Fifty one years ago the crew of the Apollo 13 moon mission was put in mortal danger by a fire that broke out in the spacecraft’s oxygen tank. The astronauts were unable to fix the damage themselves, radioing the famously misquoted “Houston, we’ve had a problem” message to mission control. 210,000 miles away on Earth, a team of Nasa scientists used a set of 15 simulators to test various technical solutions that would allow the crew to regain control.