Space Shuttle a Go for July 1 Launch

June 17, 2006 — -- After a long debate, NASA's managers said the shuttle Discovery is go for launch on July 1 -- even though two top engineers voted against flying.

"At the end of the day, some people still had reservations, and they expressed those reservations," said Wayne Hale, the shuttle program manager.

Their worry was that pieces of ice and insulating foam might still fall off the shuttle's orange external fuel tank on launch -- just as happened three years ago to Columbia.

The difference now, said NASA's administrator, Michael Griffin, is that shuttle crews will photograph the shuttle's belly inch by inch in orbit -- and if there's damage what would prevent a safe return, a second shuttle would be rushed to the launch pad and sent to rescue the astronauts.

"We are not in the situation we were with Columbia, where we didn't know that we had a problem," said Griffin. "We know we have a problem. We are electing to take the risk; we do not believe we are risking crew."

Shuttle manager Hale, an agency veteran, said he could recall only one so-called "Flight Readiness Review" in program history during which there had been a dissenting vote on whether to launch. But he said this was healthy. Before the Columbia accident, engineers who disagreed with their bosses were afraid to speak up.

"I think that is a great step forward from where we were some time in the past," said Hale.

NASA faces a difficult balancing act. It knows the shuttles have problems -- but they're the only ships that can be used to build the much-delayed International Space Station.

The mission, designated STS-121, is a 12-day flight to deliver supplies to the station; drop off a German astronaut, Thomas Reiter, to join the station's crew; and -- perhaps most important -- make sure the shuttle itself is in shape to resume a schedule of four to five flights a year.

They thought they had the problem solved last year, but during Discovery's last launch, on July 26, 2005, foam still fell from the tank.

Now, they say the risk has been reduced, though it can never be eliminated. A cover has been removed over a conduit for pipes and wiring on the tank's exterior, and more foam will be removed on coming flights.

"I think we're safer," said Steve Lindsey, the commander of next month's mission. "But in the grand scheme of things, are we an order of magnitude safer than before Columbia? No, and I don't think we ever will be with this vehicle."

That raises the question of how safe is safe enough. The answer depends on how bold the mission is.

"The public is perfectly willing to tolerate these risks if it's for something that matters," said Andrew Chaikin, the author of "A Man on the Moon" and an occasional advisor to NASA management. "The risk is worth it to do something that's never been done before."

Chaikin was in on the planning of the White House' "Vision for Space Exploration," announced in 2004. It calls for NASA to phase out the space shuttles around 2010, and return to the business of exploring -- sending astronauts back to the moon, and, eventually, on to Mars.

Chaikin said past polls show that Americans are clearly interested in exploring new frontiers -- but not so interested if all NASA does is send shuttles on glorified construction jobs.

The problem is that for the next few years the agency has no choice. It is obliged to finish the space station, and that, under current plans, will take about 16 more shuttle flights.

"The only way they can finish the International Space Station, which we are bound to do by agreements with our international partners, is to fly the shuttle," said Chaikin.

Astronauts have said privately that they're more willing to risk their lives on bold missions -- to maintain the Hubble Space Telescope, for example, or resume lunar flights in coming decades. The main reason to get the shuttles flying again, say NASA managers, is to get their job finished and go on to flying what is currently called the Crew Exploration Vehicle, scheduled to be flight-ready by 2014.

As things stand now, Discovery launches on July 1 at 3:48:15 PM, EDT. Despite the decision to go, the agency concedes it has done some mathematical analysis, and believes there is a one-in-75 chance of a catastrophic accident.