I do disagree with leaving out a mission to the Moon.  The Moon is a great base for launching missions to the asteroids and to Mars.  We know we can reach it within a few days, it has mineral resources, water, and an energy source for fusion.  The Moon’s gravity well is much smaller than the Earth’s gravity well and thus it easier to build bigger craft and launch them with less fuel.  Building a base on the Moon allows us to test out technologies and methods that can help us explore Mars.

This is not an argument for reestablishing the Constellation program.  Canceling Constellation was the right call as is the push to leave Low-Earth Orbit.  But skipping past such an obvious asset in our mission to Mars just doesn’t make sense.