On day 6 of ill-fated Apollo 13 mission the astronauts needed to make a critical course correction. If they failed they might never return to earth. To conserve power, the onboard computer that steered the craft had been shut down. yet the astronauts needed to conduct a 39 second burst of the main engines. how to steer? Astronaut Jim Lovell determined that if they could keep a fixed point in space in view through their tiny window, they could steer the craft manually. That focal point turned out to be their destination- earth. As shown grippingly in the 1995 movie ’Apollo 13’, for 39 agonising seconds, Lovell focussed on keeping the earth in view. By not losing sight of that reference point, the 3 astronauts avoided disaster.