New Delhi, April 8 -- On Christmas Day 1968 Michael Collins, who would later be the pilot of Apollo 11's command module, Columbia, relayed a question his young son had asked about Apollo 8 to Bill Anders, then on board that spacecraft: "Who's driving?"

Anders paused, then replied: "I think Isaac Newton is doing most of the driving right now." Apollo 8 had left lunar orbit earlier that day; from then until it splashed down on December 27th, about 1,600km (1,000 miles) south-south-west of Honolulu, its path was almost entirely set, like that of a falling rock, by Newton's law of universal gravitation.

Sir Isaac has been driving Integrity, the capsule that houses the crew of NASA's Artemis II mission, for almost all of its journey. Integri...