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Anna Lee Fisher

Anna Lee Fisher (born August 24, 1949) is an American chemist, emergency physician and former NASA astronaut who was the first mother to fly in space. Fisher became an astronaut candidate with NASA Astronaut Group 8 and joined the Astronaut Office for the development of the Canadarm and the testing of payload bay door contingency spacewalk procedures. She was assigned to the search and rescue helicopters for four Space Shuttle missions, then involved in the verification of flight software at the Shuttle Avionics Integration Laboratory and supported vehicle integration and payload testing at Kennedy Space Center. She flew into space on Space Shuttle Discovery for the STS-51-A mission and used the Canadarm to retrieve two satellites in incorrect orbits. Fisher then worked on procedures and training issues for the International Space Station (ISS), was a capsule communicator (CAPCOM) and the lead CAPCOM for ISS Expedition 33, and was involved in developing the display for the Orion spacecraft. (Full article...)

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August 24: Feast day of Saint Bartholomew (Western Christianity); Independence Day in Ukraine (1991)

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Baryte

Baryte is a mineral consisting of barium sulfate (BaSO4). Generally white or colorless, it is the main source of the element barium, an alkaline earth metal. It is found across the world and can be deposited through biogenic and hydrothermal processes or evaporation. Early records of baryte date to the 16th century, when a radiating form gained notoriety among alchemists for specimens found near Bologna, Italy. Carl Wilhelm Scheele determined that baryte contained a new element in 1774, but elemental barium was not isolated until 1808 by Humphry Davy, using electrolysis of molten barium salts. Modern uses of baryte include oil and gas drilling, oxygen and sulfur isotopic analysis, and radiometric dating. These crystals of baryte on a dolomite crystal matrix was found at Cerro Warihuyn in Miraflores District, Peru. This photograph was focus-stacked from 24 separate images.

Photograph credit: Ivar Leidus