A University of New York at Buffalo aerospace engineer has designed a software system that will help NASA detect and find air leaks in the International Space Station.
The software will be installed in NASA's mission control when the manned space station expands from its current eight-module configuration to a final 15-module setup.
The existing method of finding a leak is time consuming: Each module is sequentially closed off until a change in space-station air pressure indicates which one is the source of the leak. The new software developed by a team headed by John Crassidis, UB associate professor of mechanical and aerospace engineering, continuously monitors the space station for leaks and in less than one minute, can plot possible leak locations on a diagram of the space station. In some cases, it can show the exact location of a leak within a module or suggest two or three possible locations. "The idea is to localize the leak," says Crassidis. "It's a time saver for astronauts and a life saver, in a sense, because time is crucial when you're dealing with a leak."
When there's a leak the software detects a disturbance in the spacecraft's behavior and correlates the effects of the behavior with the geometric structure of the space station. This comparison makes it possible to predict leak location and the size of the hole causing the leak. "Other disturbances are always present, such as drag and solar wind," Crassidis explains. "We've developed very detailed models of these other disturbances, which are used to separate out these effects from the leak, thus isolating the leak disturbances."
The software can locate holes with a diameter of 0.4 in. and smaller. These holes are usually caused by space debris particles traveling at speeds to 17,000 mph. From the ground, NASA tracks space debris greater than 0.5 in. and can maneuver the space station away from it. The space station itself also has a shield designed to catch debris and micrometeoroids. Crassidis' software is designed to backup these systems. It can also detect leaks caused by in-space collisions, as when an unmanned cargo ship collided with Russian Space Station Mir in 1997. "NASA spends a lot of time and money making sure nothing hits the space station," says Crassidis. "This software will be part of a contingency plan if the wall of a module were to be punctured."