Space Shuttle Discovery: Launch Delayed to Nov. 30

VIDEO: Atlantis takes its final journey as NASA winds down shuttle
WATCH Swan Song for Shuttle Atlantis

If the space shuttle Discovery had launched on schedule, she would now be in orbit, docked with the International Space Station, her six astronauts joining the six currently on board the station to unload 22,000 earth pounds of equipment.

But as has often happened in 30 years of shuttle flights, Discovery still sits on launch pad 39A at the Kennedy Space Center here in Florida, waiting as mission managers worked their way through a minor helium leak, a minor electrical problem and Florida's famously unpreditable weather.

VIDEO: Atlantis takes its final journey as NASA winds down shuttle program.Play
Last Liftoff for Space Shuttle Atlantis

They delayed this morning for the fourth time, after they found a hydrogen leak while fueling. As they were inspecting the ship on the launch pad, they also found a 7-inch crack in the now-famous insulating foam on the shuttle's orange external fuel tank, potentially troublesome if some had fallen off and hit Discovery during liftoff.

The launch is now delayed to at least Nov. 30 at 4:05 a.m. ET. The angle of the sun on the orbiting shuttle would have prevented a launch after Monday, and there is also a Russian launch NASA needs to wait out.

"We're going to fly when we're ready, and clearly we were not ready to fly today," shuttle launch director Mike Leinbach said. "It's a machine, and every now and then machines break."

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Flying and Floating in an F-16

The bigger problem is that Discovery is flying for the last time, with absolutely no consensus on what will come after the shuttles are retired next year.

Forida's weather today was sunny but gusty. The longer-range forecast for the space agency: cloudy with a chance of layoffs.

People at NASA will tell you the shuttles are magnificent machines, but they were asked to do too many things and became too complicated for their own good. NASA needed them as cargo ships, orbiting laboratories and satellite launchers. The Pentagon wanted them to be able to capture Soviet satellites. It's a little like buying a car that can deliver 40 kids to school, haul lumber, and win the Indy 500.

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Newsman's Wild Loop in an F-16

"It is a vehicle the likes of which we won't see again, for probably decades if not many decades," said astronaut Michael Barratt, a Discovery crew member who has already spent 197 days orbiting in the space station. "The carrying capacity of this ship, the number of people, the fact that it can be an independent orbiting laboratory or a massive cargo hauler -- it is an incredible spaceship."

Tragically, of course, two of America's five shuttles have already been lost. Roads and buildings at NASA centers are named for the 14 astronauts who died on Challenger and Columbia.

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The Feeling of F-16 Flight

Put all those things together, and you understand why, since the mid-1990s -- half the length of the shuttle program -- NASA has been working on something to replace the shuttle. In 2004 the Bush administration ordered that the fleet be retired by now -- as soon as they could finish assembling the space station -- and replaced with an exploration program called Constellation.

NASA Forecast: Cloudy With a Chance of Layoffs

But in January, the Obama White House canceled Constellation. A panel of experts said the finances made sense back when Bush began the program, but they had since ballooned to a point where they were "unsustainable."

And that leaves NASA's astronaut program in limbo. Already, depending on whom you ask, some 8,000 space program jobs are threatened -- to say nothing of all the other people whose work depends on them.

"All we know for certain is that the shuttle program will wind down," said Discovery astronaut Alvin Drew during a preflight interview with ABC News. "We don't know what is going to come out of the backside of this thing. I don't have that sense of 'We are leaping into some great new future,' because I don't know what that future is."

Discovery is going on what, if not for the end of the program, would be a routine-sounding supply flight to the space station. It is to deliver a freezer, equipment racks, a water-recycling system, and a robot that NASA could not resist calling R2.

Everything is packed in a bus-sized container called Leonardo. It has been used for supply missions before and brought home in the shuttle's cargo bay. But for lack of future shuttle flights, Leonardo will be left docked to the station so astronauts on board have some extra room.

Mike Moses, the head of the prelaunch mission management team -- which decides whether they try for launch or not -- tried to be philosophical. The Obama administration has called on private industry to ferry astronauts to the space station, but even if they succeed, there will be a gap of several years during which America will not be able to launch astronauts. It will have to depend on the Russian Soyuz program.

"In a perfect world, if you sell your old car, you'd like to know what your new car will look like," said Moses. "But I understand what's going on. The realities are that NASA is on a fixed budget, and without a big infusion of cash you can only do a certain number of things at a time."

So Discovery waits on the ground while anxiety floats in the air.

"There's still a certain amount of disbelief that we're getting to the final launch," said Leinbach. "It's difficult to accept emotionally, but rationally we know it's coming to an end."