objectives for the space program could be more successful in gaining such long-term support.

Fletcher, J. C.↗

NASA NTRS1977

Public service satellites

The development of the communications satellite system is discussed, taking into account a suggestion by Clarke in 1945 concerning the significance of geosynchronous satellites, the establishment of Intelsat, reductions in the cost of transatlantic telephone calls as a result of satellite communications service, questions of satellite cost, and the need for larger satellites. It is pointed out that the use of the Space Shuttle will reduce the cost of placing a satellite in orbit from more than half to less than a quarter of the total cost of design, construction, and launch. Attention is given to studies of a personal communications system which involves direct broadcast from a 'wrist watch radio' to a high-capacity, multibeam satellite for retransmission to ground communications centrals.

Fletcher, J. C.↗

NASA NTRS1977

Letter to Don Fuqua on space shuttle commitment, 12 April 1977

NASA budget committments for the Space Shuttle program are delineated, estimating $6.816 billion (FY 1978 dollars) for the design, development, test and evaluation phase of operations. Current estimates for refurbishment of Orbiters 101 and 102 and procurement of Orbiters 103, 104, and 105 amount to $1.988 billion. Ground support equipment costs are estimated to be an additional $432 million.

Fletcher, J. C.↗

NASA NTRS1976

Remarks by Dr. James C. Fletcher at Conference on Satellite Communication and Public Service

The present status of communications satellites, together with the future goals and technology developments in use of public service, is assessed. Improvements in design during the last decade considerably cut the cost of their development and launching, and the systems carry information to millions of people on earth. The space shuttles will change the rules in design and make it possible for communications satellites to have multiple frequencies operating at high power.

Fletcher, J. C.↗

NASA NTRS1976

A new era of space transportation

It is pointed out that founded on the experiences of Apollo, Skylab, and the Apollo/Soyuz mission an era is entered which will be characterized by a displacement of the interface between the experimenter and his experiment from the control center on the ground to the laboratory in orbit. A new world has been opened by going into space. Economic applications are related to the achievement of an enormous efficiency in world communications at a much lower cost. However, programs of space exploration and usage are under severe economic constraints. A primary tool to lower the cost of programs is to be the Space Transportation System using the Space Shuttle. It is emphasized that the Shuttle system is an international enterprise. Attention is also given to the results of the Viking missions, the Landsat satellites, and applications of space technology for science and commerce.

Fletcher, J. C.↗

NASA NTRS1975

Aeronautics in the American Society

The trends in aeronautics and aeronautical education are discussed with respect to the roles of industry, government, and the universities. The importance of the aviation industry to the economy of the country is examined. The impact of reduced enrollment of aeronautical engineering students in the universities on the future of the aeronautical industry is stressed. It is stated that the role of the government should be to sponsor and conduct basic research and advanced technology programs for civil and military aviation, and the specification, development, procurement, and operation of military aircraft. Recommendations are made for approaches which may be taken to influence more qualified students to enter the field of aeronautics.

Fletcher, J. C.↗

NASA NTRS1974

Heat flow calorimeter

Heat flow calorimeter devices are used to measure heat liberated from or absorbed by an object. This device is capable of measuring the thermal output of sealed nickel-cadmium batteries or cells during charge-discharge cycles. An elongated metal heat conducting rod is coupled between the calorimeter vessel and a heat sink, thus providing the only heat exchange path from the calorimeter vessel itself.

Fletcher, J. C.↗

NASA NTRS1973

ERTS-1 - Toward global monitoring.

The satellite has a near-polar orbit with a mean altitude of about 547 n. mi. On the average six million square kilometers are mapped daily. The multispectral scanner and other essential systems on board the satellite have suffered no detectable degradation since the early failures of a circuit switch and one of the two tape recorders. A year of ERTS-1 experience has shown that many applications can be mechanized with the present instrumentation. New investigations planned for future satellites are discussed, giving attention to pollution monitoring, geological studies, heat-balance surveys, and the analysis of damage caused by storms and earthquakes.

Fletcher, J. C.↗