Shuttle Mission Plans to Explore Various Effects of Weightlessness
Astronauts on the space shuttle Columbia mission scheduled to begin today will investigate the behavior of various materials in a place where hot air doesn’t rise and poured water drifts away.
The low gravity of space is expected to pose challenges for people living there for extended periods and possibly provide opportunities for commercial processes that could only be performed outside the confines of Earth’s strongest gravitational pull. The 29 experiments aboard Columbia are to be carried out over 13 days in orbit in the first mission devoted solely to the mysteries of weightlessness.
NASA rushed to fix another equipment problem Wednesday, but weather appeared to be Columbia’s only remaining hurdle.
Meteorologists said there was only a 40% chance of acceptable conditions for a 9:07 a.m. PDT liftoff today because of rain and possible thunderstorms.
For the second time in a day, technicians had to replace a navigation unit in the crew cabin. Two of the three units were replaced overnight after failing tests, and one of the replacements also failed.
The technicians ran out of time before they could complete all the testing needed to verify whether the newest spare unit was working. Officials said only two units had to be working to let Columbia lift off.
Fire will be the subject of three of the experiments. Astronauts will check the effect of gravity on smoldering foam, candle flames and overheated wires.
A fire needs oxygen, fuel and heat. In space, there is little air rushing in to replenish the oxygen supply to a fire. But rather than rising as it does on Earth, hot air stays low, increasing the heat.
A planned water experiment eventually could lead to gardens in space--”astroculture,” said Roger Crouch, the National Aeronautics and Space Administration’s microgravity program scientist.
In low gravity, it is difficult to water plants without some of the liquid ending up in sensitive equipment. University of Wisconsin researchers will test two sets of pipes underneath a small bed of clay soil, one to bring the water to roots and the other to draw off the surplus.
