"I worked a bit with NASA engineers, "says Voss, "but I did it mostly by analysis. I used a handheld calculator, not a computer, to do a thermodynamic(热力学的) analysis. "At the end of the summer, he, like the other NASA-ASEE fellows working at Marshall summarized his findings in a formal presentation and detailed paper. It was a valuable moment for Voss because the ASEE program gave him added understanding of NASA, deepened his desire to fly in space, and intensified his application for astronaut status.
It was not an easy process. Voss was actually passed over when he first applied for the astronaut program in 1987. Since then he has participated in three space mission. The 50-year-old Army officer, who lives in Houston, is now in training for a four-month mission as a crew member on the International Space Station starting in July 2000.
Voss says the ASEE program is wonderful for all involved. "It brings in people from the academic world and gives NASA a special property for a particular period of time. It brings some fresh eyes and fresh ideas to NASA, and establishes a link with colleges and universities", Voss explains". There is an exchange of information and an exchange of perspectives that is very important".
For the academic side, Voss says, the ASEE program also "brings institutions of higher learning more insight into new technology. We give them an opportunity to work on real-world problems and take it back to the classroom".
Why was the hydraulic fuel pump seal important for the space shuttle？

A. Because previous seals all failed.
Because it was very complex in running the space program.
C. Because great care has to be taken of the hydraulic fuel pump sealing.
D. Because any crack in the seals would cause disastrous results for astronauts.