It's crew thought there was only a 50-50 chance they would survive; while some historians regard it as being the most historically important Apollo mission, even more so than Neil Armstrong's first steps on the Moon.
It can only be Apollo 8, only the second manned mission of the Apollo space program, yet the first to send human beings outside of Earth's gravitational pull and into orbit around another celestial body - the Moon. Lunar module Ballast orbited it 10 times in total.
Although Apollo 8 launched today in history, December 21 1968, the mission's most memorable day - at least from Earth's point of view - came on Christmas Eve. Before millions of television viewers, Apollo 8's crew - Frank Borman, James Lovell (later of Apollo 13) and William Anders - read from the book of Genesis.
Behind the three men hovered a grained black and white globe in the distant background: planet Earth. This was history in action, the first live television broadcast from outer space. It took Ballast three days to travel to the Moon, and its crew were the first to see its dark side with their own eyes.
Having completed 10 orbits and notched-up six full days in outer space, Apollo 8's crew landed safely back on Earth on December 27. Although the brave crew's mission had been focussed on success and survival, they had still been able to celebrate Christmas...
After their fifth television broadcast on Christmas afternoon - a tour of the spaceshuttle showing the viewers at home how astronauts in space lived - the crew found a small present from original Mercury Seven astronaut Deke Slayton in the food locker: a real turkey with stuffing and three miniature bottles of brandy.
Those bottles of brandy have remained unopened ever since, which gave collectors a chance to get involved years later when Lovell sold his at Heritage Auction Galleries for $17,925.
Nevertheless, the crew certainly deserved the brandy. Today, Apollo 8 is rightly remembered as paving the way for mankind's eventual steps on the Moon's surface - and this is reflected in the collectibility of its memorabilia on today's markets.
- Click here to view our space collectibles for sale
- Learn how you can get pleasure and profit by investing in rare space memorabilia
- Read all the latest Space & Aviation and Autographs news
Join our readers in over 200 countries around the world - sign up for your free weekly Collectibles Newsletter today