NASA/Planetary Robotics Laboratory

Should robots replace humans in space?NASA/Planetary Robotics Laboratory

Humans aren't suited for space. We're not good with radiation or microgravity, and extended stays in space radically increase our risk of cancer, shrink our hearts, atrophy our muscles, and make our bones brittle. But that's what happens when you're a complex organism evolving on a particular planet. You have to rely on your technology to survive the rigors of space travel.

Of course that technology has to be very complex and expensive and its designs face severe restrictions posed by the limits of the human body. And this is why some of us are starting to hear chatter about how impractical it is to send humans into space.

Send in the Robots

The argument goes something like this: Since humans either wouldn't be able to survive the stresses of prolonged space exploration, or would face immense hurdles posed by traveling to other worlds, we should be focused on sending new generations of robot probes to do our most ambitious exploration projects. Robots handle radiation much better than us. They easily withstand forces that would turn human bodies to mush. They never age. Give them some fine tuned software and they can leave our footprints on alien terrain.

BIG PIC GALLERY: Although you can't beat the human experience, robots have proven time and time again how good they are at exploring alien worlds. Check up on Mars rover Spirit's adventures in this special selection of images from the Red Planet.

So why not make exploration easier on us and stay in the comfort of home while our machines do all the hard work? Sure they're no match for human intellect and insight, but if we're creative enough with our programming and have our hands on the controls, they'll benefit from our brainpower just the same.

It's hard to argue with this logic because sending humans into space really is much more challenging than building a mechanical probe. But while manned spaceflight may be impractical for all intents and purposes, it's absolutely vital to our space programs.

The Human Requirement

Humans are explorers. We want to go to new places, see new things and experience new worlds for ourselves. The world was excited to watch Neil Armstrong and Buzz Aldrin walk on the Moon because there were people on another world. We didn't send a high tech camera to photograph objects of interest and send them down to a laptop at JPL. Human eyes were looking at alien rock and human feet were making prints in dirt that lay untouched by any living thing. Maybe in the future, we could do it too? That's where the excitement lays, in the possibility of science fiction novels about humans living on multiple worlds coming true, not in the joy of sending robots to look around another world for us.

WIDE ANGLE: How did the world react to Neil's "one small step" and will we be making a return trip?

Don't get me wrong, machines designed to explore another planet are very tough to build. It takes many years of software development and hardware assembly and testing which is going to be fraught with a lot of problems which require a lot of ingenuity to solve. But in the end, what we get is the equivalent of sending a digital camera millions of miles away to send us tantalizing pictures of things we're being told are "too impractical" for us to see.

Who cares about practicality? We need to be lighting up imaginations and getting people excited about our potential future in space. We need another one small step on alien soil. We need crews of ready and willing astronauts. And we need engineers and designers ready to help them get into space as effectively as possible.

If humans can't go, how are we ever going to get support for bigger and better space programs? By using only robots, we're effectively cutting the ultimate "cool factor" out of space exploration; the hope that one day, someone watching astronauts hopping on the Moon or jogging on Mars, or looking at the rings of Saturn from a command center of a ship in orbit around the gas giant, would get to do the same thing and see at least a tiny part of the cosmos firsthand. Why bother if that's never going to happen? Why spend any money on exploring places where we'll never tread? May as well just stay home, turn up the TV and continue not to care.

What's the Point?

Of course there's another big question: Why should we even bother investing billions into the space program? Aside from the concept that scientific exploration and pushing technology to the limits of what's possible always yields something useful, we should also note that developing the kind of compact, highly efficient methods of generating energy, growing food and avoiding the dangers of solar flares and alien storms could be directly applied to Earth to boost our infrastructure.

The same kind of technology that would help us build and maintain a base on Mars could be scaled up and applied to the developing world to radically stabilize their energy supplies, manage the spread of disease and help boost foreign and local direct investment by giving businesses a robust infrastructure they can use to hit the ground running. And of course there's always the potential for high tech spin-offs to be used in the consumer markets and by the military.

Simply put, companies who can build and test technology for space flight could use their new libraries of patents and apply them into innovative business models or drastically upgrade their existing product lines.

Exploring space can only help expand our knowledge and improve our lives in the long run, but as long as it depends on government funding or the whims of wealthy thrill-seekers, we need to make people care and offer them real inspiration for one day walking on the Moon or surfing on Titan's lakes. Just sending a robot or two when the budget allows for it is not going to motivate us to care about the future of space travel, no matter how practical or efficient it is.

Greg Fish works with technology and digital media. He is a regular guest writer for Discovery News. He also contributes essays to on the Internet, business practices, and current events. In addition to this, he researches and covers a wide variety of popular science topics on his blog,