Veteran astronaut John Phillips, flying on the current mission, said the legacy of the space shuttle is in its uniqueness.
"We have had a vehicle that would fly for 30 years. It is still the only reusable spacecraft. No one else has one," Phillips said. "It will fly for 30 years and do things no other spacecraft can do, and no other spacecraft in the foreseeable future can do -- carry these big things up and grab it with a robot arm and dock to the space station and bolt something on the side and send spacewalkers out and launch satellites and do scientific laboratory experiments, all of these things together. ... It is a remarkable vehicle."
The first mission to the moon may not happen until 2020, but the work to get there is intensive. It's no small task to design rockets, space capsules, lunar landers and lunar rovers.
But NASA has a head start.
They've been there, and they've done that.