vehicle that placed the first artificial satellite in space, Sputnik, on 4 October 1957, and the first human spaceflight in history was accomplished on a derivative of the R-7, the Vostok, on 12 April 1961, by cosmonaut Yuri Gagarin. A modernized version of the R-7 is still in use as the launch vehicle for the Russian Federation, in the form of the Soyuz spacecraft. Weather satellites The first true weather satellite, the TIROS-1 was launched on the Thor-Able launch vehicle in April 1960. The PGM-17 Thor was the first operational IRBM (intermediate ballistic missile) deployed by the US Air Force (USAF). The Soviet Union's first fully operational weather satellite, the Meteor 1 was launched on 26 March 1969 on the Vostok rocket, a derivative of the R-7 ICBM. Lubricants WD-40 was first used by Convair to protect the outer skin, and more importantly, the paper thin "balloon tanks" of the Atlas missile from rust and corrosion. These stainless steel fuel tanks were so thin that, when empty, they had to be kept inflated with nitrogen gas to prevent their collapse. Thermal isolation In 1953, Dr. S. Donald Stookey of the Corning Research and Development Division invented Pyroceram, a white glass-ceramic material capable of withstanding a thermal shock (sudden temperature change) of up to 450 °C (840 °F). It evolved from materials originally developed for a US ballistic missile program, and Stookey's research involved heat-resistant material for nose cones. Satellite assisted positioning Precise navigation would enable United States submarines to get an accurate fix of their positions before they launched their SLBMs, this spurred development of triangulation methods that ultimately culminated in GPS. The motivation for having accurate launch position fixes, and missile velocities, is twofold. It results in a tighter target impact circular error probable and therefore by extension, reduces the need for the earlier generation of heavy multi-megaton nuclear warheads, such as the W53 to ensure the target is destroyed. With increased target accuracy, a greater number of lighter, multi-kiloton range warheads can be packed on a given missile, giving a higher number of separate targets that can be hit per missile. Global positioning system During a Labor Day weekend in 1973, a meeting of about twelve military officers at the Pentagon discussed the creation of a Defense Navigation Satellite System (DNSS). It was at this meeting that "the real synthesis that became GPS was created." Later that year,