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von Braun became the head of a rocket research program at Kummersdorf—the thesis for his 1934 degree was classified and unpublished until 1960—and civilian testing of rockets was banned.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.

Sidebar: Sonnengewehr, the “Sun Gun”

sonnengewehr

Illustration of the Sonnengewehr “Sun Gun” as published by Life magazine on July 23, 1945. Image copyright status unknown, possibly owned by Time, Inc.. Click for a larger view.

At the end of World War II the United States famously snapped up as many German scientists as it could with Operation Paperclip. While they were from a wide variety of disciplines, the ones most remembered today were the rocket designers and, as London and Amsterdam were still sporting spectacular V-2 craters, public interest in them was high at the time.

By the end of 1945 most of them would relocate to the United States, but in the period immediately following the end of fighting in Europe they were still in Western Europe and being interrogated by US intelligence personnel keen to learn about a line of weapons development in which the Nazis had jumped far ahead of the rest of the world.

It was in this setting that a few articles were published in major US newspapers and magazines (Time, Life, the New York Times and others) during July 1945 outlining one bit of information the US was getting from the captured scientists. All the articles were based on a single news conference held in Paris at the end of the previous month. While the conference apparently covered a wide variety of weapons that had been under development when the war ended, the articles picked up on one spectacular one and focused on it: the Sonnengewehr, quickly dubbed the “Sun Gun”.

The Sun Gun idea had been brought to the attention of the US by a group of scientists and engineers at Hillersleben, Germany (now part of the town of Westheide in Saxony-Anhalt, which was once part of East Germany). Though mostly unassociated with Wernher von Braun’s more-famous group they too had experience with rocketry, having worked on rocket-assisted artillery weapons and tank shells during the war.

As reported, in an unfortunately garbled way that makes it clear the reporters didn’t understand the underlying physics, the Sun Gun would have been a disc-shaped space station in a 3100-mile (5000-kilometer) orbit; some sources say 5100 miles, but this seems unlikely as German engineers would have expressed themselves in kilometers and that would be an unwieldy 8208 of them. Either way, neither would have been geosynchronous, an oddity pointed out even by some of the reporters in 1945.

Regardless, the station would have been coated with metallic sodium—chemically reactive and so easy to tarnish in the atmosphere, but which would stay clean in vacuum—polished into a mirror. The mirror would be pointed at a receiver off the coast of Europe and used to boil ocean water for power, but when the need arose it could be used on military targets—it had a projected ability to heat anything on the surface to 200 Celsius. Other numbers are scant and not clearly from the scientists themselves, but one that raises an eyebrow is that the mirror would have had an area of 5000 square miles (a round number in non-metric units, which is suspicious, and matches a diameter of 128.4 kilometers). Other sources suggest a much more realistic 9 square kilometers.

Life magazine was the most expansive on the topic, and published several drawings on the construction and operation of the station. Unfortunately their accompanying text and some of the details in the illustrations themselves suggest that the article’s authors were engaging in speculation on both topics. For example, they have the station being built of pre-made sections—cubes, oddly enough, which makes it a bit hard to produce a disk—when there’s reason to believe that it would have been made on a skeleton of long cables reeled out from a central station. Also contrary to this, Life has the inhabitable area around the edge of the disk, though this would have turned the Sonnengewehr into a “filled-in” version of the torus-shaped stations so favoured by von Braun during his lifetime

Immediate post-war reports to the contrary, it’s very unlikely that there was any sort of official work done on the Sonnengewehr beyond some tentative memos and discussions. If nothing else, consider the sheer mass of material that would have to be lifted into high orbit to build it. One source suggests one million tonnes of sodium metal, a figure considerably larger than the mass of everything ever lifted into orbit by all the world’s nations between 1957 and the present day.

Instead it seems to have been at best something batted around as a possible ultimate destination—even the scientists involved were thinking along the lines of the year 2000—in the culture of grandiosity that Nazism embraced and that also produced things like the Landkreuzer P. 1500 and Hitler’s architectural enabler Albert Speer. Even the mainstream rocketry program at Peenemünde was looking to run before it learned to walk, and this was just an extreme example of this attitude in the embryonic German space program. It may not have even been as tentative as that: at worst, it was merely discussions of an idea floated by the father of German rocketry, Hermann Oberth, in 1929.

Any gloss of reality the Sonnengewehr got likely came once the war was over and the Hillersleben group were under the control of the American military. In that precarious situation they would have been searching for anything to impress their captors of their usefulness and the Sun Gun inflated from cafeteria-table discussions to the preliminaries of a project. It did get them a little attention at the time, to be sure, but its sheer fantasticalness made it quickly drop back out of the limelight.

Sidebar: Von Braun’s Moonship

von-brauns-moonship-header

Detail from the diagram of Wernher von Braun’s conjectural Moon ship published in the Collier’s Magazine issue of October 18, 1952. Click for a larger, complete view of the whole diagram.

Wernher von Braun, Willy Ley, Fred Whipple, and others famously jump-started American interest in space with their series Man Will Conquer Space Soon!, published over eight different issues of Collier’s Magazine between March 1952 and April 1954. This is from the second one, October 18, 1952’s “Man on the Moon”.

Though unsigned, it is likely the work of magazine artist Rolf Klep—Chesley Bonestell is remembered for the paintings he did for the series, but Klep did most of the more diagrammatic images. It depicts two variants of the same basic ship, one a passenger ship and one a cargo ship. Both would have been built in orbit after a space infrastructure of orbital rockets and a space station had been put in place.

Two of the “passenger” version would have carried a total of 50 scientists and technicians between them, while the “cargo” version would have been on a one-way trip to the Moon carrying the supplies the 50 men (and the title of the series leaves little doubt that it would have been only men) would need for a six-week stay on Earth’s nearest neighbour. Their goal would have been the Sinus Roris near the Moon’s North Pole—and later used by Arthur C. Clarke as the setting of his A Fall of Moondust, in all likelihood because of its mention in this article.

The ships are 160 feet tall, which is to say just about the same height as the entire Space Shuttle stack. They were to have burned nitric acid and hydrazine, which was quite prescient on the part of Dr. von Braun as that’s one of the three most popular rocket fuel combinations (along with LOX/LH2 and LOX/Kerosene) down to the modern day. Less prescient is its mercury-vapour powered turbine, which uses the parabolically concentrated light from the Sun to evaporate liquid mercury and generate 35 kilowatts. They were the hot new thing in 1952, but fell out of favour not long after. So far as I know there’s never been one in space.

Naturally on arriving at the Moon, the astronauts would set about building a Moon base using the cargo they brought as well as the one ship that brought it. From there von Braun confidently predicted that it would not be too much longer before the first manned trip to Mars ensued.

While this ship was never a serious proposal like all the other posts to this blog have been, it’s historically significant. Though published in 1952 it originally dates back to a non-fiction book written by von Braun in 1948, Das Marsprojekt. Bearing in mind that this is only three years after he was forced to leave Germany, it likely reflects his long-term goals for the German V-rocket program. As is well-known, he was highly interested in diverting it from focusing solely on weaponry into space exploration—indeed the winged rocket ships used to get von Braun shipwrights into orbit to builld these Moon ships look like a hybrid of the most speculative and advanced idea Peenemünde floated, the A12 and the winged A6. Who knows? In a different, more peaceful world we may have seen Germany sending something like this to the Moon in 1980, dedicated to the memory of the recently deceased father of the German space program.

MTFF/Columbus: Europe’s Space Station

Columbus docked to Hermes

The initial module of Columbus, the MTFF, docked with the proposed mini-shuttle Hermes. At this point the space station would be unpressurized and unmanned except when astronauts were retrieving its experiments, but the APM (which eventually evolved into the ISS module Columbus) would be attached later to add a small living space. Image source unknown, believed to be the ESA; if you know the source of this picture, please contact the author. Click for a larger view.

What it was: A European effort to turn their contribution to the American space station Freedom into an independent space station of their own, hoisted into orbit by ESA rockets and serviced by an ESA shuttle.

Details: The European Space Agency signed on to Ronald Reagan’s suggested internationalization of the Freedom station right from the moment he made the offer in 1984. They had been developing the pressurized Spacelab module for use in the Space Shuttle’s cargo bay since the early 1970s, and now pushed for the new space station to build on components derived from their work. As part of this they started the Columbus project, which among other goals would have them make one such component—the Attached Pressurized Module (APM)—on their own for inclusion in the completed Freedom.

Another part of the project was to be semi-autonomous right from the initial planning, though. The Man-Tended Free Flying Platform (MTFF) was to have been a two-segment unmanned Spacelab module which would detach from Freedom and move to a nearby orbit. This would allow for sensitive, teleoperated microgravity experiments away from the noisy, manned Freedom and, a round of experiments completed, it would return for maintenance at the main station.

During the mid- to late-1980s, though, Freedom had a rough ride in the US Congress and the ESA started developing contingency plans for what to do with Columbus if the American station was cancelled. Couple this with massive increases in prices to use the Space Shuttle—then the Challenger disaster temporarily making its cargo bay unavailable at any price—and from 1989-92 these plans culminated in an entirely autonomous station that the Europeans would try if remaining part of the now downsized and re-named Alpha (AKA “Space Station Fred”) became too unpalatable.

The initial station would have been the unmanned MTFF, but now the experiments would have been retrieved by the ESA’s Hermes shuttle, which along with the Ariane-5 rocket had been approved as an unrelated project in 1987. In 1991 the three were melded into one big project.

altenative-expansions-of-columbus

Two suggested expansions of Columbus beyond its initial two modules. Image source unknown, believed to be the ESA. Click for a larger view.

The MTFF, Hermes, and the French launcher were to be joined by a fourth piece of the puzzle: the APM, now divorced from Alpha. Once the unmanned MTFF-based station was proven, the APM would be completed and launched on an Ariane-5 (or possibly in an US Shuttle’s cargo bay, if renting it turned out to be cheaper and more convenient). It would then dock with the MTFF to produce an entirely European manned facility, Columbus. The long-term, if somewhat nebulous, plan was then to add more and more modules as time went by.

Statistics on the Columbus are surprisingly hard to come by. Based on the actual ISS module that was derived from it, though, we can presume that its two working modules would totaled about 14 meters in length, with the power module and station-keeping ion engine at the MTFF end adding about another 5 meters.  Its total mass would have been in the range of 25 to 30 tonnes, which would have made it a bit bigger than the Soviet Salyut stations, but less than 25% the size of Mir and about 6% the size the ISS. Accordingly it probably would have had the same sort of missions as the Salyuts, involving two or three astronauts for a few days up to several months.

The budget for the station was calculated at US$5.3 billion, including operations for five years.

What happened to make it fail: Two trends pulled the APM back to where it started: attached to the ISS.

First, the United States got its act together. The Space Station passed through another session budget shrinkage and soul-searching under Bill Clinton in 1993, but finally stabilized into what is recognizably the ISS that got built. As uncertainty over the American contribution faded away, and the Russians signed on to ISS rather than build Mir-2, it became clear that it would be safe to co-operate rather than go it alone—though the ESA did keep contingency plans for Columbus in place as late as 2001.

The ESA itself was also running into budget difficulties. The collapse of the Soviet Union did open up another possibility, as there was talk for a while of perhaps attaching the APM to Mir-2, but a related event back down on Earth proved to be more important. The costs of German reunification made Germany scale back its contributions to the ESA by nearly a fifth, which brought a budget crunch to the agency as a whole. With Hermes already over-budget, it was cancelled entirely, as was the MTFF, and the APM’s costs were scaled down by committing to the American station project after all—the name Columbus was co-opted for it alone rather than the entire project, and it became the Columbus science laboratory module that was attached to the ISS in February 2008. Only the Ariane-5 launcher managed to emerge from the crisis unscathed. As it turned out, the late 80s and early 90s were something of a Golden Age for European manned space exploration. Not only has the over all ESA budget been declining slowly since then, the percentage of it devoted to manned space travel has dropped precipitously. The ESA’s focus has shifted to more commercial uses of space such as telecommunications satellites and the Galileo satnav system.

What was necessary for it to succeed: The main necessity is the stillbirth of the ISS, which isn’t too hard to engineer. The Challenger disaster had called it into question, repeated budget cuts hit it in 1989 and 1990, and in June 1993 a bill to cancel its immediate ancestor Alpha had failed by only one vote in the House of Representatives.

Given that event, the budgets floated for MTFF even after the Germans had run into reunification money problems had it flying by 1999 so long as the ESA doesn’t make the real world turn into budgeting more for commercial applications that it did. This gives us the first component of the station.

If MTFF did get off the ground, the next component of the program was still very likely to have changed. Hermes was not going to fly on a reasonable budget in a reasonable timeframe, which kicks out one leg of the station’s autonomy. However if the MTFF had gone ahead it’s likely that the ESA could service it with an (relatively) quick upgrade to the simpler Automated Transfer Vehicle they had begun developing in the mid-1990s. It flies in the real world on unmanned missions to the ISS, and its manufacturer EADS Astrium has been floating a proposal to turn it into a manned capsule since 2008. British Aerospace had actually suggested manning and supplying the station using a capsule of their own design in the mid-80s, only to have it squelched in favour of the French mini-shuttle.

The combination of an MTFF serviced by a manned ATV would likely have worked, leading to the attachment of the APM and a completed, manned ESA station Columbus sometime in the middle to late 2000s.

Sänger-Bredt Silbervogel: The Nazi Space Plane

Sänger-Bredt Silbervogel spaceplane

Image of the Silbervogel taken from the 1952 translated edition of Eugen Sänger and Irene Bredt’s 1944 A Rocket Drive for Long Range Bombers. An inset of the entire craft at launch is at upper left. Public domain image.

What it was: A boost-glide intercontinental spaceplane. It would reach space, if not orbit due to lack of speed, but manage to get all the way around Earth once by repeatedly skipping off the upper atmosphere to gain more altitude. During World War II it was positioned as an extreme long-distance bomber (capable of, for example, carrying a 3600-kilogram bomb to New York City from a launch site in Germany), but it also would have made an interesting surveillance vehicle—utterly immune to being shot down and the next best thing to a spy satellite.

Details: Ever since space travel became even marginally possible doing so has been torn between two approaches. One is to stick a one-shot capsule of some sort on top of a rocket and then let it return ballistically after the mission is over; the other is to build a spaceplane which either gets to space under its own power or is launched on a rocket, and then is capable of gliding back to Earth. Theoretically planes are cheaper because of their reusability while capsules are easier to build. In practice, though, no-one’s ever been able to develop a spaceplane that could undercut a capsule because the added complexity of the plane adds back on to the saved costs. As a result, with the exception of the Americans’ long excursion into the Space Shuttle program, all spacecraft that were successful for more than one or two flights have been capsules.

Both approaches date back to the first time and place that had any chance at all of putting something into space, which is to say Germany in the 1940s. Wernher von Braun’s ballistic rocket approach has been the one followed by the USSR and China, while the United States used it into the 1970s and is returning to it now with the upcoming Orion MPCV.

Less well-known is Eugen Sänger and Irene Bredt’s Silbervogel (“Silverbird”) which was the first serious attempt at building a spaceplane, work on which contributed to the success of several other later spaceplanes that flew, and which itself was refactored and raised as a possibility as late as the 1980s.

Sänger began work on the concept in his original engineering thesis for the Vienna Polytechnic Institute. When it was rejected as too radical in 1931, he submitted a second, more acceptable thesis on a different subject, but arranged for the original to be published by a different route in 1933. At the same time he perfected a regeneratively-cooled rocket engine (which is to say that it used the expansion of the rocket fuel’s gases to carry away heat and keep the engine from overheating). His research couldn’t secure funding in his native Austria, but an article in the journal Flug (“Flight”) in 1935 attracted the attention of the Luftwaffe in Germany. He was invited to set up a research facility there, which he did in 1936 and then the real work on Silbervogel began.

By 1942 he had advanced the rocket engine which would power the craft, worked on the rocket sled and track which would be used for its initial boost launch, and worked out the aerodynamics of a plane that would be both subsonic and supersonic as well as flying in the near-vacuum of space.

The Silbervogel would have been a two-part ship. The spacecraft itself was to have been a 10-ton, streamlined plane with two stubby wings and two tailfins, both raked upwards at about ten degrees. Four fuel tanks took up most of the fuselage and contained liquid oxygen and kerosene which would burn in a single rocket engine over the course of 168 seconds. On the ground the plane would be mated with a rocket sled which would give it an initial boost from behind along a rail track for a mere ten seconds but with nearly five times the thrust as the spaceplane’s engine.

Once the Silbervogel completed both burns it would be moving at a minimum of Mach 13 (15,926 km/h) and as much as Mach 20 depending on its mission and payload, and reach a maximum altitude of anywhere from 31 to 121.5 kilometers, the latter value being well into space. Just to put this in perspective, the air speed record in 1944 was 1130 kilometers per hour (Mach 0.92), while the altitude record in an aircraft was 17.3 kilometers. Sänger and Bredt did not think small.

The Silbervogel would then begin a roller-coaster-like ride up and down into the Earth’s atmosphere, using its wings and angle of attack to skip off the denser air at about 20 kilometers up and regain altitude for another distance-eating hop. An example diagram in the 1944 paper discussed below shows no less than eight such skips before settling into a steady flight at 20 kilometers and a return to base after a complete trip around the world.

What happened to make it fail: It was too advanced for the time, and even Sänger (who underestimated the technical difficulties of the heat Silbervogel would have to endure when skipping into the atmosphere) thought that it would not fly for many years. As World War II heated up, the Nazi government officially put the program on hold in 1942 to save money and resources for weapon systems that could be used before the end of the ongoing fighting. Oddly enough, despite the stop Sänger was still assigned to it and continued work on it until 1944, as the Nazis looked at several possibilities for being able to bomb the United States from the Azores if fascist Spain and Portugal could be brought into the Axis.

In that year he and Bredt published their final version of their research, which was published as Über einen Racketantrieb für Fernbomber (translated after the war as A Rocket Drive for Long Range Bombers, a copy of which can be downloaded as a PDF). This remarkable document outlines how the Silbervogel would have looked and worked, as well as how it might have been used in a variety of ways—for example avoiding the difficulty of having to go the whole way around the Earth by setting up a second Silbervogel landing and launching base in the Japanese Marianas Islands or, better, in the occupied territory in California which the Japanese would helpfully conquer for the Nazis. A cheerful diagram showing the complete destruction of Manhattan from roughly Union Square north to the corner of 27th Street and Broadway and south to Houston Street is included, as this would be possible with a mere 84 sorties with 3600-kilogram bombs. Note that the Space Shuttle Discovery holds the record for the most flights above 100 kilometers by any one spaceplane, 39, racked up over the course of 27 years.

What was necessary for it to succeed: Under any reasonable circumstances, it wasn’t going to work as initially designed.  The design was simply too far advanced for the time, and Germany couldn’t come up with the physical resources or money to build one.

That said, if there had been no war, and if the Germans had had access to high melting-point molybdenum for its belly (or developed heat-resistant ceramic tiles as would be used on the US’s Space Shuttle), and if there had been the political will to spend those marks and metals—and that’s an awful lot of “ifs”—something like the Silbervogel could have flown around 1960. It likely would have been heavily redesigned by then.