The launch of NASA’s Mars Explorer spacecraft was pushed back to Tuesday because of bad weather at the Cape Canaveral, Florida launch pad. The spacecraft was originally supposed to lift off on Sunday, but storms forced the controllers to delay the launch, and then again on Monday. If the weather behaves, Explorer will lift off at 1758 GMT (1:58 pm EDT) and carry the newly named rover “Spirit” towards Mars. The second rover, “Opportunity” will follow on June 25.