Phoenix spacecraft preparing for polar Martian landing.

In continuing coverage from previous editions of Daily Launch, the San Francisco Chronicle (5/13, Perlman) reported, "Defying the odds, a Mars-bound spacecraft named Phoenix is headed toward a landing this month on the planet's icy north polar surface to search for evidence that liquid water and chemicals crucial for life existed there long, long ago." According to the article, scientists are "anxiously counting the minutes to touch-down" as the Phoenix is "perilously different" from other lander missions. The spacecraft "must land upright on three slender legs" instead of being cushioned by giant air bags, and must be "slowed in the final 18 seconds above the surface by downward-facing jets that, if they function properly, will fire automatically." On the planet, the lander will analyze soil samples to look for water. "If Phoenix lands successfully on May 25, it will be the fourth American spacecraft to get to Mars."

        Arizona's Tucson Citizen (5/14, Fischer) adds, "The Phoenix Mars Lander spacecraft continues to operate exceptionally well, but mission officials said during a NASA briefing Tuesday that the complex May 25 soft landing scenario poses huge challenges." According to Ed Weiler, associate administrator for the Science Mission Directorate, "Fifty-five percent of all human attempts to land robots on Mars have failed." Barry Goldstein, Phoenix project manager at NASA's Jet Propulsion Laboratory, explained that the Phoenix "is a sister craft to the Mars Polar Lander, which was lost in 1999 to a presumed crash landing." However, Goldstein pointed out that "[y]ears of testing have discovered and resolved spacecraft problems that could have possibly caused the Polar Lander failure, along with other unrelated issues that could mean problems with Phoenix."