Up, up, up went the temperature in a fuel line on the descent engine. Up, up went the pressure. Rocket science rule number one? Do not allow the fuel to become unstable. Instability equals unpredictability – and unpredictability is just another word for random explosions and all sorts of unwanted chaos. —Team Moon: How 400,000 People Landed Apollo 11 on the Moon, Catherine Thimmesh Why might the author have chosen to include this problem in the text? It shows that the spacecraft was not ready for flight. It shows that NASA had not prepared the astronauts. It shows how difficult the Apollo 11 mission really was. It shows how unpredictable rocket science really is.