NASA has decided that its next launch vehicle for getting humans into space will be based on the space shuttle system, including its main engines, solid rocket boosters and external tank. There will be one big difference, though, instead of riding along the side of the new rocket, astronauts in the future will be riding on top on top of their next launcher — above any debris that might fall off. Speaking to reporters via telephone July 29, NASA Administrator Mike Griffin said the agency’s plans are the result of an intensive Exploration Systems Architecture Study he ordered in late April to plot NASA’s return to the moon by 2020. That study will be publicly unveiled in “a few weeks,” Griffin said.