Fifty years ago, the Apollo 8 mission gave the world an especially exciting Christmas, as it became the first ever manned space flight to leave Earth orbit and travel to the Moon.
The crew of Apollo 8 consisted of commander Frank Borman, command module pilot Jim Lovell, and lunar module pilot Bill Anders. Borman and Lovell had previously flown together on the two-week Gemini 7 mission in December 1965, the longest spaceflight up to that point. Lovell had flown once more after that as commander of Gemini 12, giving him the distinction of having spent more time in space than any other astronaut or cosmonaut, which he would retain until 1973. For Bill Anders, on the other hand, Apollo 8 was his first and only spaceflight.
Originally, Borman and Anders had Michael Collins as their command module pilot; but earlier in 1968, Collins developed a bone spur in his spine, which required surgery to correct, and put him out of action for several months. As a result, Jim Lovell joined the crew instead, while Collins was given what would have been Lovell’s spot alongside Neil Armstrong and Buzz Aldrin, the eventual Apollo 11 crew.
Apollo 8 wasn’t originally intended to fly to the Moon, either. The plan for the first manned Apollo missions was to have a C-mission, testing the command and service module (CSM) in Earth orbit; then a D-mission, testing the CSM and lunar module together in low Earth orbit; then an E-mission, repeating the D-mission in high Earth orbit, to practice for the high-speed re-entries that would be necessary when returning from the Moon. Apollo 8 was to be the D-mission, crewed by Jim McDivitt, Dave Scott and Rusty Schweickart; Frank Borman’s crew had been assigned to Apollo 9, the E-mission. However, the D-mission’s lunar module experienced delays in its construction, and was not forecast to be ready until the spring of 1969, throwing the whole schedule back. George Low, manager of the Apollo Spacecraft Program Office, came up with an idea: cancel the E-mission, and replace it with a CSM-only flight around the Moon in December 1968, before the D-mission. Apollo 9 subsequently became the D-mission, and as McDivitt’s crew had already spent so much time training for that particular flight, they switched places with Borman’s crew, who would fly on the new Apollo 8. This meant that Borman’s crew had less than four months to train for their mission.
An important factor in the decision to send Apollo 8 to the Moon was the risk that the Soviet Union might get a manned mission there first. Indeed, in September 1968, a Soviet spacecraft named Zond 5 – which carried various biological specimens, including a couple of tortoises, but no cosmonauts – successfully passed once around the Moon and returned to Earth.
Apollo 8 launched from Cape Kennedy, Florida at 7:51am local time on 21st December 1968. Borman, Lovell and Anders were the first astronauts to ride the massive Saturn V rocket, which had only had two unmanned test launches. Two hours and 47 minutes after launch, the crew performed their Trans-Lunar Injection burn, which propelled them towards the Moon. As a safety measure, the spacecraft initially travelled on a free-return trajectory, which meant that if left to its own devices, it would swing around the Moon and straight back to Earth in a figure 8, as Zond 5 had done. This inspired the design of the Apollo 8 mission patch, which was drafted by Lovell. On the outbound flight, no significant problems were encountered with the spacecraft, but Borman did experience a short bout of space-sickness, which was rather unpleasant for everybody in the cramped command module.
On 24th December, after travelling across the trans-lunar void for 2 days and 18 hours, Apollo 8 passed behind the far side of the Moon and fired its main engine, slowing down enough to enter lunar orbit. It would stay there for 20 hours, completing ten orbits, while the crew took photographs and observed landmarks, reconnoitring potential landing sites for future missions. From an altitude of 70 miles, Lovell described the Moon’s surface as resembling “plaster of Paris or…a greyish beach sand“.
As Apollo 8 began its fourth orbit, the astronauts managed to get a view out of their windows of Earth, rising above the bleak lunar surface. Bill Anders took the Earthrise photo that would be one of Apollo 8’s greatest legacies, an image perfectly encapsulating the beauty and isolation of our planet and everything on it. Later, during the ninth orbit, the crew made a television broadcast back to Earth, presenting live images of the Moon, and rounding off by reading the beginning of the Book of Genesis. Frank Borman ended by saying, “And from the crew of Apollo 8, we close with good night, good luck, a merry Christmas, and God bless all of you, all of you on the good Earth.”
A few hours later, Apollo 8 passed behind the Moon for the final time, out of contact with Mission Control; on the far side, the crew would perform the Trans-Earth Injection burn that would propel them out of lunar orbit. 37 minutes later, to the relief of Mission Control, signals from the spacecraft were re-acquired exactly when expected, indicating that the burn had been fine. Soon after, Jim Lovell reported, “Please be informed, there is a Santa Claus.” On the journey home, the crew enjoyed a surprise Christmas dinner of turkey, gravy and cranberry sauce, a pleasant change from their usual freeze-dried food. Apollo 8 landed in the Pacific Ocean on 27th December, bringing the six-day mission to an end, and bringing NASA significantly closer to achieving President John F Kennedy’s challenge of landing a man on the Moon by the end of 1969.
If you would like to know more, check out the Apollo 8 Flight Journal, or Andrew Chaikin’s book A Man on the Moon.