As many close friends can attest, I dream of the future human colonization of planets in our solar system and beyond. Ah, how I stew in the romance of this idea.

After doing some math prompted by lively debate on the BBC’s forum radio show “World Have Your Say”, I fear I must let go of this dream, or at least that this dream will take place during my lifetime.

It is simply too cost prohibitive to send humans as our primary explorers. Robots can do as much, or more, at a fraction of the cost. (Perhaps humans could be the next ‘wave’ of Mars visitors.)

The juxtaposition of two recent news stories serves as a stark reminder of the difference between man and machine’s space exploration abilities: while the Phoenix lander paves new ground in the exploration of the Red Planet, the International Space Station toilet breaks, forcing its human occupants to poop in bags.

Humans are fickle organic creatures with exceedingly precise operational conditions (from the maintenance of proper temperatures to providing constant breathing air, food intake and waste disposal). The cost of maintaining these human operational conditions are astronomical compared to sending a lone machine. The International Space Station cost $157 billion since project inception. This individual Phoenix lander cost $420 million.

Yes, these projects accomplish different goals with different timelines and cannot be directly compared. But, the stark difference between cost and output — we could have sent 373 Phoenix landers for one space station — is indisputable.

Robots for the win!