Today, 46 years ago, on July 11, 1979 (Lunar Calendar June 18, 1979), the U.S. "Sky Lab" burned. The Sky Lab was the first space station in the United States to orbit the Earth. With the "Saturn 5" launched a rocket. The orbit was about 435 km high, operating cycle 93 minutes, angle of 50 degrees. It was composed of the orbital working cabin, transition cabin, multi-purpose coupling cabin, solar telescope and Apollo spacecraft 5 parts, full length of 36 meters, maximum diameter of 6.7 meters, weight of about 80 tons. The astronauts were shipped by the Apollo spacecraft. From May 1973 to February 1974, they received three batches of astronauts, each group, worked on the station for 28 days, 59 days