NASA’s new administrator, Michael Griffin, faced the press today for the first time since being confirmed by the Senate last week and vigorously defended the Bush administration’s ambitious plan to send human beings to the moon and Mars. “We could probably go to Mars for what we spent on Apollo” in today’s dollars, he said. “It is a journey, not a race,” Griffin said. If the country put aside “a few billion a year,” the Mars plan would be “very affordable.”