Releases : Science

The Space Shuttle Discovery is scheduled to launch this Saturday, July 1, for a 12-day mission, with a primary mission of testing methods of repairing the shuttle while in orbit. The director of the astronomy lab program at the University of North Texas says these repair tests are crucial for NASA to keep the shuttle program alive.

Discovery's mission will be the second Return to Flight Testing mission after the Space Shuttle Columbia disintegrated during re-entry on Feb. 1, 2003, killing all seven crew members. Foam falling from the fuel tank damaged the Columbia's wing, leading to the vehicle's disintegration as it tried to land.

Ron DiIulio, a NASA/Jet Propulsion Laboratory Solar System Ambassador as well as the director of UNT's astronomy lab program, says NASA has made a few modifications to the foam on the Discovery's external fuel tank since its last mission in July 2005 - the first of the Return to Flight testing missions marking NASA's return to space. DiIulio says, however, that some NASA administrators "have raised a few questions."

DiIulio says use of the shuttles is critical to both complete the International Space Station and to repair the Hubble Space Telescope. Safe, consistent operation of the shuttle program is integral to both missions, he says.

"(The Russian) Soyuz equipment doesn't have the payload capability of the shuttle fleet," he says. "The shuttle is basically our truck into outer space. It's needed to do the hauling and heavy lifting of equipment, because there's nothing out there to replace it in the short term."

In addition to testing methods of repairing the shuttle, the Discovery crew will visit the International Space Station during its mission, delivering supplies and a German astronaut, who will join the Russian station commander and an American astronaut on the station.

Last week, NASA announced that it was reinstating the Dawn mission, a robotic exploration of two major asteroids, after canceling it in early March because of technical problems and cost overruns. The mission, named because it was designed to study objects dating from the dawn of the solar system, involves sending a probe to Vesta and Ceres, two of the largest asteroids orbiting the sun between Mars and Jupiter. Dawn will use an electric ion propulsion system and orbit multiple objects.

The director of the planetarium and astronomy lab at the University of North Texas says he is pleased that NASA is reinstating the funding for a July 2007 launch of mission to two large asteroids. The university has a meteorite from one of the asteroids.

"Most of the work has already been done for the project; the preparations were in place, and so was the systems and geology work," says Ron DiIulio. "The scientific community is glad to have this program back."

The Dawn project was originally budgeted to cost $373 million. NASA has agreed to spend an extra $73 million to complete the project.

DiIulio says he is excited about the potential of the Dawn project, noting that the mission will increase the knowledge of the universe.

"This mission will help us to understand these two asteroids. We know what makes up the surface of these asteroids, but the Dawn mission will let us learn about what makes up their cores," he says.

Scientists believe Ceres and Vesta were formed about 4.5 billion years ago in different parts of the solar system. They think the asteroids may have clues on the formation of the solar system.