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Murphy, J. T.

Publications and source records attributed to Murphy, J. T..

6 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1979

Orbital transfer vehicle requirements and concepts

The requirements, definitions, and current planning for cost effective transportation from low earth orbit to higher energy earth orbits and other orbital transfers, to complement the Space Shuttle, are discussed. The issues that arise from the uncertainties of future priorities and funding as well as the maintenance of a development capacity for a future new space engine are examined. Attention is given to mission requirements including orbiter transfer requirements and power module specifications and also to candidate and cryogenic OTV concepts. The configurations for the solar electric propulsion system are presented along with the program and space transportation system evolution.

Murphy, J. T.↗
NASA NTRS1977

Development of shuttle payloads

The development of payloads for the Shuttle is described in terms of two activities - one is oriented towards development of payload hardware, while the other is oriented towards the development of payload/Space Transportation System (STS) planning, scheduling, and integration techniques. This second activity is called STS Utilization Planning (SUP). In addition to describing the major aspects of SUP, a discussion of development activities on three payloads that typify direct Shuttle placement missions is included. These payloads are the First Spacelab Mission, the Atmospheric, Magnetospheric, and Plasmas in Space (AMPS) payload, and the Large Space Telescope (LST).

Murphy, J. T.↗
NASA NTRS1977

Transportation concepts for space industrialization

Space shuttle and heavy lift launch vehicle concepts are described with attention to transportation cost trends. Chemical (LOX/LH2), nuclear, and electric propulsion systems are considered. Suggested space shuttle projects include the support of manned geosynchronous missions and the transfer of bulk cargo and large-delicate space structures from fabrication/assembly orbits to their operational locations. It is thought that development of the space shuttle will stimulate interest in space industrialization.

Murphy, J. T.↗
NASA NTRS1976

Development and integration of Spacelab payloads

Planning of payloads for future space missions requires that goals and objectives established by the scientific community be transformed into various instruments and equipment which can most effectively gather the scientific data necessary to realize these goals and objectives. The methodology for accomplishing this transformation is discussed, including the specific application of these methods to the development of Spacelab payloads. Several Spacelab payloads currently undergoing preliminary design are described together with their objectives, potential benefits, and the scientific requirements which 'drive' the payload concept and design. The concept for integrating the instruments and equipment into a Spacelab payload is discussed. This integration process is highlighted by describing two classes of Spacelab flights - one where the entire Spacelab is dedicated to a single scientific discipline and the other where the Spacelab is configured to accommodate payloads from several scientific disciplines. A brief description of the engineering approaches to the solution of some of the more interesting design problems is included.

Murphy, J. T.↗
NASA NTRS1973

Lower payload costs through refurbishment and module replacement.

Payload benefits to be derived from refurbishment can be related to individual spacecraft programs directly and for planning purposes to the entire shuttle mission model. In the case of the large space telescope program, cost savings obtained through the use of the shuttle for maintenance operations have been estimated to be in the range from 30 to 40%. This saving is realized over an operational lifetime of 15 years by reducing, through refurbishment on orbit, the number of flight units along with 'optimized' reliability goals commensurate with periodic maintenance revisits at one-year intervals. Shuttle-era payload implications are discussed together with a pressurized on-orbit maintenance configuration, an earth observation satellite, and some typical teleoperator-serviced spacecraft.

Murphy, J. T.↗