Engineering topics

Shawhan, Stanley D.

Publications and source records attributed to Shawhan, Stanley D..

3 records

NASA NTRS1988

Cluster and SOHO - A joint endeavor by ESA and NASA to address problems in solar, heliospheric, and space plasma physics

The NASA/ESA Solar-Terrestrial Science Program, which consists of the four-spacecraft cluster mission and the Solar and Heliospheric Observatory (SOHO), is examined. It is expected that the SOHO spacecraft will be launched in 1995 to study solar interior structure and the physical processes associated with the solar corona. The SOHO design, operation, data, and ground segment are discussed. The Cluster mission is designed to study small-scale structures in the earth's plasma environment. The Soviet Union is expected to contribute two additional spacecraft, which will be similar to Cluster in instrumentation and design. The capabilities, mission strategy, spacecraft design, payload, and ground segment of Cluster are discussed.

Schmidt, Rudolf↗

NASA NTRS1988

Opportunities for Space Station wave experiments

The solar terrestrial observatory (STO) concept is discussed as well as Space Station accommodations for STO. Instruments for the initial STO which can be used to excite and detect waves include the electrodynamic tether, waves in space plasmas, space experiments with particle accelerators, vehicle charge and potential experiments, recoverable plasma diagnostics package, magnetospheric multiprobes, and theoretical and experimental beam plasma physics. An example is given of a typical campaign mode of operation which is appropriate for active experiments.

Shawhan, Stanley D.↗

NASA NTRS1986

Plasma diagnostics package measurements of ionospheric ions and Shuttle-induced perturbations

The plasma diagnostics package (PDP) on the Space Shuttle STS-3 mission in March 1982 carried among its instrument complement a retarding potential analyzer. This instrument measured both the ambient ion plasma density and temperature, and perturbations to the plasma produced by Shuttle Orbiter effects. Whenever the plasma flow streamline at the instrument was more than a distance of the order of thermal ion gyroradii away from any Orbiter surface, the measurements were characteristic of the ambient ionosphere. In several situations, the PDP was positioned so as to scan the wake in the plasma flow produced by Orbiter surfaces. The density profile of the major species O(+) was consistent with a classic Mach cone. However, strong perturbations extended for several meters outside the Mach cone, which resulted in failure of flowing Maxwellian distributions to represent the data. Configurations where the plasma-flow-impacted Orbiter surfaced downstream of the PDP resulted in generation of a suprathermal ion component. The observations are discussed in terms of a recent model of the mechanism for generation of Shuttle glow.

Reasoner, David L.↗