Sending human astronauts to Mars is a dream shared by many, but there are still challenges to overcome and the question of just how to accomplish it is a subject of intense debate. Some supporters advocate sending a mission directly to Mars, while others think that returning to the Moon first, for potentially beneficial training, is the way to go. Indeed, former astronaut James Lovell, who flew on two trips to the Moon, has also called for a return to the Moon first. NASA itself has stated its desire to send a crewed mission to a nearby asteroid first, instead of the Moon, going a bit farther into space than the Moon as its idea of preparation for the much longer journey to Mars. A major problem has been that NASA has still not set a firm timetable for such a mission; it wants to go to Mars, but the steps to achieving that goal are still unclear.