Word: vega
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...This is the first time we've gone to the comet," said Carl Sagan. The Cornell University astronomer was one of about 100 foreign scientists who gathered at Moscow's Institute of Space Research to observe the eagerly awaited rendezvous of the Soviet spacecraft Vega 1 with Halley's comet. At 2:30 a.m. (EST) on March 6, as Vega passed within 5,300 miles of Halley's nucleus and as images of the legendary comet flashed on television screens at the institute, Sagan joined the other foreign scientists in applause, while Soviet scientists and technicians hugged and kissed...
...their supervision by scientists from ten nations -- had become the first man-made object to record close-up views of a comet's coma and nucleus, and send the images and other data back to earth.* It also served as the advance guard for four other craft -- the Soviet Vega 2, the Japanese Suisei and Sakigake, and the European Space Agency's Giotto -- that were to sweep by Halley's in the following week...
...Vega 1's camerawork was a triumph of technology. While whipping by Halley's at a speed of 175,000 m.p.h. (relative to the comet), the spacecraft's TV cameras shot some 500 pictures in about three hours. Transmitted across 109 million miles of space, each picture took nine minutes to arrive in Moscow, where it was colored by computer to emphasize differences in brightness. The first images showed only the coma, the great cloud of gas and dust surrounding the nucleus, as a fuzzy, violet-fringed, blue-green ball with a yellow center. But in images that Vega...
Early evaluation of data from Vega 1 showed that the craft encountered less dust than expected as it approached the comet. But Physicist John Simpson of the University of Chicago, who designed the only American instrument -- a dust detector -- aboard Vega, noted that as the spacecraft departed, it passed through a "huge spike of dust" with particles about the size of those in cigarette smoke. Simpson and other scientists interpreted the spike as a burst of dust and gas erupting from the surface of the nucleus. Other Vega instruments seemed to show that the icy cometary surface was being evaporated...
...Vega 1 also served as a pathfinder for two other craft in the Halley's flotilla. By helping scientists determine the comet's precise path, it enabled them to make accurate last-minute corrections in the courses of Vega 2 and Giotto. The second Vega was to pass within 5,000 miles of the comet on March 9, supplementing Vega 1's findings. Giotto's mission four days later was to swoop to about 300 miles of the nucleus, shooting close-up pictures as it passed. Precision pathfinding was less important for the Japanese craft. Suisei, designed to study...