Welcome to This Date in Aviation History, getting of you caught up on milestones, important historical events and people in aviation from March 14 through March 16.


NASA

March 15, 1972 – NASA announces the final design of the Space Shuttle. Even before the first astronaut set foot on the Moon on July 21, 1969, NASA had already begun thinking about what future space travel would look like. Throughout the manned space program, from Mercury to Gemini to Apollo, all parts of the launch system, from booster rockets to crew capsules, were expendable. But as NASA started formulating the next generation of space vehicles, they considered ways to make at least part of the system reusable. In 1969, President Richard Nixon formed the Space Task Group to investigate and develop a new launch system and vehicle that would be less expensive than previous systems, and one that could be used by NASA, the Department of Defense, and perhaps non-government commercial entities. But the biggest question that needed to be answered was just what form this new spacecraft, dubbed the Integrated Launch and Re-entry Vehicle (ILRV), would take.

A model of a concept by North American Rockwell for a shuttle with an expendable booster (National Air and Space Museum)

From the start, engineers envisioned a two-stage system that had the smaller vehicle, caller the orbiter, sitting atop a larger launch vehicle called a booster. In its earliest guise, the booster wasn’t just a rocket, but had wings and pilots. The orbiter and booster would have launched vertically and, after the separation of the orbiter, the booster would be piloted back to Earth to be refueled and reused. Like the final Space Shuttle design, the booster would essentially be a flying fuel tank, but both the orbiter and booster were envisioned with air-breathing jet engines to allow controlled flight for landing. However, like so many other aspects of the post-Apollo space effort, economics played a major role, and NASA simply didn’t have the money to pursue such an ambitious system, along with the creation of the orbiting space station that the new orbiter was meant to service. The original concept would only lift about 25,000 pounds of payload into orbit, and the US Air Force, whose money was vital to the program, wanted a payload of 65,000 pounds for launching military satellites. NASA had to go back to the drawing board.

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An early design concept for the Shuttle, with a piloted fuel tank below and the orbiter above. (NASA)

Not only did they have to redesign the Shuttle, they had to rethink the entire space station concept. Initial plans were for the station to be a large, single unit like Skylab. But changing the concept of the space station to one of modular construction, as we see today in the International Space Station (ISS), allowed NASA to reimagine the Shuttle as a vehicle that would carry those modules into orbit while also providing the payload space the Air Force required. Two basic design concepts then emerged. The first was called parallel burn, where the orbiter’s engine would be ignited at launch and burn in tandem with solid rocket boosters. The second was called series burn, where the orbiter’s engines would not fire until after the booster rockets were finished. After careful analysis of the cost of both systems, NASA opted for parallel burn, and announced on March 15, 1972 that the final design would be essentially what we see today: an orbiter attached to a external fuel tank (EFT) and lifted by two solid rocket boosters (SRBs). Of these three elements, the orbiter and the SRBs would be reusable. After their solid fuel was expended, the SRBs would separate from the fuel tank and parachute back to Earth to be reused, and the orbiter would re-enter Earth’s atmosphere and glide to a landing. The external fuel tank, which carried liquid hydrogen fuel and liquid oxygen oxidizer to power the orbiter’s main engines, would be expendable, breaking up before impacting the Indian Ocean. The idea of using turbine engines to control landing, and even fly the Shuttle from point to point, was scrapped, and the Shuttle was designed to glide unpowered back to Earth.

A cutaway view of the final Space Shuttle design, with reusable booster rockets, external fuel tank, and the orbiter (NASA)

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On July 25, 1972, NASA awarded a contract for development and construction of the Space Shuttle to the International Space Division of Rockwell, as well as management of the overall integration of the vehicle and the launch system. With the general design finalized, the prototype orbiter Enterprise was the first to be built in 1976. Though it never went to space, it was used primarily for critical free-flight testing. Four operational Shuttles were built (Columbia, Challenger, Discovery, Atlantis), and Columbia took its first flight on April 12, 1981. Two Shuttles, Challenger and Columbia, were lost to accidents, and a fifth operational Shuttle, Endeavour, was built in 1991 to replace Challenger. All told, the five Shuttles completed 133 missions during their 30 years of service, and the Space Shuttle program ended with the final flight of Atlantis on July 21, 2011.


US Library of Congress

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March 16, 1926 – Robert Goddard launches the first liquid-fuelled rocket. The earliest rockets date back to 13th century China., where there were used as weapons and fireworks. As development of the rocket progressed, they primarily became weapons of siege warfare, though the fuel for the rockets remained relatively unchanged. Today, many rockets and missiles are still powered by solid fuels, but it was the work of American Robert Goddard with liquid-fueled rockets that helped to usher in the Space Age, and Goddard is generally accepted to be the father of space flight and modern rocketry.

Though Goddard is best known for his pioneering work with rockets, he was also a physicist and engineer who held 214 patents, and his revolutionary work in the field of rockets and orbital theory laid the groundwork for all those who followed. His work also led to developments in atmospheric research, ballistic missiles and manned space travel. As a young boy, Goddard was influenced by the science fiction writings of H.G. Wells, particularly The War of the Worlds, and he began to study the works of other inventors, such as Samuel Pierpont Langley, who wrote about flight for Smithsonian Magazine. By 1913, Goddard was studying calculus and developed the mathematics that made it possible for him to calculate the position and velocity of a rocket in vertical flight, as well as to calculate the force necessary to get rockets of differing weights into the atmosphere.

NASA

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After first working with solid-fuel rockets, Goddard realized that, in order to gain the velocities necessary to reach space, he would need to use a liquid propellant. When compared to solid-fuel rockets, liquid propellants have the benefit of providing greater power at lower volumes of fuel and provide a greater power to weight ratio. The use of a liquid fuel also allows for the throttling of the rocket engine, where once a solid rocket is ignited its burn rate can only be controlled by the shape of the fuel block. Starting in 1921, Goddard began to experiment with liquid-fueled rockets using a liquid oxidizer, and he successfully tested the first rocket engine using a liquid propellant in 1923. His first successful launch using a rocket fueled with gasoline and liquid oxygen took place on March 16, 1926 at Auburn, Massachusetts. Though that first flight only lifted a mere 41 feet into the air, it demonstrated the potential of the liquid fuel engine. Goddard and his team launched a total of 33 rockets, and they eventually reached altitudes as high as 1.6 miles and speeds up to 550 mph.

Goddard with one of his later rockets (NASA)

Goddard not only created the rockets, he also developed a means to control them. He pioneered three-axis control, the use of gyroscopes for stability, and steerable-thrust rockets to direct the rocket in flight. His first rocket used static fins for stability, but later models employed gyroscopically controlled vanes in the exhaust, a method that was later copied by the Germans for use in the V-2 rockets used to attack England in the later stages of WWII. Goddard also pioneered a system that steered the rocket nozzle itself, a control method that is still in use today. Unfortunately for Goddard, many in the US government and military failed to appreciate the importance of his work, and by the end of WWII, the Germans had outpaced the US in rocket development, possibly using Goddard’s own data that had been transferred to Germany by spies in the US. However, in a bit of historical irony, the advances made by Germans like Werner von Braun would return to the US following the war, when many captured German scientists were brought back to America to work on its nascent space program. Nevertheless, Goddard’s work cemented him in the history of space exploration, and the Goddard Space Flight Center in Maryland, as well as the Goddard crater on the Moon, are named in his honor. (US Library of Congress photo; NASA photo)

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Short Takeoff


Photo author unknown

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March 14, 1947 – The first flight of the Lockheed L-749 Constellation, an improved version of the Lockheed L-649 Constellation and the first Constellation to make regular crossings of the Atlantic Ocean. The “Connie” originally entered service with the US Army Air Forces in WWII, and it became one of the great intercontinental airliners when it entered commercial service after the war. The L-749 provided increased range, plus the addition of jet stack exhaust manifolds that increased speed. Further development yielded the L-749A in 1949, which featured a strengthened fuselage and more robust landing gear. The first L-749 was delivered to Pan Am on April 18, 1947, and ultimately 119 L-749s were produced between 1947-1951 before the introduction of the L-1049 Super Constellation. Photo


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March 14, 1927 – Pan American World Airways is founded. Better known as Pan Am, the company was started by the United States government in 1927 as a shell company to counter the German-owned Colombian carrier SCADTA. Under the leadership of Juan Trippe, Pan Am grew rapidly by aggressively buying small airlines and expanding mail and passenger routes in South America. By 1937, Pan Am was providing Sikorsky S-42 seaplane service to Europe, and had started pushing westward from the US to Hawaii and the Far East flying the Boeing 314 Clipper and the pressurized Boeing 307 Stratoliner. Following WWII, Pan Am continued to expand its routes as it entered the jet age, and was the launch customer for both the Boeing 707 and Boeing 747. At its peak in the 1960s, Pan Am carried 6.7 million passengers and served 86 countries on every continent except Antarctica. By the 1970s, the oil crisis led to higher fuel prices and fewer travelers, and Pan Am found themselves in massive amounts of debt. After attempting to acquire domestic airlines and selling off major portions of its assets, the remainder of the company was purchased by Delta Air Lines in 1991 for $1.39 billion.


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March 16, 1947 – The first flight of the Convair CV-240. Originally designed as a larger, more modern replacement for the Douglas DC-3, the prototype 240 was unpressurized, and the airlines’ requirement for a pressurized fuselage led to a redesign. Convair lengthened the fuselage and added 10 more seats, bringing initial capacity to 40 passengers. Continued development of the CV-240 resulted in a number of variants, each one lengthening the fuselage and wings, and the eventual incorporation of turboprop engines. The CV-240 was the first private aircraft to be used in a US presidential election when John F. Kennedy flew in a CV-240, named Caroline in honor of his young daughter. The 240 also served with the US Air Force as the C-131 Samaritan and with the US Navy as the R4Y. Just under 1,200 aircraft were produced between 1947-1954.


Connecting Flights


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If you enjoy these Aviation History posts, please let me know in the comments. And if you missed any of the past articles, you can find them all at Planelopnik History. You can also find more stories about aviation, aviators and airplane oddities at Wingspan.

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