In April, the Smithsonian X 3D team pointed their lasers and scanners at the Bell X-1, the same iconic aircraft that shot Capt. Charles ‘Chuck’ Yeager across the pristine skies of the Mojave Desert to a record-breaking speed. On October 14, 1947, in the Bell X-1, Yeager became the first pilot to fly faster than sound. Now, we can all get as close to the Bell X-1 as Yeager himself with the recently released 3D model of the exterior of the aircraft. In honor of the new 3D model and that resounding flight, we’ve compiled five facts to help you begin your exploration of the aircraft and that key moment in history. We also reached out to Smithsonian X 3D team to find out exactly how one goes about capturing a 3D model. But first, our five facts:
1. To conserve fuel, the X-1 was flown up to 7,620 meters (25,000 ft) attached to the bomb bay of a modified Boeing B-29 bomber and then dropped.
2. Yeager named the Bell X-1 Glamorous Glennis after his first wife.
3. The aircraft’s iconic orange paint scheme made it easier to spot during flight tests, but some time after the record-breaking, 1.06 Mach-speed flight the aircraft was re-painted with accents of white. The Museum eventually restored the aircraft to its original 1947 paint scheme.
4. Glamorous Glennis used a 6,000-pound-thrust, liquid-propellant rocket engine, known as Black Betsy, from Reaction Motors, Inc.
5. Before the scheduled flight, Yeager broke two ribs. Afraid of being removed from the mission he told only his wife and fellow project pilot Jack Ridley. With two broken ribs, Yeager was unable to seal the hatch of the X-1 by himself. The end of a broom handle used as a lever made it possible for Yeager to seal the hatch on the day of the flight.
To get the facts on 3D scanning, we reached out to Vincent Rossi, a 3D digitization program officer with the Smithsonian, to find out exactly how the Bell X-1 was captured digitally.
We used laser scanners for geometry capture and Photogrammetry to capture the color information of the Bell X-1. With Photogrammetry we are able to turn our digital cameras into 3D scanners using post processing software. The laser scanners capture over 1 million data points per second. The data we collected on the Bell X-1 is accurate to about one millimeter. The laser scanner works by emitting pulses of laser light, and the time it takes for the laser to be emitted, hit the object, and return to the sensor equates to a measurement or a point in space (of which we capture millions). Certain materials on the Bell X-1 did not scan well and presented challenges for the scanning team. We had difficulty with two types of surfaces on the aircraft: the glass windshield and the painted blue areas around the stars on the wings. Glass does not scan well because the laser mostly passes right through it. Luckily, we were able to get enough points on the glass surface to accurately reconstruct the windshield using CAD (Computer Aided Design) software. The blue graphic areas around the stars did not scan well either because the dark colors absorbed the laser light. Because the laser did not get a good return measurement on these dark areas, we had to manually touch up and edit these sections. The final Bell X-1 3D model is a combination of two data sets, the high resolution geometry captured with the laser scanner and the color Photogrammetry model.
The 3D scan of Bell X-1 is available online and also available for download. Have access to a 3D printer? We encourage you to print your own Bell X-1 at home or in the classroom. Make sure to share your mini Bell X-1 with us—@airandspace and @3D_Digi_SI—and stay tuned for more 3D releases of National Air and Space Museum artifacts.
Jenny Arena is a digital content manager at the National Air and Space Museum.
In this four-part series, curators Russ Lee and Evelyn Crellin take an in-depth look at the Lippisch DM 1, an experimental German glider. At the conclusion of Part 1, construction of the glider had begun in August 1944 by students of the Flugtechnische Fachgruppe (FFG).
Construction of the experimental glider was derailed dramatically on September 11 and 12, 1944, when Allied bombers struck Darmstadt, including the building that housed the FFG D 33 project. Everything the students could salvage from the rubble was moved to Prien Airport at Chiemsee in Bavaria, where students of FFG Munich had operated a large workshop since 1924. Prien had been the starting point of many famous gliding events from 1918 to 1939 including attempts to cross the Alps in gliders and set altitude records. Now, Prien Airport and the FFG Munich workshop became the new home of the glider, where both FFG groups—Darmstadt and Munich—combined their efforts to continue building the aircraft. This collaborative effort led to a new designation for the glider using the letters ‘D’ for Darmstadt and ‘M’ for Munich to rename the aircraft the DM 1. Increasingly difficult wartime conditions, however, prevented Lippisch from assisting further with design and construction.
Students glued, bolted, nailed, and screwed together the cantilever fuselage and various components made of wood, plywood, and steel tubes. They covered the entire glider with 1.6 mm (1/16-inch), 3-ply birch plywood. To cover the very thick leading edges of the wings and vertical stabilizer, the students had to first heat the plywood with steam. These very thick sections were unsuitable for high-speed flight and suggested that Lippisch designed the DM 1 for experiments at low flying speeds. They gave the pilot a window on the cockpit floor to see ahead of the glider at the high pitch angles that would be necessary during launch and landing. To evaluate how the glider handled in flight with the center of gravity at various locations, the pilot could hand-pump 35 liters (9 gallons) of water between two tanks inside the nose and tail of the aircraft. Armament was not planned for this experimental glider.
The students fashioned the wheeled, three-strut, tricycle undercarriage from steel. Contrary to a recent published account stating that the gear was fitted with shock absorbers that had 60 cm (2 ft) of travel, direct observation of the DM 1 aircraft in the Mary Baker Engen Restoration Hangar at the Steven F. Udvar-Hazy Center in Chantilly, Virginia, confirms that the struts are solid steel with no capacity to absorb shocks. To reduce the stress of landing at the high angles of attack required for delta wing aircraft, the struts are set so close together that the glider appeared ready to tip over. Lippisch may have imagined the test pilot would land on a wooden skid or even on the smooth belly of the aircraft since touching down on the gear legs without shock absorbers would probably have damaged the delicate internal wooden structure. Museum treatment specialist Matt Nazarro likened the structure to the fragile insides of a wooden guitar. The design called for ground technicians to retract the undercarriage after they had mounted the glider piggyback onto a larger powered aircraft, so the gear may only have provided the techicians with a convenient way to move the aircraft around on the ground.
Authorities had planned to carry the experimental glider into the air piggyback atop a twin-engine and propeller-driven Siebel 204 A aircraft. The DM 1 pilot would have released from the carrier aircraft at altitude and descended with additional thrust from two solid-fuel rockets at an estimated speed of around 800 kph (500 mph). A former coworker of Alexander Lippisch, test pilot Hans Zacher from the DFS (Deutsches Forschunginstitut für Segelflug, German Research Institute for Gliding), was designated to perform the DM 1 test flights. However, Zacher joined the project at a late stage, and the war ended before the students could finish building the glider.
On May 3, 1945, American troops occupied Prien Airport and found the incomplete glider. German historian and author Hans-Peter Dabrowski wrote in his article Flying Triangle (Klassiker der Luftfahrt, July 2014, p.61) that when U. S. Army General George S. Patton and other high-ranking officers visited Prien on May 9, 1945, the advanced design features of the aircraft impressed them and Patton ordered the students to resume construction and complete the aircraft. Dabrowski also wrote that Dr. Theodore von Kármén argued vehemently to finish the DM 1, and that Major A. C. Hazen of the Air Technical Intelligence Section, U. S. Army Air Forces in Europe, became the project manager.
Hazen worked closely with test pilot Hans Zacher who remained very involved with work on the DM 1. On one particular day, Zacher was visited by group of Americans who had come to study the glider. At the time, they were unknown to Zacher. During small talk he mentioned that he had studied the work of Walter Stuart Diehl, the famous American pioneer of aerodynamics and author of the authoritative Engineering Aerodynamics (1928), who actively participated in and strongly influenced continuing advances in aerodynamics and hydrodynamics. To Zacher’s surprise, one of his counterparts identified himself as Walter Diehl. From this encounter a lifelong friendship arose between Zacher and Diehl.
The workshop at Prien Airport would also receive a visit from another famous American before construction of the DM 1 was completed. Find out who next week, but feel free to guess in the meantime.
Russ Lee is the Chair of the Aeronautics Department and the Curator of Gliders and Sailplanes, and Evelyn Crellin is the Curator of European Aircraft at the National Air and Space Museum.
Dabrowski, Hans-Peter. “Flying Triangle,” Klassiker der Luftfahrt, July 2014.
Lindbergh, Charles A. The Wartime Journals of Charles A. Lindbergh, (New York, 1970).
As summer heats up in Washington, DC, swimming pool attendance skyrockets. For Women Air Service Pilots (WASPs) training to fly military aircraft during World War II at Avenger Field in Sweetwater, Texas, a dip in the pool was more than fun and games.
For any pilot, there exists the possibility of an aircraft going down over water. To prepare, WASPs without any swimming abilities were enrolled in a regular swimming class.
The reality of a water landing or parachute jump is that a pilot will still be wearing all of her clothes. WASPs trained for that scenario by jumping into the pool fully clothed.
Training time in the pool was commemorated in a poem in Bernice Falk Haydu’s 318th WASP Yearbook, a rhyming laundry list of common experiences and slang:
It ain’t right
Just can’t think
In stinky Link
Dirt on floor
Sweep some more
Shots and such
Don’t help much
BUT DAMN IT ALL WE GRADUATE—”
Elizabeth C. Borja is an archivist in the National Air and Space Museum’s Archives Department.
In this four-part series, curators Russ Lee and Evelyn Crellin take an in-depth look at the Lippisch DM 1, an experimental German glider.
The Lippisch DM 1 played a vital role in the development of the first jet-propelled delta wing aircraft to fly, the Convair XF-92A. The extensive flight tests that Convair and the U. S. Air Force conducted with the XF-92A led the company to develop the Convair F-102 Delta Dagger and the F-106 Delta Dart, both delta wing fighters, as well as the B-58 Hustler supersonic delta wing bomber. The United States Air Force and the Air National Guard operated more than 1,400 of these aircraft from 1956 to 1988. For its role in the advancement of delta wing fighters, the Lippisch DM 1 warrants further examination from its early days in war-torn Germany to wind tunnels studies in the U.S.
Alexander M. Lippisch, a German aircraft designer, devoted much of his career to understanding and developing advanced, unconventional aircraft. Between 1921 and 1945, he embarked on more than 100 projects that led to the construction and successful flight of about 60 different aircraft including the Messerschmitt Me 163 Komet rocket fighter, currently on display at the Steven F. Udvar Hazy Center in Chantilly, Virginia. The Komet was the world’s first operational fighter aircraft powered by a liquid-fueled rocket engine becoming operational in May 1944.
By the late 1930s, aircraft designers and engineers began to understand that traditional straight wings and relatively thick airfoils were not ideal for flight at the speed of sound or beyond. Sound travels at different speeds primarily due to variations in air temperature. At sea level and under normal atmospheric conditions it travels at 1,220 km/h (760 mph). To reduce the drag of the air that quadruples when airspeed doubles, and to solve other problems that arise at transonic speeds, Lippisch proposed a delta wing configuration so named because it resembles the fourth letter ‘Delta’ of the ancient Greek alphabet whose uppercase form looks like this: ‘Δ’. This shape has several advantages for high-speed flight. It combines sharply swept leading edges to minimize drag at high speeds with a large surface area needed to make lift at low speeds. The delta had favorable structural characteristics, too. It allowed engineers to build thin wings making less drag without losing the strength needed to withstand the powerful air loads encountered at transonic speeds.
In spring 1943, Lippisch took charge of the Luftfahrt-Forschungsanstalt Wien (Aeronautical Research Establishment Vienna, or LFW). He began working on several projects. One of them was the project “P 13 a,” the idea for a semi-tailless supersonic fighter aircraft. At the time, Allied bombing operations were increasing in scope and intensity. To counter the bombers, Germany needed new fighter aircraft with performance superior to Allied aircraft. The new designs also had to be quick to build using inexpensive materials that were easily obtained. To boost high-speed performance, Lippisch envisioned powering the P 13 a with a ram-jet engine that consisted of just a few moving parts and operated by burning a mixture of coal dust and heavy oil or gasoline.
The Reichsluftfahrtministerium, or German Air Ministry (RLM), became interested in this project, perhaps because several firms were already developing unusual forms of semi-tailless or all-wing designs for fighter aircraft powered by either jet turbine or rocket engines. In addition to the Me 163 B-1a already mentioned, another notable example is the all-wing Horten Ho 229 V3 (‘aich-oh two-two-nine vee-three’) currently on display in the Mary Baker Engen Restoration Hangar at the Steven F. Udvar-Hazy Center. Lippisch designed the P 13 a to be built of aluminum and he hoped it could attain supersonic speeds. The wing would be a cantilever structure, a smooth outer surface without external supports such as struts or wires. It would also have a 60° nose angle and a profile thickness of 15%—the thickness of the wing as a percentage of the width of the wing from leading to trailing edge.
Beginning in May 1944, experts evaluated the design at Spitzerberg Mountain near Vienna using a scale-model of the P 13 a. In August 1944, the aerodynamic characteristics of a P 13 a wind tunnel model were tested in the supersonic wind tunnel at Aerodynamische Versuchsanstalt, the Aerodynamic Research Institute (AVA) in Göttingen. Following these tests, Lippisch pushed to build a full-size version without an engine. A powered aircraft would tow aloft the experimental glider manned by a test pilot who would study the takeoff, landing, and handling qualities of the design in flight. A young man assisting Lippisch at the LFW was Wolfgang Heinemann, persuaded the designer that he and his fellow students of the Flugtechnische Fachgruppe (aeronautical expert groups, FFG) at Darmstadt Technical College could build the experimental glider according to Lippisch’s specifications. Heinemann was one of many German students majoring in engineering and aeronautics who joined such academic flying groups where they obtained their pilots’ licenses, tried to solve various aeronautical problems, and were not afraid to tackle challenges at the limits of the aeronautical sciences. The students began their work in August 1944. Since FFG Darmstadt numbered their designs sequentially, the new aircraft became the D 33. Lippisch later said the designation should have been “P 13 a V1” (Project 13 a, prototype 1).
Construction of the aircraft, however, was abruptly halted when Allied bombers struck Darmstadt, including the building that housed the FFG experimental glider project. Next week in Part 2, we will see what impact this had on the completion of the D 33.
Russ Lee is the chair of the Aeronautics Department and the curator of gliders and sailplanes, and Evelyn Crellin is the curator of European aircraft at the National Air and Space Museum.
Chambers, Joseph R. Cave of Winds: The Remarkable History of the Langley Full-Scale Wind Tunnel, (NASA SP-2014-614), 2014.
Dabrowski, Hans-Peter, Überschalljäger Lippisch P 13 and Versuchsgleiter DM-1 (Supersonic Flighter P 13 abd Experimental Glider DM-1), Podzun-Pallas Verlag Stutgart 1986
Dabrowski, Hans-Peter. “Fliegendes Dreieck (Flying Triangle),” Klassiker der Luftfahrt, July 2014.
Lippisch, Alexander M. The Delta Wing-History and Development, Gertrude Lippisch translator, (Ames, Iowa, 1981).
When the Boeing Milestones of Flight Hall opens in the summer of 2016, one of its central artifacts will be the Star Trek starship Enterprise studio model, used to film the original television series. As a member of the curatorial team that has been working on this exciting revision of the Milestones Hall, I have been immersed in the culture and lore of that artifact, as I have sought to place it in the context of the Lunar Module, Spirit of St Louis, Bell X-1, and other iconic artifacts that will populate the space. What follows are some observations.
On September 12, 1962, at Rice University in Houston, Texas, President John F. Kennedy gave a speech that stated the country’s commitment to landing human beings on the Moon and returning them safely by the end of that decade. In the speech’s most memorable passage, he said:
“We choose to go to the moon. We choose to go to the moon in this decade and do the other things, not because they are easy, but because they are hard, because that goal will serve to organize and measure the best of our energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone, and one which we intend to win…”
That statement echoed one that was given over six decades earlier in 1900. At the second International Congress of Mathematicians in Paris, Professor David Hilbert listed a set of mathematical problems that he suggested his colleagues ought to be able to work on for the coming century. Like President Kennedy, Hilbert was remarkably prescient. His list of 23 problems served to define mathematics for the following century and beyond. In choosing such problems, Hilbert acknowledged that he could not foresee the future with any clarity, but he was guided by this criterion:
“…a mathematical problem should be difficult in order to entice us, yet not completely inaccessible, lest it mock our efforts.”
Though a much shorter passage than Kennedy’s, it stated the same thing. Progress in science and technology requires defining and attacking problems that are just within the realm of possibility, but not so far advanced that they doom us to frustration and endless disappointment. Before committing the nation to a Moon landing, the President conferred with advisers who told him that the United States, at the time behind the Soviet Union, could with a strenuous effort beat the Soviets to the Moon by the end of the decade. Like Hilbert before him, President Kennedy made the right call, although it was close.
How are we to know which current problems meet that criterion? The answer brings us to the current U.S. space program, and to the television series Star Trek, which aired for three seasons on network television beginning in the fall of 1966. There is no need to enumerate the many scientific theories and technical advances in that show; these have been documented and explained in the excellent book by professor Lawrence M. Krauss, The Physics of Star Trek (Revised Edition, Basic Books, 2007).
This book is owned by many Trek enthusiasts—among them Stephen Hawking, who wrote the forward to the second edition. Hawking makes the important point that, “There is a two-way trade between science fiction and science. Science fiction suggests ideas that scientists incorporate into their theories, but sometimes science turns up notions that are stranger than any science fiction.”
Why then the title of this blog post, which the reader may interpret as having a somewhat pessimistic attitude toward the show? Star Trek assumes a speed of travel that essentially places the entire galaxy within the range of a normal adult human lifetime. That concept does not pass David Hilbert’s test. Faster-than-light travel is worthy of study by physicists, and Hawking and his colleague Kip Thorne (whose ideas formed the basis of the recent movie Interstellar) have suggested avenues of research that may lead to it. But without an extreme form of warp drive, the entire premise of the television series collapses. Meanwhile, the popular press complains that the U.S. space program is moribund because we aren’t planting colonies on the Moon, sending humans to Mars, or building ships to take humans to Saturn, Jupiter, and their moons. All of this noise obscures the tremendous advances right in front of us. Among them are, to name a few:
Some of these were hinted at in Star Trek episodes, but for me, the sum of these goes far beyond the world envisioned by Gene Roddenberry 50 years ago.
We will restore the Enterprise, and it will be a fantastic addition to the Milestones Hall. But as I have said elsewhere, space exploration does not always follow the trajectories we want it to. As for visiting other intelligent civilizations in our galaxy? An attempt to develop warp drive would “mock our efforts,” as Hilbert warned. I suggest an avenue of research that is “difficult enough to entice us, yet not completely inaccessible.” That would be the development of AI to a point where we can download our consciousness onto swarms of robotic spacecraft and send them out into the galaxy. I predict that a first step along these lines will become a reality within my lifetime.
Among the problems that David Hilbert proposed in 1900 was #10: whether it could be “decided” that a certain mathematical function was solvable or not. A variant of that problem was eventually solved, in the negative, by the Cambridge mathematician Alan Turing. Hilbert had hoped for a positive answer to the “Decision Problem,” but Turing’s 1936 paper laid the theoretical foundations for the digital computer—a device that is only present in a rudimentary form in Star Trek, by the way. Hilbert was on to something after all.
To the skeptics who wonder why the Utopia of space travel implied by the Apollo landings of 1969-1972 has not come to pass, I would only say that we are living in an age of discovery that has no parallel in human history. Let’s embrace it.
Paul Ceruzzi is a curator in the Space History Department at the National Air and Space Museum.