Everyone seems to be focused on Mars, but the fact is we haven't been to the Moon since 1972 — so we should probably start there. Lockheed Martin's Moon Lander Concept is designed to do exactly that, piggybacking on work already done on the Orion spacecraft to get humans back to the lunar surface by 2024. It would rely on the planned Gateway space dock, and would simply take astronauts from the station to the moon and back. The two-stage design would include an Orion-based crew module and ascent stage, with a larger descent element that would make transfer vehicles unnecessary. Unlike the Apollo missions, this setup would allow for repeated landings in new, unexplored areas of the lunar surface and serve as a springboard for missions to Mars and beyond.