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.

Answer this series of questions:

1. Who lost his life in the accident?
2. how old was he?
3. do they know what caused the accident?
4. who reported they had not found a cause?
5. what agency does he work for?
6. what is his title?
7. what is it that fell apart in the air?
8. does it have a name?
9. what might have been moved too soon?
10. was anyone else in the craft with the person who died?
11. did he die?
12. is he unconscious?
13. what is his name?
14. and his last name?
15. has he been interviewed yet?
16. why not?
17. what day of the week did the craft fall apart?
18. did that happen a long time after separation?
19. how high up was it?
20. what city was it closest to?
1. Michael Tyner Alsbury
2. 39
3. No
4. Christopher Hart
5. NTSB
6. Acting Chairman
7. the spacecraft
8. Galactic SpaceShipTwo
9. A lock-unlock lever
10. Yes
11. No
12. No
13. Peter
14. Siebold
15. No
16. doctors did not recommend an interview
17. Friday
18. two minutes
19. 45,000 feet
20. Mojave