Engineering topics

Whitaker, Ann

Publications and source records attributed to Whitaker, Ann.

6 records

NASA NTRS2002

Science@NASA: Direct to People!

Science@NASA is a science communication effort sponsored by NASA's Marshall Space Flight Center. It is the result of a four year research project between Marshall, the University of Florida College of Journalism and Communications and the internet communications company, Bishop Web Works. The goals of Science@NASA are to inform, inspire, and involve people in the excitement of NASA science by bringing that science directly to them. We stress not only the reporting of the facts of a particular topic, but also the context and importance of the research. Science@NASA involves several levels of activity from academic communications research to production of content for 6 websites, in an integrated process involving all phases of production. A Science Communications Roundtable Process is in place that includes scientists, managers, writers, editors, and Web technical experts. The close connection between the scientists and the writers/editors assures a high level of scientific accuracy in the finished products. The websites each have unique characters and are aimed at different audience segments: 1. http://science.nasa.gov. (SNG) Carries stories featuring various aspects of NASA science activity. The site carries 2 or 3 new stories each week in written and audio formats for science-attentive adults. 2. http://liftoff.msfc.nasa.gov. Features stories from SNG that are recast for a high school level audience. J-Track and J-Pass applets for tracking satellites are our most popular product. 3. http://kids. msfc.nasa.gov. This is the Nursemaids site and is aimed at a middle school audience. The NASAKids Club is a new feature at the site. 4. http://www.thursdaysclassroom.com . This site features lesson plans and classroom activities for educators centered around one of the science stories carried on SNG. 5. http://www.spaceweather.com. This site gives the status of solar activity and its interactions with the Earth's ionosphere and magnetosphere.

Koczor, Ronald J.↗

NASA NTRS2001

Chandra Observations of Io and the Io Plasma Torus

Chandra observed the Jovian system for approximately 1 day with ACIS-S in Nov, 1999, and approximately 10 hours with HRC-I in Dec, 2000. Among the many results of great interest to planetary scientists are the detection of x-ray emission from the Io Plasma Torus (IPT) and, very faintly, associated with the Jovian moon Io itself. The IPT is an almost self-generating donut of S and O ions in Io's orbit that ultimately derive from volcanoes on the surface. While EUV and visible emissions from the IPT are relatively well understood to result from low charge state transitions of S and O and from electron impact, the x-ray emissions are too energetic to be explained this way and seem to require the presence of higher charge states of S and O. We present current ideas as to origins of these x-ray emissions.

Elsner, Ronald F.↗

NASA NTRS2001

Computer Simulation of the Forces Acting on a Submerged Polystyrene Probe as it Approaches the Succinonitrile Melt-Solid Interface

A Modeling approach to simulate both mesoscale and microscopic forces acting in a typical AFM experiment is presented. A mesoscale level interaction between the cantilever tip and the sample surface is primarily described by the balance of attractive Van der Waals and repulsive forces. Ultimately, the goal is to measure the forces between a particle and the crystal-melt interface. Two modes of AFM operation are considered in this paper - a stationary and a "tapping" one. The continuous mechanics approach to model tip-surface interaction is presented. At microscopic levels, tip contamination and details of tip-surface interaction are modeled using a molecular dynamics approach for the case of polystyrene - succinonitrile contact. Integration of the mesoscale model with a molecular dynamic model is discussed.

Bune, Andris V.↗

NASA NTRS2000

Manufacturing and NDE of Large Composite Aerospace Structures at MSFC

NASA's vision for transportation to orbit calls for new vehicles built with new materials technology. The goals of this new launch system development are to improve safety, dramatically reduce cost to orbit, and improve vehicle turn around time. Planned Space Shuttle upgrades include new reusable liquid propellant boosters to replace the solid propellant boosters. These boosters are to have wings and return to the launch site for a horizontal landing on an airport runway. New single and two stages to orbit concepts are being investigated. To reduce weight and improve performance composite materials are proposed for fuel and oxidizer tanks, fuel feedlines, valve bodies, aerostructures, turbomachinery components. For large composite structures new methods of fabrication are being proposed and developed. Containment of cryogenic fuel or oxidizer requires emphases on composite material densification and chemical compatibility. Ceramic matrix and fiber composites for hot rotating turbomachinery have been developed with new fabrication processes. The new requirements on the materials for launcher components are requiring development of new manufacturing and inspection methods. This talk will examine new and proposed manufacturing methods to fabricate the revolutionary components. New NDE methods under consideration include alternative X-ray methods, X-ray laminagraphy, advanced CT, Thermography, new ultrasonic methods, and imbedded sensors. The sizes, complexity, use environment, and contamination restrictions will challenge the inspection process. In flight self-diagnosis and rapid depot inspection are also goals of the NDE development.

Whitaker, Ann↗

NASA NTRS1997

Institute Study Report

This report documents a study conducted by the MSFC working group on Institutes in 1995 on the structure, organization and business arrangements of Institutes at a time when the agency was considering establishing science institutes. Thirteen institutes, ten science centers associated with the state of Georgia, Stanford Research Institute (SRI), and IIT Research Institute (IITRI), and general data on failed institutes were utilized to form this report. The report covers the working group's findings on institute mission, structure, director, board of directors/advisors, the working environment, research arrangements, intellectual property rights, business management, institute funding, and metrics.

Whitaker, Ann↗

NASA NTRS1987

Effects of Monatomic Oxygen on Coatings

Report describes tests in which paints, metals, and optical materials carried in orbit around Earth determined how monatomic oxygen in rare orbital atmosphere affects them. Specimen disks carried aloft on Space Shuttle and exposed for 41.17 h at altitude of 120 nmi (222 km).

Whitaker, Ann↗