What specific roles are the commander and pilot responsible for during the mission?
The Commander is the captain of the ship, and makes all real-time critical decisions on behalf of the crew and in coordination with the MCC. The Commander also flies the shuttle during approach and landing, and is trained and ready to take over from the computers and fly at all other times. The Pilot is the Commander's understudy, and is fully trained to do all the same tasks as required. Commanders fly at least once as Pilots before they move into the left seat. Both participate in experiments and on-orbit operations, with some limitations. They are not allowed to do spacewalks, as we can't afford to have them stuck outside during an emergency deorbit. They also don't normally operate the Canadarm, as it is a specialised task separate from flying the vehicle. (A Canadarm is a 15 metrelong robot analog of the human arm: nerves of copper wiring, bones of graphite, fibrereinforced tubing, muscles of electric motors and a multilayered skin of special cloth materials. Embedded within, thermostatcontrolled heaters prevent drastic temperature fluctuations. Controlled by an electronic brain, its computer, Canadarm can be operated under human control or automatically to perform retriving and repairing of instruments in space.)