We have felt this before. Watching the fiery remains of space shuttle Columbia streak across the blue Texas sky Saturday was like being forced to relive the past. Didn't we experience the same disbelief, sadness and horror when a flash fire killed three Apollo astronauts during a launch pad test in 1967? And again in 1986, when the space shuttle Challenger exploded just after liftoff, killing all seven on board? It only magnified the sense of deja vu this weekend to learn that Columbia's demise on Feb. 1 was linked with almost sinister precision to the dates of those earlier disasters. The Apollo fire occurred 36 years ago on Jan. 27. Nineteen years later, Challenger blew up on Jan. 28. Just last Tuesday, Columbia's crew members joined NASA mission control in a moment of silence at the exact hour of the Challenger tragedy. Four days later, they, too, were gone.

We extend our deepest condolences to the families of those seven courageous astronauts, five of them eager rookies, one of them -- Col. Ilan Ramon -- the first Israeli in space and the pride of his country during this mission. We also convey our heartfelt sympathy to the astronauts' NASA family -- and family is the right word, as anyone could tell who saw the stricken faces and heard the halting words of Mr. Milt Heflin, chief flight director of the Columbia mission, and Mr. Ron Dittemore, shuttle program manager, at NASA's initial news conference in Houston.

Finally, those feelings of commiseration flow to all Americans, a nation still so shaken in the aftermath of Sept. 11, 2001, the anthrax attacks and last fall's sniper crisis that the first thing U.S. government spokesmen felt compelled to do Saturday was to send out signals that terrorism was not suspected in the Columbia accident.