From the second installment of PBS Chasing the Moon, culminating with the description of the successful mission of Apollo 8 that left the earth orbit and circled the moon. And this, after the tragic death of the Apollo 1 astronauts where, even today, the exact reasons are not known:
"Everything seemed to come to a head in '68. There were the assassinations of two of the leaders of the more liberal causes. Bobby Kennedy, shortly after winning that election in California that probably would have put him over the top as the presidential candidate that year, and Martin Luther King, of course, in Memphis, was a terrible blow to the entire cause of civil rights. By the summer of '68 the Democratic convention turned out to be a terrible shambles of violence and counter-violence by the Chicago police... By December the country was pretty far down."
In other parts of the world, violence escalated. The year had begun with the Tet offensive, and the American death toll in Vietnam would surpass fourteen thousand by year's end. Soviet tanks in Czechoslovakia prompted President Lyndon Johnson to cancel arms treaty negotiations with the U.S.S.R. Student protests in Paris escalated into a battle between unions and the de Gaulle government. Hundreds of students were killed in Mexico, just weeks before the Olympic Games in which African Americans raised their black-gloved fists in protest against American racism.
Historian Andrew Chaikin recounts, "Inside NASA, they were almost in a cocoon of focus and determination and just the absolute all-out effort to get to the moon by the end of the decade. They really couldn't afford to be too distracted by what was happening in the rest of the country. It wasn't out of a callousness; it was just that that's what the program demanded of them, that kind of total focus.
The program ended:
"We got millions of telegrams after we landed, but the one I remember most was, 'Congratulations to the crew of Apollo 8. You saved 1968.' We didn't save it [ourselves] — but a lot of the people who made Apollo work saved it."
— Frank Borman, Apollo 8 astronaut
https://www.pbs.org/wgbh/americanexperi ... aved-1968/