NASA Administrator Sean O'Keefe will host today's Day of Remembrance ceremony on NASA TV starting at 2:00 p.m. EST.
"It gives us an opportunity for us to look back and honor these people," said NASA's Lynn Cline, deputy associate administrator for space operations at the agency's Washington D.C. headquarters, in a telephone interview. "But it's also a very important to move forward, to return the space shuttle to flight and complete the International Space Station."
No NASA shuttles have flown since the loss of Columbia, though shuttle managers, engineers and astronauts are working to resume flights with the Discovery orbiter and STS-114, currently slated for a May 2005 launch.
"We really want to get the ball rolling again," said astronaut Jim Kelly, shuttle pilot for the planned STS-114 mission, during televised interviews with reporters this week. "Right now, that [May 2005] timeframe is looking pretty good."
Not just for astronauts
In addition to the lost Apollo 1, Challenger and Columbia crews, NASA has lost other astronauts in training accidents and aircraft crashes.
But NASA has also lost ground personnel too. This year, the space agency plans to memorialize the loss of three employees of its Jet Propulsion Laboratory who died in an automobile accident in December 2004.
"It's not just about astronauts," Kennedy told SPACE.com, adding that, in one accident NASA did lose several shuttle technicians who asphyxiated in the aft compartment of an orbiter. "They sacrificed so others could explore."
Maintenance accidents have also claimed the lives of workers supporting NASA launch pads.
NASA officials said that it is imperative the agency continue to press forward shuttle flights and working toward President George W. Bush's vision of returning human explorers to the moon and lofting them onward to Mars.
"It's a very challenging objective to be able to launch people into space," Kennedy said. "Yes, we've lost people on the way, but nobody ever said this would be easy and I'm proud the agency pauses at least once a year to honor them."
Fixing NASA: Continuing Coverage of the Space Shuttle Return to Flight