People Who Put Magellan Into Orbit Around Venus

CIRCLING, circling, circling, Magellan spins around the evening star. Scanning the Venusian surface and sending a detailed map back to Earth, in three short years this spacecraft has broadened our understanding of both planets.

In "The Evening Star: Venus Observed," Henry Cooper offers a unique perspective on the Magellan program, seen through the lives of the engineers and scientists working on it.

As the book opens, Magellan is preparing to enter orbit around the second planet. It's a simple, but critical, maneuver. Magellan must fire its main rocket at the precise moment to slow itself down, then jettison its main rocket. If everything doesn't go precisely as planned, the spacecraft will keep going toward the sun and will not return to Venus for 100 years.

The engineers are confident, but anxious. Magellan, after all, was built from parts left over from other missions. Parts of the spacecraft are falling apart. The rocket itself was originally miswired; all would have been lost if an engineer had not woken up in a cold sweat realizing that he had done something wrong.

Cooper plays these moments for all they are worth, sharing the engineers' suspense, fears, and finally their exhilaration with the reader.

It takes a lot of people to run a space mission, and it seems that Cooper is friends with them all. He tells the reader who likes what hobbies, who was whose graduate student, the topics of scientists' undergraduate and doctoral theses, and which are the most important and interesting labs around the country.

Backing up these lives is Cooper's sense of space-exploration history, the result of covering space for 25 years for The New Yorker magazine. The richness and depth of the story makes the reader one of the gang.

Like many news accounts, the bulk of "The Evening Star" is devoted to the science of the Magellan project: discovering exactly what is on Venus and trying to come up with plausible theories to explain the observations. Venus, as Cooper explains, is an interesting place, requiring a whole host of new theories.

Dark spots are scattered on the ground, which one scientist deduces are "slaps," the remnants of shock waves from meteors that burned up in the thick Venusian atmosphere. (The findings from Venus have helped explain the 1906 Tunguska Event in northern Siberia, when trees were flattened for a 50-mile radius.)

In other places, Magellan discovers 20-mile wide "pancakes." A bright graduate student proclaims that they are lava that bubbled up to the surface and then spread out, like batter on a hot griddle.

But unlike accounts of discoveries in the newspapers, "The Evening Star" describes the theories as they are under development. One aspect of science that most nonscientists do not understand is just how subject to change scientific thought actually is. Theories keep changing as new data are sent back and reanalyzed. Cooper shows how some scientists hold onto their theories, even when all of their colleagues have changed their minds, sometimes correctly, sometimes incorrectly.

The fluidity of the process leads Cooper to conclude that: "Science is not an art - though some may feel it resembles art in certain respects. Science may not even be a science. What it most likely is, is a very human process for arriving at the closest approximation to the truth - as elusive an ideal, perhaps, as the last dance."

The Magellan spacecraft is still going strong, yet its fruitful mission may soon be at an end. Having weathered the dangers of space, Magellan has lost its funding battle in Washington.

With limited funds and other spacecraft to fly, it now seems that the National Aeronautics and Space Administration will shut down Magellan before the end of its useful life - the first time NASA has ever shut down a working spacecraft. It won't be a tragedy, but it will be a shame for the men and women of the Magellan project - people whom the reader has come to care for quite a bit by the end of Cooper's remarkable volume.