This article highlights that for centuries although space was the realm of wonder and fascination, of fiction and children’s bedtime stories, of shooting balls of fire and faraway heavenly bodies; still it was less than 50 years ago that things began to change in earnest. Enormous engineering resources were invested in the US space program during the 1960s. By the end of the decade, engineers had gained a sufficient level of knowledge about chemical rockets and storable propellants and turned their attention to other technologies, such as noise control and advanced computer systems. In its tradition of recognizing technological achievement, ASME has bestowed honors and awards on numerous engineers and scientists associated with the nation's space program. ASME’s publications and conferences have been important vehicles for disseminating technical information on aerospace and aeronautics technology. The Society’s Aerospace Division, which predates the lunar program, has been one of the most active sectors of ASME's technical divisions.
Some generations create a system of law; other generations build cathedrals or pyramids. We today have had the good fortune to inherit a great body of scientific knowledge, and on this base we have created a technology such as the world has never seen. We are the first generation in this history of mankind with the technical capability to reach out beyond our earth, to realize the age-old dream of our fathers. Our cathedral is to reach the moon in 1970, and well beyond in the next decades.
—Mechanical Engineering, May 1967
For centuries, space was the realm of wonder and fascination, of fiction and children's bedtime stories, of shooting balls of fire and faraway heavenly bodies. It was less than 50 years ago that things began to change in earnest. Since then there has been a landing on Titan; there are two rovers on Mars, and to celebrate the Fourth of July this year, a NASA spacecraft made contact with a comet.
As ASME celebrates its 125th anniversary this year, Mechanical Engineering is running an article each month highlighting key influences in the Society's development. This, the ninth in our series, recalls the U.S. space program in the 1860s and the historic moon landing of Apollo 11.
Scientists for years had told us that the moon contained a craggy surface and a strange gravitational pull. Beyond that we knew little, other than that it stirred romantic moods. Ages-old conventional wisdom said that we would never grasp a thorough understanding of the moon, simply because humans had no means of getting there.
Most Americans still considered travel to the moon unthinkable when President John F. Kennedy issued his famous challenge in 1961. "I believe this nation should commit itself to achieving the goal, before this decade is out, of landing a man on the moon and returning him safely to Earth," the president announced before a joint session of Congress on May 25 of that year.
Kennedy's bold pledge inspired the technical community, which by the late 1950s believed that available rocket science and knowledge gleaned from the intercontinental ballistic missile program of the U.S. Air Force provided the capability to launch payloads into space. The suborbital flight of Mercury 3, with former Navy pilot Alan Shepard on board-completed less than three weeks before JFK's speech-provided added motivation as well as a platform for research and experimentation into more ambitious space flights.
Mercury 6, which was launched on Feb. 20, 1962, advanced the U.S. space program to orbital flight. Tucked inside his Friendship 7 spacecraft, the astronaut John Glenn circled the Earth, marveling at the beauty of orbital sunrises and sunsets, before returning to an enthusiastic nation. The Gemini program, including spacewalks and the use of on-board computers, followed the Mercury flights and set the stage for the Apollo program and the historic lunar landing of Apollo 11.
The chemical rocket was the enabling technology for space travel and moon exploration. Scientific research sponsored by the U.S. military's missile program and Atmospheric Research Panel, carried out in the years immediately following World War II, demonstrated the amazing thrust of rockets containing hydrocarbon fuels. Rocket science research advanced through the late 1940s and into the 1950s, and by 1963 scientists at the newly established National Aeronautics and Space Administration launched the powerful Centaur rocket, using a propellant combining liquid hydrogen and liquid oxygen.
The high energy produced from the liquid hydrogen and liquid oxygen fuel gave the Centaur the pushing force to carry payloads beyond Earth's atmosphere and into space. The Centaur contained specially designed fuel tanks, two main engines along with several smaller thruster engines to fire and steer the rocket, and sophisticated navigation and computer systems.
Scientists and engineers faced significant challenges regarding the safe and reliable propulsion of the Centaur and the other NASA rockets that followed. "The high-energy hydrogen-oxygen propellants in the combustion stage created pulses, pressure fluctuations, and instabilities that engineers had to solve before the nation's space program could move forward," said Lou Povinelli, an ASME Fellow who was at NASA Glenn Research Center in Cleveland during the rocket development programs of the 1960s.
"We focused strongly on the injection systems of the rockets to produce the optimum distribution of liquid hydrogen and liquid oxygen to avoid combustion instability within the rocket chamber."
Adding to the engineering challenges was the unavailability of analytical tools and methodologies to test efficiencies. "The industry worked primarily by trial and error, developing and testing literally hundreds of components," said John Robinson, chair of the ASME Aerospace Division who worked at the rocket design company Rocketdyne from 1959 to 1965. "Analytical methods at the disposal of engineers today were not yet widely available to NASA and its industrial partners," he recalled.
Centaur and Atlas rockets were used for NASA's Mercury program through the early 1960s and served as the learning platform for the Saturn V rocket, which lifted Apollo 11 and three astronauts to the moon. Five F-1 engines were docked to the Saturn V, which contained 1.5 million pounds of thrust—10 times the force of any previous NASA rocket, according to Steve Dick, chief historian at the space agency.
The Saturn V, an AS ME Historic Mechanical Engineering Landmark, consisted of three stages, an instrument unit, and, at the top of the 363-foot vehicle, the Apollo spacecraft housing Neil Armstrong, Buzz Aldrin, and Mike Collins. On July 20, 1969, as millions around the world watched, the lunar module Eagle descended to the moon and settled gently into the dust of the lunar surface. Seven hours later, Armstrong planted his left foot on the moon, making history.
Enormous engineering resources were invested in the U.S. space program during the 1960s. By the end of the decade, engineers had gained a sufficient level of knowledge about chemical rockets and storable propellants and turned their attention to other technologies, such as noise control and advanced computer systems. The popular computer-aided engineering system Nastran, which provided NASA engineers with a wide range of modeling and analysis capabilities, was created in the mid-1960s.
For mechanical engineers at NASA and the agency's numerous subcontractors and partners, the 1960s were the glory days. Virtually every area of mechanical engineering knowledge was required to build space vehicles and send them into space—thermodynamics, heat transfer, applied mechanics, aerodynamics, structural design, materials design, systems control, and so on.
Indeed, the 1960s may have been the best time to be an engineer, as seemingly unlimited resources and funding were directed toward space exploration and ancillary national technology programs. Perhaps at no other time were engineers prouder of their work, contributions, and professional and civic responsibilities. Each successive space mission was an achievement for engineering, for the nation, and for mankind.
"As engineers working in the nation's space program in the 1960s, we viewed ourselves performing outstanding tasks for which there was no precedent," said Povinelli, who has been with NASA Glenn Research Center for 45 years and currently serves as a senior technologist. "We believed we were on the forefront of technology, and rightfully so."
Just as NASA's astronauts were heroes to America's '60s generation, engineers enjoyed a high level of respect, professional status, and prestige. In its tradition of recognizing technological achievement, ASME has bestowed honors and awards on numerous engineers and scientists associated with the nation's space program. Besides the Saturn V rocket, ASME has identified the RL-10 engine (which launched the Centaur), Atlas launch vehicle, and crawler transporter as Historic Mechanical Engineering Landmarks. (The crawler transporter is the subject of this month's Input/Output on page 64.)
ASME's publications and conferences have been important vehicles for disseminating technical information on aerospace and aeronautics technology. The Society's Aerospace Division, which predates the lunar program, has been one of the most active of ASME's technical divisions.
Having reached the moon, built the International Space Station, and dispatched probes to the far reaches of the solar system, what is next in space technology? President Bush has expressed a commitment to exploring the planet Mars. Engineers will be ready for the challenge, as they were a half-century ago.