A few years ago, NASA put out a call for mission proposals to explore the Martian atmosphere. They wanted to do it as inexpensively as possible, with a robust mission plan that had a "low implementation risk." In other words, it'll be tough to screw up. They chose MAVEN over more complicated proposals like the Aerial Regional-scale Environmental Survey of Mars (ARES, pictured) because it's basically a satellite that will orbit Mars for a year and report back what it finds.

As it orbits the Red Planet, MAVEN, which is the somewhat tortured acronym for "Mars Atmosphere and Volatile EvolutioN," will use a suite of eight instruments to sample the atmosphere. It will track the composition of the Martian air and create a precise record of current atmospheric loss on Mars. That will give scientists a window to Mars' mysterious past. One theory suggests that the loss of the planet's magnetic field led the atmosphere to be stripped away. Image by: NASA.

NASA Selects 'MAVEN' Mission to Study Mars Atmosphere. [NASA]

According to Yahoo! News:

They call their project Jupiter, and like Ares, it's a brainchild of workers at the Marshall Space Flight Center and other NASA facilities. The engineers involved are doing the work on their own time and mostly anonymously, with the help of retirees and other space enthusiasts. A key Ares project manager dismisses their design as little more than a sketch on a napkin that won't work.

A spokesman for the competing effort, Ross Tierney, said concerned engineers at NASA and some contractors want a review of the Ares plans but can't speak out for fear of being demoted, transferred or fired.

It's depressing to think that NASA engineers are so frustrated by their current projects that they have to strike out on their own. But looked at another way, it's fantastic that they're giving NASA a run for its money. I want to see more amateur and private moon rocket projects creating a competitive market for space travel. Image by Phillip Metschan for Horizons.

NASA Engineers Work on Alternative Moon Rocket [Yahoo! News]