CAPE CANAVERAL, Fla. (Reuters) - The thought of test launching a new spaceship with people aboard is unfathomable to NASA, which hopes to have a replacement for the space shuttle ready for test flights as early as 2016.
But 25 years ago, the agency did just that with the shuttle Columbia. John Young, a veteran of the Gemini and Apollo programs of the 1960s and early 1970s, and rookie astronaut Robert Crippen were strapped inside for the debut launch.
"This was the boldest test flight anyone ever did," NASA administrator Michael Griffin said on Wednesday during a commemoration of the first shuttle launch on April 12, 1981.
So brash was NASA that original designs included no means for safety officers to destroy the shuttle if it strayed off course and threatened populated areas.
Remotely controlled explosives were eventually added to the shuttle's booster rockets, which raised another uncomfortable issue: What about the people aboard?
Engineers added ejection seats for Young and Crippen, though Young said it was doubtful they would have survived flying through the 5,000-degree F (2,760 C) rocket plume.
After four flights, the shuttle was declared operational, and emergency exit gear removed.
"They left the (explosives) package on and took the seats out. That was really surprising to me," said Young.
The Columbia was lost in a 2003 accident and the remaining shuttles are scheduled for retirement in four years. NASA wants to incorporate what it learned from the shuttle program into a new manned spaceship, called the Crew Exploration Vehicle.
Two teams are bidding to build it. Either Lockheed Martin or a partnership of Northrop Grumman and Boeing will be selected as prime contractor later this year.
"The shuttle is a step along the way," Griffin said. "We will take those lessons and apply them to a new generation of machines."
One of the shuttle's key features, re-usability, proved too costly to continue. NASA is returning to using capsules perched atop expendable rockets to carry future crews into space.
Like the Mercury, Gemini and Apollo vessels that preceded the shuttle, the new ship will have an escape system to give crews a chance of surviving launch pad accidents.
The anniversary was a somber reminder that 14 astronauts have died in two shuttle accidents and the fleet remains grounded to fix fuel tank flaws.
The Columbia disaster exposed an ongoing problem with the tank's insulation breaking off during launch and posing a threat to the heat shields. Columbia was destroyed due to damage from falling tank debris and when Discovery flew last year, its tank also lost big foam chunks.
The shuttles never flew as often as projected and proved hideously expensive to operate. But NASA said the program has been a boon to technological advances, including astronomy with the launch and servicing of the Hubble Space Telescope.
NASA plans to use the Crew Exploration Vehicle to fly crews to the space station, return astronauts to the moon and eventually send them on to Mars. The vehicle's first moon landing is targeted for 2018.
"Space is one of the best ways to push technologies, other than going to war," Young said. "And it is technology that has kept us on the leading edge of being a world power."