英語翻譯
after man landed on the moon in 1969 ,astronauts around the world had a problem-there were no other places they could go even today ,the other planets are still too far away for astronauts to fly to .so ,while rockets and robots can go to other planets ,manned flights have to stay closer to home ,for the time being .therefore ,since visiting the moon ,manned space programs have turned their attention to solving problems related to living and working in space .
currently ,nasa’s [（美國）國家航空航天局] manned space exploration program focuses on the space shuttle program .nasa now operates three space shuttles ,discovery ,atlanatis ,and endeavor .unfortunately ,two of nasa’s shuttles ,challenger and columbia ,have been lost through accidents .seven astronauts died in each accident .since the beginning of the shuttle program ,the shuttles have flown more than a hundred missions .these missions have included putting satellites into orbit ,photographing the earth ,studying space ,conducting experiments related to working in space ,and conducting with various manned space station in orbit .
throughout the short history of the exploration of space ,several space stations have been put into orbit .the first manned space station was the soviet station salyut 1 ,put into orbit in 1971 .later ,in 1986 ,the soviet union launched the mir space station .mir stayed in orbit until march 23 ,2001 ,over that time ,104 astronauts visited the station to stay for various lengths of time .the person who has spent the longest in space so far is russion astronaut valeri polyakov .working as the doctor aboard the station ,he lived on mir for 438 days without returning to earth .in total ,polyakov worked aboard mir for 678 days before retiring .
today ,astronauts from around the world are working together to complete the inernational space station（iss）.the first part of this space station was launched in 1998 .nasa predicts the iss should be completed by 2011 .in the long run,it is hoped that the iss will be a place where people can live and work all year round .