The Phoenix Mars Lander “fell well short of [its] ambitious goals, largely because Mars failed to cooperate” but the planetary science community still believes the mission has been worthwhile. [right, credit NASA-JPL/UA]
In a mission review (“Phoenix Rose Again, But Not All Worked Out as Planned”), Richard Kerr of Science magazine, concludes that “harrowing accounts of balky equipment, frustratingly sticky soil samples, and terminal hypothermia, and it was hard to remember why NASA sent Phoenix to Mars in the first place: to try to decipher the history of water and to see whether, at some point in that history, liquid water could have let martian life bloom.”
The inlet doors of one of Phoenix’s principal instruments, the Thermal and Evolved Gas Analyzer (TEGA), wouldn't open fully. Although the TEGA team had found the problem early, they “missed several opportunities to ensure that it had been corrected.” As a result, “operators managed to fill only five of TEGA's eight single-use analysis chambers, none with the desired amount of ice.”
But planetary scientists say that Phoenix’s discovery of a diversity of chemical processes operating in a moderate pH and low saltiness environment provided great information about the habitability of the planet.