On the Human Exploration of Space

In the early morning hours of January 15th, a capsule from the Stardust space probe smashed into the atmosphere and fell to Earth on a tail of fire. It descended by parachute, delivering a precious cargo of interstellar and comet dust to the high desert of Utah, having journeyed for seven years and over two billion miles. A few days later, the New Horizons space probe departed for an even greater voyage, to Pluto and the Kneiper Belt beyond. Meanwhile, two robotic rovers continue to roam the surface of Mars and Cassini continues to unlock the secrets of the Saturn system.

Forty or so years ago, astronauts had all the glory of the exploration of space. Now, robots are exploring places that currently no astronaut can go. For the past twenty five years, no human being has journeyed beyond low Earth orbit. There are some for whom this situation suits just fine.

The arguments are familiar. Robots are cheaper than humans. Using robots mean that human beings will not have to risk dying on space missions, as have the crews of the Challenger and Columbia space shuttles. The macabre confluence of the three anniversaries of space tragedies—Apollo 1, Challenger, and Columbia—drive the price of human space exploration home.

The final argument is the claim that robots can do all that humans can do. Indeed robotic space probes are very useful for tasks like remote observation and for measuring certain physical phenomenon.

The first two suppositions are true.  The second is demonstrably false. That seems to be the growing consensus among scientists, engineers, and space policy experts.