While NASA works on a multibillion-dollar, decades-long space exploration plan that relies on monster rockets, an informal cadre of engineers is laying out a different vision that would take advantage of cheaper, smaller spacecraft that can fuel up at “truck stops” along the way.
Right now, the alternate vision, known as the “Stairway to Mars,” is little more than an engineering exercise. But the plan’s proponents on the Space Development Steering Committee say their scenario for Mars missions in the 2030s may have a better chance of becoming a reality than NASA’s scenario.