More Stories
	Neutron Star Still Shining Light on Hard Science Fiction
	An Interview with Larry Niven

I grew up knowing that Mars was the home of intelligence.

But telescopes got better. When cameras replaced eyes, the canali went away. The more we learned, the less hospitable Mars became. I published my first stories in the days when human-built robots were sending data back from every world in the solar system. None of them showed signs of life.

It was becoming obvious: if we wish to learn of intelligent life in the universe, the taking of Mars will teach us only about ourselves.

We will learn our limits.

In those early stories I took an extreme position. Mars is not wanted. The wealth and the opportunities are all in the asteroids and outer moons. A planet is a gravity well: the bottom of a hole.

Extreme positions are more interesting than compromises. Still, why do we want Mars?

My viewpoint may be peculiar. I've wanted to walk the surfaces of other worlds ever since I found Heinlein. Any excuse will do.
     

1. Knowledge is always of value, and the value is never predictable. This, at least, we are doing right. We are learning what we can of Mars, for its own sake. What will come of it, we cannot know.

But a science fiction writer can guess. Try this:

Five billion years of water erosion is hell on the geological record. The geological history of Mars may be easier to read than Earth's. If Mars can tell us anything of ice ages, then we will have learned something of the behavior of the sun. We may be able to predict our own next ice age ... or heat age.

Then what? Freeman Dyson has said, "It's best not to limit our thinking. We can always air condition the Earth."

* * *

2. We'll be sending more little wheeled robots. The ambition to put a tiny automated airplane on Mars hasn't died. VR sets get smaller, cheaper, more dependable. A martian entertainment industry waits to be born.

We could all be flying or wheeling over the surface of Mars in virtual reality.

VR channels could pay for the space program.

* * *

3. There are better ways of reaching orbit than rockets. A teacher under the czar, Konstantin Tsiolkovsky, described what we now call an orbital tower, or Beanstalk: a cable roughly a hundred thousand miles long, its lower end anchored on the Earth's equator, its center of mass in geosynchronous orbit. Use it as an elevator cable. Launch from the far end, you're beyond Mars or inward from Venus.

Half a dozen other devices exist, all still imaginary, each an attempt to design a rocket-free launching system.

Despite conceptual improvements, the Beanstalk is still the most costly, but also the most convenient. But each of these skyhooks would be very expensive to build and very cheap to run: a few dollars per kilogram to orbit. They have more in common:

Each requires materials we can't manufacture yet, though such materials are well within theoretical limits.

Each holds awesome energies imprisoned. After all, each was built to transfer awesome energies to a spacecraft and (in some cases) collect it again by decelerating the spacecraft. Any such device would be a disaster of awesome proportions, if its energies were accidentally released on Earth.

Most of these skyhooks depend on low gravity and high rotation. The Beanstalk, for instance, won't work at all on any world in the solar system, barring Earth and Mars. Mars is smaller and spins just as fast.

And each would be safer, smaller, cheaper and require less robust materials if built on Mars. If something went wrong, no city would die, and Mars could bear the scars.

If we are to claim the solar system, we need Mars as a test bed for skyhooks.

Robert Forward has made an extensive study of orbital tethers. He intends to build and sell them. He's starting small, with a tether designed to drop a used-up satellite out of orbit.

* * *

4. To take the universe, we must learn how to build habitats, and how to reshape worlds. By the time we set our feet on Mars, we will know a little about both.

The Apollo capsules weren't much of a habitat. There was no attempt at recycling. There wasn't room for the kind of exercise that could keep a human being human during years in free fall. Artificial gravity wasn't even considered.

A mission to Mars would need all of that. A habitat on Mars would benefit from all we will have learned from the taking of the moon.

* * *

5. We're already learning how to reshape a world: the Earth.

We speculate that Mars could be made habitable -- by releasing buried water or water in hydration, by warming the planet, or by bashing it with comets.

(The skyhooks come first. To reach the comets, bringing enough horsepower to hurl them into the inner solar system, we will need easy access to orbit.)

* * *

6. It bothers me a little to be so treating a planet as raw material. Arrogance may come naturally to me, but I remember wanting Mars because it was . . . well, Mars.

If I've slighted your own reasons for claiming Mars, forgive me. My viewpoint may be peculiar. I've wanted to walk the surfaces of other worlds ever since I found Heinlein. Any excuse will do.

* * *

7. A successful species evolves in many directions. Species that follow one line of development, like humans or horses, are unusual, and it isn't a mark of success. Where did Homo erectus go, anyway?

If we do not first destroy ourselves, we will make our own aliens.

If we intend to take the universe for ourselves, we will need Mars. Our selves will change in the process.

The martians may not remain human. The entities that reach the nearest star may be beyond imagination. The trick is to remain adaptable.