NASA says the decision to use shuttle technology was based on analysis that showed it would cost less and provide more flexibility for planned upgrades. Initially the new launcher would be able to carry between 70 and 100 metric tons to orbit (about three times as much as the now-retired space shuttles). For missions to Mars, the rocket would be upgraded to carry about 130 metric tons.
In all, the United States plans to spend $18 billion on the project through 2017, including $10 billion for the rocket, $6 billion for the Orion capsule to carry crews and $2 billion to upgrade the Kennedy Space Center launch site to accommodate the new booster.
Image: Artist's concept of Space Launch System. Credit: NASA