On its annual Remembrance Day, NASA is marking the anniversary of the loss of Columbia's crew as the shuttle broke up over Texas during re-entry in 2003, officials said Friday.
The anniversaries of all three disasters fall within a week -- the 1967 Apollo fire on Jan. 27, the 1986 explosion of the Challenger on Jan. 28 and Columbia on Feb. 1.
At the White House, President Obama remembered the Columbia's crew.
"Ten years ago, seven brave astronauts gave their lives in the name of exploration when America's first flight-ready space shuttle, Columbia, failed to return safely to Earth," he said.
"Each year, on NASA's Day of Remembrance, we honor the crew of that Columbia flight, as well as those of Challenger and Apollo 1, and all the members of the NASA family who gave their lives in the pursuit of expanding our Nation's horizons in space -- a cause worthy of their sacrifice and one we must never forget."
NASA Administrator Charles Bolden echoed those sentiments.
"These explorers, and their families, have our deepest respect," he said. "We work every day to honor and build on their legacy and create the best space program in the world -- to infuse it with the life and vitality that they worked so hard to achieve."