It’s getting to be that time again: A Mars Launch window is approaching. If you play close attention to space exploration programs you may have noticed that we only fling things at Mars ever two or so years. In 2003, the year of the rovers, NASA launched Spirit and Opportunity and ESA launched Mars Express and Beagle 2 (which died on landing). During the 2005 launch window the Mars Reconnaissance Orbiter started to make it’s way to Mars. Now, in 2007, its the Phoenix Landers turn to take on Mars. Sadly, just as Phoenix readies to launch, many Mars fans are watching the rovers Spirit and Opportunity and fearing for their future as dust storms threaten their power supplies. (image credit: Corby Waste / JPL)
People on Earth have been trying to launch things to Mars since 1960. Of the 44 missions listed in wikipedia (yes, I can be just that lazy), only 17 have been complete successes. This failure to land (or orbitally insert) has caused more than a few editorial cartoons and even some random NASA humor as things ranging from a Mars curse to a Galactic Ghoul to aliens of every imagining have been blamed (mostly with tongue in check). The Mars rovers, Spirit and Opportunity, had seemly put the curse thoroughly in NASA’s past. Launched in 2003, these twin 6 wheeled explorers landed on what was expected to be a 90 day mission way back in January of 2004. Now, roughly 1100 days after bounce down, the rovers are still working, but they are seriously struggling for the first time.
The rovers are powered by solar panels. The initial 90 day life expectancy was based in part on how long NASA engineers believed it would take for dust to accumulate on the panels and cause the computers to shut down. What hadn’t been correctly accounted for was the wind. While dust on the solar panels has caused the rovers to have periodic decreases in power, the wind has consistently blown the dust off the panels, bringing the rovers back up to satisfactory power levels. This year’s storm, however, is not only directly effecting the storms, but it is also so thick that it is blocking 99% of the Sun’s light. If the batteries on the rovers drain entirely, the rovers will not be able to turn back on. Still, its been a good ride and the scientists and engineers who have spent the past couple years monitoring what was supposed to be a three-month mission are to be commended for their dedication (and their spouses deserve a special science-spouse medal!)
But, as one pair of rovers may be facing the end of their mission, another mars explorer is preparing to launch. The Phoenix lander is getting set to launch at the beginning of August. The next launch window for Mars missions opens August 3 and 5:35am EDT. These specific launch windows are set by when the orbits of Mars and Earth are aligned. It takes 2.135 years for the Mars, Earth and Sun to return to the same configuration. In other years, when Mars and Earth are aligned with one another, but not at the same position relative to the Sun, their orbits and their inclinations aren’t optimally aligned for missions to make it from Earth to Mars with minimal fuel. The extreme costs of the journey cause NASA, ESA and other agencies to generally wait for the optimal years.
The Phoenix lander should launch in August, and hopefully land in May of 2008. Unlike NASA’s last three landers that used airbags to safely land, Phoenix will use a parachute to slow and make it’s final approach to the Martian surface using thrusters to slow its descent. Set to land on polar ice, this lander will set itself up to dig and run careful tests on the soil and ice that it finds within reach of its almost 8 ft long arm. This arm will be used to dig through the surface to find and sample stuff below.
Like the Mars rovers, Phoenix is also powered by solar arrays. This mission will last one Martian summer. Just like the Earth’s arctic and antarctic region, during its winter the Martian pole experiences no Sun-light. Thus, with the coming of Martian winter, Phoenix will die. Unlike the mythical animal, it will not be able to resurrect itself, but rather it shall become a part of the Martian ice caps: An artifact of 21st century terrestrial life that will be preserved potentially for eons in the ice of another world.