SpaceX blasts Dragon capsule away from pad, testing rescue system

CAPE CANAVERAL, Fla. — With the prospect that one day astronauts may be aboard as something goes terribly wrong with a rocket, SpaceX jettisoned its Dragon capsule from a launch pad Wednesday, sending it to safety thousands of feet into the air, then parachuting to a gentle splashdown. The test demonstrated the spacecraft’s ability to get…