But there’s another technology that’s developing at a breakneck clip, and with which our grandchildren could make virtual trips to other solar systems. It’s called telepresence  a collection of technologies that extends vision, hearing and touch far beyond the corporeal confines of our nervous system.

Consider that in 1965 the Mariner 4 spacecraft made the first fuzzy photos of Mars with a black-and-white TV camera boasting 40,000 pixels. The HiRISE camera now operating onboard NASA’s Mars Reconnaissance Orbiter sports 200 million pixels. It can snap photos of objects just three feet across.

That’s resolution comparable to what’s on Google Earth, which many people use to examine remote parts of the globe or inspect cities known only from the nightly news. Google Mars takes advantage of the high-quality imagery being collected by our robotic orbiters, enabling armchair astronauts to peruse the red planet in considerable detail without the angst of transporting their delicate protoplasm 34 million miles into space.

Photography from the Mars Exploration Rover is so good that the data have been interpreted in an IMAX film, giving audiences a near-lifelike experience in strolling the red planet’s rusty, dusty desert. The Phoenix Mars lander has sent back pictures of individual sand grains. In other words, it’s already possible for anyone to make a rigorous reconnaissance of another planet  even though not a single human has yet stomped his boots in the Martian dust.

This is not merely the tired argument over manned versus unmanned space missions. Sending humans to the stars is simply not in the offing. But this is how we could survey other worlds, around other suns. We fling data-collecting, robotic craft to the stars. These proxy explorers can be very small, and consequently can be shot spaceward at tremendous speed even with the types of rockets now available. Robot probes don’t require life support systems, don’t get sick or claustrophobic and don’t insist on round-trip tickets.

A plausible solution would be to re-energize NASA’s development of nuclear-powered rockets, with the intention of building a craft able to send clusters of micro-bots into deep space at velocities of, say, one-tenth light speed. Depending on financing and our ability to garner international cooperation, these probes could be sent off before the 21st century starts to wane. By the middle of the following century, on-the-scene data from Epsilon Eridani, the nearest known planetary system, could be in our hands.

These microbots would supply the information that, fed to computers, would allow us to explore alien planets in the same way that we navigate the virtual spaces of video games or wander through online environments like Second Life. High-tech masks and data gloves, sartorial accessories considerably more comfortable than a spacesuit, would permit you to see the landscape, touch objects and even smell the air.

Our desire to walk a landscape that basks in the light of another star, to hear the whistle of an alien planet’s wind and feel its sting on our faces, will not  any century soon  be sated by hurling massive, human-filled starships into space. Instead, we will extend our senses light-years beyond Earth with these telepresence proxies and data collectors. That’s a far more realistic version of the “Star Trek” future: to explore distant worlds, under alien suns, without leaving the familiar surroundings of our terrestrial home.