1970: Critical explosion cripples Apollo 13 An explosion on board Apollo 13 has caused one of the most critical situations in American space history and put the lives of the three astronauts on board in severe jeopardy. The explosion happened in the fuel cells of the spacecraft’s service module approximately 56 hours after lift-off. This resulted in the loss of Apollo 13’s main power supply which means oxygen and water reserves are now critically low. The safety of the three astronauts, Captain James Lovell, Jack Swigert and Fred Haise, is uncertain although Nasa is hoping emergency contingency plans will ensure their safe return. Certain death The cause of the explosion…