Washington: A year after the space shuttle Columbia disintegrated midair, killing all seven astronauts on board, including Kalpana Chawla, NASA (National Aeronautics and Space Administration) regroups and readies its fleet of spacecraft for manned missions with President George W Bush directing the space agency to aim at placing a man on Moon and Mars.

NASA, having learnt its lessons the hard way, is not taking any chances about the human space flight, which is likely to resume in September.

"One of the things we're not going to do is take all the pieces of Columbia and bury them in a silo like we did in 1986 after Challenger," NASA administrator Sean O'Keefe said earlier this week.

The Columbia accident investigation board, in its report released last August, strongly indicted NASA's work culture for the loss of lives, and the space agency seems to be aware of it.

"They are not with us today because when it mattered most, we failed," said O'Keefe as he read the roll of dead astronauts from Columbia and from other accidents on Thursday (Jan 29, 2004) a day of remembrance, which will now be observed every year at NASA.

NASA will also dedicate a memorial to the departed heroes of the Columbia mission at the Arlington National Cemetery tomorrow (Feb 2, 2004), one year and one day after the tragedy.

The Columbia crew, who travelled to yonder spaces to probe the beginnings of life and carry out experiments to make life on earth better, has been fondly remembered world over.

Besides Chawla, others who perished in the tragedy were Rick Husband, William McCool, Michael Anderson, Dave Brown, Laurel Clark and first Israeli astronaut Ilan Ramon.

Apart from tributes in their respective countries, the spacefarers have been honoured on Mars, with the spirit rover-landing site being named as the Columbia Memorial Station.

A befitting tribute to the spacefarers will be the re-launch of manned missions in September when space shuttle Atlantis soars into the realms of outer space in quest of the unknown. No doubt, NASA plans it to be the safest of manned missions.

"There's absolutely no doubt in my mind, we'll come back much stronger," said William Readdy, associate administrator for Spaceflight at NASA.

"When Atlantis roars off into orbit, that will be the safest mission we've ever flown, and each flight after that will be safer than the last."