Friday, December 11, 2009

Total number of astronauts flown to space to increase by 600% within 5-7 years

As of 2009, only 500 people have flown to space. By 2016, that number will be 3,500 thanks to private space tourism.

SpaceShipTwo (legendary aircraft engineer Burt Rutan's follow-up to his 2004 X-Prize-winning SpaceShipOne) was unveiled earlier this week. The spacecraft, launched from a larger aircraft from 60,000 feet will be capable of sending six passengers and two pilots more than 100 km, just past the edge of space for a brief sub-orbital flight after which it glides  gently back to Earth.

SS2 will enter service with billionaire Richard Branson's Virgin Galactic after a battery of ground and flight tests starting around 2011. So far, 300 people have signed up (and paid deposits) for a $200,000 per flight ticket. Though pricey, this is still much less than the $20-30 million paid by space tourists who visit the International Space Station (albeit, their flights are orbital). Branson has stated that within five years, he expects that about 3000 tourists will have flown on his spacecraft. If true, this will mean that the total number of people to have flown into space will have increased by 600%.

For some perspective, between 1961 and 2009, slightly more than 500 people have flown into space. That's it. Many of these people flew multiple missions, so presently there have been a little over 1,100 trips into space. So it's taken a little less than 50 years for a little more than 1000 trips. Branson is hoping to add THREE TIMES as many tourists into space within FIVE years as there has been total trips to space in the past FIFTY.

But is Branson's estimate achievable? Assuming the spacecraft works as planned, I think so. Let's look at some numbers:

3000 tourists in 5 years averages out to 600 tourists per year. Each flight will carry 6 tourists, so that's 100 flights. Now there will be more than one SS2. One spacecraft, the VSS Enterprise has already been built and is set to begin testing and another, the VSS Voyager, is already being constructed. In total Virgin Galactic has ordered seven spacecraft. But even assuming only two of them are operational within the first five years, that works out to 50 flights per plane, per year with a turnaround time of about 1 week per flight. (I have read a more optimistic prediction which states that there will be two flights per day. With 7 operational spaceships, that means a turn-around time of ~3 days per spaceship.) Compare that with SpaceShipOne which was able to complete two spaceflights within 5 days. So it appears that at least technically, 3000 tourists within five years is feasible. What about economically?

As mentioned before, 300 people have already booked a flight with Virgin Galactic at $200,000 each. Several surveys conducted in the 1990s found that there is significant market demand for space tourism which is (expectedly) a strong function of price. The survey found the following:

Price per Ticket (1994 $)
Passengers per Year

20 million
5 million

Comparing those values with initial ticket sales and prices for Virgin Galactic, we see:

Clearly, the model indicates that there should be about 1000x more people interested (per year) than have currently applied for tickets. Does that mean that the model is wrong? Possibly not.

As of now SS2 is an untested craft and the first commercial flights are still a year and a half away. There are likely to be many people who are holding off booking a flight until the technology is proven. Heck, even when William Shatner, (captain Kirk himself!) was offered a free ticket on the spaceships inaugural flight, he turned it down. Even though by then the spacecraft would have undergone extensive test-flights and the fact that the deposits are refundable, people are still apprehensive about being on those first batch of flights. Additionally, with the uncertain economy many potential clients don't want to be dishing out hundreds of thousands of dollars when they're not sure where they will be financially in a couple of years. Still, I believe the market is there and it's significantly higher than those first 300. But exactly how many tickets does Virgin Galactic actually have to sell to be viable is unknown. Branson has invested between $200 million - $400 million in the project already and isn't commenting on how well the company needs to perform to break even.

Whatever happens though, SpaceShipTwo and Virgin Galactic will be responsible for making astronauts out of hundreds and likely thousands of ordinary people.


  1. This is what I wanted to hear because I want to travel to the space actually I like to buy some part of the moon because I'm thinking on my future.

  2. In fairness, you treated this subject realistically and honestly, put you've hit on my pet peeve: many folks (and unfortunately many who ought to know better) will all too eagerly mix apples and oranges of orbital and sub-orbital flight. Some X-15 flights should have resulted in blips in your charts. And not to be pessimistic, but merely realistic, how will that steep spike look the first time you have to add something like "Starship 2 disaster"?

  3. I believe the graphs do include X-15 flights (of which, only two flew higher than 100km)

    Yes, this there is a huge difference between suborbital and orbital flights, but the point of my article was to address how many people will have flown in space.

    The graphs need refinement, as the SS2 program likely won't be flying paying customers until next year.