NASA Delays Mars Probe's Launch, Eyes Shuttle Cabin Leak

NASA delayed the planned launch of its Phoenix Mars lander by 24 hours Tuesday as engineers trace an apparent cabin leak aboard the shuttle Endeavour for a separate spaceflight.

The two closely-spaced missions are slated to launch within days of each other from Cape Canaveral, Florida, with Phoenix initially targeted for an Aug. 3 launch and Endeavour's STS-118 astronaut crew aiming for an Aug. 7 liftoff.

But the threat of poor weather Tuesday prevented pad crews from fueling the second stage of the Delta 2 rocket to launch NASA's Phoenix probe towards Mars from the Cape Canaveral Air Force Station. The delay forced mission managers to reset the planned launch for Saturday, Aug. 4 at 5:26:34 a.m. EDT (09:26:34 GMT).

"Thunderstorms are rolling in so we're rescheduling the fueling for [Wednesday] morning," NASA spokesperson George Diller, at the agency's nearby Kennedy Space Center (KSC), told SPACE.com. "There's not enough contingency time to get to the third, so we're slipping one day."

NASA's Phoenix lander is designed to study the northern polar regions of Mars using a robotic, shovel-like scoop to dig into the martian terrain and analyze the planet's water ice. NASA must launch the $420 mission within a 22-day window that closes Aug. 24 or else wait another two years until Mars and Earth are in the proper orbital positions for another attempt, mission managers have said.

Given Phoenix's limited launch window, NASA space shuttle program managers have said the Mars mission is a high priority and could prompt a few days of delay for Endeavour's own August liftoff. Currently, the Phoenix probe has launch opportunities through Sunday before any shuttle delays would be required.

http://www.space.com/missionlaunches/070731_phoenix_sts118_updt.html