Three weeks from now, NASA will be launching space shuttle Discovery and an astronaut crew into space in the STS-121 mission. This is another attempt by the agency to save its ailing and aging shuttle program. Blastoff is scheduled for July 1 from the Kennedy Space Center in Central Florida, though the launch window can remain open until July 19.

Space engineers have been busy prepping the Discovery and ensuring that the tragedy of Columbia will never happen again. The engineers have made sure that there are no foam debris in Discovery and they recently discovered a faulty electrical box that they are working on. If you would recall, an almost 2 pounds of foam debris in the heat shield caused the untimely demise of the shuttle Columbia and its crew.

But still, they offer no assurance even if they are backed by twenty-five years of flight experience. Four years before the program is scheduled to end, NASA officials still consider the shuttle an "experimental vehicle." According to Wayne Hale, NASA's shuttle program manager, "this is a risky vehicle to fly...There are a number of things that can cause a bad outcome with this vehicle. What we have done is...try to reduce the risk."

Two years and $1.5 billion in modifications later, NASA launched Discovery last summer, only to discover that large chunks of foam again peeled away from the tank. That crew landed safely, but only pure luck prevented another accident, engineers said. "We have made the largest aerodynamic change to this tank that we have ever made since we began flying 25 years ago," Hale said.

If, God forbid, another major incident occur, NASA's run might just come to an end. According to John Logsdon, one of the members of the board that investigated the Columbia tragedy and director of the Space Policy Institute at George Washington University - "another major incident would probably lead to the [permanent] grounding of the fleet".

Even amidst unsure and risky scenarios, Discovery's astronauts said they still have faith in the shuttle and in NASA engineers. STS-121 mission specialist Lisa Nowak said, "it's been a long wait, but it's worth the wait...I feel that we're prepared and ready to go." We wish them all the luck in the world, they will surely need it.