WASHINGTON, Feb 3: A former NASA safety official wrote to US President George W. Bush last year to warn of “another catastrophic space shuttle accident,” but Bush did not see the letter and the writer’s plea was rejected, the White House said on Monday.

Columbia broke up on Saturday as it began to reenter the atmosphere over Texas, shortly before it was to land.

White House spokesman Ari Fleischer said Bush had not seen the letter written to him on Aug. 25, 2002, by former NASA safety engineer Don Nelson expressing concerns over shuttle safety. “Your intervention is required to prevent another catastrophic space shuttle accident,” he said.

He cited specific safety incidents including a 2000 inspection of Columbia which found 3,500 wiring defects, as well as charges such as a July 2002 inspector general’s report that the shuttle safety programme was not properly managed.

“The lives of our astronauts and the future of our space programme must not be ignored,” he said. He urged Bush to limit the size of the shuttle’s crew to four until an escape pod was built.

Such a pod would not have saved Columbia’s astronauts, experts have said.

White House science adviser John Marburger wrote back to Nelson on Dec. 4, saying his office had discussed the concerns with NASA officials. “NASA places a high priority on safety and has instituted a programme of developing and implementing safety upgrades to reduce the risk to space shuttle crews,” he said.

“Based on these discussions I do not think that it is appropriate for the president to issue a moratorium on space shuttle launches at this time.” Fleischer said on Sunday that an escape pod would not have saved Columbia’s astronauts.

Bush, who is to attend a memorial for the astronauts at the Johnson Space Flight Center in Houston on Tuesday, received a briefing on Monday from NASA administrator Sean O’Keefe on the investigation into the Columbia disaster and the two spoke of their determination to return to space.

“While we grieve for these astronauts, the cause for which they died will continue. America’s journey into space will go on,” Bush said in a speech to employees.

As he briefed the president O’Keefe said he intended “to get back into space as soon as possible with all safety issues having been fully, fully explored,” Fleischer said.—Reuters