Raver32 writes: An American astronaut has brought social networking to new heights aboard the International Space Station, where he is "tweeting" about the ups and downs of life onboard a $100 billion laboratory that flies 220 miles above Earth. NASA astronaut Tim Kopra is the latest active spaceflyer to use the Twitter microblogging site, and he's the first to do it from the space station as an Expedition 20 flight engineer. He was dropped off at the station by the space shuttle Endeavour's STS-127 mission, which landed July 31. Kopra is due to return home to Earth aboard the shuttle Discovery's STS-128 flight in early September. "What a fun shuttle mission — especially w 13 people on board station. Life here is amazing — still getting used to floating!" Kopra tweeted Tuesday under the name "Astro_Tim."