Colorado, a space industry “powerhouse,” could corner up to half of the contracts in a nearly $3 billion proposed mission to bring martian rocks and soil back to Earth for study. The state’s know-how includes Lockheed Martin Space Systems’ Atlas rockets, which could power a craft to Mars; Ball Aerospace’s expertise in snaring samples and sealing them against contamination; and the University of Colorado’s skill in recognizing the signature of fossilized life forms.