One of my first, most thrilling memories was watching rocket launches. They fueled my interest both in science and science fiction.

I admired the courage it took to be crammed into a tiny metal box, just a couple of feet away from the vastness of space. Or to walk in space!

I remember being glued to the TV, awestruck, as Neil Armstrong and Buzz Aldrin bounded over the lunar landscape.

I've learned that there's another dimension to exploration: the encouragement, the hope, and the fear of the families left behind. It's the human condition -- whether they are waiting for the return of the hunter, the sailor, or the pioneer, there are always those who wait.

And the sad truth is, sometimes the explorers do not return. Hunters are overmatched, sailors are lost, pioneers fall victim to unknown peril.

We mourn them.

The loss of the Columbia, and its seven shining representatives of the human race, now seems to carry a unique poignancy. It has a resonance in the post 9/11 world, another national tragedy when it seems we have
already had more than our share.

But there is really only one way to honor them. We must keep the dream alive.

There will be some, as there were after the Challenger disaster, who call for an end to space exploration. "What a waste of time, talent and dollars!" they'll say.

They are wrong. The research that has gone into rocketry, into protecting humans from the rigors of space, into remotely monitoring all kinds of devices, have had countless applications on earth. Those advances include a host of medical breakthroughs that save lives every
day.

Space challenges us. Our response pushes back many frontiers of our understanding.

Maybe it's all the science fiction I've read, but I think there's another reason why we must continue to push for human exploration of space. I believe our survival as a species depends on it.

Comets and meteors have crashed into our planet before. That's the likeliest cause for the extinction of the dinosaurs, whose reign lasted far longer than ours has, and whose end came so suddenly. The collision of another such object with our planet might well wipe us out.

Not that we require outside help. The human race, since Hiroshima, is more than capable of wiping itself out. Or, we might be undone by some new disease, racing around the globe too fast for us to fight it.

It may be possible to head off celestial collisions. Diplomacy may triumph over self-destruction. Human beings are hardy.

But it might not be a bad idea to have a few of us somewhere else, just in case.

I've also been intrigued by something called the Gaia Hypothesis (look for the author "Lovelock" in the library catalog). Here the notion is that the planet earth itself is alive, is a consciousness, and is driven as are other living things to reproduce.


How does a planet reproduce? By sending parts of itself into space, to transform other places into look-alikes. If earthlings go to Mars, introduce more oxygen into the atmosphere, and begin cultivating Earth plants and animals (a process called "terraforming"), then Mars becomes
a sort of planetary "child."

We think of ourselves as great explorers. Maybe the real purpose of humans is to serve as nothing more than interplanetary spermatozoa.

All of that may sound fanciful. But this week seven brave and brilliant people died. Why? For the great adventure, for the triumph of the human spirit against everything that seeks to bind us, to hold us down.

They believed that this effort was for the betterment of humankind. So do I.