As early as 2015,the Ares 1 rocket could replace space shuttles. And if something goes wrong within the first 300000feet (91440m),the Launch Abort System (LAS) will take the astronauts to safety.
The Ares one rocket works like this:
Step one: The abort motor fires and shoots the Orion capsule away from the rocket.
Step two: the attitude-control motor spins the LAS upright for preparation for the next step.
Step three: The third motor pulls the spent sbort system away from the crew capsul,then the parachutes will help slow them down on their way to earth.
I think LAS is a great idea because the astronauts will have less chance to have an accident.