Atlantis will be landing soon, bringing the STS program to an end. After this historical final landing, the US will lose the capability of launching Astronauts in Space, until one or more of the commercial alternatives will be ready with a platform which NASA can use. The foreseen gap is about 5 years. Meanwhile NASA will concentrate on building the next major stepping stone for inter-planetary flight by creating the capability for humans to reach Asteroids and Mars.
