[Surviving Atmospheric Spacecraft Breakup, Wilderness & Environmental Medicine] 2005; Vol 16 (1):27-32
Newswise — Not all life was lost in the Columbia breakup during the space shuttle's reentry into the Earth's atmosphere on Feb. 1, 2003. Hundreds of tiny worms onboard for an experiment survived the tragedy, demonstrating that atmospheric spacecraft breakup is survivable, according to a new study. Researchers say their survival reveals possible inadequacies in the search-and-rescue procedure and in crew survival systems that need to be reevaluated.
Published in the latest Wilderness & Environmental Medicine, the study is thought to be the first to report an animal surviving the atmospheric breakup of the spacecraft supporting it. The article's authors are Nathaniel J. Szewczyk of the NASA Ames Research Center, and William McLamb of Bionetics Corporation.
Reconstruction suggested that the spacecraft's main body broke up at a speed and altitude of Mach 19 and 61 km, respectively. Canisters housing the worms, known as Caenorhabditis elegans, exited at a speed of 660 to 1,050 km · h-1 and at an altitude between 42 and 32 km above Earth. Researchers had suspected that Columbia survived long enough into breakup to protect the worms from some of the aerodynamic shear forces, frictional heat, shock waves associated with deceleration and decomposition of the cabin, and freezing temperatures of the upper atmosphere.
The recovered canisters were opened almost three months after Columbia's breakup. With a life cycle between seven and 10 days, the live worms were several generations removed from those originally placed inside.
The C. elegans experiment was designed to validate its on-orbit growth on a media. Already, the worm was considered to have a model system for biomedical research because it has nervous, muscular, digestive, and reproductive systems. It also was hoped to be useful for space life science research.
One of the study's suggestions for greater potential of crew survival is the use of spacesuits, an encapsulating escape system, or other technique that could prevent structural failure from thermal degradation. Not all spacecraft designs have required suits to be worn while traveling through the atmosphere. The canisters housing C. elegans acted as a sort of spacesuit, helping to protect the worms during breakup and reentry, impact with the Earth's surface, and the interim between impact and examination.
An animal's potential for survival differs with respect to its size, physiologic system, survival requirements, and tolerance. The survival potential of C. elegans is much higher than a human's because of its ability to withstand 100,000 gravities, a day of anoxia, and the absence of food for six months by entering a "dormant" dauer state. Despite the differences, the article's authors said they hoped the worm's survival would further the study of the human physiologic ability to survive spaceflight.
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Wilderness & Environmental Medicine is a peer-reviewed quarterly medical journal published by the Wilderness Medical Society. For more information, visit http://www.wms.org.