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Kari Fluegel April 26, 1993

Release No. 93-031

STS-55 ASTRONAUTS TO DOCUMENT EARTH OBSERVATIONS


Low Earth orbit gives space shuttle astronauts a unique vantage point from which to observe and document photographs a variety of meteorological, environmental, oceanographic and geological features for scientific researchers back home.

STS-55 will not be an exception. The nine-day mission will orbit at an altitude of 160 nautical miles and an inclination of 28.45 degrees, taking the astronauts over the Kennedy Space Center in Florida, the Red Sea, and the Himalayas to the north and over Asuncion, Paraguay; Johannesburg, South Africa; and Brisbane, Australia, to the south.

The photographic documentation of Earth observations is dependent on several factors including lighting, crew activities and weather. A change in the launch time could affect the daytime lighting conditions at planned observation points. Steering maneuvers may turn orbiter windows away from the Earth. Crew activities with higher priority often are rescheduled during missions, thus precluding planned Earth observations, and clouds frequently interfere with the planned photography.

Still, Earth Observation is a favorite activity for astronauts, and crew members usually return from space with hundreds of photographs and thousands of feet of film. A large assortment of cameras, lenses and films are carried on each shuttle flight, and astronauts participate in a series of science training sessions before their mission so they can optimize the limited observation time. The STS-56 crewmembers, for example, took more than 6,000 photographs on their nine-day flight last week, including a duststorm that stretched from Mongolia east to the Aleutians and south to near the Hawaiian Islands, and an eruption of Unzen Volcano in southern Japan.

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For STS-55, the subjects chosen for thorough Earth observation include the weather effects of the Benguela Current on the coastal desert of Namibia, geological features such as the meteorite impact crater occupied by Lake Bosumtwi in Ghana, volcanic eruptions of Mt. Pinatubo in the Philippines and lakes within the Cameroon Volcanic Line, from which poisonous gases emanated in 1984 and 1986, killing hundreds of people. Other subjects chosen for thorough Earth observation are

Lascar Volcano, Chile -- Lascar Volcano, located 170 miles from Calama, Chile, erupted April 20 sending a smoke and ash plume an estimated 40,000 feet in the air. Since that time, preventive measures in the surrounding area have been intensified as authorities evacuate residents of nearby communities. A thick lava layer has closed the International Highway linking the El Loa Province and Salta, Argentina. Lava also has contaminated the drinking water for surrounding communities, and the smoke and ash cloud has drifted over several Argentine provinces including Tucuman, Salta and Santiago Del Estero, where skies are cloudy and strangely colored. Chilean officials have stated that the volcano has not been behaving normally. Photographs taken during STS-55 will help characterize the situation.

The Sudd Swamp, Sudan -- The hydrology/ecology of the Sudd Swamp and proposals for reducing the overflow from the White Nile river system into the swamp have been studied for years. An author of a book on this subject, soon to be published by the Cambridge University Press, has requested shuttle photographs for use as illustrations in his book. Overall interest in the area has heightened in recent years because of the great expansion of the swampland. Before 1960, the area was estimated at approximately 13,000 square kilometers, but today the estimate has increased to 29,000 sq. km. Shuttle photographs have great value for illustrating this change. Future space photographs will record the effects of a new canal being constructed which should reduce the overflows from the White Nile and increase the amount of arable land. The area inundated by water spilling not only varies over years but also expands and contracts with the seasons. Shuttle photographs acquired during dry as well as wet periods can be compared.

Panama -- The Panama Canal, an 80-km shortcut linking the Atlantic and Pacific Oceans, is a major route for world shipping. Gatun and

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Madden Lakes supply water for operation of the locks and ships'

boilers, but rapid deforestation of the watersheds of these lakes is resulting in erosion and siltation. Water storage capacity is declining. At this time, rainfall is the only means of replenishing the lake. Environmentalists are interested in assessing the damage caused by deforestation and in tracking the rate at which deforestation is occurring.

The Irrawaddy River Basin, Burma -- The Irrawaddy River Basin and Delta in the heartland of Burma have been undergoing rapid deforestation and land use changes. Land erosion, river bed siltation and estuary sedimentation are the result. Shuttle photographs will aid in documenting the progress and consequences of changing land use patterns and deforestation.

The Persian Gulf and the Strait of Hormuz -- Even before the recent invasion of Kuwait, researchers estimated that 250,000 barrels of oil polluted the Persian Gulf yearly from tanker spills, bilge pumping and wellhead leaks and spills. It takes more than five years for all the water in the Gulf to circulate completely through the narrow Hormuz Straits and be replaced by new water. The inflow of fresh water from the Tigris-Euphrates Basin is progressively reduced as the water supplies cities and vast agricultural developments. The result is progressive pollution of the water body, visible along the coastlines since the enormous war-related oil slick moved from the north to the south end of the Gulf. The post-fire landscape appears different in numerous details from the pre-war landscape. Soot and oil from the oil well fires completely blankets hundreds of square kilometers of the desert surface around Kuwait. Shuttle photographs will continue to be useful in determining the extent of the damage.

Lake Volta, Ghana -- Lake Volta, a large dammed lake, has been difficult to successfully photograph from space. The dam on Lake Volta supplies about 92 percent of all the electricity used in Ghana, Benin and Togo and a lesser amount for Burkina. The water level of Lake Volta is very low as a result of the drought that has impacted most of the countries on the southern fringe of the Sahara. The drop in water level has forced a cut in hydroelectric power generation. The dam is now producing electricity for only about two hours a day. Any photographs of the region will be useful.

El Chichon Volcano, Southern Mexico -- The first historic eruption of

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El Chicon started on March 29, 1982, and created a massive cloud of ash, some of which fell on Texas and Louisiana. This previously inconspicuous volcano now has an enlarged crater that can be easily seen from space. A series of photos over the next few years will help document revegetation of the devastated area.

Cameroon/Benue Rift Valley -- The Gotel/Shebshi/Mandara Mountain Ranges, also known as "the Cameroon Line" are volcanic in origin. With the exception of Mt. Cameroon, located near the coast, the volcanoes are inactive. In August 1984, an explosion in Lake Monoum produced shock waves and a 5-meter water wave that flattened vegetation around the lake. A poisonous gas cloud in the area caused the death of 37 people, and the lake water remained reddish for an undocumented period of time. A similar incident occurred in August 1986 at Lake Nios, which is located in the same volcanic mountain chain as Monoum. An explosion in the lake released poisonous gas fumes that blew over a nearby village killing more than 1,200 people. These incidents and the 1982 eruption of Mt. Cameroon have stimulated scientific interest in the region, but, because the area is frequently cloud-covered, there are very few oribtal photographs of it.

Following each mission people working on the Space Shuttle Earth Observations Project catalog each photograph for an electronic data base which is used by hundreds of researchers. SSEOP personnel also describe and analyze many of these photographs for their scientific colleagues, students and the public.

Another Earth-observing system, the Modular Optoelectronic Multispectral Scanner, will be carried on STS-55 as part of the second German Spacelab but outside it on a unique support structure. The instrument, known as MOMS-2, combines a digital camera with a four-band electromagnetic spectral sensor. An improvement over the MOMS-1 camera operated on STS-7 and STS-41B, the MOMS-2 camera takes stereo images. Using this advanced system, researchers will be able to derive digital terrain models containing such thematic information as the location of iron-bearing rocks, the discrimination of stressed and flourishing vegetation, and land use.

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