SS1 took 6 months from its first powered flight until it reached 100+ km. That was on a very aggressive schedule with only a handful of flights. I’d guess it’ll take SS2 a year to do the same, especially if RM2 isn’t fully verified (at least for full duration burns) when powered flight testing commences. I’d then expect several months of repeated flights to 100+ km before they have enough assurance to begin passenger operation. Of course they also need FAA approval and I can’t see that happening without significant flight test evidence. So I’d guess it’ll be 18 months from the first powered flight test until commercial operation.

So end of 2013 still looks optiimstic to me, I’d say H1 2014 more likely.

Regarding the motors, it was always my understanding that they would start with short-duration powered flight tests and work their way up to full-duration powered tests into space, in much the same way SpaceShipOne did in late 2003 through mid-2004. So I’m not sure how that approach automatically keeps them from achieving that schedule, unless there’s a long delay in the transition to the full-duration motor.

I think you meant that they would start commercial service by the end of next year, not this year.

If they only have a starter motor that will begin test flights by late this year, I don’t know how that puts them on a course for commercial flights by the end of 2013 with the full motor. I don’t understand that.