Elon Musk will be able to offer space tourism flights for a fraction of Virgin Galactic's cost -- but not just yet.It's official now. Virgin Galactic (SPCE -6.23%) is out of the space tourism business -- at least for a while.On Saturday, June 8, Virgin Galactic's "Galactic 07" mission successfully took off, briefly visited space, and landed with all passengers safe and sound. This was the company's seventh revenue-generating commercial flight. Now, Virgin intends to retire its single operational "Unity" spa ...