The total tourism market was about $324 billion in 1993 (source: CSTS, section 22.214.171.124.4, page 205). Of this about $30 billion is adventure tourism (climbing Mount Everest, etc.) (source: usenet), which is often presumed to be more or less similar to space tourism.
One example of adventure tourism is Antarctica. One can pay roughly $5000 and up for a 14 day cruise (Destination: Antarctica, Lonely Planet), or something like $40,000 for a flight to the south pole ("How can I get to Antarctica?", Antartica FAQ, Rob Holmes). Qantas also offers 12 hour flights over Antartica which do not land, according to the Lonely Planet site, but I don't know the price. I haven't seen figures on volumes for these products, but the Lonely Planet site makes it clear that it is at least thousands of people per year. I believe the book Lonely Planet Antarctica : A Survival Kit, 1st edition, Jeff Rubin, Nov 1996, has potentially useful information such as lists of cruise lines which go to Antarctica.
Microgravity aircraft are aircraft which fly a trajectory which provides about 30 seconds of weightlessness at a time. A number of companies are offering microgravity rides, or have talked about it; see the list of space tourism companies at the end of this page for more information. Prices tend to start at something like $2000 per passenger per trip. Reliability is high; I would guess about as good as general aviation (I don't have the numbers on that handy, but general aviation is 1/10 as reliable as commercial aviation).
Suborbital space vehicles have the additional advantage of saying that one has been to space and a better view out the window, in addition to a longer period in weightlessness.
The following discussion focuses on transportation rather than lodging and other on-orbit facilities because the transportation must be available for the lodging to make sense, because joyrides (short trips involving no on-orbit facilities) seem to be a significant market, and because I did a back of the envelope calculation (not shown here) in which the cost of a simple orbital facility, while significant, was smaller than the cost of transporting the tourists (CSTS, section 126.96.36.199.1, page 201; CSTS, section 188.8.131.52, page 291).
In doing rough conversions between dollars per kilogram and dollars per passenger, one needs a figure for kilograms per passenger (including supplies). There are lots of details in the CSTS, section 184.108.40.206.1, page 215.
There have been quite a few studies which have suggested that at prices like $10,000 to $100,000 per trip, there would be hundreds of thousands of passengers per year or more. The reliability of these studies is somewhat iffy. "These wide variations in numbers led [Tom] Rogers [of Space Transportation Association] to call for better and broader market surveys . . . Patrick Collins noted that less than $100,000 has been spent to date on all space tourism market surveys combined", from Barriers to Space Tourism, SpaceViews, 1 Jul 1999.
One major problem is "[many pre-1994 surveys have suffered from] a questionable correlation between survey results and actual ticket purchases . . . the U.S. Travel Data Center . . . is experienced in developing and phrasing the proper questions to correlate responses with actual sales" (CSTS, section 220.127.116.11, page 199). The Stockmans 1996 study and the 1995 study mentioned below also have the same problem. As far as I know there are no studies underway to do this right (for example, by studying high-income frequent fliers and trying to compare space tourism purchases with analogous purchases).
Another good check, which as far as I know has not been done in the published studies, is to do the same study regarding trips to Antarctica or some other existing form of adventure tourism. Then compare the predicated market with the actual one.
Extrapolating from these studies to higher price points is somewhat hazardous, because demand at the higher price points depends on the preferences of the rich, which may or may not match those of the general population. But here is a quick-and-dirty attempt at a rough extrapolation. From the STAIF'96 data above, 6% of the people would spend one years income and 2% of the people would spend three years income. In the following, columns (1) and (3), for how many households there are at or above each income level worldwide, are from the CSTS, section 18.104.22.168.3, page 202, and are very rough (based on extrapolating US income distribution to the rest of the world, for one thing).
(1) (2) (3) (4) (5) millions millions millions millions total households households households households millions one year willing 3 year willing households income to pay income to pay willing one year 3 year to pay dollars income income 6% of (1) 2% of (3) (2) + (4) 150k 7.72 0.463 77.29 1.546 1.999 300k 2.59 0.155 17.33 0.346 0.501 500k 0.896 0.0538 6.62 0.132 0.186 750k 0.308 0.0185 3.51 0.0702 0.0887 1500k 0.0772 0.00463 0.896 0.0179 0.0225Divide the above numbers by 30 or so to get yearly demand, and multiply by 2.63 to get people instead of households. Again: the numbers are very rough, with uncertainties and loose numbers everywhere (one specific note: the above table counts people twice, although that doesn't throw things off too much because the 2% number dominates over the 6% one. Sigh. Does anyone want to publish a more careful analysis of this sort?).
There is also anecdotal evidence to suggest some demand at high price points. TV news reporters have flown to Mir, or considered it, for something like $15 million (see the movies/TV page for specifics).
John Denver considered a flight to Mir for $10 million, according to "John Denver harbored dream to fly in space", Florida Today Space Online, 15 Oct 1997; this price is about what France paid to send a person to Mir, according to "Russian Yuri's and French woman return to Earth", Florida Today Space Online, 2 Sep 1996. Germany paid $60 million, according to "Russia-German space team blasts off for Mir station", Florida Today Space Online, 10 Feb 1997. My guess would be that the difference between the figures for France and Germany reflect differences in which costs are counted, but I have no information on that.
Dennis Tito is paying $20 million for 7-10 days on Mir, according to " U.S. businessman plans stay aboard Mir", Florida Today Space Online, 17 Jun 2000. Best Tito article I've seen is "Earth's First Self-Financed Astronaut", SpaceRef, Keith Cowing, 10 Dec 2000.
According to "Space Tourism Contest Announced", SpaceViews, November 1996, Space Marketing, Inc. plans to hold a lottery. Note that they still need to find a sponsor, and there is no financial data there. There is more background on Space Marketing, Inc., on my advertising page. Buzz Aldrin talks about lotteries in "From moonwalker to professional hawker: The selling of Buzz Aldrin", Florida Today Space Online, 10 May 1997.
1991: "In 1991, a female British candy factory chemist won a contest sponsored by the London-based Moscow Narodny Bank and spent eight days in orbit on Mir with four cosmonauts", "To Outdo 'Survivor', NBC Shoots The Moon", The Washington Post, 13 Sep 2000, page C7. Anyone have details on this one? I don't recall seeing much about it.
Can Lance Sing His Way Into Space, by James Oberg, spacer.com, 28 Aug 2002 is a great summary of all the projects to send privately funded tourists to Russian space stations, from the 1991 contest to Lance Bass in 2002.
Usually I try to make my pages be more than just a list of references. But especially in the case of space tourism there seems to be a lot of confusion about what studies say what, so I've attempted to survey the field. Please note that methodologies vary and results may or may not be any good. The following studies/articles are in chronological order:
Three years 2.9% One year 10.6% Six months 18.2% Three months 45.6% (less) the restBased on the average yearly salary of $24,000, this leads to a conclusion that at a price point of $10,000 to $20,000, there might be about 100 million people worldwide who would like to go to space. The study didn't publish data on how many times each person would want to go, so it is a little bit hard to extrapolate this into a yearly volume other than to say "more than one million trips per year".
This is pretty dated, but here are some of the companies which were or are in the space tourism field: