Chief Designers 5: Wernher von Braun

von Braun and Nebel, c.1932

Wernher von Braun, right, and VfR compatriot Rudolf Nebel, circa 1932. Image origin unknown, believed to be in the public domain. Please contact the author if you have more information. Click for a larger view.

For many years Wernher von Braun was considered the paramount figure in the history of spaceflight. Certainly he had the unique distinction of being a key figure in two national space programs: the precocious and abortive German one, and the dominant American one. However against this we need to set the fact that he was “only” a rocket designer and was not intimately involved in developing the spacecraft that rode on top of them—one could make the argument that Max Faget was the most important figure in American manned spaceflight history because he was dominant in that role—and he pales in comparison to what we have learned about Sergei Korolev’s role in the Soviet space program since the 1980s. He and Korolev were the two greatest visionaries of the early space program, but then von Braun also suffers from having the most morally problematic career of any leading person in the history of space as well.

Wernher Magnus Maximilian, Freiherr von Braun was born in Wirsitz, Germany (now Wyrzysk, Poland) on March 23, 1912. From 1915 he and his family lived in Berlin. Reportedly the present of a telescope and later a copy of Herman Oberth’s seminal book Die Rakete zu den Planetenräumen (By Rocket into Interplanetary Space) fascinated him and drew his attention to space.

A peripatetic school career let him develop his skills in physics and mathematics, ultimately leading to a degree in aeronautical engineering from the Technische Hochschule Berlin in 1932 and a degree in physics from Friedrich-Wilhelms-Universität in 1934. It was in 1930, however, that his future was cemented by his joining the Verein für Raumschiffahrt (“Spaceflight Society”, commonly known as VfR), which had been founded three years previously. Their experiments with rocketry drew the attention of the German Army, particularly Walter Dornberger.

Under Dornburger, von Braun became the head of a rocket research program at Kummersdorf—the thesis for his 1934 degree was classified and unpublished until 1960—and civilian testing of rockets was banned. Unfortunately for Germany and the world as a whole, these preliminary steps were taken under the new German government of Adolf Hitler and the Nazi party. Von Braun’s fortunes and that of German rocketry would rise and fall with them.

After several years of success at Kummersdorf, von Braun’s group was moved to Peenemünde on the Baltic coast. There they developed the A4 rocket, better-known as the V-2. This was the first man-made object to reach space, doing so several times on suborbital test flights, possibly as early as the steep misfire that was the fourth V-2 test flight on October 3, 1942 and certainly no later than the end of 1944. Unfortunately for von Braun’s future legacy it was used to launch conventional warheads at the UK and later the invading Allied armies after D-Day. Both London and Antwerp suffered under his rocket. Perhaps even worse was the fact that from the autumn of 1943 the V-2 was built in the Mittelwerk using slaves taken from Mittelbau-Dora concentration camp. Von Braun managed to distance himself from this during his lifetime by pointing to his imprisonment by the Gestapo for two weeks in the spring of 1943, but the historical consensus since then is that von Braun knew more than he let on during his life and did little to resist the SS (who ran Mittelwerk, and of which von Braun had been an honorary member since 1940) after his release from prison so long as he could continue his rocketry work.

Ultimately his efforts to clandestinely jumpstart a German space program as a side effect of his military research came to a halt with the end of World War II. He and some 500 others of his Peenemünde group surrendered to the American 44th Infantry Division and were eventually sent to the United States as part of Operation Paperclip, a program to transfer as many key German scientists as possible out of Germany and away from the USSR and UK. Upon arriving in the US he and his compatriots had their war careers and Nazi activities hidden by the American government. For the next five years his role was to teach the US Army about the V-2 and its underlying technology while essentially under house arrest at Fort Bliss, Texas.

In 1950 he and what was left of the Peenemünde group were transferred to Huntsville, Alabama, where their conditions were relaxed and they were allowed to enter civilian life in the United States. Von Braun became technical director of the Army Ballistic Missile Agency, whose purpose was to develop a long-range ballistic missile. This they did, the Redstone. During this time, von Braun also became famous as a public advocate of spaceflight, helping to write a popular series on the future possibilities called “Man Will Conquer Space Soon!” for Collier’s magazine in 1952-4; later he was technical director and a spokesperson for a highly rated television special on the same topic for Disney in 1955. He also became an American citizen during this time.

At this point the United States was close to launching its first satellite into space, but the government was loath to have it done by the German expatriates. Only after the launch of Sputnik 1 and the answering failure of the United States’ first Vanguard launch on December 6, 1957 was the Army and von Braun able to overcome this reluctance. On January 31, 1958, the first American satellite, Explorer 1, rode into orbit on top of a Jupiter-C rocket—a Redstone derivative produced by the Huntsville team.

Wernher von Braun's NASA portrait, 1960

Wernher von Braun’s NASA portrait, 1960. At age 48 he had just become director of Marshall Space Flight Center after already being the most important person in Germany’s wartime rocketry program. Public domain image.

For the next two-and-a-half years, von Braun’s responsibilities were slowly transferred from the Army to the US’ new civilian space agency NASA. Project Mercury was begun, and used Redstone derivatives for launches. Hunstville began work on a heavy launcher named Saturn, initially for an Army space program but then that was transferred to NASA too. Finally all Army space activities were passed over to NASA on the order of President Eisenhower. On July 1, 1960 the Redstone Arsenal in Huntsville was renamed the Marshall Space Flight Center and put entirely in the hands of the civilian space agency. Von Braun was to be its first director, a position he held until 1970.

Those ten years saw von Braun living his dream, developing the Saturn V and being a key contributor to the Apollo program that landed men on the Moon. His vision of America’s future in space began to diverge from reality post-Apollo 11, however. He was a strong advocate of continuing on to Mars—the Integrated Program Plan’s Mars mission was largely his baby—and after two years in Washington following his transfer from Huntsville he came to realize that it was not going to happen. He resigned from NASA on May 26, 1972.

In 1973 he was diagnosed with kidney cancer, which slowly sapped away his life. Before he was done, however, he helped to found the National Space Institute, one of the precursors the National Space Society, a major space advocacy and education group. He served as its first president before his hospitalization and then death on June 16, 1977 at age 65.

Project Horizon (Part III): Landing Soldiers on the Moon and Keeping Them There

project-horizon-lunar-outpost

A depiction of the construction of the second, larger part of the 12-man Moon base proposed as the end goal for Project Horizon. The initial part of the base, shown covered in lunar material at left, was to be built within two months of the first manned landing. The proposed Lunar Landing Craft can be seen soft-landing in the background. Public domain image from Project Horizon: Volume I. Click for a larger view.

What it was: The culmination of the US Army’s Project Horizon proposal of 1959: sending a direct descent/ascent spaceship to the Moon, then building and populating a twelve-man Moon base shortly thereafter.

Details: Having taken off from Christmas Island Launch Facility in the Pacific aboard a Saturn I to the Minimum Orbital Station (MOS), two Army astronauts would receive further fuel launches and then finally an unloaded Moon craft perched on top of a Saturn with a specialized third stage. The third stage has already burned through its fuel to get the heavy direct descent ship into orbit, so after matching orbits with the MOS the Moon crew and the other men living longer-term on the station refuel it. Then the two men bound for points further afield climb aboard and use the stage to burn for their trans-lunar trip.

As well as the TLI stage, the proposed Horizon lunar craft consisted of two more stages. One soft-landed the spaceship on the Moon, and the other would detach from that one (leaving it behind) and return its astronauts to Earth directly. It in turn would separate from a crew return capsule used for re-entry into the atmosphere and splashdown into the ocean.  Altogether this two-stage vehicle would have been some 16 meters long and weighed 64 tonnes. This is huge: the Apollo CSM/LM combination was 45 tonnes, and even at that carried three men instead of two. Even a Saturn V (which was still in its early development during the times of Project Horizon, and is only roughly spec’ed out as a “Saturn II” here) wouldn’t be able to lift that off of Earth, and so the need for refueling in orbit.

To make up for this, there were actually two different types of landers suggested, one of which could be launched directly from Christmas Island on a Saturn I. To meet that requirement, this second type would have been relatively small: 12 tonnes with a payload to the Moon of 2.5 tonnes, a figure made possible only by the fact that they didn’t have to return to the Earth. One would be sent before the first two astronauts started on their journey to the Moon, carrying construction materials for the base. By the end of 1966, there would be four in all sent on their way.

The first manned lunar landing, of two men, would be in April 1965, guided into the site where the base is to be built. In the 1959 report, the Army even had three possible sites picked out: “the northern part of Sinus Aestuum, near Eratosthenes, in the southern part of Sinus Aestuum near the Sinus Medii, and on the southwest coast of the Mare Imbrium, just north of the Appennies”; the last of these is actually not far from where Apollo 15 landed. The Army astronauts’ job would be to explore the immediate area and make sure that the site was acceptable for building a base. They would live in their landing craft until the construction crew arrived in July 1965 (ninety days or so, as compared to Apollo 11’s 21 hours and 34 minutes) at which point they would head home.

horizon-base-component-cross-sectional-view

A cross-sectional view of the initial two compartment quarters that would house nine to twelve men while they built the larger remainder of the base. Public domain image from Project Horizon, Volume II. Click for a larger view.

This construction crew would consist of nine men, and they would get to work using explosives and tools to dig a deep trench in which they would build their own quarters within fifteen days (or at least no more than thirty) and then cover them with lunar material for protection; a ramp at either end would allow entry and exit from their quarters’ airlock. These accomodations would necessarily be Spartan, but when done the crew would have a small underground base with a cylindrical cross-section (double-walled with vacuum between for insulation), while leftover cargo pods and the like would be buried nearby to hold LOX/nitrogen tanks and waste. The crew would also set up two nuclear reactors to power the base and erect communications equipment so they could stay in permanent contact with Earth.

Now enhanced to twelve men by another landing, the construction crew would get down to building a second, larger cylindrical section at a right angle to the first. When completed the living quarters would be moved here, and it would also contain an office and a sickbay. The original cylinder would be fitted out as two labs, one for biological studies (the proposal charmingly suggests it could be used to check for life on the Moon) and one for physical experiments. The sections of the base wouldn’t link up, but the ramps on one end of each would touch for relatively easy access between them, or as easy as having to put a spacesuit on to walk a few feet can be. A diagram of a remarkably odd-looking spacesuit is included for reference in the report; it has mechanical hands (the astronauts’ real hands were to be cocooned inside the sleeves), and large plates attached to his feet to support him if the lunar dust turned out to be thick.

project-horizon-spacesuit

A diagram of the Horizon spacesuit. Note the odd mechanical hands and “lunar dust walking” plates. Public domain image from Project Horizon: Volume I. Click for a larger view.

By the end of 1968 there would have been ten manned missions in all to the Moon, and eight returns, meaning that the Horizon base would still be inhabited into the indefinite future after that.

What happened to make it fail: The first part of Horizon that we discussed, the launch facility, was perfectly well laid out and not overly different from what ended up being built at Cape Canaveral (though it was bigger and had more pads). The second part is more speculative and is fairly different from what actually happened, but this is mostly because of the change to a Lunar Orbit Rendezvous mission by NASA a couple of years after Horizon was proposed. Still, in retrospect it looks as if they didn’t quite think their station through.

When we get to this third part, though, the speculative nature of what the Army wants to do is front and center. The ways they propose to build and maintain a Moon base are bizarre to modern eyes, mostly because they literally didn’t know the extent of the problems they would face. A close read of the relevant documents reveals a large number of weasel words embedded in every attempt to describe the way things would be done on the Moon if Horizon got the go-ahead. Even Horizon’s summary report admits that the Army wanted another eight months and US$5.4 million dollars just to nail things down before moving on to starting the hardware development for the program.

Having a Moon base was a possible ultimate goal for an American space program, but planning one down to the point of having dates and proposed sites was very premature. Ultimately Project Horizon didn’t fool enough people into thinking that the Army knew what they were doing. Even looking past the previously-discussed antipathy that President Eisenhower had for the military in space, he was known to have used the words “Buck Rogers” more than once to describe the nebulous plans he got from the Army and others, and he was justified in saying so.

What was necessary for it to succeed: The Project Horizon proposal wasn’t actually about how to get to the Moon. It was an attempt by the US Army to establish precedence over the other armed services and, later, the upstart NASA. With Horizon filed away in various Washington bureaucracies, they could point at their long-standing work on manned space travel and plausibly say “Why give money to these newcomers? They’d be starting from scratch and you’d have to pay for that! Give it to us; it’s the wise course to take”.

Then, if anybody bought what they were selling, the way they actually went about it would conform to Horizon only incidentally as they got around to determining how to build this part of their empire. They could always go back and get more money and more time if they needed it, once the US committed to doing it through them.

So Horizon Base was never going to get built. It’s not an appropriate way for housing 12 men on the Moon because when it was designed the proper ways to do it were literally unknown, and would remain unknown for some time. But all it needed to succeed at its actual goal was to fend off Eisenhower long enough for someone in Congress to step up for them and ram through a bill giving the Army control of manned space exploration. It was a decent bet, just one that didn’t pay off.

Project Horizon (Part II): The Minimal Orbital Station and the Orbital Return Vehicle

project-horizon-minimal-orbital-station-01

A “conceptual view” of the Minimal Orbital Station. Based on the mockup of the initial two-module station (linked below), the actual MOS would have looked somewhat different, but one module would be for human habitation and the rest would be gas tanks for fuelling the Moon ship and its injection stage, top. Another tanker is approaching, as it would take four fuellings in total to top up for a journey to the Moon. Image from Project Horizon: Volume I. Click for a larger view.

What it was: Project Horizon was the US Army’s full-blown proposal to put a man on the moon (and, in fact, start up a whole lunar base) by the end of 1966. While much of its focus was on the base itself, it also included extensive discussion of both the Earth-bound and orbital infrastructure they felt was necessary to reach their goal. The Minimal Orbital Station (MOS) was essentially a gas station in LEO for ships headed to the Moon, while the Orbital Return Vehicle was to be used to bring the gas station’s attendants back down to Earth when their tour of duty was done.

Details: In Project Horizon, Part I we discussed the US Army’s proposed launch facility on Christmas Island in the Pacific. Had it gone ahead, American soldiers and civilian experts would have been loaded on Saturn I rockets (or possibly a “Saturn II”, an early design of what would lead to the Saturn V) and launched into orbit.

Where would they go? To the space station, of course. The Project Horizon proposal blandly asserts “It is very likely that a previously constructed completely equipped space platform will be available in 1965 for use as housing facilities and for other support for the refueling operation.” It does then admit that it’s at least possible that 1965’s near-inevitable space station might not be suitable as a base for the Moon mission (by, for example, being in the wrong orbit). On the off chance that this happened, they proposed the Minimum Orbital Station.

project-horizon-minimal-orbital-station-02

A view of the MOS mockup shown in 1960. The bottom module is a Saturn stage converted for habitation. The cone at top is the ORV. Public domain image from NASA. Click for a larger view.

Building the station would start with a launch of a Saturn I with a payload of men in the nosecone. Once in a 640 kilometer equatorial orbit (a height selected so that the station would circle the Earth in an even fraction of a 24-hour period, making it easier to return to the launch point after the mission was over) the nosecone and the upper stage of the rocket would both reach orbit, at which point the two would disengage. The upper stage’s remaining propellant would be blown out, and the aft end of the nose cone would be mated to the top of the stage—or possibly the side if this variety of Saturn I was redesigned to have an airlock there. The astronauts could then enter the empty stage and fit it out as a living and working space; this “wet workshop” concept would appear again in the designs of the Manned Orbiting Laboratory and the original Skylab.

This basic MOS was enough to house the astronauts, but not to support a Moon mission. Project Horizon assumed that the lunar landing would be a direct descent, which implies a considerably heavier load of fuel than was needed for the Lunar Orbit Rendezvous approach that NASA came to favour in the years following the Army proposal. The Saturn I was completely incapable of lifting both a direct-descent landing craft and the necessary fuel at the same time, so the two had to go up separately. Once the MOS had one empty stage housing its crew, another Saturn I would be sent up, only this time it was carrying a full load of fuel instead of men. The fuel-laden tank would attach itself to the side of MOS, and then the process would repeat: the baseline lunar landing mission in the proposal suggested four tanker launches would be needed before enough fuel was in orbit. More missions might be sent up carrying men, depending on how many orbital personnel were deemed necessary for the next step: getting the lunar craft fuelled and underway.

One final Saturn I launch would loft an unfuelled direct descent ship (that’s six launches now, if you’re keeping count), which would rendezvous with the MOS. The station’s crew would get into their spacesuits, spacewalk out into LEO, and transfer the fuel from one to the other. Three crew would then get aboard the lander and head off to the Moon. The remainder would either re-board the station for the next mission (the pace of Project Horizon’s launches, as discussed in Part I, was downright frantic), or head back to Earth.

Those headed back to Earth would use the Orbital Return Vehicle. This is where the word “minimal” really comes into play, as it was essentially just a conical capsule roughly 7 meters long and 4 meters at its base. After detaching from the MOS, a small retrorocket would knock it out of orbit and its crew would ride down to the ground. Astonishingly, the Project Horizon report suggests that it would have carried anywhere from 10 to 16 men at a time—bear in mind that the actual Gemini capsule gave its two astronauts 5.7 x 3.05 meters to play with, and no-one ever described the Gemini as “roomy”. This feat was accomplished by dividing the interior into no less than three decks (four, if you count the equipment compartment in the nose). There would be no room for sitting or standing here, so the astronauts would lie prone for the entire trip. Here’s hoping they didn’t miss their initial de-orbit burn time and have to wait 90 minutes for the next.

project-horizon-orbital-return vehicle

An unfortunately blurry diagram of the ORV from Project Horizon: Volume II. Notice the number of astronauts depicted. Click for a larger view.

Ultimately, the plan was to turn the MOS into a destination in its own right, chaining together more and more Saturn stages converted for habitation and then eventually curving the chain back on itself to form a ring station that could be spun for artificial gravity.

What happened to make it fail: As mentioned in Part I, Project Horizon fell afoul of Eisenhower’s dislike of military activity in space. He’d already tried to pry manned space programs away from the Army, Air Force, and Navy by forming ARPA in February 1958. When that failed (ARPA then famously moving on to other projects like the development of the primitive Internet), he tried again and got them transferred to NASA.

In the particular case of the Horizon space station part of the larger Project Horizon. The Army’s main interest was militarizing the Moon, and the station was just a step toward that was made necessary by an EOR mission profile. When Eisenhower specifically took space exploration missions away from the services and gave them to NASA, the Army Moon program was dead and an Army space station to support it became superfluous.

What was necessary for it to succeed: The station was only going to go ahead if the Army had been given the green light on all of Project Horizon. Something like it might have been built if NASA had decided to use an EOR strategy for the Apollo program, but even that isn’t certain. The USSR considered a similar approach and felt that they didn’t need a station: their Moon ship would have fuelled up directly from the tanker rockets.

When NASA decided to go with a Lunar Orbit Rendezvous lunar landing in July 1962, the chances of seeing something like the MOS dropped from “maybe” to “none”. Space stations would be built in future, from Salyut to Skylab to Mir and the ISS, but none of them would serve the peculiar function of the MOS. Any similarity between them and the Horizon station was a function of position only, and not purpose.

As it was, the MOS and ORV made it to the mockup phase and no further; a diagram of one of these mockups can be found further up this page. Oddly enough it was put on display at the Daily Mail‘s 1960 Ideal Home Show in London, of all places. Somewhere between 150,000 and 200,000 visitors passed through it, and by all accounts it was one of the hits of the show.

Project Horizon (Part I): Christmas Island Launch Facility

Christmas Island Launch Facility

The Christmas Island Launch Facility, proposed by the US Army in 1959 as part of their ambitious Project Horizon. Once built they looked to launch more than 200 missions that would end with a twelve-man lunar base before 1968. Public Domain image taken from Project Horizon, Volume II: Technical Considerations and Plans. Click for a larger view.

What it was: An American spaceport, proposed by the Army in 1959. As part of their Project Horizon to build a base on the Moon by 1968 they decided that the United States should have a launch facility directly on the Equator, and came to the conclusion that Christmas Island in the Pacific Ocean was the best bet.

Details: One of the less-discussed aspects of launch vehicles is exactly where you launch them from. The closer one is to the equator, the more one can get a hand from the rotation of the Earth if you launch to the East. Cape Canaveral is where it is because it’s quite far south in the continental United States: 28.5°N. It also helps that, when launching east from the Cape there’s open ocean for a very long way. If something goes wrong, it’s mostly a problem for fish. By contrast the USSR was handicapped by the location of Baikonur at 46.0°N; the N-1 was actually more powerful than the Saturn V, but would have lifted noticeably less into orbit because of where it was based.

During the scramble following the launch of Sputnik, the US Army explicitly rejected Cape Canaveral (then known as the Atlantic Missile Range) for not being expandable enough. On the grounds that they were going to have to build a new launch facility from nothing anyway, the Army decided to look at sites no more than 2.5° on either side of the equator and decided that the advantages outweighed the disadvantages (most notably that none of them would be in the United States). They specifically looked at four locations:

  • The Jubba River estuary, near Kismayo in southern Somalia. Logistic difficulties were considered too great and this site was quickly eliminated.
  • Manus Island, in the Bismarck Archipelago off the north coast of New Guinea. Like Somalia, distance and logistical difficulties eliminated this site.
  • The north side of the Baía de São Marcos, in Maranhão State, Brazil. The main problem here was considered to be building in a jungle with no land or air connections and poor access from the ocean, as well as the disease climate. It was still considered a strong contender
  • Christmas Island (now Kiritimati) in the Line Islands in the central Pacific Ocean. It had been occupied by the US during WWII and so though it was owned by the British, it was practically a condominium of the two countries. The British had also proved that it worked for large technical projects, as they’d used it to test several hydrogen bombs. It also had the advantages of being relatively easy to reach by air and being intermixed with two smaller nearby islands (Jarvis Island and Palmyra Atoll) that were formal American possessions. Along with Brazil it was considered a prime site, especially if speed of construction was wanted.

Having selected Christmas Island (without eliminating Brazil, but not getting into much more detail there), the Army laid out how it planned to build a launch facility.

Launch complex diagram

Diagram of a launch complex, four of which would be built on Christmas Island. Image also from Project Horizon. Click for larger view.

The basic unit was a launch complex, which consisted of a block house on the western vertex of a triangle and two launch pads, one each on the northern and southern points of same. The pads would be 961 meters apart with a liquid oxygen plant halfway in between them. Four of these launch complexes would be placed on Christmas Island’s eastern shore, separated by a bit under two kilometers from each other, and be supported by a channel dredged into the western approach of the atoll, where a port would be constructed. Two large airstrips would be built, and the whole works would be used to launch no less than 229 of the upcoming Saturn C-1 and proposed Saturn C-2 rockets between August 1964 and December 1967, with as many as 6 in one month. In a burst of realism, the facility was planned for Saturn C-1 and C-2s only because the Saturn C-5 (what became known as the Saturn V) was not going to be ready in time to help. The report does point out that expanding the lunar outpost after 1970 would need the bigger rocket, and so a large stretch of coast stretching to the southeast of the four launch facilities was set aside for expansion. They do sadly note that nuclear boosters would be even more efficient, but couldn’t be accommodated on Christmas Island’s 100 square miles; nearby Jarvis Island would have to be converted for that purpose. Personnel and their families would be housed on the north side of the island, and so the hospital and recreational facilities went there too.

Construction of the spaceport was to begin in January 1960 and was estimated to cost US$426 million. Running it from 1962 (when it would become operational if not complete—that would take until the end of 1965) to 1968 would cost an additional US$883.1 million for a grand total of US$1.309 billion—just over one-fifth of the entire cost of the Army putting a twelve-man base on the Moon by the end of 1968. Given that the real Apollo program cost US$25.4 billion, there probably would have been cost overruns on all of it, not least the Christmas Island Launch Facility.

What happened to make it fail: NASA was formed just after the Project Horizon report was completed (but before it was published) and, on examining the space programs of the Army, Navy, and Air Force, decided that Saturn was the launch system closest to completion. Though there was some resistance the Army’s attitude in general was that it was acceptable for the Army’s Ballistic Missile Agency (which is to say Wernher von Braun and the Huntsville facility that would become Marshall Space Flight Center) to be transferred to NASA, bringing the Saturn with it.

That was the lynchpin of Project Horizon, and the Eisenhower administration was leery of military control of the space program in any case so it was not going to go forward even if NASA had let them keep Saturn.

The Christmas Island facility itself fell to the wayside because NASA was of a different opinion about Cape Canaveral than the Army. They were of the opinion that it was better to have their launch facilities in the United States, and where there was already infrastructure to use. This pointed to Florida over any of the sites the Army had examined. More cynically, if the launch facility was built outside of the US, no congressman would be able to point at the jobs and money the space program was bringing to his state, and NASA needed Congress on their side.

What was necessary for it to succeed: A more ambitious Apollo program might have made the difference. An equatorial launch site is most useful when you want an orbit with low inclination, and that’s most wanted when you’re going to use a LEO space station to build your Moon-bound spacecraft—as Horizon was going to do. The ISS, for example, is nearly useless as a stepping stone to the Moon as its inclination was increased to 51.6° to make it easier for Russia to contribute.

If NASA had been charged with the goal of starting a scientific base on the Moon instead of “landing a man on the moon and returning him safely to the Earth” then the advantages of an equatorial site might have overridden Cape Canaveral’s advantages. This is especially true if they had decided to stay with an Earth Orbit Rendezvous mission profile rather than Lunar Orbit Rendezvous as they used, or if there had been problems with the development of the Saturn V that had forced them to use smaller rockets. In both those situations every extra ton would count and Christmas Island might have looked like what they needed.