Ah, space exploration! The term had started to sound quaint in recent years--certainly when applied to things like the space shuttle and International Space Station. But as we watch rovers work like robotic field geologists on Mars (see p. 28), words like discover and explore are not forced.
Now, consider what Cassini has done, barely into its four-year mission about Saturn. Last week, Cassini gave humanity its first look through the murky haze of Titan, a moon nearly as big as Mars (see p. 42). The last large unseen piece of real estate in the Solar System--the real final frontier--Titan's surface was mystery with a capital "M" until these first images were sent home. And more are coming. Within weeks, Cassini will deploy the Huygens probe, which will parachute to Titan's surface, taking hundreds of pictures as it descends, not to mention figuring out its chemistry. Such moments of revelation stir the spirit and tickle the intellect.
But Cassini is also an inspirational organizational achievement. In an age when international scientific projects often move in fits and starts or collapse of their own weight, scientists and engineers from 19 nations have come together in a $3-billion-plus effort lasting nearly two decades. And their governments actually backed them over this long haul!
Some may draw the conclusion that spacecraft as marvelous as Cassini and the Mars Exploration Rovers obviate ever sending humans out into the Solar System, that astronautics is an extravagant adventure but hardly an advancement of scientific exploration. Such a conclusion would be unfortunate--and wrong.
The Jet Propulsion Laboratory--populated with people who certainly have an interest in promoting the capabilities of unmanned spacecraft--recently tried to informally compare the scientific output of men and machines. Their conclusion was startling: One day of rover operations equals about one minute of what a human could do on the surface. History suggests that is more than a supposition. In 1971, Apollo 15 astronauts James Irwin and David Scott barely had to glance at a particular Moon rock to decide it was significant. And they were pilots tutored by scientists, not professionals. But when the geologists saw the sample back on Earth, they said it was a 4-billion-year-old piece of the Moon's original crust, and dubbed it the Genesis Rock.
Robots and machines greatly expand humanity's reach and view. But they are the tools of man, not our replacements.
Yeah...I agree, why send a robot to do a human job. In the end humans would have to learn to live and thrive in some areas of the solar system other than earth.
Robots have their place and uses. Preliminary reconnaissance can be done with robot probes. However, to get the job of understanding really done--you've got to send human beings eventually. There's just no substitute for actually being there...
