With the first anniversary of the Columbia (search) tragedy just a few days away, NASA (search) employees throughout the country paused Thursday to remember the 17 astronauts who lost their lives over the years "because we failed."

NASA Administrator Sean O'Keefe declared that the last Thursday in every January be set aside as a Day of Remembrance within the space agency to honor the memory of the crews of Columbia, Challenger (search) and Apollo 1 (search).

Space exploration is dangerous enough, and accidents should never be the consequence of it mattered most, we failed. And so it is incumbent upon us to remember not just today, not once a year, not on the anniversaries, but every day, every single day that the consequences of us not getting it right are catastrophic, and each of those families will live with this consequence for the rest of their lives."

All three anniversaries fall within a week.

The Apollo 1 spacecraft fire on the launch pad occurred Jan. 27, 1967. The Challenger launch explosion occurred Jan. 28, 1986. The Columbia disintegration during re-entry occurred Feb. 1, 2003, killing seven astronauts.

At Kennedy Space Center in Florida, a minute of silence was observed at noon and flags flew at half-staff. Later in the day, Kennedy officials and some who helped in the Columbia debris recovery effort gathered in the giant Vehicle Assembly Building to dedicate the new resting place for the crated wreckage.

NASA workers were asked to also remember the two men who died in a helicopter crash in Texas last March while searching for Columbia debris, and all the early aviation pioneers who were killed pushing the limits.

O'Keefe noted that three peaks on Mars seen from the first of the two newly arrived rovers would be named Grissom Hill, White Hill and Chaffee Hill after the Apollo 1 astronauts. The space agency named the rover landing sites after the Challenger and Columbia crews.

The widow of Challenger commander Dick Scobee told NASA's spaceflight chief, William Readdy, that she knew her late husband would be proud.

"In our lifetimes, people will walk on the surface of Mars and they will see that tribute to the Challenger crew," Readdy quoted June Scobee Rodgers as saying.