EXPLORING THE MARS:

A small group of robotic space exploration geeks decided to venture out of our comfort zone and began brainstorming different approaches to flying people into space. We were spurred into action when the Augustine com­mission, a blue-ribbon panel that President Barack Obama set up earlier that year to review the space shuttle and its intended successor, reported that “the U.S. human spaceflight program appears to be on an unsustainable trajectory.” Having worked in an exciting robotic exploration program that has extended humanity’s reach from Mercury to the edge of the solar system, we wondered whether we might find technical solutions for some of NASA’s political and budgetary challenges.

Ideas abounded: using ion engines to ferry up the components of a moon base; beaming power to robotic rovers on the Martian moon Phobos; attaching high-power Hall effect thrusters to the International Space Station (ISS) and putting it on a Mars cycler orbit; preplacing chemical rocket boosters along an interplanetary trajectory in advance so astronauts could pick them up along the way; using exploration pods like those in 2001: A Space Odyssey rather than space suits; instead of sending astronauts to an asteroid, bringing a (very small) asteroid to astronauts at the space station. When we crunched the numbers, we found that electric propulsion—via an ion drive or related technologies—could dramatically reduce the launch mass required for human missions to asteroids and Mars.