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Weddell, J. B.

Publications and source records attributed to Weddell, J. B..

7 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1978

Self-powered electric propulsion of satellite power systems

Electric propulsion using argon ion bombardment thrusters is described as a means of transferring solar power satellites from low earth orbit (LEO) to geosynchronous equatorial orbit (GEO). A portion of the satellite GaAs solar array is constructed in LEO and provides power for ascent propulsion; the remainder of the array is constructed in GEO. The electric propulsion system is returned to LEO by detaching a section of the solar array. Alternatively, an autonomous electric propulsion vehicle is assembled in LEO and transports power satellite materials to a GEO construction site. Maximum thrust per thruster and minimum argon consumption are achieved at specific impulse (Isp) 13,000 s. The thrust/power relationship leads to minimum transportation vehicle mass, including the solar array, at Isp 9,000 s. Thruster screen, accel, and discharge supplies are obtained directly from the solar array.

Weddell, J. B.↗
NASA NTRS1973

Encke flyby science package

Cometary exploration objectives are considered, giving attention to reasons for the selection of Encke as a target for early exploration missions. An Encke environmental model is discussed together with the scientific requirements of an exploratory mission, instrument selection criteria, and the science payload. The instruments to be used include a television camera, an IR radiometer, a UV spectrometer, a mass spectrometer, a Sisyphus dust detector, devices for the measurement of the EM field, and instruments for the determination of plasma characteristics. It is pointed out that solar electric propulsion affords the only practical, currently available means of reaching Encke with the desired encounter velocity below 7.5 km/sec.

Newburn, R. L.↗
NASA NTRS1971

Remote sensor support requirements for planetary missions

The study approach, methods, results, and conclusions of remote sensor support requirements for planetary missions are summarized. Major efforts were made to (1) establish the scientific and engineering knowledge and observation requirements for planetary exploration in the 1975 to 1985 period; (2) define the state of the art and expected development of instrument systems appropriate for sensing planetary environments; (3) establish scaling laws relating performance and support requirements of candidate remote sensor systems; (4) establish fundamental remote sensor system capabilities, limitations, and support requirements during encounter and other dynamical conditions for specific missions; and (5) construct families of candidate remote sensors compatible with selected missions. It was recommended that these data be integrated with earlier results to enhance utility, and that more restrictions be placed on the system.

Weddell, J. B.↗