the space agency's shuttle program, which had a successful —
yet stressful — return to flight this summer.
NASA's space shuttle program suffered a terrible blow Feb. 1, 2003, when the Columbia and its crew of seven were lost upon re-entry into Earth's atmosphere.
The cause of the tragedy: seemingly harmless foam insulation from the external fuel tank collided with one of the shuttle's wings on liftoff, compromising the craft's structural integrity.
The remaining shuttle fleet was grounded for two-and-a-half years. Then on July 26, the shuttle Discovery was launched successfully into space in a mission billed "Return
to Flight."
NASA engineers were at first jubilant — until they noticed bits of foam falling from the external fuel tank in video footage of the liftoff. Upon further inspection, two pieces of ceramic-coated fabric meant to fill gaps between the shuttle's heat-shield tiles were discovered protruding from their gaps. In a groundbreaking — and breathtaking — spacewalk, astronaut Steve Robinson removed the errant material, and the Discovery returned to terra firma safely on Aug. 9.
"We had a great mission," says Stan Schaefer '87, chief of NASA's Systems Division. "But we have to understand the problems we had with the foam shedding on the tank. We did a lot of work after Columbia, and we've been going through an effort since the Discovery landing to find out where that foam came from, why we think it came off, and to redesign future tanks to make sure it doesn't happen again."
Though Schaefer is characteristically optimistic, the shuttle program's days are numbered. Launched dozens of times since the first flight of Columbia in 1981, the orbiters are beginning to show their age. Two of the craft have disintegrated in flight, federal funding is difficult to acquire and maintain — and now Hurricane Katrina has added to NASA's headaches.
The Stennis Space Center, located near Gulfport, Miss., and the Michoud Assembly Facility, near New Orleans, have both been adversely affected by the cataclysmic storm. The former facility is responsible for testing the shuttle's main engines; the latter is where the enormous external fuel tanks — with their controversial foam — are constructed. None of this bodes well for the next scheduled shuttle flight, currently set for May 2006. (A mission to the International Space Station in October utilized a Russian-launched Soyuz craft.)
But far from having all its eggs in one basket, NASA has in its pipeline a new generation of workhorse spacecraft. "We're working on development of the Crew Exploration Vehicle," says Schaefer. "It won't be a direct replacement for the shuttle, but it will be what we use to carry people to space and back. We'll send cargo up in unmanned vehicles. The projected launch date for the cev is 2011."
Schaefer also envisions a move toward modular design in spacecraft, in which basic components can be expanded upon as needed. And he cites a President Bush initiative as a building block of that effort: "The Vision for Space Exploration is to begin the process of moving out of low Earth orbit. The first step in that is to build the CEV to use to move people to the moon and back — and possibly Mars."
When asked what he foresees 25 years from now, Schaefer relates: "We'll still have a space station, but also have a lunar base. We'll be sending people there to do science and learn about the moon, and use it to gain knowledge about living on other planets. A lot of stuff has to happen between now and then, and the country's budget and the desires of the people and the administrations have to be considered. But I certainly think if NASA was given that mandate, that challenge, we could do it."
