Earthrise: Apollo 8's Surprise Gift
Fifty-years ago, NASA launched Apollo 8 moonward with an official mission: photographing the moon’s surface. The flight’s unofficial mission was to travel to the moon and back before the Soviet Union accomplished the same feat. The astronauts and the NASA ground crew accomplished both of these goals.
Earthrise, taken on December 24, 1968, by Apollo 8 astronaut William Anders. Source: NASA/Bill Anders Earthrise, taken on December 24, 1968, by Apollo 8 astronaut William Anders. Source: NASA/Bill Anders
No one at NASA thought that the mission would also produce an unexpected result, one that author Jeffrey Kluger contends has had the greatest impact on the Apollo 8 crew (Frank Borman, James Lovell and William Anders), subsequent astronauts and those who remain earthbound: the overview effect. The genesis of this effect was a picture that Anders, the mission’s official photographer, almost did not take, on a mission that was not intended to fly to the moon at all.
Apollo 8’s Mission Shift
Earthrise, taken on December 24, 1968, by Apollo 8 astronaut William Anders. Source: NASA/Bill Anders
Anders would not have had this photo opportunity had NASA not changed Apollo 8’s mission in an uncharacteristic deviation from its carefully planned flight schedule. Apollo 7, which launched as scheduled in October 1968, was the first manned mission since the Apollo 1 fire in January 1967. Apollo 8’s original mission was, like Apollo 7's, confined to Earth orbit and intended to test the lunar module (LM). Severe delays in LM production threatened to delay Apollo 8 well into 1969, a delay which in turn would quash hopes of fulfilling President Kennedy’s goal of landing a man on the moon before 1970.
NASA administrator George Low had a radical proposal for keeping to the moon-landing schedule: send Apollo 8 into lunar orbit without the LM on board. Low made this proposal in August 1968, less than four months before the December launch window.
Low and NASA faced formidable obstacles. The Saturn V rocket necessary to launch the spacecraft was undergoing a critical redesign and could not be tested before December. The command module was also being redesigned, and no flight-simulator models were available for crew training. In addition to these hardware limitations, NASA had to completely redesign mission activities, recalculate trajectories and flight paths, conceptualize problems and solutions – and all within an extremely compressed time frame.
The Saturn V rocket caused particular concern since its test flight in April 1968 had revealed multiple serious problems: a phenomenon known as pogo oscillation in its first stage; two second-stage engine failures; and a third stage that failed to ignite in orbit. Pogo oscillation occurs in liquid-fueled rockets when unstable combustion produces engine thrust variation, ultimately resulting in longitudinal vibration similar to that produced by a pogo stick. To absorb some of these vibrations, engineers at the Marshall Space Flight Center in Huntsville, Alabama, introduced a helium-damping system between the rocket and the spacecraft. Marshall engineers identified and corrected fuel-line and igniter issues that had caused the engine problems and gained NASA approval to build Apollo 8’s Saturn V launch vehicle.
To the Moon and Back NASA mounted Apollo 8’s spacecraft and Saturn V rocket on Sept. 21, 1968, in Cape Canaveral, Florida. Prior to launch, the assembly stood 363 ft tall and weighed 6,218,558 lb. The spacecraft, comprising the command module (CM) and service module (SM), weighed 63,650 lb. Subsequent Apollo missions included LMs, which increased spacecraft weight and the thrust required at liftoff. Apollo 11 stood one foot taller at launch (364 feet) and weighed 6,484,280 pounds.
Apollo 8 liftoff. Source: NASA
Apollo 8 pushed skyward at 7:51 a.m. on Dec. 21 and completed two shakedown Earth orbits to ensure that the spacecraft was functioning properly, before flight commander Borman received permission to head to the moon: "Apollo 8, you are go for TLI." The acronym referred to trans-lunar injection, one of the mission’s critical navigation events; the others remaining were lunar orbit insertion (LOI), a lunar orbit correction, and trans-Earth injection (TEI) for the return to Earth. Imprecise navigational corrections could have meant fatal results for the Apollo 8 crew, sending them off into space or crashing into the moon. If NASA found a reason to scrub the lunar-orbital mission, the spacecraft could use the moon’s gravity to slingshot around the moon and return to Earth, a technique Lovell used to bring Apollo 13 home.
Apollo 8 correctly executed its TEI maneuver on Dec. 25 and headed back to Earth. In the process of moving the spacecraft to view star formations, Lovell erased some navigational memory, a human error that caused the spacecraft’s inertial measurement unit (IMU) to fire thrusters to “correct” the craft’s trajectory.
Fortunately, the same human responsible for the error was able to figure out the right information to feed the IMU to get back on track. The balance of the flight home and the splashdown landing on Dec. 27 proceeded according to NASA’s elaborate plan.
The Picture Anders Almost Missed Several factors had to line up to make the iconic "Earthrise" picture possible. Anders’ job was to photograph the far side of the moon and specific areas on the opposite side, sites that NASA was considering as landing zones. Strict, detailed schedules governed all space flight activities, including picture taking. As Apollo 8’s mission commander, Borman was a stickler for keeping to schedules.
Anders had been using black-and-white film to photograph craters on the moon’s dark side when he saw the Earth rising over the moon’s horizon. He later commented that the contrast between the Earth’s vibrant colors and the moon’s darkness caused him to feel that the Earth was the true center of the universe.
Unsurprisingly, Anders wanted a color photograph but he had no color film close at hand. He asked Lovell to toss him a roll of color film. In the time that elapsed between making the request and loading the film, however, the earthrise scene vanished from Anders’ window. NASA released a video in 2013 that captures Anders’ awestruck comments and the back-and-forth between him and Lovell.
Borman had not seen the earthrise and was insisting on sticking to the photographic schedule. Since Borman had initiated a slow rotation, however, the spacecraft gradually rotated to frame the scene in the window nearest the commander. Anders captured the picture; later, both Lovell and Borman would claim authorship.
Without the original photographic schedule, Anders would not have been snapping photos when the Earth appeared; without the craft’s slow roll, the image would not have reappeared; and without a bit of defiance, Anders might have relinquished the camera to Borman and missed the shot entirely. Both Borman and Lovell took pictures, but not the one that became Earthrise.
The Overview Effect The schedule of photography Anders followed did not include taking pictures of the Earth from space. Such an omission seems unthinkable – but as Anders pointed out, the moon, not the Earth, was the mission. The sight of Earth suspended in the blackness of space affected the Apollo 8 astronauts and those who followed on later missions. Some of them reported feelings of awe, an understanding of the interconnection of life and a sense of responsibility for the environment.
Writing in 1987, author Frank White named this cognitive shift in astronauts’ perspectives the overview effect. White interviewed multiple astronauts who recounted experiences like those described above; people around the astronauts also detected a psychological difference. Observing the planet from a quarter-million miles away – where the entire planet is visible – accounts at least in part for the overview effect.
The Most Important Photo Ever? Apollo 8 entered lunar orbit on Dec. 24, 1968, at the end of a turbulent year that started with the violence of the Tet Offensive in Vietnam and included the assassinations of Martin Luther King Jr. and Robert F. Kennedy, the Prague spring, student riots in the U.S. and in Europe and confrontations at the Democratic Party convention in Chicago – Apollo 8’s successful insertion into moon orbit was good news. Later on that Christmas Eve, the astronauts read to their earthbound audience from the book of Genesis.
Apollo 8 mission patch. Source: NASA/Jim Lovell
Earth’s citizens did not yet know about the photo since it was stored on Anders’ Hasselblad camera, along with his more scientific shots. The spacecraft splashed down in the Pacific Ocean on Dec. 27, 1968; the stunning photograph did not appear until later. Over the past 50 years, Earthrise has become one of the most familiar and most reproduced images in history. Those born after Earthrise have always known what our planet looks like from space. For those alive in 1968, seeing Earthrise for the first time was astonishing.
Jeffrey Kluger, author of "Apollo 8: The Thrilling Story of the First Mission to the Moon," claims that Earthrise was among the mission’s greatest achievements. National Geographic photographer Brian Skerry believes that it is the most important photograph ever made, as it allowed mankind to see itself in a mirror for the first time. Future Apollo missions captured other iconic images – most famously the Blue Marble, shot by the Apollo 17 crew in Dec. 1972.
Earthrise first captured the quiet beauty of a planet that had spent a year rocked by trouble, and provided a peaceful end to a tumultuous year, helping to launch the environmental movement and raising new awareness of human strength and fragility.
This article was originally published on Globalspec.com.