Wernher von Braun, 1912-1977
ISBN 0-252-06227-2 (alk. Paper)
Read 2002 June 25 – August 29
Reviewed 2002 August 29
When I was in fifth and sixth grades at John Ireland Elementary School of Pleasant Grove, part of the Dallas Independent School District, I had a good history and social science teacher, Mrs. Tandy. She would go on adventures every summer and, if we were good, would show us her slides at the end of the year. Her family was then about the age that mine is now. The two years I had her, she went to climb Mt. Whitney (in far off California!) and Alaska. My own desire to go to Alaska was spawned at that time.
Mrs. Tandy had a nice bookshelf library in her room. I remember two of the titles, Codes and Ciphers, which ultimately had to be removed for the rest of the year because several of us used it to set up rival gangs and The Mars Project which I did not recognize by title again until recently.
The Mars Project was the genesis of my interest in interplanetary navigation and as such was a big part of the motivation for me to learn trigonometry and higher math and to develop computer programming skills. It is not too much of a stretch to claim that my career at NASA – JPL today was seeded by exposure to some of the material in this book.
A couple of years ago, I decided to work on a small dream to see if I could recover the information about this book and perhaps a copy of it. This was no more difficult than a simple amazon.com search on the author and soon a copy, with a modern Foreword by Thomas O. Paine, was in my reading stack. Trained to obsessively save dessert for last, I wouldn’t start into it until a few days after Field Day 2002 when I had broken my arm returning from our annual radio outing. Laid up and in need of some cheer, I started into this text. This was a good time too since I am about to transfer to JPL’s navigation section (312) and this material is a good warm up for the software I’ll be dealing with there. I hope.
Von Braun started the space age with his successful V-2 flights in WW II. It is claimed that he got in trouble with the Nazi establishment for caring more about interplanetary space travel than pummeling the enemy. In 1953, shortly after the war when he and his team had been relocated to America, he published this book that lays out a plan and solves all of the major engineering problems of sending a first expedition to our neighboring planet, Mars. His Gauss-like genius (and presumably that of his team) is evident throughout the text as it addresses one major science or engineering problem after another. Some of his solutions are out of date given new technologies and some are overly conservative but none are impossible. Some are estimates since the task of numerical integration in 1953 was done laboriously by hand, but his estimation skills are acute and his ability to find a solution to problems of any type is incomparable.
This is even more remarkable in that, in 1953, the majority of the general public and their leadership believed that all space travel was and always would be science fiction. “That Buck Rogers stuff” as one Congressman put it. JPL was named “Jet Propulsion Laboratory”, not “Rocket Propulsion Laboratory” for this exact reason. (At the time, JPL, an Army research institution, was only well known within the military world.)
Von Braun was in the right place at the right time and was able to synthesize the work of generations into the birth of the space age. It is unfortunate that his dream is now further from reality than he would have thought fifty years ago, but at least he lived to see Viking land on Mars and scoop up some red dirt.
The mission is to assemble ten trans-Martian craft in earth orbit, man them with seventy men and go off to Mars. Once there, some of the men would land in three “landing boats”, two of which (after re-assembly without descent fuel tanks and wings) would return to Mars orbit. When the alignment was right, all of the men and their stuff from Mars would return to earth orbit and thence to the terra firma.
He solved, at least in principle, every conceivable major problem, never sweeping anything under the rug, never leaving anything to show-stopping objection by politicians or scientists. One quasi-technical example illustrates this tenacity. The landing boats were to be winged craft that would descend to the surface and land on wheels. The calculations are immaculate; the wing area per landed mass is computed for the presumed pressure and gravity then known for the surface of Mars. But there was a problem. Not much was known about the surface at the scales necessary for landing landing boats and trying to land on, or even find, a smooth surface was going to be problematic. He equips the expedition with telescopes to survey the surface from orbit, but this wouldn’t reveal enough detail to reduce the risk to acceptable levels.
The solution? Land one of the boats on skids at a smooth spot on one of the polar (presumed) ice caps. This is much less risky (but not totally risk-free). Then, unload tractors and other equipment, drive down to the equator (2000ish miles!) and when there grade and build a suitable runway for the other two landing boats!
Since there was no space infrastructure in 1953 at all, von Braun must begin from the very beginning. In Section A, he develops the “Three-Stage Ferry Vessels.” They burn hydrazine and nitric acid (well developed technology at the time) to ascend into orbit and return by winged flight. There is no hand waving in any of the development. He draws on his rocket experience to design the entire craft and to numerically integrate, considering all relevant forces, its ascent and descent. Every calculation is timed to the second; every operation is carried out to two or three digit precision, characteristic of the slide-rule age, or to greater precision when necessary. He deals with everything from burning temperature and constituencies (Section E) to nozzle areas, exit pressures, wing lift, orbital mechanics, mechanical loads and stage recovery and reuse.
He doesn’t deal much with “human factors,” presumably because of the post WW II mindset at the time: Expendable men do their duty without complaining.
This 28 pages of development is just to get cargo (mostly fuel), equipment and men into the orbit from which the expedition will be assembled and launched. Section B deals with the Mars ships themselves in similar detail and includes the astrodynamic development of the entire flight (with scale diagrams!) and rocket calculations, which so fascinated me in the sixth grade.
In equally intense detail, Section C deals with the “Landing Boats” themselves. From a circular orbit, the craft burns into a descent ellipse (same as at earth). At its perigee [sic, peri-are or peri-apse, but this is the only sic that I found in this translation from German] the boat wings provide “negative lift” until the craft has slowed to the point where zero or positive lift is needed. Once subsonic, the landing is piloted as with any glider. Extended by modern automated computation, this is roughly how the space shuttle operates today.
A mass budget for everything to be carried on the trip is developed along with a “staging” plan. It is rather quaint that, error free (as far as I can tell) everything in the book is in centimeter-gram-seconds presentation as opposed to meter-kilogram-seconds, which most engineers in the field today seem to prefer. An altitude will be given as 80 X 105 cm, by which they mean 80 km. Masses are given as 0.8 X 106 gm, by which they mean 800 kg or 0.8 metric tons.
Nearly as an afterthought, but a well-thought-out one, Section D deals with the number of ferry flights needed to put the expedition mass (mostly fuel) into earth orbit. The cost of these operations and the fuel itself, dwarfing the rest of the mission, is about a half billion 1953 dollars.
Finally, Section F deals with interplanetary radio communications. Using my own link budget spreadsheet, I checked his calculations today and found them sound within a few dB. He has carefully surveyed the radio technology of the time and worries about slightly different issues than an experienced radio engineer or technician would (for example, he notes several times that noise is doubled unless image-rejection in the receiver is employed, something that was then and is now trivial and standard in receivers and he also worries more about maximum range than delivered signal to noise ratio at a given range) but his physics is sound and he has an obvious grasp of both the fundamentals and the essentials of the problem.
After reading Section E, more detail on engine performance, I found myself back in Halliday and Resnick (my Physics text) relearning about entropy and searching for a definition of enthalpy.
Everything I was ever required to take in engineering school and a bunch more has been mastered and correctly applied by von Braun and his team and I must say, this has been a more enjoyable and faster read than it was back in, what was it, must have been about 1968 when I flipped through the pictures and tried to make sense of hyperbolic trigonometry in Mrs. Tandy’s equivalent of Sustained Silent Reading.
In sending men to the moon, von Braun superceded many of the technologies he discussed in this book but never by falsifying, only by improvement. Rocket fuels and radio science, not to mention computing equipment, advanced greatly in the decade and a half that he led development of the great moon ships. When I discussed the book with friends at lunch today, some of their questions showed a much more modern focus. “Which Mars opportunity did he specify? (None.) Did he realize that, due to ellipticity of Mars’ orbit, some opportunities are difficult or impossible?” And, had we discussed further, they might have brought up the question of why not recycle crew water better (leading to modern hydroponics) or why carry all that fuel all the way out and back when you could manufacture some there and use aerobraking? Valid questions all, but they just reflect our more modern focus on refinements to the basic problems. Refinements aside, nothing that von Braun proposes was impractical. He had solved all the major problems in his own mind and all of his solutions were workable, in 1953 technology.
In his introduction, von Braun makes the distinction between science fiction of his day in which loner geniuses did things like travel to other planets, and the reality of this sort of undertaking that is so major that it requires government or at least major institutional support. Half a billion 1953 dollars was no trivial matter then or now. This political savvy and his willingness to do nearly anything for anybody with a deep pocket to the advancement of the goal of space exploration (things like going to the moon for military reasons such as weapons basing) are perhaps his most under-appreciated genius.
This was certainly a remarkable man who lived a remarkable life in remarkable times. His inspiration of people like me is not the least of his contribution. I can only wish to see his dream of a human expedition to another planet come true.