Apollo 8 launches on December 21, 1968

(CNN) -- Christmas Eve 1968. Three U.S. astronauts round the edge of the dark side of the moon. Firing its engines, the spacecraft sprints to the other side. But as it does it passes out of communication range with the Earth.

Did the thrusters fire properly? Or would the astronauts remain trapped forever in space?

The world held its breath, waiting for the crew and ship to reappear.

And they did. Everything worked fine on the Apollo 8, the first spacecraft to orbit the moon. And its crew provided other unprecedented, breathtaking moments as well.

The world watched a lunar sunset the same day. A live telecast beamed down the unforgettable shot: shadows crawling across the moon's barren landscape, seen for the first time.

During the broadcast, astronaut Bill Anders read from Genesis: "In the beginning, God created the heaven and the earth. And the earth was without form, and void; and darkness was upon the face of the deep."

Jim Lovell and Frank Borman took turns finishing the Old Testament reading.

After a flawless Pacific splashdown on December 27, a flurry of public appearances and a brief outcry over the use of a religious text on government time, Apollo 8 sailed quietly into the history books.

Lovell and Borman flew two missions together. The first was Gemini 7, which rendezvoused in space with Gemini 6 in December 1965.

Borman, left, Lovell and Anders arrive on board the USS Yorktown on December 27, 1968

The astronauts also learned from two weeks aboard Gemini that Apollo 8 would be roomier.

"Gemini was a tough go," Borman recalls now. "It was smaller than the front seat of a Volkswagen bug. It made Apollo seem like a super-duper, plush touring bus."

Apollo 8 lessons also helped Lovell handle near-tragedy on Apollo 13 in 1970.

Lovell said Friday he accidentally erased navigational data from Apollo 8's computer. He had to manually reposition the capsule for re-entry into Earth's atmosphere.

"That training really helped us on the second time around," said Lovell, who had to reposition manually Apollo 13 for re- entry as well. "It was one of those acts of fate."

After retiring as an astronaut, Borman went on to run Eastern Airlines. He stays in touch with Lovell and Anders, with whom he restores old airplanes.

They launched December 21, 1968, from Cape Canaveral, Florida, the first human spaceflight atop the monstrous Saturn V rocket. Beforehand the Apollo 8 crew met aviation pioneer Charles Lindbergh.

They all laughed, Borman says, when Lindbergh related how pioneering rocket researcher Robert Goddard once told him he could build a rocket that would reach the moon for only $1 million.

Earth on December 22, 1968

Lindbergh and his wife sat on a dune and watched Apollo 8 rise into the Florida sky.

"I remember how it really was the mission with the most cultural and historic impact at the time," said Robert Zimmerman, who has written a new book, "Genesis: the Story of Apollo 8."

Of all the accomplishments of Apollo 8, the one Borman recalls most fondly is what the mission did for a nation and world in serious need of good news.

"The feedback was overwhelmingly positive," he said. "1968 was a bad year -- riots, assassinations, the Vietnam war."

To the former astronaut, one telegram stood out: "Thank you, Apollo 8. You saved 1968."

The Associated Press contributed to this report.