Historians disagree whether the agency truly feared being beaten to the moon that year or was just keen to get back on schedule. In either case, Commander Borman was called into a closed-door meeting: Would he like to go around the moon in December? This was a far riskier venture: if the command module rocket failed to fire and break them out of orbit, the astronauts would never come home. In September, while NASA pondered the mission, the Soviets kept busy, launching a rocket, Zond 5, around the moon and safely returning its crew of worms and tortoises. The Apollo 8 flight was not approved until October, after a crewed flight of Apollo 7 had tested the newly rebuilt command module.

Source: New York Times December 21, 2018 15:43 UTC