Wernher von Braun, seen above with John Glenn (left), was forced to select lunar orbit rendezvous for fiscal as much as technical reasons. (credit: NASA)
by Tom Hill
Monday, November 9, 2004
As part of the 35th anniversary celebration of the Apollo 11 landing on the moon, NASA reprinted a small book titled Apollo: A Retrospective. It is a collection of documents relating to discussions and decisions made before and during the Apollo program, and serves as a reference to those who want more information about the thought processes of decision makers that led up to that day in July 1969. One document in particular, Wernher von Braun’s concluding remarks from an all-day meeting on June 7th, 1962, sheds light on an early, critical decision in the Apollo program: which method should America use to land humans on the Moon? The author captured the document in electronic format (the book version is typewritten with sections underlined by hand, and an Internet search did not reveal a copy on the Web. If there is one, don’t tell me), and it can be found here.
Imagine the scene: A smoke-filled room at Marshall Space Flight Center, with representatives of every specialty at Marshall present. Dr. Joseph Shea, the Deputy Director (Systems) of the Office of Manned Space Flight, has been hearing presentations for the last six hours. The American effort to reach the Moon has been scattered, with various centers pushing their own method of accomplishing President Kennedy’s goal, and the diffuse effort is hampering real progress towards that goal. Throughout the day, executives from Marshall present their ideas as to why Earth Orbit Rendezvous is the way to go to the Moon, despite a rising tide of opinion throughout NASA that there may be better, faster ways.
|Wernher von Braun was a rocket builder. In many ways, he was the ultimate rocket builder.|
Then, the time comes for Dr. von Braun to speak. Wernher von Braun, the German ex-patriot who ran the Nazi ballistic missile effort starting at 25 years of age. The man who, while always dreaming of building rockets and spacecraft for journeys to the Moon, put those dreams on hold while at the same time allowing them to come true as he worked to build the first large rocket, knowing that it would be used to rain terror on the people of London. After World War 2, seeing that exploration was not yet a priority, he stayed with military programs for the United States, building missiles to carry nuclear warheads for the next envisioned war in Europe. Once the US consolidated its peacetime space efforts under one agency, his goal came closer to reality.
Wernher von Braun was a rocket builder. In many ways, he was the ultimate rocket builder. When asked his opinion of how America should tackle the goal of landing a man on the Moon by the end of the decade, his plans involved building many rockets to assemble a craft in Earth orbit (a plan known as Earth Orbit Rendezvous, EOR) or to build a massive rocket and blast directly to the surface of the moon (Direct Ascent). EOR had always been Dr. von Braun’s favorite, because he saw it as the most flexible method, one that would validate techniques for use in travel to the Moon and beyond. While the retrospective does not have documents describing the rest of the meeting leading up to this moment, other references here and here describe the June 7 meeting as the follow-up to center negotiations on one hand, and a heated discussion on the other.
Dr. von Braun prepared his speech throughout the daylong meeting. Reading from handwritten notes he stunned his colleagues by some accounts, but by all accounts he changed the course of America’s space effort.
After a meeting reportedly in “pro-EOR” mode, the director of the Marshall Space Flight Center listed the modes in preference order to the audience:
- Lunar Orbit Rendezvous, or LOR (with a recommendation to proceed with development of an uncrewed lunar logistics vehicle immediately)
- Earth Orbit Rendezvous, Tanking Mode
- Saturn 5 Direct Mode with a minimum-size Command Module and High Energy Return
- Nova or Saturn 8 Direct Mode.
Next, Dr. von Braun gave a little insight into why his opinion changed. In an underlined passage within the text, he said “it is absolutely mandatory that we arrive at a definite mode decision within the next few weeks, preferably by the first of July, 1962”. He went on to give both hardware and fiscal reasons why a final mode decision was critical. The hardware example described the S-IVB rocket stage, designed to serve as the second stage of the Saturn 1B, as well as the third stage of the Saturn 5. Because of its dual use, the stage was required earlier, so any delay in decision-making, putting production of the S-IVB in jeopardy, would be doubly felt in operations. The fiscal example called into question how planning and budgeting could go on for more than one year without a mode decision.
The reasons for choosing LOR were spelled out in list fashion, with considerably more detail provided for each item than is shown here.
- Highest confidence of success of any method in this decade
- Adequate performance margin
- Splitting of the hyperbolic return vehicle (command module) and lunar landing vehicle (lunar module), simplifying development of both
- Growth potential of the plan, assuming the logistics vehicle is adopted
- Growth potential into a Saturn 5 direct option, using high-energy propellants for landing and taking off from the Moon
- Even better potential for Saturn 5 direct mode after adoption of a nuclear third stage
- Choice of other booster option (Saturn 8) would upset the development of the nuclear third stage
- Studies showed that precision landing on the Moon shouldn’t be difficult (for use with either the logistics vehicle or the lunar landing vehicle)
- Clean management interfaces through separate development of logistics vehicle, landing vehicle and return vehicle.
- No existing contracts need to be cancelled.
- While Marshall was skeptical about the safety of a rendezvous in lunar orbit at first, Dr. von Braun felt that the previously-mentioned advantages outweighed that risk.
|EOR is more complex and costlier, and it also requires two successful launches of the Saturn 5 for a successful landing.|
Next, he went into a small discussion of how the LOR plan, since it wasn’t developed at Marshall or Johnson (then simply named the Manned Spaceflight Center), didn’t suffer from the “not invented here” problem, so the fact that both groups now supported it was a good indication of the strength of the plan.
Why not EOR?
Dr. von Braun took a moment to reiterate that he and his center felt that EOR was a viable method for reaching the Moon, especially in the form of the tanking mode, where a lunar craft was launched separately from another craft carrying its propellant. The two ships would dock in orbit, and propellants would transfer into the lunar craft. He brings up three issues with the method:
- EOR is more complex and costlier, and it also requires two successful launches of the Saturn 5 for a successful landing.
- The technical interface problems between Marshall and the Manned Spaceflight Center would be increased.
- The Apollo module, as currently designed, would require the lunar landing to take place with the astronauts in a supine (lying-down) position.
Why not Saturn 5 Direct?
Once again, the speaker took a moment to state that he felt this method would eventually become feasible, once the problems of hyperbolic reentry and high-energy propellant use in return stages were faced. Four problems pushed this option to number 3, however:
- Marginal weight allowances requiring high-energy return propulsion and longer development times.
- Non-realism of being able to build a lunar craft light enough for the job by the end of the decade (basically a repeat of the first argument)
- One requirement of the return propulsion system is an escape from the booster later in its flight, and it was thought that the simplicity of storable propellants (over cryogenics) would be a plus.
- Previous experience with the Centaur upper stage where “performance claims for (the) launch vehicle and demands for payload weights were drawn too closely.” Here, Dr. von Braun was basically saying, “let’s not promise more than we can deliver like we did before”
Why not Saturn 8 (Nova)?
Some of his strongest arguments were saved for the discussion of the Saturn 8 or Nova booster launching a very large lunar landing vehicle directly to the moon. As with all his other arguments, Marshall’s director went out of his way to state that a booster larger than the Saturn V would be required, and that his team could deliver it, but that it would be much better to develop it at a more relaxed pace. The primary arguments dealt with facilities’ ability to handle such a large booster, and the time and money requirements to build such a booster:
- The Apollo craft, as described earlier, had its astronauts lying down. This was not a good position to land in.
- Using stage 2 of the Saturn 5 for the Nova would create a vehicle without the necessary lift weight to land a command module on the moon.
- The Michoud plant (used to build the 1st stage of the Saturn 5, and now used to produce space shuttle external tanks) is 40 feet high, and the Nova vehicle would be 50 feet in diameter. Also, the soil situation there makes load-bearing foundations very difficult to build.
- The test stand for the Saturn 5, as being built at the time, could not be altered for a Nova configuration. The as-yet-to-be-named Stennis Space Center was described as “a cow pasture that NASA doesn’t even own yet” with no facilities and no realistic ability to build a large test stand in the necessary period of time.
- A second stage for Nova, requiring eight to nine J-2 engines or 2 M-1 engines, again 50 feet in diameter, might be able to be built at the Downey/Seal Beach facility, but the testing site set for the Saturn 5 second stage could not support the Nova second stage.
- Another reminder of the impact that canceling Saturn 5 would have on the nuclear third stage for such a booster.
- A change in approach would cause a collapse of the current contractor structure, describing teams of engineers deployed around the country away from their home plants. Here, Dr. von Braun cites one interesting anecdote describing uncertainty of where Saturn 5 second stages being produced causing a six-month delay, and caps this point with an estimate made by “key Marshall executives” that a total booster switch would cause a delay of between 14 and 24 months.
- A decision change would require engine teams to remain on NASA payrolls for the additional time.
- Marshall Space Flight Center’s own efforts on the Saturn 5 would have to be abandoned as a total loss, estimated in excess of $100 million.
- This is an overarching statement saying that the sheer size of the unknowns means that any estimates are likely to be very low.
- Lastly, Dr. von Braun reiterates that he and his team think the Nova option is the worst of the options to consider.
|One striking fact is how many of the arguments made are fiscal and contractual compared to technical.|
In a short summary, he reiterates his recommendations, presented here in their entirety:
- The Lunar Orbit Rendezvous Mode be adopted.
- A development of an unmanned, fully automatic, one-way Saturn 5 Logistics Vehicle be undertaken in support of the lunar expedition
- The Saturn 1 program as established today be retained and that, in accordance with progress made in S-IVB development, the Saturn 1 gradually be replaced by the Saturn 1B.
- A Saturn 1B program be officially established and approved with adequate funding.
- The development of high energy propulsion systems be initiated as a backup for the Service Module and possibly the Lunar Excursion Module.
- Supplements to present development contracts to Rocketdyne on the F-1 and J-2 engines to be let to increase thrust and/or specific impulse.
One striking fact is how many of the arguments made are fiscal and contractual compared to technical. Dr. von Braun was likely accepting the fact that resources, while not sparse, were not infinite either, and adjusting planned modes and activities accordingly.
By all accounts, Dr. von Braun’s acceptance of Lunar Orbit Rendezvous closed the mode discussion and allowed work to begin in earnest on the task itself.
Throughout the article, the author referred to actual flying hardware (Saturn 1B and Saturn 5) by their typical designations, and then maintained those designations with vehicles that did not fly (Saturn 8, also known as Nova). While some may not like the designation, it was used to minimize additional required descriptions. In the original text, Dr. von Braun referred to the Saturn C-1, C-1B, C-5, and C-8.