| by
John Varrasi |
As ASME celebrates its
125th anniversary this year,
Mechanical Engineering will run articles each month highlighting
key influences in the Society's development. This, the ninth in our series,
recalls the U.S. space program in the 1960s and the historic moon landing
of Apollo 11.
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.
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 boardcompleted
less than three weeks before JFK's speechprovided 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.
 |
| On the way to space: The Atlas
launch vehicle is one of the many Mechanical Engineering Landmarks
that marked the progress of the space program. |
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 thrust10 times the force of any previous NASA rocket, according
to Steve Dick, chief historian at the space agency.
The Saturn V, an ASME 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.
 |
| Apollo on the moon: Every space
mission was a new achievement. |
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 spacethermodynamics, 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.)
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.
John Varrasi is a senior writer in the Public Information
Department of ASME in New York.
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