Tomorrow will be the 100th anniversary of the Wright brothers historic first flight at Kitty Hawk and falls within the 200th anniversary of the Lewis and Clark expedition. Such a portentous occasion cannot go by unmarked, and the word is out that President Bush will travel to the scene of the aviation pioneers’ triumph to make a statement reaffirming America’s commitment to exploring new frontiers, which now lie in space. The question is, what will the vision be? For the past 30 years, since the conclusion of the Apollo Moon landings, humans to Mars has been the challenge staring the space program in the face. Because it once had abundant flowing liquid water, Mars could have been, and may yet be, a home for life. The Red Planet thus is the Rosetta stone that holds the key to our enlightenment on the issue of the prevalence and diversity of life in the universe. Uniquely among all the worlds within our reach, it possesses all the other resources needed for not only life, but technological civilization. Mars is also the critical test that will determine whether humankind can transcend its limits and become a multi-planet species.