Somewhere between you and Mars, the Odyssey orbiter surfs the sky. Named for Arthur C. Clarke’s science-fiction novel and movie, “2001: A Space Odyssey,” the $300 million probe left Cape Canaveral, Florida, on April 7, with the hopes and, some say, the fate of NASA riding on it. Less than a week after it launched aboard a Delta II rocket, the Mars Odyssey was already around a million miles from Earth — with 285 million miles to go before it reaches Mars.