Kilopascal, I bought my copy of von Braun's "Das Marsprojekt" (which was printed in 1952), later, while traveling in Germany.
I have never seen the English language translation that was published at the UI in 1953. Although von Braun used a horrible mix of cgs and "metric gravitational" units prior to 1960, he vigorously promoted SI within NASA after 1960. His influence led to the official adoption of SI by most NASA Centers subsequently. However, there has been substantial backsliding since then, particularly at the Johnson Manned Spaceflight Center in Houston and with its contractors. The robotic Mars Curiosity Program at the NASA-Cal-Tech-JPL Center is the most-obvious activity faithful to SI! Although von Braun had substantial control of the Propulsion Designs for the Apollo Manned Lunar Landing Program, designs of other hardware were under the control of the Center in Houston and its contractors, and were ofter not faithful to NASA official policy favoring SI. Sadly, these "deviations" from SI persist to this day in Houston. Incidentally, in von Braun's Introduction to "Das Marsprojekt" he credits contributions by Krafft Ehricke (also an immigrant from Germany to the USA, but not a local member of the von Braun team in Huntsville, Alabama). Five other individuals (all Ph.D.s) are credited with contributing to the numerical calculations. Von Braun's title in the German version is "Prof. Dr. Wernher von Braun" a title not used in the USA. Unfortunately, all of these spaceflight experts, including Herbert Oberth (an immigrant to Huntsville) but not cited as a contributor to the monograph did not appreciate the substantial objections to sets of units based on earth-gravity for application to exploration of our solar system, at least not until SI was formally defined in 1960 by the CGPM. Eugene Mechtly ________________________________ From: Kilopascal [[email protected]] Sent: Sunday, May 12, 2013 8:46 AM To: U.S. Metric Association Subject: [USMA:52761] RE: Numerical Verification of lbf and lbm with 9.80665 in Newton\'s Second Law Eugene, That book you have by von Braun may be very important to the cause of metrication. Opponents of metrication love to harp on the belief that America put men on the moon using USC. But I have heard in a TV interview after von Braun had retired from NASA that he loathed English units and never used them. If he did all his calculations in metric, then it proves that metric was the basis for the success of the moon flights. >From Wikipedia on the book you posses: http://en.wikipedia.org/wiki/The_Mars_Project The book was also translated into English by the University of Illinois press in 1953. I would be curios to know if the German edition you possess is entirely in metric (I'm sure it is mostly cgs units) and if you have seen an English copy and is it metric or USC? Are you aware of any other publications that von Braun may have written, either in German or in English that used measurements and were they metric or USC? Here are other web pages concerning involving von Braun's projects in metric. http://www.astronautix.com/craft/vonn1952.htm partially metric but where the USC is used, the numbers are obviously conversions of rounded metric: http://www.dvice.com/archives/2012/08/wernher-von-bra.php [USMA:52761] RE: Numerical Verification of lbf and lbm with 9.80665 in Newton's Second Law<http://www.mail-archive.com/[email protected]&q=subject:%22%5BUSMA%3A52761%5D+RE%3A+Numerical+Verification+of+lbf+and+lbm+with+9.80665+in+Newton%27s+Second+Law%22> mechtly, eugene a<http://www.mail-archive.com/[email protected]&q=from:%22mechtly%2C+eugene+a%22> Sat, 11 May 2013 21:18:24 -0700<http://www.mail-archive.com/[email protected]&q=date:20130511> John, I don't understand your second paragraph. I never advocated "inventing" or even using any "gravitational" units; not the pound-force (lbf), and certainly not the kilogram or ton (t) defined as 1000 kg, and treated as a unit of force. And as to rocket engineering, I have in hand a copy of Von Braun's "Das Marsprojekt" (published in 1952). On Page 10, he begins a list of numerical parameters (for each of the three propulsion stages. Some excerpts, for the first stage are: Schub (thrust) "12 800 t" Treibstoffgewicht (propellant weight) "4 800 t" Treibstoffverbrauch (rate of propellant use) "55,81 t/sec" Duesenenddruck (pressure at end of nozzle) "0,7 kg/cm^2" As you can see, these are an abuse of units of mass (kg and t), and an atrocious mix of mass and force ? (also t) units in a "gravitational" non-system of units, non-system by 1960 SI Standards of coherence, but that was 1952. Just as the pound can not coherently be both mass and force at the same time in f = m a; neither can the kg and t. To the credit of Von Braun and his immigrant engineers from Germany, they quickly endorsed SI shortly after 1960 when they became aware of the "definition" of SI by the CGPM. Eugene Mechtly
