it is already available for free!
I cant remember where I got it from but there are two download. One for
the white knight, and one for Spaceshipe One.
You take off in the White Knight with SS1 underneath, reach altitude,
and Drop the SS1. Then pause and switch to Spaceship one and light that
big candle, vertical you will go.
Now someone needs to put out a patch that allows you to go higher than
99,999 feet~!