The Other Phoenix

by Lisa Chu-Thielbar, Science Communication, Carl Sagan Center

Date: 26 July 2007 Time: 06:04 AM ET

An artist's conception of the Mars Phoenix Scout Mission.
CREDIT: SETI

The world may be abuzz these days with the release of the movie "Harry Potter and the Order of the Phoenix," but there is a real magical Phoenix in the news.

The Phoenix Mars Mission, the first in NASA's "Scout Program", is set to launch the first week in August 2007 for a 10 month journey to the northern plains of Mars. Mars Scouts are low cost, competitively selected missions that are intentionally outside the mainstream of NASA's Mars Exploration Program and are the scrappy underdogs of the space world. Phoenix certainly fits this description, and for those who are always tempted to root for the underdog, Phoenix is a great cause.

After the very public failures of two NASA missions (Mars Climate Orbiter and Mars Polar Lander) in 1999, NASA set out to completely restructure the Mars Exploration Program (MEP). Scott Hubbard (currently Carl Sagan Chair for the Study of Life in the Universe, SETI Institute) was sent to NASA Headquarters and dubbed NASA's "Mars Czar" in the press when he was chosen to head the reorganization. Hubbard designed a program of alternating landers and orbiters to take advantage of each two-year launch opportunity to Mars (when Mars is in the right position in its trip around the sun to be more easily reached from earth), and to have enough time between similar type missions to take advantage of lessons learned. The strategy has worked very well, and the Mars Exploration Program (MEP) has been amazingly successful since the restructuring.

The Mars Scout Program was created when Hubbard and the science community sought opportunities for missions outside the main stream of the MEP. This program was specifically established to provide an opportunity to capitalize on advancing technologies and innovations as well as to give the broader scientific community the ability to explore Mars. Even though Mars Scouts were intended to be low cost, relatively straightforward missions, few things about space exploration are ever simple or easy. The Phoenix mission development is no exception. Most of the Phoenix mission is the rebirth (hence, the name Phoenix) of the Mars Polar Lander (MPL) that crashed onto Mars in 1999. As always, during the development of any space mission lots of hardware was built for all the tests and redundancies required to safely fly a space mission. In addition, a follow-on mission to MPL had been planned, and then cancelled, which left a further legacy of hardware. Some of the instrumentation was usable on Phoenix, which made it ideally suited to uncover the clues to the geologic history and biological potential of the Martian arctic.

The story of MECA, (Microscopy, Electrochemistry, and Conductivity Analyzer) which includes a wet chemical analyzer with a dual-use microscope, is a great example of how science instruments could be reused for a later mission. The Co-Investigator for the microscope, John Marshall, of the Carl Sagan Center at the SETI Institute, felt strongly that Phoenix needed the microscope to fully understand the processes that have influenced the northern terrain, but there was a funding crisis and MECA was going to be cancelled. Marshall needed $250,000-and fast-to rescue the microscope. He cornered Scott Hubbard, then Director of NASA Ames Research Center, the man who had signed off on the Scout Program to begin with, and convinced him to find the money. In 48 hours, the $250,000 had been scraped together and MECA was saved.

Phoenix's mission is to use a robotic arm to dig through the protective top soil layer to the water ice below and, ultimately, to bring both soil and water ice to the lander platform for sophisticated scientific analysis. But, like most scientific endeavors, finding what you are looking for is just the first step. Next you need to understand how it, in this case, soil and the water mixed with it, got there and how it has affected, and been affected by, its environment. The science team wants to understand the origin of the soil. Was it brought by wind? By water? Affected by water and ice? What processes has it gone through? No single instrument can tell the whole story.

Think of the investigation as a several step process. MARDI, the Mars Descent Imager, will take pictures on the way to the Martian surface to give context. Are we landing on bedrock? Is this soil volcanic, blasted here by an ancient eruption? After landing, the solar arrays will be deployed, the MARDI images will be sent and the host of instruments will start whirring to action. Then, a Robotic Arm will reach out and deliver samples to either the TEGA (Thermal and Evolved Gas Analyzer) or MECA instruments. Now comes the turn for John Marshall's microscope. MECA consists of two microscopes, an optical microscope and an atomic force microscope (AFM) sharing some common parts, and complimenting one another. The optical microscope looks down to the level of silt and dust, and the AFM looks further still, down to superfine dust.

Another Phoenix instrument, TEGA, a combination high-temperature furnace and mass spectrometer instrument, will carry the story even further by looking at the chemistry of the icy soil to determine ratios of various isotopes of hydrogen, oxygen, carbon, and nitrogen, providing clues to origin of the volatile molecules, and possibly, biological processes that occurred in the past.

NASA's Phoenix Scout isn't a bit of fantasy, but it has, metaphorically, at least, risen from the ashes and its full suite of instruments was saved by a hair's breadth. Skill and passion, patience and hard work, lessons learned, care and expertise will all come together very soon to make something that is its own kind of magic – a space exploration mission.