Tuesday’s Washington Post had an article about the Phoenix lander (and I really do hope it’s meant as a reference to the mythological creature and not a revelation that they’re exploring Arizona) which includes a photo inset showing a soil indentation from the lander’s arrival. Under the picture, there’s a note which among other things points out that it cost $420 million to send the probe a distance of 422 million miles.
At first, $420 million sounds like a lot of money, and in absolute terms, it is. But looking at it from another perspective, that’s less a dollar per mile. That’s significantly cheaper than taking a cab.