NASA Administrator Charles Bolden announced the selection of four astronauts to train and prepare for commercial spaceflights that will return American .\r<br>\r<br>NASA has selected four astronauts to train and prepare for commercial spaceflights that will return American launches to U.S. soil and further open up low-Earth .\r<br>\r<br>Nasa selects four astronauts to fly first commercial space missions: Boeing and Space X test flights scheduled for 2017 could bring landing on Mars closer to .\r<br>\r<br>Commercial spaceflights may be available as early as 2017. NASA has selected Robert Behnken, Eric Boe, Doug Hurley and Sunita Williams as the first four .
