Cape Canaveral, Fla. -- What happens to computer chips in space?
At what rate do micro meteors hit the shuttle?
More than 100 Penn State students and alumni will watch the sky, waiting for these answers and more, when NASA's Space Shuttle Endeavour takes off on May 19, according to William A. Durbin, graduate student in electrical engineering and current payload manager for Penn State's second Get Away Special. Durbin took over from George Evanisko who graduated.
The Get Away Special program was established by NASA as an inexpensive way to fly research on the shuttle. For $10,000, NASA provides a canister for experiments that won't harm the shuttle or crew and are completely self contained. Penn State's canister has four compartments to hold three experiments and the batteries to power them.
The micro meteor detection experiment will measure how much micro debris hits the shuttle. The equipment takes vibrations caused by impacts and converts them to electrical impulses via a piezoelectric device. Piezoelectric materials produce electricity when deformed.
"We don't know how many micro impacts there will be," says Durbin. "If there are a lot, we will have to turn the gain down so that the system is not overwhelmed."
But, Get Away Specials must have no outside adjustments. So for a period of time, the device collects background noise and automatically adjusts readings before recording impacts.
"Eventually these detectors can be placed around the space station to determine where micro meteor or debris impacts occur and to monitor the force of the hits," says Tom Rusnock, electrical engineering student and head of the orbital debris experiment.
"In the Space Station, the astronauts can decide if the damage is sufficient to require an extra-vehicular activity to do repairs."
Currently, cosmonauts aboard the Russian Space Station Mir periodically go EVA to check the Station's skin."
In the semiconductor experiment, the students will test off-the-shelf semiconductor chips. NASA only takes hardened computers into space because natural radiation can alter information stored on an unprotected chip. Anil Nanduri, graduate student in electrical engineering, and his team hope to learn the effect of high energy particle radiation on standard semi-conductor chips. Developed by Martin Pechanec who has graduated, the semiconductor experiment will record single events that cause software errors.
A program stored in the experimental chips will be compared to a program stored in a protected computer. Any changes to the original program will be recorded and the times noted. A radiation monitor will also record any incidents of radiation during that time period. The experimental chip will then be refreshed with information from the protected computer and the experiment will continue.
"We already know that radiation effects information stored on semiconductors, we want to know where and when these errors occur," said Nanduri. "Someday, this information will enable us to design less susceptible chips."
While magnetometers have been used by other Shuttle missions to map the Earth's magnetic field, the Penn State magnetometer experiment turns inward and maps how the shuttle effects the magnetic fields as it flies through them.
Powering the three experiments also took planning and ingenuity.
"We looked at lithium batteries, but they were more explosive and harder to handle," says Durbin. "It turned out that alkaline batteries were the best choice."
The power source will be 160 D-cell batteries that will supply 170 hours of power. The students are using 3 dc-to-dc converters to step down the 30 volts produced by the batteries. The converters will operate until the battery output falls below 10 volts.
Throughout the project, Dr. C. Russell Philbrick, professor of electrical engineering has advised the students. Lockheed Martin, by purchasing three Get Away Specials, has greatly contributed to the educational experience of more than 100 undergraduate and graduate students who have worked on these experiments.
Students became involved through various electrical engineering, astronautical or aeronautical courses and by volunteering. A variety of companies donated equipment and time to help the students accomplish their goals.
A third Penn State Get Away Special canister may be used to continue these experiments or to test other areas where the special properties of microgravity or space are required.
EDITORS: Mr. Durbin may be reached at (814) 863-0851.
A'ndrea Elyse Messer (814) 865-9481 (office)/(814) 867-1774 (home)
firstname.lastname@example.org or email@example.com
Vicki Fong (814) 865-9481 (office) (814) 238-1221 (home) firstname.lastname@example.org