The Fourth Crewmember

Armed with their checklists, the Apollo astronauts literally read themselves to the moon.

A cuff checklist from the Apollo 16 mission gives detailed instructions for collecting rocks and taking photographs during a lunar excursion. NASA

The interior of a spacecraft of the 1960s was hardly a paperless office. In fact, it could be a positively 19th-century environment, where information was printed in small pamphlets or handwritten on paper cards and notebooks. Flight plans, checklists, navigation aids, and data cards—laboriously drafted, reproduced, and distributed to ground and flight crews—became what Apollo 11 astronaut Michael Collins called the spacecraft’s “fourth crewmember” and, in flight, its real commander.

Checklists proliferated to every corner of Apollo’s habitable environment. Launch stowage lists for the first lunar landing mission detailed 34 separate pieces of documentation, including letter-sized data cards and 8-inch-by-5.5-inch three-ring binders of white and red cardstock. Apollo 11’s Launch Operations Checklist had 113 pages; its Command Module Operations Checklist more than 200. In excruciating detail, these books instructed crews on matters both obvious and obscure, including which switches to flip and when, where and how to stow or unstow equipment, and how to operate the onboard computers that would guide them to the moon.

No detail seemingly escaped the checklists’ omniscience, instructing crews (in a clipped series of abbreviations and verbs) how to shut down the Lunar Module’s descent engine or exit from an inverted Command Module so as not to bump their heads (EXIT FEET FIRST). Even the hatch of Apollo 11’s CM, now preserved at the Smithsonian’s National Air and Space Museum, bore two checklists, describing the two dozen steps required to depressurize and repressurize the cabin.

When freed from the confines of their craft, Apollo astronauts still relied upon checklists. Spacesuits carried various instructions; the left extravehicular gloves of Apollo 11 astronauts Neil Armstrong and Aldrin, for example, bore sewn-on cloth checklists of lunar surface activities. In time, though, the increasing complexity of Apollo’s mission goals required separate “cuff checklists,” small spiral-bound booklets affixed to the astronaut’s wrist and containing more exacting instructions and diagrams, separated by tab dividers.

To aid in the production of these documents, the Astronaut Office assigned to each Apollo flight a dedicated support crew to assemble and update the mission’s flight plan, checklists, and mission rules. Typically, the men assigned to support duties were junior astronauts who, by virtue of their late arrival in NASA, could not receive immediate crew assignments and found themselves, instead, employed as engineers designing hardware that they hoped they might one day fly. Rather than bemoaning such work, astronauts embraced the opportunity to influence spaceflight operations and prepare for future flights. Junior astronauts Bill Anders and Alan Bean, anticipating their first flights as Lunar Module Pilot (LMP), conspired, while supervising construction of the spacecraft at the Grumman factory in Bethpage, New York, to prepare checklists that would enable them to disembark on the moon’s surface before their crewmates. Though eventually countermanded by a veteran astronaut, the change might have permitted either Bean or Anders to become the first human to step foot on the moon had they been assigned to the first landing mission.

The astronauts’ training entailed both reading checklists and writing them, and flight crews often travelled into space having already logged long hours writing the manuals for their space vehicles. Training summaries for flight and backup crewmembers for Apollo 11, though, still allocated 100 hours to familiarization with these materials; Commander (CDR) Armstrong, Command Module Pilot (CMP) Michael Collins, and LMP Aldrin exceeded that quota by more than 40 hours each, and their backup LMP, Fred Haise, spent 131 hours. Rather than relying upon these written materials less as the program progressed, the last Apollo crew (on 1972’s Apollo 17 mission) was “more wedded to following checklists than other crews,” according to LMP Jack Schmitt, in part because they had trained with them so closely.

Armed with their checklists, America’s astronauts literally read themselves to the moon. Occasionally during flights, they modified incorrect procedures on the fly, but contrary to their cowboy image, they did so reluctantly. “I don’t enjoy making changes to procedures,” Collins declared in his post-flight briefing. “It seems like the crew only does that when they feel there’s some good need for it.” Mistakes to complex procedures discovered in flight often required immediate written correction. Armed with a variety of writing implements (including the legendary pressurized-ink Fisher Space Pen, produced through a $1 million private research and development program), astronauts would alter procedures, enter data, check-off completed activities, or make notes for the future. Apollo 11 checklists used by Collins bear multiple annotations in neat black felt-tip pen concerning navigation, procedures, and systems monitoring. Other notations in blue ink and pencil attest to more harried jottings suggestive of a seafaring captain’s log. Empty spaces on the checklists bear the occasional note for posterity, or for engineers combing the documents after the flight for information about the performance of flight hardware. The cover of the Apollo 11’s Launch Operations Checklist, for example, bears a penciled note in hurried script that a leg pocket of Armstrong’s spacesuit “interferes with abort handle,” a potentially mission-ending problem that Collins later described in his post-flight debriefing. “He was worried about that,” Collins noted, “and I was worried about that.”

While critically involved in their construction, astronauts were not the only people who had access to in-flight documentation, and ground personnel frequently annotated the materials with messages, cartoons, jokes, and their signatures. Expressions of support were frequent in in-flight materials, with ground crews poking fun at the astronauts but also praising Apollo 11’s CM Columbia and LM Eagle, noting that ‘COLUMBIA & EAGLE ARE THE GREATEST MAN HAS CREATED’ and wishing the ‘MOONMEN’ luck on their voyage.

Cartoons depicting Snoopy, the daydreaming beagle of Charles Schulz’s Peanuts cartoon strip, make particularly frequent appearances. First doodled on daily schedules by NASA pre-flight operations chief Ernie Reyes, Snoopy served as an unofficial mascot of the Apollo program. A ‘Silver Snoopy’ award honored excellent performance by NASA employees and the black-and-white communications-carrying headgear that Apollo astronauts wore was quickly dubbed the “Snoopy Cap”; Apollo 10’s LM even bore the cartoon beagle’s name. In the unsigned cartoons drawn on various checklists, Snoopy appears as a narrator perched forlornly atop his doghouse describing mission events or, as a surrogate for the crew, clad in a spacesuit. Beneath their helmets, the characters wear Snoopy’s distinctive leather flying helmet and goggles, known to readers from his imaginary duels with the famed World War I flying ace the Red Baron. Apollo 11’s Command Module Operations Checklist bears two Snoopy cartoons, in which the dog wonders whether “THEY HAVE DOGGIE BAGS ON THE MOON” and, later, ‘HOW CAN I EAT WHEN WE’RE APPROACHING A LUNAR LANDING?’ One cartoon depicts Snoopy’s doghouse as a surrogate for the Apollo spacecraft stack, with stick figure astronauts quietly smuggling personal items into the vehicles, a longstanding and occasionally controversial feature of the human spaceflight program.

Checklists could also be, like many of America’s early astronauts, imperfect, jocular, and blatantly sexual. On the lunar surface, Apollo 12 astronauts Bean and Pete Conrad found that the cuff checklists had been littered with cartoons by Reyes depicting the astronauts as incompetent Snoopy-style characters floundering on the lunar surface. In a 1998 interview, Reyes described composing the cartoons at the request of an unnamed member of the Apollo 12 crew (possibly CMP Dick Gordon, who remained in lunar orbit as Bean and Conrad walked on the surface). Conrad apparently enjoyed them. Accompanying the cartoons, though, were black-and-white reproductions of Playboy magazine photographs of nude women, an addition for which Reyes denied responsibility. The images bear smutty captions playing upon the scientific tasks to be done on the lunar surface, admonishing Bean to “SURVEY HER ACTIVITY” and “DESCRIBE THE PROTRUBERANCES,” and inquiring whether Conrad had “SEEN ANY INTERESTING HILLS & VALLEYS?” Conrad and Bean later told a Playboy reporter that they hadn’t noticed the Playmates in their checklists until well into their moonwalk, and thoroughly enjoyed them. Somewhat more tame was a mock glossary of abbreviations included on Gene Cernan’s cuff checklist for his second spacewalk on Apollo 17. Playing upon NASA’s penchant for cryptic acronyms, the glossary offered a range of observational terms unlikely to be of any use to Cernan on the moon, including “btw” (“big tall women”), “cra” (“loco moon person’”), and “xln” (‘Mr. Lincoln’s ex-wife’). Such jokes were magnified by the profound distance between the author and recipient: on the surface of the moon, no one could hear the astronauts groan.

Cartoons, jokes, and more staid notations about navigation, photography, and other operations appear throughout Apollo 11’s checklists, but one Velcro-studded card in Apollo 11’s Command Module Operations Checklist invited more thoughtful commentary. Entitled in Gothic black script “Ye Ole Lunar Scratch Pad,” the page, by mission’s end, was filled with pencil scribbles and remarks apparently drafted by Collins, probably during the extended period in which he orbited the moon alone. While strings of numbers and lists of objects (ROCK BOXES FOOD WATER SPOON; Trash Underwear Helmet Protector) grace the sheet, so do random observations and musings. URINE PARTICLES LIKE ANGELS reads one notation, as does the following, chilling description of the work of spaceflight:

SWITCHES >300 + etc
SPS4 must light or stranded

The checklist-style comments appeared to form a rough draft of the remarks Collins broadcast while returning to Earth on July 23, in which he focused not on the magnitude of his achievement but upon the difficulty he had encountered managing Columbia’s huge cockpit:

This trip of ours to the moon may have looked, to you, simple or easy. I’d like to assure you that has not been the case. The . . . rocket which put us into orbit is an incredibly complicated piece of machinery. . . . This computer up above my head has a 38,000 word vocabulary. . . . This switch which I have in my hand now, has over 300 counterparts in the command module alone. . . . In addition to that, there are myriads of circuit breakers, levers, rods, and other associated controls. . . . The parachutes up above my head must work perfectly tomorrow or we will plummet into the ocean. We have always had confidence that all this equipment will work, and work properly, and we continue to have confidence that it will do so for the remainder of the flight.

Collins concluded by thanking the manifold NASA personnel responsible for the crew’s survival and success; like the periscope of a submarine, Apollo 11’s crewmembers were only the most visible part of an effort much larger than themselves, but a part combining extreme danger with almost unimaginable responsibilities, aided by checklists that had guided them through every stage of their flight.

Excerpted and condensed from an essay published in Space Travel and Culture: From Apollo to Space Tourism, Wiley-Blackwell, 2009. Matthew Hersch, an HSS/NASA Fellow in the History of Space Science at the University of Pennsylvania, is writing a labor history of American astronauts.

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