However, should a major accident occur to Discovery, Griffin said at a June 17 press briefing, "I would be moving to figure out a way to shut the program down."
Risk and Reward
John Logsdon is the director of the Space Policy Institute at George Washington University in Washington, D.C. He agrees with NASA Administrator Griffin's go-ahead for the coming Discovery launch.
"At a certain point, only time will tell," Logsdon said.
"But this was a decision by Mike Griffin to balance risk with reward, and in his judgment the reward outweighs the risk."
"It wasn't a black-and-white decision," Logsdon added. "It was a nuanced decision, and he is extremely well qualified to make that decision."
Should the risk of future shuttle flights prove to outweigh the reward and Griffin shuts the program down, Logsdon says, it would certainly doom the International Space Station to incompletion.
The space shuttle has been ferrying parts and crew to the station since its construction began in 1998.
"You can't finish the space station without [the shuttle]," he said.
Nor is there a shuttle replacement at the ready. NASA's next-generation spacecraft, the Crew Exploration Vehicle, is scheduled for completion in 2014.
(Watch video animation of NASA's next mission to the moon.)
"You can't wave a magic wand and—poof!—get a spacecraft qualified to carry humans," Logsdon said.
Alex Roland is a space-policy analyst at Duke University in Durham, North Carolina. He says the shuttle is an inherently flawed vehicle and should not be flown at all, or at least not with humans at the controls.
Nevertheless, NASA has committed itself to using the shuttle to meet its obligations on the International Space Station.
"They are in a real mess," Roland said. "I think they should have abandoned the whole enterprise, but if they are going to try and play out the string, this is not an unreasonable chance they are taking."
Ready to Fly
Weather permitting, Discovery will lift off Saturday from Kennedy Space Center in Florida at 3:49 p.m. ET.
"We're really excited to be here and ready to go do this for real," Mission Commander Steven Lindsey told reporters Tuesday.
The shuttle will dock at the International Space Station, where it will drop off European Space Agency astronaut Thomas Reiter and supplies.
Crew members will also perform a series of tests to verify that the shuttle updates made before launch are still in place.
In addition, two spacewalks are planned at the station. A third spacewalk will be added if the shuttle has enough power to remain in orbit for an extra day, extending the mission to 13 days.
If all goes well on the nearly two-week mission, NASA will fly two more shuttles this year.
Ultimately, with a total of 17 flights by 2010, the space agency aims to complete the International Space Station and perhaps repair the aging Hubble Space Telescope.
(Download wallpaper photos of space exploration.)
First, Discovery must complete this mission successfully.
"There is every reason to believe it will be successful and very little reason to believe it will have the same type of problems we've had in the past," Launius, the National Air and Space Museum historian, said.
"Clearly everyone's going to be on their toes," he added.
Free Email News Updates
Sign up for our Inside National Geographic newsletter. Every two weeks we'll send you our top stories and pictures (see sample).
|
SOURCES AND RELATED WEB SITES
|
