NASA Administrator Michael Griffin, saying the space agency has done everything humanly possible to fix the problems that led to the Columbia disaster, told reporters today the shuttle Discovery is "go" for launch Wednesday, weather permitting, on an "utterly crucial" mission.

"I just came from a very interesting mission management team meeting," Griffin said after the management poll to clear Discovery for flight. "The net result of all that is we're go for launch tomorrow, pending weather. We're not really working any significant issues, just working through normal closeouts and hoping the weather gods are kind for tomorrow."

Late today, after Griffin's remarks, engineers were called to launch pad 39B to troubleshoot damage to protective heat shield tiles on Discovery's left-side orbital maneuvering system rocket pod. A protective plastic cockpit window cover somehow fell off and struck a tile-covered panel. The so-called carrier panel protects attachment fittings that hold the rocket pod to the shuttle's fuselage.

A replacement carrier panel was taken to the launch pad for installation, a job engineers said typically takes about an hour. As of this writing, the work was not expected to impact Discovery's launching Wednesday.

NASA's mission management team reviewed a handful of other open issues today, including concern about excessive heating on the strut fittings that hold Discovery's nose to its external fuel tank and concern about suspect components in one of the ship's electronic "black boxes."

Griffin said all the open issues were resolved to the management team's satisfaction and Discovery's launch on the 114th shuttle mission, the first since Columbia's destruction two-and-a-half years go, remained on target for 3:50:53 p.m. Wednesday. The launch window closes at 3:55:53 p.m.

On board will be commander Eileen Collins, pilot James Kelly, flight engineer Stephen Robinson, Andrew Thomas, Wendy Lawrence, Charles Camarda and Japanese astronaut Soichi Noguchi. The goal of the mission is to deliver critical supplies to the international space station; to bring trash and no-longer-needed gear back to Earth; to install a replacement gyroscope in the station's orientation control system; and to test rudimentary shuttle heat-shield repair techniques.

"I had a chance earlier this morning to walk down the orbiter and to meet with the crew and the crew families and I can tell you that the crew is just raring to go and they guys who are doing all the closeout work on the orbiter and at the pad are also raring to go," Griffin said. "They're pumped. So we're looking forward to tomorrow, as I'm sure you are, after two and a half years down."

Forecasters are calling for a 60 percent chance of good weather Wednesday through Friday. One long-range concern is tropical storm Emily and even though its current track carries it well to the south of Cuba and into the Gulf of Mexico, NASA managers are paying close attention.

"Hurricanes are always out there, weather's always out there, we'll just deal with that as it comes," Griffin said. "Our job for tomorrow - and the whole team knows this - is to figure out if it's OK to fly tomorrow."

Given the long-range weather prospects - and the fact that Discovery's launch window closes July 31 - it could be argued NASA is under a fair amount of pressure to get the shuttle off the ground as soon as possible. But Griffin said that was not the case.

"How do we know we're not getting 'go' fever? Because we're working through the process, we're asking all the questions and answering them appropriately. If we can't answer them, we'll stop. It's that simple."

Asked how important Discovery's flight was to NASA, Griffin said: "Obviously, it is utterly crucial for NASA, for the nation, for our space program to fly a safe mission."

"We take it seriously. We have done everything that we know to do," he said. "I think we got everything that everybody knows about out on the table. Can there be something that we don't know about that can bite us? Yeah. This is a very tough business. A very tough business. But everything we know about has been covered."

He said he viewed Discovery's launch and "every space launch we do" as a "tribute to all those who have gone before, the crews who have died as well as the crews who have lived."

"In the course of trying to conduct spaceflight activities, we in the United States have lost three crews," Griffin said. "Russia has lost two. It's a dangerous business, it will be for the foreseeable future. We work every time to make it less dangerous than the time before. ... But this is a matter to be regarded with the perspective of generations, and not weeks and months. So I think every launch is a tribute to all those who have chosen to risk their lives for the benefit of this nation's progress in space exploration."

Asked if Discovery's flight would be the safest in shuttle history, Griffin said the spaceplane has not flown enough times to provide the statistical data needed to answer the question. While the problem that doomed Columbia presumably has been fixed, "I don't think you can ever take the viewpoint that with a given launch or a given success that we have vindicated ourselves."

"There is no recovery from mistakes we've made, whether it goes back to the Apollo (launch pad) fire, the loss of Challenger or the loss of Columbia," Griffin said. "Going back even further, through a hundred years of aviation, the safety lessons that we who fly have learned and know are written in other people's blood.

"The minute we say we're good enough, we start getting bad again and we need not to do that. So we'll be looking at our management culture, our decision-making processes, our engineering processes aggressively as long as we hope to continue to fly safely."

He reiterated that NASA had done "everything that we know to do" to make Discovery as safe as possible.

"There is nothing that we know of that we have not addressed," he said. "Are there things out there that we don't know about? There may be. We sure hope not."

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