Engineering topics

Penzo, Paul A.

Publications and source records attributed to Penzo, Paul A..

26 records · Page 2

NASA NTRS1988

Space tethers

The principles involved in various applications of space tethers are discussed, with emphasis placed on tethers approved for flight on the US Shuttle. Special consideration is given to the NASA-Italy Tethered Satellite System (TSS) experiment, which will consist of three missions. The purposes of these missions and the types of experiments planned for the TSS are described. Other scientific applications of thether use in the fields of aeronomy and aerodynamics, geodynamics and remote sensing, electrodynamics, physics, astronomy, and life sciences are discussed together with particulars inolved in the measurements.

Ionasecu, Rodica↗

NASA NTRS1988

Orbit/deorbit analysis for the Mars rover sample return mission

Four astrodynamic problems involved in a combined Mars rover and surface sample return mission projected for the early 1990s are explored. Two of the problems are associated with the satisfaction of the specific mission requirements at Mars, calling for the initial orbit entered into at Mars to be highly eccentric and to have a very low periapsis altitude (about 250 km). The problem of placing an areosynchronous communications satellite in orbit around Mars is then discussed. Finally, the problem of deorbiting to a specified landing site from a highly eccentric orbit is considered.

Penzo, Paul A.↗

NASA NTRS1988

A low earth orbit skyhook tether transportation system

This paper discusses the design concept of a structure, called the Skyhook Tether Transportation System (STTS) which may be used to transport mass to higher or lower orbits or to capture objects from higher or lower orbits. An analysis is presented for the possibility of the STTS to perform the function of transporting masses suborbitally, capturing the objects, and then releasing them to a higher orbit, the GEO, the moon, or for an escape. It is shown that, although the possibility of such a system is limited by the tether strength, even a modest system can yield considerable benefits in propellant savings if it is used in combination with chemical propulsion.

Penzo, Paul A.↗

NASA NTRS1988

Innovative uses of tethers in space

Potential uses of tethers in the fields of science, transportation, electrodynamics, and space exploration are discussed. Special attention is given to the use of tethers for scientific and planetary application, with descriptions of the type of measurements to be performed in a given science field or a planetary body and the particular method of tether use. Experiments proposed regarding the use of tethers will address some of the pending issues regarding the use of tethers, such as the tether deployment and control laws, the recoil, electrodynamic effects, the strength and survivability of tethers in the lower atmosphere, the stability of a tethered platform, and the propulsion through momentum exchange.

Ionasescu, Rodica↗

NASA NTRS1987

Low-gravity facilities for Space Station planetology experiments

For experimentation, space offers an environment which is unobtainable on earth. One characteristic is a gravity force less than 1 g, where g is the mean earth gravity acceleration of 9.8 m/sq s. The production of uniform gravity levels above zero g in space is discussed in relationship to experimental needs. For planetology experiments, providing gravity in space will make it possible to more nearly simulate conditions on natural bodies. The g-level is but one parameter involved in the design of a specific experiment. Other requirements may be: g-level range; g-level tolerance value; Coriolis tolerance value; volume requirement g-level duration; power and materials for the experiment; and automated or man-tended operations. These requirements, and certainly others, will dictate the type of facility which should be considered. The use of the Space Station of the Tethered Satellite System configurations is discussed.

Penzo, Paul A.↗

NASA NTRS1987

Tethers in space; Proceedings of the International Conference, Arlington, VA, Sept. 17-19, 1986

A collection of papers on the applications of tethers in space is presented. Tether flight experiments of the past, in planning stages, and in the future are examined. Tether dynamics and the applications and technical aspects of electrodynamic tethers are addressed. The use of tethers on the Space Station and applications in the Space Station era are considered. Individual tether technology issues, including tether materials and instrumentation for atmospheric measurements are discussed.

Bainum, Peter M.↗

NASA NTRS1987

A survey of tether applications to planetary exploration

Concepts for the use of tethers in various hypothetical astronomical research missions are discussed. Tethers used to study the atmospheres of Venus and Mars and the magnetosphere of Jupiter are examined, and possible orbiting tether systems at the moon and Mars are shown and described. A tether method for collecting a sample from Comet Halley is addressed along with a system for hovering near a comet. A multiple sample return system for asteroids is described, and a heliocentric Alfven engine concept to study the solar wind is discussed.

Penzo, Paul A.↗

NASA NTRS1987

Prospective lunar, planetary and deep space applications of tethers

Projected flights of an internationally managed Tethered Satellite System from the Space Shuttle in the early 1990s will investigate the behavior, first, of an insulated conducting wire 20 km long as it travels at orbital speeds through the ionosphere and earth magnetic field; subsequently, a nonconducting tether will be used to lower an instrumented 'subsatellite' 100 km downward to investigate upper-atmosphere conditions. Further consideration is presently given to other scientific, electrodynamic, transportational, and artificial gravity-generating applications of the tether concept.

Penzo, Paul A.↗