A lock-unlock lever on the doomed Virgin Galactic SpaceShipTwo was moved earlier than it should have been , the National Transportation Safety Board said Sunday night . But the agency 's acting chairman stressed it was unclear whether pilot error , mechanical problems or a host of other possibilities caused the spacecraft to disintegrate in the air . `` We are still a long way from finding a cause . We are months and months away , '' NTSB Acting Chairman Christopher Hart said . And despite a debris field spanning 5 miles , investigators have found almost all the parts of the spacecraft needed for the investigation , Hart said . The accident killed co-pilot Michael Tyner Alsbury , 39 . A memorial fund has been set up for him . Co-pilot alert and talking . The surviving co-pilot is `` alert '' and speaking , the company that partnered with Virgin on the test flight program said Sunday . `` Peter Siebold , the director of flight operations at Scaled Composites , was piloting SpaceShipTwo . He is alert and talking with his family and doctors , '' the company said in a statement . `` We remain focused on supporting the families of the two pilots and all of our employees , as well as the agencies investigating the accident . '' NTSB investigators have yet to interview Siebold . `` We have not because doctors did not recommend we do an interview at this stage , '' Hart said . Inflight breakup ? SpaceShipTwo disintegrated Friday , just two minutes after the space plane separated from the jet-powered aircraft that carried it aloft . At the time , it was about 45,000 feet above , and about 20 miles northeast , of Mojave , California . SpaceShipTwo helmed by experienced pilots when flight failed . While the NTSB has n't determined what broke the test aircraft apart , `` when wreckage is dispersed like that , it indicates the likelihood of in-flight breakup , '' Hart said . A team of 13 to 15 investigators from the National Transportation Safety Board will be on site in the Mojave Desert for about a week . But analyzing the data from the test aircraft will take much longer . Analysis : Will space accidents deter pioneer tourists ? 'We 're going to learn ' Virgin Group founder Richard Branson said Sunday he did n't personally know Alsbury , but had the privilege of knowing Siebold . `` Mike was a dear friend and inspiring colleague to the many , many friends he left behind . My heart goes out to his parents , his wife and children , his sister and the rest of his family and friends , '' he said about Alsbury . He wished Siebold a speedy recovery . On Saturday , Branson said that the company is `` determined to find out what went wrong . '' When asked about the future of Virgin Galactic , Branson said the company 's goal is still putting people safely into space . `` I think millions of people in the world would love one day to have the chance to go to space , and this is the start of a long program , '' he said . Years of flight experience . The two test pilots had both had a great deal of flight experience . Alsbury worked at Scaled Composites and logged more than 1,600 hours as test pilot and test engineer in Scaled aircraft . Siebold had worked for Scaled Composites since 1996 and had 17 years and more than 2,000 hours of flight experience . Both had degrees in aeronautical engineering from California Polytechnic State University . Deadly day for space tourism -- but future 'rests ' on such days , official says . As for the program itself , SpaceShipTwo had flown 55 times , 35 times on its own , Branson said in a statement . WhiteKnightTwo , the jet-powered `` mothership '' charged with transporting SpaceShipTwo to altitude , has flown 173 times , Branson said . `` We 've always known that the road to space is extremely difficult -- and that every new transportation system has to deal with bad days early in their history , '' Branson said . `` Space is hard -- but worth it . We will persevere and move forward together . '' Future of the program . For years , Virgin Galactic has planned to sell trips in which SpaceShipTwo would transport passengers about 62 miles above Earth -- the beginning of outer space -- and let them experience a few minutes of weightlessness before returning to the ground . It 's unclear what the failure of the space plane will mean for the program . Virgin Galactic planned to send paying customers on SpaceShipTwo as early as next year . The company released a statement late Sunday . `` At Virgin Galactic , we are dedicated to opening the space frontier , while keeping safety as our 'North Star ' . This has guided every decision we have made over the past decade , and any suggestion to the contrary is categorically untrue , '' it said . `` Now is not the time for speculation . Now is the time to focus on all those affected by this tragic accident and to work with the experts at the NTSB , to get to the bottom of what happened on that tragic day , and to learn from it so that we can move forward safely with this important mission . '' Virgin has sold more than 700 tickets , each costing more than $ 250,000 , for future flights . Several celebrities have already signed up , including Justin Bieber , Ashton Kutcher , Leonardo DiCaprio and Stephen Hawking . Opinion : The truth about launching spaceships .
A lever on SpaceShipTwo was moved earlier than it should have . But the NTSB says the cause of the accident is still unclear . A memorial fund is set up for Michael Tyner Alsbury . The co-pilot `` is alert and talking with his family and doctors ''