From what I have read. This is tryed and proven Tech. in an effort to keep costs at a minimum. And a realistic launch date. A 2017 launch date is not to shabby. All the people laid-off from shuttle program I am sure some will be getting a call back. So we have the technology,we have the enigines,crew capsule,the man power,and the funding to get this done. Its just a matter of building it EDIT: prolly using these modified shuttle boosters