What happened

One day after the stock of Virgin Galactic Holdings (SPCE -7.28%) went to the moon on news that it has reopened ticket sales at a much higher price, shares of the space tourism company are losing a bit of altitude on Wednesday, down 4.3% as of 11:20 a.m. ET.

So what

As my fellow Motley Fool contributor Matthew Frankel reported yesterday, Virgin Galactic announced on Tuesday that it will reopen ticket sales to the general public today, at $450,000 per ticket. And, in a bit of new news, it will require would-be space tourists to put down a $150,000 deposit per ticket up front.  

Virgin Galactic also confirmed that it is aiming to start commercial service later this year, although it did not give a specific date. It has previously said that the end of 2022 is actually the earliest it expects to be able to begin flying paying customers.

VSS Imagine side view.

Virgin Galactic's space plane. Image source: Virgin Galactic.

Now what

Investors viewed yesterday's news as good enough to lift the stock nearly 32% from Monday's closing price. But today they seem to be rethinking that math.

We already knew before this week's announcement that Virgin Galactic had 600 customers signed up at prices of $250,000 or less per ticket. Now we know that the company expects to add 400 more customers at prices of $450,000 per ticket by year-end.  

That adds up to about $150 million in future revenue from the first batch of 600 customers, and a further $180 million from the next 400 customers -- so $330 million in future revenue all told.

Now the question is: How long will it take Virgin Galactic to actually fly all those customers to space, and collect all that future revenue, at a rate of six passengers per flight, on perhaps one or two operational planes at present, and an unknown amount of time between flights on each space plane, given the need to replace the entire engines between flights?

Those are the questions that need answering to determine whether Virgin Galactic stock is still a buy.