The Mars mission aims to unlock the story of past climate change.
By TAL INBAR
Just like its namesake, the Phoenix Mars mission raises from the ashes both a spacecraft and instruments from two previous unsuccessful attempts to explore Mars: the Mars Polar Lander and the Mars Surveyor 2001 Lander.
The Polar Lander failed to return data upon its arrival to Mars' antarctic region on December 3, 1999, and left many ambitious science goals unreached.
Phoenix is a robotic spacecraft that was designed to land on Mars's water-ice-rich northern polar region and use its robotic arm to dig into the arctic terrain.
The Phoenix mission is a partnership of universities, NASA centers and the aerospace industry. The scientific instruments and operations are the University of Arizona's responsibility.
The Jet Propulsion Laboratory in Pasadena, California, operated under contract by Caltech for NASA, manages the project and provides mission design and control. Lockheed Martin Space Systems in Denver, Colorado, built and tested the spacecraft.
The Phoenix Lander is about 5.5 meters long with the solar panels deployed. The science deck by itself is about 1.5m in diameter. The Lander measures about 2.2m tall.
The Phoenix mission has two goals. One is to study the geological history of water, the key to unlocking the story of past climate change. The second is to search for evidence of a habitable zone that may exist in the ice-soil boundary, the "biological pay dirt."
Phoenix's instruments are suitable for uncovering information on the geological, and possibly biological, history of the Martian arctic. Because Phoenix will be the first mission to return data from either of the poles, it will contribute to NASA's main strategy for Mars exploration of "follow the water."
The primary mission is anticipated to last 90 sols (a sol is a Martian day, almost 24 hours).
The Phoenix spacecraft and its scientific instruments are suited to uncover clues to the geological history and biological potential of the Martian arctic. Phoenix is the first mission to return data from either polar region and could be instrumental in achieving the main goals of NASA's long-term Mars Exploration Program: to determine whether life ever arose on Mars, to characterize the climate and geology of Mars, and to prepare for human exploration.
Despite the success of Pathfinder and the Mars Exploration Rovers, Phoenix will use a lander because it is simply a different type of mission.
The rovers were designed to study rocks at different locations, looking for evidence that liquid water once flowed on the surface of Mars. Unlike the rovers, which were hunting for evidence of water at points along the Martian surface, the Phoenix lander knows exactly where to go to find water. To reach it, however, the spacecraft must dig down below the surface. The Phoenix lander is in an area of Mars where water is believed to exist in the form of ice just below the surface. This water ice is probably spread fairly uniformly throughout the northern plains, so the lander should be able to uncover ice wherever it lands.
Phoenix will assess the habitability of Mars' northern environment by using sophisticated chemical experiments to assess the soil's composition of life-giving elements such as carbon, nitrogen, phosphorus, and hydrogen. Identified by chemical analysis, Phoenix will also look at reduction-oxidation molecular pairs that may determine whether the potential chemical energy of the soil can sustain life, as well as other soil properties critical to determine habitability such as pH and saltiness.
Despite having the proper ingredients to sustain life, the Martian soil may also contain hazards that prevent biological growth, such as powerful oxidants that break apart organic molecules.
Powerful oxidants that can break apart organic molecules are expected in dry environments bathed in UV light, such as the Martian surface.
But a few centimeters below the surface, the soil could protect organisms from harmful solar radiation. Phoenix will dig deep enough into the soil to analyze the soil environment potentially protected from UV looking for organic signatures and potential habitability.
The writer heads the Space Research Center, The Fisher Institute for Air and Space Strategic Studies