The first Space Tourism Study Conference of the Japanese Rocket Society ( JRS) was held on April 14 1993, as part of the JRS Annual General Meeting (1). The choice of space tourism as a study topic arose from consideration by the JRS Committee for Academic Activities of the future direction of rocket vehicle development around the world, at the suggestion of JRS Vice-President Makoto Nagatomo, who also prepared the initial guidelines for the JRS Study Program. Following the pattern of recent decades, high-performance rockets suitable for advanced missions such as planetary research will be developed by government space agencies responsible for developing new technology.

However, low-cost rocket launch systems suitable for large-scale passenger space transportation are not being studied elsewhere, and so this subject was chosen for the JRS study: "As shown by the history of aircraft design, most cargo vehicles have been modified versions of passenger vehicles. Accordingly, passenger rockets are likely to be converted to carry cargo for space industrialization. This is the reason for this committee to choose rocket research for space tourism" (2). Although a controversial subject, this logic was accepted by the then JRS President who agreed that the JRS should "adopt space tourism as the main topic of its research" (3).

Presentations were made at the Study Conference on four main subject areas: medical aspects, business development, transportation aspects and passenger service. The structure of the JRS Space Tourism Study Program is shown in Figure 1, and the initial activities are described in a special issue of the Journal of Space Technology & Science published by the Japanese Rocket Society (1).

Figure 1: Research disciplines of the JRS Space Tourism Study Program (4)

As the next step of the JRS study, the Transportation Research Committee was established to prepare a conceptual design of a vehicle suitable for space tourism. Design criteria for the vehicle were based on the services required, the initial requirement in the first phase of operations being to provide an orbital tour for 50 passengers in a highly-inclined low Earth orbit of 200 km altitude lasting 3 hours, and lasting up to 24 hours in a later phase of operations.

The Transportation Research Committee is led by Kawasaki Heavy Industries, and members of the committee include staff from Mitsubishi Heavy Industries, Fuji Heavy Industries, Ishikawajima Harima Heavy Industries, Nissan Motor Company, All Nippon Airways, Teisan, Japan Aircraft Development Corporation and the Institute of Space and Astronautical Science. The Committee held 9 meetings during 1993 and 1994, and produced the conceptual design of the " Kankoh-maru" vertical take-off and landing ( VTOL) single-stage to orbit ( SSTO) vehicle. This has been described in a number of papers (4, 5), and is published in detail in the Transportation Research Committee's report (6).

Figure 2: " Kankoh-maru" passenger launch vehicle

Using existing and near-term technology, the vehicle design has a length of 22 meters, a width of 18 meters, and a take-off mass of 550 tons. The dry mass is 50 tons, and the structure is made largely from composite materials. Each vehicle is designed to fly 300 times per year, and to have a 10 year life. A 5% scale model of " Kankoh-maru" was built and has been exhibited at a number of exhibitions including the 1994 Farnborough air-show, 1995 Tokyo international aerospace exhibition and the 1995 Paris air-show.

Figure 3: 5% scale model of Kankoh-maru

Another paper published by members of the Transportation Research Commitee described the Kankoh-maru propulsion system (7). There are 12 main engines, to provide redundancy for higher system reliability, comprising 4 booster engines with nozzle expansion ratio of 15, and 8 sustainer engines with nozzle expansion ratio of 40 initially, changing to 80 at altitude using a nozzle extension. The engines use an augmented expander cycle, and are to have a life of 300 flights. The design also requires them to have a reduced number of life-critical parts as compared to existing rocket engines (7).

The liquid hydrogen fuel supplies needed for a commercial space tourism industry have also been analysed in some detail (8). Cryogenic propellants are considerably more expensive than the kerosene used in aircraft, and the propellant cost is expected to comprise some 50% of the flight cost of Kankoh-maru. As a result, a space tourism industry operating on a scale large enough to carry hundreds of thousands of passengers to orbit each year would represent a market for liquid hydrogen many times larger than the existing demand, reaching several $ billions per year. This in turn will require very substantial investment in facilities for production and transportation, including fabrication and operation of a new generation of bulk cryogenic tankers.

In June 1995 the Transportation Research Committee started a second phase of activity aimed at estimating the development and manufacturing costs of the " Kankoh-maru" vehicle. In addition to the technical requirements in the vehicle specification, these costs are influenced by the planned development and production schedule (see Figure 4).

The analysis of development costs currently under way involves breaking the vehicle design down to a more detailed level than that in (6), identifying the components and their specifications, and considering the extent to which development work is required. For some components which are not currently available in Japan, an alternative to domestic development is to purchase from abroad, since the range of aerospace technology available throughout the world is wider than that available in Japan alone. Thus, one matter for consideration is the extent to which parts should be developed in Japan, and the extent to which it might be desirable to import them from foreign manufacturers. Several different factors enter such a decision, including the relative cost of imports and of domestically developed components; the relative market potential of different components; and the scale of foreign participation in the project financing.

Analysis of the production costs of Kankoh-maru and its various components involves comparison of the parts and sub-systems with other products of which companies have production experience. The production costs will also depend on the rate of production. Thus for example, in the scenario shown in Figure 4 the rate of production of Kankoh-maru vehicles reaches a steady level of 8 vehicles per year. Since each vehicle uses 12 rocket engines, the rate of production of rocket engines is some 96 per year. However, if these engines have a lifetime of 1 year each, the annual production rate would increase every year: 96, 192, 288, 384... and so on. This has important implications for achieving low unit costs through mass production.

A report on the results of the Phase 2 study is due by the end of fiscal year 1995. As the study continues, the results are being used by the Space Tourism Business Research Committee, a second committee established by the JRS to study the overall feasibility of space tourism.

During 1994 and early 1995, a series of preparatory meetings were held to plan the establishment of a Space Tourism Business Research Committee to work in parallel with the Transportation Research Committee. Participants in these discussions included members of Kawasaki Heavy Industries, Dentsu Communications, Shimizu Corporation, the Institute of Space and Astronautical Science, and Tokyo University. One activity of this preparatory committee was to prepare a document giving a general outline of the concept of space tourism to be used to explain the possibility to people and companies unfamiliar with it. Discussions were also held on suitable objectives for a formal Committee, and on possible steps towards the development of space tourism services.

Considered from a business point of view, the project is clearly not yet sufficiently advanced to approach potential investors, and so a Business Research Committee is needed to improve understanding of various aspects of the subject. To simplify somewhat, as a result of their studies to date the manufacturing members of the Transportation Committee became keen to develop and manufacture the Kankoh-maru passenger vehicle. However, as in the aircraft industry investment in developing a new vehicle is not committed until manufacturers obtain firm orders, so it is necessary to obtain orders from potential operators of Kankoh-maru. These companies in turn, before they can make a commitment to purchase or operate the vehicle, need to have a clear understanding of many issues concerning its operation, which are currently uncertain. These issues therefore need to be studied further.

Another foundation of the preparatory committee's discussions was the understanding that unless a space tourism service was planned to grow to a substantial level - that is, of the order of some hundreds of thousands of passengers per year or more, requiring the operation of 50 or more Kankoh-maru vehicles - the development of this vehicle would probably not be feasible on a commercial basis. From the results of the market research performed in Japan in 1993, a market of such a scale seems feasible, possibly even in Japan alone - provided that the cost of a flight can be reduced to a level of between 2 million Yen and 1 million Yen per person (9, 10). Aiming at a market of this size has a number of important implications for selecting the subjects which the members of the committee are studying.

The establishment of the JRS Space Tourism Business Research Committee was formally approved at the JRS Directors' meeting on April 27, 1995, and met 5 times through October. The Committee, which is composed of preparatory committee participants plus Teisan, Rocket Systems Company and retired experts from Chiyoda Corporation and All Nippon Airways, is currently planning to publish a report by the end of fiscal year 1995 which will outline a commercial space tourism industry based on operating the Kankoh-maru vehicle, as conceived by the members of the committee in as realistic detail as possible. This report will cover several main topics.

A major implication of aiming at a market of hundreds of thousands of people per year is that, although this level of activity would be very much less than that of aviation (currently some 1000 million people travel in commercial aircraft each year), space travel will nevertheless become an ordinary, "day-to-day" activity for members of the public, on a reasonably large scale, that is of the order of tens of flights per day, carrying thousands of passengers per day. Since it is necessary to minimize costs in order to reach the cost target mentioned above, building dedicated "spaceports" which would cost billions of Yen or even tens of billions of Yen would not be attractive, and so it is preferable to plan to use existing transport infrastructure.

The Committee is therefore studying the changes that are required in order for existing airports to accommodate Kankoh-maru operations. These changes include cryogenic propellant facilities; vehicle handling systems; passenger handling arrangements; compliance with noise regulations; integration into air traffic management systems, and other matters. The committee also aim to select certain airports around the world as potential candidates for hosting the first generation of space tourism services.

Using existing airports will also be appropriate for realising point-to-point suborbital passenger and cargo transport, which could be additional commercial uses of " Kankoh-maru". By using existing airports rather than dedicated facilities, these services could be readily integrated with existing transport systems.

Another subject for the committee to study arises from the fact that a large majority of the market research participants who express the wish to travel to space state that they would prefer to stay in orbit for several days than for only a few hours (9, 10). Carrying out more detailed market research is highly desirable, in order to elucidate this and other matters. However, at present the Committee are assuming that in order for demand for orbital travel to reach the level of hundreds of thousands of passengers per year, it will be necessary to offer customers the possibility of staying at orbiting accommodation. The committee are therefore also studying the requirements for orbital accommodation that will be needed to provide such a service; possible specifications for commercial facilities; possible design approaches; operational details, and other related matters.

Using estimates of demand for space tourism services based on market research performed on a sample of 3030 people in Japan in 1993, and the Kankoh-maru cost estimates being developed by the Transportation Research Committee, scenarios for the possible growth of a commercial space tourism industry are being prepared. These help to reveal the commercial potential of space tourism activities in more detail, by identifying the financial flows that would arise; the relative shares of participating industries, and so on. The main scenario being prepared assumes a steady production rate of 8 Kankoh-maru vehicles/year after a 5-year development phase (see Figure 4). This scenario is not a prediction but a model to facilitate understanding of the potential industrial, commercial and financial impacts that could be expected from developing the Kankoh-maru successfully and creating a space tourism industry.

Figure 4: Space tourism scenario based on constant Kankoh-maru production rate

A production rate of 8 vehicles per year was selected as a rate convenient both for manufacturers and for the growth of cryogenic propellant production. That is, since each vehicle's life is to be 10 years, a constant production rate of 8 Kankoh-maru vehicles per year entails a growth rate of flight activities of 2,400 flights per year per year, or up to 120,000 passengers per year per year. Likewise the production of cryogenic propellants will grow by approximately 1,200,000 tons per year per year, and the number of engines manufactured per year will increase by 96 per year per year, if they are all replaced each year. Drawing out the manufacturing implications of an operation scenario in this way is very helpful in understanding the requirements and implications of this new industry.

The Business Research Committee is also considering a range of near-term activities, some of which might be sponsored commercially, and that could have a beneficial influence in publicising and popularising the concept of space tourism. One such possibility is to cooperate with McDonnell Douglas Aerospace and partners to perform flights of the DC-XA re-usable experimental rocket in Japan, possibly as part of a "world tour".

Like other transport activities, a commercial space tourism industry will need insurance, which is ultimately based on the demonstrated reliability of the vehicles insured, as measured by accumulated operating statistics. During the 1960s rocket-assisted aircraft employing reusable rocket engines were operated in several countries. In recent years, however, such activities have almost ceased, and resuming demonstrations of reusable rocket operations is desirable. From 1993 to 1995 the DC-X has performed 8 rocket-powered flights in the USA, and the committee is cooperating with US researchers to consider possible international cooperation using this vehicle.

The JRS is currently studying space tourism because it seems to have the potential to create near-term demand for launch operations on a scale large enough to justify the commercial development of low-cost reusable launch vehicles. Consequently the " Kankoh-maru" reference vehicle is being designed to be capable of low-cost, airline-like operation; the procedures and facilities needed for commercial space tourism operations are being studied in detail; and essential preparations needed to develop a space tourism industry such as new technology development, safety regulations, and accumulation of reusable rocket operation statistics are being assessed.

Future launch activities based on the use of low-cost reusable passenger vehicles will be very different from today. In particular, as in the aviation industry, they will be integrated with other transportation systems; launch vehicle operations will grow larger than vehicle manufacture; and all space activities will be much less expensive than today. Furthermore the potential for further growth of such activities through the development of more advanced launch vehicles, a wider range of service offerings, and larger and more varied orbital accommodation facilities seems essentially limitless.

The JRS study aims to create a clear and detailed image of how a space tourism industry can grow to become a major new direction for commercial space activities, involving a much wider range of businesses than have participated in space activities to date, and on a much larger scale. In doing so it hopes to persuade others in companies and relevant regulatory organisations to join in and work towards this goal and thereby open the space frontier to humankind.

1. M Nagatomo, Preface, Journal of Space Technology and Science: special issue on space tourism, vol.9, no.1, p 1.
2. M Nagatomo, "On JRS space tourism study program", Journal of Space Technology and Science: special issue on space tourism, vol.9, no.1, pp 3-7.
3. R Akiba, Foreword, Journal of Space Technology and Science: special issue on space tourism part 2, vol.10, no.2, p 1.
4. K Isozaki et al, 1994, " Considerations on vehicle design criteria for space tourism", IAF paper no. IAF-94-V3.535.
5. K Isozaki et al, 1994, "Vehicle design for space tourism", Journal of Space Technology and Science: special issue on space tourism part 2, vol.10, no.2, pp 22-34.
6. Japanese Rocket Society, 1995, "" Kankoh-maru" standard vehicle for space tourism" (in Japanese), JRS report.
7. K Mon et al, 1994, "Design study on propulsion systems for space tourist carrier vehicle", Journal of Space Technology and Science: special issue on space tourism part 2, vol.10, no.2, pp 35-44.
8. T Hanada et al, 1994, "Liquid hydrogen industry: a key for space tourism", Journal of Space Technology and Science: special issue on space tourism part 2, vol.10, no.2, pp 45-51.
9. P Collins et al, 1994, " Potential demand for passenger travel to orbit", Engineering Construction and Operations in Space IV, American Society of Civil Engineers, pp 578-586
10. P Collins et al, 1994, "Commercial implications of market research on space tourism", Journal of Space Technology and Science: special issue on space tourism part 2, vol. 10, no.2, pp 3-11.