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. 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. This universal testing machine has been used, for example, to test the performance of concrete columns under simulated earthquake conditions. 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. It reduced calibration time and cost by a factor of 10. 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. (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. 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. A key feature of the program was the independent assessment of the accuracy of data published in the scientific literature. 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. Meanwhile, the Institute continued to provide leadership in measurements and standards. NIST still has the nation's largest universal testing machine, capable of supplying 53.4 MN (12 million pounds) of force in compression. 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. 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. 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. Measurement capabilities were extended to new realms. NIST was already working on such problems as a result of the Army's first supersonic flight in the late 1940s. 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. Kennedy committed the nation to landing a man on the moon and returning him safely to the Earth. The National Aeronautics and Space Administration was formed, and, in May 1961, President John F. The launch of the satellite Sputnik I in 1957 precipitated the space race. But it was a golden age for science, with ample funding and broad industrial and public support. The 1960s were a time of social turmoil, marked by the civil rights movement, political assassinations, the Vietnam War, and the antiwar movement. Wisconsin Governor's Letter about Centennial.Washington Governor's Letter about Centennial.Virginia Governor's Letter about Centennial.Tennessee Governor's Letter about Centennial.South Carolina Governor's Letter about Centennial.Rhode Island Governor's Letter about Centennial.Pennsylvania Governor's Letter about Centennial.Oklahoma Governor's Letter about Centennial.Ohio Governor's Letter about Centennial.North Carolina Governor's Letter about Centennial.

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1960s space age