The onboard computers relayed pressure readings from inside the boosters’ combustion chambers down to the consoles in Mission Control, providing a real-time forecast of when their burn would be complete; but the flight controllers knew that any attempt to jettison them before the fuel was consumed—a little more than two minutes after launch—would result in the prompt immolation of the spacecraft. With no control and no means of escape, this made the first 122 seconds of flight the most dangerous part of any mission aboard the shuttle.
