LAST THURSDAY, on a high Afghan plain seven miles east of Bagram air base, a Blackhawk helicopter went down, killing the entire crew. The four U.S. soldiers who died in the accident, like the seven astronauts who perished Saturday, were volunteers, taking on risks they understood well in service of their country. Beyond their units and their families, their deaths attracted little notice -- a paragraph or two in some newspapers, not even that in others.

The tragedy of the space shuttle Columbia grips the nation as do few other catastrophes, and for good reasons. Even this many decades into space exploration, the astronauts embrace dangers that the rest of us can only imagine -- but that many of us do imagine, and even dream of. As they fling themselves into orbit and float in the void while trying to tell us what they see and feel, men and women like David M. Brown and Kalpana Chawla and the others who died Saturday become more than role models of discipline and courage and good cheer in cramped circumstances. They come to embody national aspirations of greatness, and human aspirations to reach beyond ourselves.

Yet as we read the biographies of these brave seven, replay their buoyant interviews of recent days and come to know the grief-stricken but proud surviving spouses and parents, we might spare a moment also for the four who died near Bagram, and the others most of us will never hear about. As their remains were transported to Germany for autopsies on the way home, the victims were identified as Chief Warrant Officer Mark S. O'Steen, 43, of Alabama; Chief Warrant Officer Thomas J. Gibbons, 31, of Tennessee; Sgt. Gregory M. Frampton, 37, of California; and Staff Sgt. Daniel L. Kisling Jr., 31, of Missouri. They joined 18 other service members who have died in accidents in the Afghanistan campaign and 25 killed by hostile fire -- a total of 47 deaths since the fall of 2001. Thousands risk their lives every day in that distant country and in the skies over Iraq, and thousands more may soon be asked to do so. With so many reserves being pressed into service and scheduled retirements from the military being delayed, the term "volunteer" is stretched and tested. But these are all people who know, or who knew, they might face danger. These casualties, too, leave empty spaces in the lives of loved ones.

The prayers of a nation were offered yesterday in memory of seven astronauts and their families, and rightly so. They gave everything in service to the nation, as did the Bagram four and so many more.