NASA has been developing the Space Launch System (SLS) [1] since the 2010 Authorization Act killed the Constellation program. If it means anything, they're thr

NASA has been developing the Space Launch System (SLS) [1] since the 2010 Authorization Act killed the Constellation program. If it means anything, they're through their Preliminary Design Review and heading towards their Critical Design Review. They expect somewhere between 70 metric tons to 155 metric tons to LEO depending on the version of the design. Whether it will fly, who knows, but they are actually farther along than NASA has gotten on a space vehicle in a while. [1] http://en.wikipedia.org/wiki/Space_Launch_System http://en.wikipedia.org/wiki/Space_Launch_System