NIST EXPERIMENT'S DATA ACQUIRED BEFORE SPACE SHUTTLE TRAGEDY

摘要

NIST scientists used an experiment aboard the STS- 107 mission of the space shuttle Columbia to look for a particular type of flow behavior, never before seen in a pure liquid, that may have practical applications in products ranging from paints and plastics to foods and pharmaceuticals. Almost all of the data from the experiment-sent by telemetry to the ground during the mission-were acquired before the tragic loss of the shuttle orbiter and its seven-member crew on Feb. 1, 2003. The "Critical Viscosity of Xenon-2" (CVX2) experiment measured the changes in viscosity (resistance to flow) of a xenon sample as it was stirred rapidly and approached the "critical point." Xenon, an inert gas, exhibits unusual behavior near its critical point, at which it turns into a milky fluid with properties between those of a liquid and a gas. The experiment was conducted in the microgravity of orbit because the changes in viscosity that take place in the critical state cannot be measured accurately in Earth's gravity.