A SpaceX rocket soared into the sky Saturday with two passengers on board, leaving two seats empty to return American astronauts who have been stranded for months on the International Space Station, NASA said. A SpaceX rocket soared into the sky Saturday with two passengers on board, leaving two seats empty to return American astronauts who have been stranded for months on the International Space Station, NASA said. Space Exploration Phys.org – latest science and technology news stories