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The
Space Age
he 1960s were
a time of social turmoil, marked by the civil rights movement, political
assassinations, the Vietnam War, and the antiwar movement. But it
was a golden age for science, with ample funding and broad industrial
and public support.
The launch of
the satellite Sputnik I in 1957 precipitated the space race. The
National Aeronautics and Space Administration was formed, and, in
May 1961, President John F. Kennedy committed the nation to landing
a man on the moon and returning him safely to the Earth. The U.S.
space program required new measurements of the combustion of missile
fuels and of rocket thrust in the million-pounds range, as well
as the effects of extreme and sudden changes in temperature and
pressure on materials and mechanisms of rocket engines. NIST was
already working on such problems as a result of the Army's first
supersonic flight in the late 1940s.
Measurement
capabilities were extended to new realms. In the 1950s, NIST could
measure temperatures reliably only up to 3000 OC; by 1964, thanks
to improved instruments and techniques, it was routinely measuring
in the 20,000 OC range. To calibrate the devices used to measure
the forces on large rockets, giant machines were built, such as
a 4.5 meganewton (1 million pound) force machine that was 29.3 meters
(96 feet) tall. The device to be calibrated was set at the top of
a loading frame, and weights as heavy as 23 metric tons (50,000
pounds) were loaded in increments; the applied force was calculated
from the mass of the weights. NIST still has the nation's largest
universal testing machine, capable of supplying 53.4 MN (12 million
pounds) of force in compression.
Meanwhile, the
Institute continued to provide leadership in measurements and standards.
The National Standard Reference Data System, centered at NIST, was
established by law to provide critically evaluated quantitative
data on the properties of chemical substances and materials important
to science and technology. A key feature of the program was the
independent assessment of the accuracy of data published in the
scientific literature.
In 1960, the
international scientific community adopted a new standard of length,
replacing the old platinum-iridium meter bar with a wavelength of
a specific frequency of visible light. (An Institute invention of
the 1940s was influential in demonstrating the precision and practicality
of a wavelength standard of length.) The new measure was based on
atomic properties and could be reproduced with great accuracy, whereas
the meter bar could be damaged or change over time. Shortly thereafter,
NIST designed and built one of the first fully automated measuring
machines, an interferometer (which used wavelengths of light as
the unit of measure) for calibrating the intervals on length scales.
It reduced calibration time and cost by a factor of 10. Before the
end of the decade, a new method of stabilizing lasers was discovered
by NIST scientists, yielding a 1,000-fold improvement in reproducing
measurements made with an interferometer.
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| This
universal testing machine has been used, for example, to test
the performance of concrete columns under simulated earthquake
conditions. |
The growth of
science, military and space requirements, and the explosion in communications
traffic demanded ever more accurate time standards, beyond that
provided by NIST's original 1949 atomic clock. In 1960, a clock
called NBS II, based on the natural frequency of the cesium atom,
became the national standard of frequency, supplanting a set of
quartz crystal oscillators. It measured frequency and time intervals
to an accuracy of one second in 3,000 years. Since then, six even
more accurate cesium-based clocks-the latest is accurate to one
second in nearly 20 million years-have taken over as keepers of
official national time, which is determined through a coordinated
effort with the U.S. Naval Observatory. NIST shifted from an astronomical
to an atomic definition of the second in 1967, when the international
community defined the second as 9,192,631,770 oscillations of a
particular type of cesium atom. To reconcile differences between
the atomic time scale and the Earth's rotation, "leap seconds" are
added from time to time.
The proliferation
of computers also demanded standards. NIST issued the first Federal
Information Processing Standard in 1968, a coded character set called
the American Standard Code for Information Exchange, more commonly
known as ASCII. All computers procured by the federal government
after mid-1969 had to be capable of using ASCII, which was originally
developed by an industry standards committee chaired by an Institute
staff member. Advances in computing and modeling technologies also
led to new tasks for NIST, which began performing systems analyses
and operations research for other federal agencies. It studied transportation
patterns, modeled patent activities, studied earthquake prediction,
helped the U.S. Postal Service with mail handling and proc- essing
systems, and evaluated the performance of the hurricane warning
center.
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| ©
Geoffrey Wheeler |
| NIST-F1, unveiled in December 1999, is one of the most accurate
clocks in the world. |
Institutionally,
NIST matured. The main Institute campus moved from its aging, urbanized
site in the District of Columbia to a 227 hectare (560 acre) former
farm in Gaithersburg, Md. Another important addition, in Colorado,
was the Joint Institute for Laboratory Astrophysics (later called
JILA), which has been a model of interaction between government
and academia. This cooperative effort of NIST and the University
of Colorado went on to develop an international reputation in fields
such as atomic physics (see Creating
a New State of Matter).
NIST continued
to perform research supporting industry. With U.S. highway fatalities
exceeding 50,000 a year, the Institute also focused on auto safety.
Working with the Society of Automotive Engineers, NIST prepared
specifications for brake fluids and seat belts, either adopting
or modifying existing standards. Through the use of a unique testing
facility, a uniform quality grading system was developed for tire
treadwear, traction, and temperature resistance. NIST also sought
to improve the dynamic performance of the dummies used in crash
testing. Once the fidelity of dummy tests was established, these
tests were cited as justification for mandating shoulder harnesses
in motor vehicles. Just as many other Institute efforts have been
spun off to other agencies, this work eventually was transferred
to the National Highway Traffic Safety Administration.
Important advances
were made in materials science. NIST staff developed a reliable
procedure for determining polymer melting points and proposed a
new theory of polymer crystallization, both of which became mainstays
of polymer science. In 1964, using the apparatus designed for one
of NIST's most famous experiments (see parity
experiment photo), a NIST/University of California group showed
that superconductivity (the disappearance of resistance to the flow
of an electrical current) could occur in an oxide semiconductor,
strontium titanate. This work foreshadowed Nobel Prize-winning research
in the mid-1980s by two IBM Corp. researchers, who discovered an
oxide material that was superconducting at much higher temperatures
than was generally believed possible.
At least two
major policy trends of the 1960s had long-lasting effects on NIST.
First, a White House panel began encouraging the use of new technology
in the civilian economy. The Department of Commerce was chosen to
help spur economic growth, a formal mission that continues today:
to find ways for government and science to interact in the realm
of science and technology to stimulate economic prosperity. Second,
the U.S. Congress became increasingly active with respect to environmental
issues, passing laws and amendments recognizing various forms of
pollution and requiring research and control efforts by both industry
and government.
Next Section
(Energy and Environment)
Previous Section (Postwar Years)
Back to Table of Contents
Date created:
11/2/00
Last updated: 11/6/00
Contact: inquiries@nist.gov
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