Engineering topics

Helms, David R.

Publications and source records attributed to Helms, David R..

4 records

NASA NTRS1994

Earth observations during Space Shuttle Flight STS-49: Endeavor's Mission to Planet Earth

A brief mission overview of STS-49 is given, and some of the pictorially outstanding and scientifically interesting photographs obtained during the mission are presented. The Earth observations are described and include the following: the Southwestern Pacific Ocean -- wind and water; the Southwestern Pacific Ocean -- coasts and volcanoes; the US; Cuba and the Bahamas; South America; Africa; the Red Sea and Western Indian Ocean; and the Indian Subcontinent.

Amsbury, David L.↗

NASA NTRS1992

Earth observations on Space Shuttle Flight 43 - It was a dirty world

Attention is given to earth observations made by the crew of Space Shuttle Flight 43, during which atmospheric haze and its various aerosols were investigated. The length-of-record time series from the Space Shuttle Earth Observation Program was used to photograph some of the sites under active investigation. It was found that Lake Chad's northern basin remained dry, and the southern basin showed no appreciable changes in water level. The Okavango Swamp areas in Botswana showed agricultural burning at several sites, and increasing evidence of land use activity in the areas of the swamp that previously had been under natural cover. Consideration is also given to Hurricane Fefa and Tropical Storm Guillermo, the smoke from the Kuwaiti oil fires, Mount Pinatubo, dust storms in the Sahara, biomass burning, South Asian monsoon runoff, land use patterns, landforms and geology, and oceans and coastal features.

Amsbury, David L.↗

NASA NTRS1992

Ice patterns and hydrothermal plumes, Lake Baikal, Russia - Insights from Space Shuttle hand-held photography

Earth photography from the Space Shuttle is used to examine the ice cover on Lake Baikal and correlate the patterns of weakened and melting ice with known hydrothermal areas in the Siberian lake. Particular zones of melted and broken ice may be surface expressions of elevated heat flow in Lake Baikal. The possibility is explored that hydrothermal vents can introduce local convective upwelling and disrupt a stable water column to the extent that the melt zones which are observed in the lake's ice cover are produced. A heat flow map and photographs of the lake are overlaid to compare specific areas of thinned or broken ice with the hot spots. The regions of known hydrothermal activity and high heat flow correlate extremely well with circular regions of thinned ice, and zones of broken and recrystallized ice. Local and regional climate data and other sources of warm water, such as river inlets, are considered.

Evans, Cynthia A.↗

NASA NTRS1990

The NASA Environment Remote Sensing Analysis Facility (ERSAF) support for Space Shuttle earth observations

It is shown that dedicated premission, real-time, and postmission support for planning, acquiring, and interpreting remotely sensed data of specific sites in terms of illumination geometry, atmospheric transmissivity, and preferred viewing is required in order to acquire the best possible earth-viewing photography for each Shuttle mission. Mission support has resulted in significant advances for the earth observation activities and other experiments carried out by astronauts. Scientific and mission support are described and equipment and capabilities are reviewed. Future advances listed include improvement of existing data bases, expanding access to climatological databases of atmospheric constituents and aerosols, and expanding access to image data such as the DMSP, while Space Station Freedom will require 24-hour operational support.

Helms, David R.↗