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From Milk to Bones, Moving Calcium Through the Body: Calcium Kinetics During Space FlightDid you know that when astronauts are in space, their height increases about two inches? This happens because the weightlessness of space allows the spine, usually compressed in Earth's gravity, to expand. While this change is relatively harmless, other more serious things can happen with extended stays in weightlessness, notably bone loss. From previous experiments, scientists have observed that astronauts lose bone mass at a rate of about one percent per month during flight. Scientists know that bone is a dynamic tissue - continually being made and repaired by specialized bone cells throughout life. Certain cells produce new bone, while other cells are responsible for removing and replacing old bone. Research on the mechanisms of bone metabolism and the effects of space flight on its formation and repair are part of the exciting studies that will be performed during STS-107. Calcium plays a central role because 1) it gives strength and structure to bone and 2) all types of cells require it to function normally. Ninety-nine percent of calcium in the body is stored in the skeleton. However, calcium may be released, or resorbed, from bone to provide for other tissues when you are not eating. To better understand how and why weightlessness induces bone loss, astronauts will participate in a study of calcium kinetics - that is, the movement of calcium through the body, including absorption from food, and its role in the formation and breakdown of bone.
Document ID
Document Type
Smith, Scott (NASA Johnson Space Center Houston, TX United States)
Bloomberg, Jacob (NASA Johnson Space Center Houston, TX United States)
Lee, Angie
Date Acquired
August 21, 2013
Publication Date
December 16, 2002
Publication Information
Publication: STS 107 Shuttle Press Kit: Providing 24/7 Space Science Research
Subject Category
Aerospace Medicine
Report/Patent Number
Distribution Limits
Work of the US Gov. Public Use Permitted.

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IDRelationTitle20030011376Analytic PrimarySTS 107 Shuttle Press Kit: Providing 24/7 Space Science Research
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