The Japanese Rocket Society ( JRS) is the oldest established academic astronautical society in Japan, and one of the oldest surviving rocket societies in the world, having celebrated its 40th anniversary in 1996. It became a member of the IAF in 1958; it hosts professional meetings; and co-sponsors a number of national and international conferences, including the biennial International Symposium on Space Technology & Science ( ISTS) in Japan, the biennial International Space Conference of Pacific-basin Societies ( ISCOPS), and the annual congress of the International Astronautical Federation ( IAF). The JRS also publishes the monthly newsletter "Rocket News", the bi-annual Journal of Space Technology and Science ( JSTS), and occasional monographs.

On April 14 1993 a Study Conference on Space Tourism was held, as described in a special issue of JSTS (1). Space tourism was chosen as a study topic at the suggestion of Professor Makoto Nagatomo, who also prepared the initial guidelines for the JRS Study Program. Over recent decades government space agencies have developed a range of new technologis, but these do not include low-cost rocket launch systems suitable for passenger space transportation. This creates an interesting opportunity: "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 industrialisation. This is the reason for this committee to choose rocket research for space tourism" (2). Presentations were made at the Study Conference by the four members of an invited panel of experts, who covered the main topics to be included in the Study Program: medical aspects, business development, transportation and passenger service.

JRS Transportation Research Committee

As the next step of the JRS Study Program, a 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 service required, initially a tour for 50 passengers lasting a few hours in an inclined low Earth orbit - to be extended to 24 hours at a later phase.

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 for Space and Astronautical Science. The Committee held 9 meetings during 1993 and 1994, and produced the 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 (3, 4), and in detail in the Transportation Research Committee's report (5).

Using existing and near-term technology, the Kankoh-maru reference vehicle has a height of 22 meters, a maximum 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 1/20 scale model was built and has been exhibited at a number of exhibitions including the 1994 Farnborough air-show, 1995 Tokyo international aerospace exhibition, 1995 Paris air-show, 1996 Farnborough air-show and elsewhere. It has also appeared on television both in Japan and abroad.

As described in another paper published by members of the Transportation Research Commitee, there are 12 main engines, providing 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 (6). The reference engines use an augmented expander cycle, and are to have a life of 300 flights, extendable through overhauls and replacement of parts. It is also intended that they should have a reduced number of life-critical parts as compared to existing rocket engines (6).

The liquid hydrogen fuel supplies needed for a commercial space tourism industry have also been studied (7). 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. The activities of the first phase of the study have been usefully summarised in (8).

Figure 1: Kankoh-maru passenger launch vehicle

In June 1995 the Transportation Research Committee started a second phase of activity to estimate the development and manufacturing costs of the " Kankoh-maru" vehicle. In addition to the technical requirements in the vehicle specification, these costs are strongly influenced by the planned development and production schedule.

The analysis of development costs has involved breaking the vehicle design down to a more detailed level than before, identifying the components and their specifications, and considering the extent to which development work is required. For some components not currently available in Japan, an alternative to domestic development is to purchase from abroad. Several different factors will enter such a decision, including the relative cost of imports and of domestically developed components, the expected market for different components, and the scale of foreign participation in the project financing. The H2A launch vehicle currently under development by NASDA includes several components and technologies purchased from abroad.

The production costs of Kankoh-maru and its various components will also depend on the rate of production. As a reference scenario the rate of production of Kankoh-maru vehicles is assumed to be 8 vehicles per year. Since each vehicle uses 12 rocket engines, the rate of production of rocket engines is some 96 per year. However, the engines will require regular overhauls, and so parts production will grow in proportion to the cumulative number of Kankoh-maru vehicles in operation - giving good potential for reducing unit costs through mass production.

During 1994 and early 1995 a series of preparatory meetings were held in parallel with the work of the Transportation Research Committee to discuss business aspects of the project. As a result of their studies the members of the Transportation Research Committee had become 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 will be necessary to obtain orders from companies wishing to operate Kankoh-maru. These companies in turn, before they can make a committment to purchase or operate the vehicle, need a clear understanding of many issues concerning its operation, which are currently uncertain. These issues therefore need to be studied further.

Another foundation of these 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 market research performed in Japan since 1993 and in Canada, Germany and USA in 1995, a global market of such a scale seems feasible if the price of a flight could be brought as low as about \2 million ($20,000) per person (9, 10, 11). Aiming at a market of this size has important implications for selecting the subjects to be studied.

The establishment of the JRS Space Tourism Business Research Committee was formally approved at the JRS Directors' meeting on April 27, 1995, and meetings were held monthly thereafter. Attendees at these meetings included staff of Kawasaki Heavy Industries, Dentsu Communications, Shimizu Corporation, the Institute of Space and Astronautical Science, Tokyo University, Teisan, Rocket Systems Company and retired experts from Chiyoda Corporation and All Nippon Airways. The following are some of th main issues considered by the Committee.

A major implication of aiming at a market of hundreds of thousands of people per year is that this would involve reaching a level of activity of 10s of flights per day. Although this level of activity would be less than 0.1% that of commercial aviation which carries 1 billion passengers per year (that is, 3 million passengers per day), space travel will nevertheless become a relatively large-scale activity, and an "ordinary" means of travel for members of the public. Since it is necessary to strictly minimize costs in order to reach the price target of \2 million per passenger, building dedicated "spaceports" costing tens of \ billions would not be attractive. It would be far preferable to use existing airports if possible.

The Committee has therefore studied the requirements for operating Kankoh-maru operations from existing airports (12). Required 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 is also considering certain airports around the world as candidates for case studies as first-generation space tourism service sites.

Using existing airports will also be appropriate for realising point-to-point sub-orbital passenger and cargo transport, which are considered to be additional commercial markets for Kankoh-maru. By using existing airports rather than separate launch sites, these services could be readily integrated with existing transport systems.

Using estimates of both demand for space tourism services based on market research, and of Kankoh-maru development and manufacturing costs, operating costs have been estimated, and scenarios for the possible growth of a commercial space tourism industry have been 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 other aspects. The main scenario being prepared assumes a 7-year development phase, and a 3-year period of test-flights to obtain certification for passenger carrying, followed by a production rate of 8 Kankoh-maru vehicles/year.

This rate of production was selected as being feasible both for vehicle and engine 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 some 100,000 passengers per year per year. Likewise the production of cryogenic propellants will grow by approximately 1,000,000 tons per year per year, and the number of sets of engine spare parts replaced during overhaul assumed necessary every 100 flights will increase by 288 sets per year per year to 1800 sets per year once 50 Kankoh-maru are in operation, providing scope for cost reduction.

Preparing this scenario facilitates understanding of the potential industrial, commercial and financial impacts that could be expected from creating a space tourism industry based on Kankoh-maru. For example, launch vehicle manufacturers, rocket engine and aerospace component makers, propellant producers and materials companies will all participate in the cash-flows received from the public by the vehicle operating companies. Architecture, construction, component production, interior design, building utilities, food, drink and entertainment companies will all participate in the cash-flows of the operators of hotels in Earth orbit. New business opportunities will also arise for companies providing investment, insurance, leasing, banking, marketing, media and law services. A level of activity of 1 million customers per year would generate revenues of trillions of Yen per year (tens of billions of US dollars), which would clearly infuse new life into the aerospace industry of countries which participate.

Figure 2: Annual level of space tourism activity following growth scenario based on constant Kankoh-maru production rate of 8 vehicles per year (from year 8).

Another subject which the Committee has considered arises from the fact that a large majority of those who wish to travel to space state that they would prefer to stay in orbit for several days rather than for only a few hours (9, 10, 11). Carrying out more detailed market research is highly desirable, in order to elucidate this and other matters. Provisionally the Committee have assumed 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 in orbiting accommodation for a few days. The Committee have therefore also been studying the requirements for "space hotels", albeit only at a preliminary level.

JRS Rocket Symposiums

In addition to the regular meetings of the JRS Space Tourism Research Committees, during 1996 and 1997 a series of "Rocket Symposiums" is being held to discuss and disseminate the issues raised by these Committees' research, and the results of other research on Kankoh-maru. To date this includes wind tunnel research on re-entry and precision landing; rocket nozzle design to reduce noise; feasibility of attitude control using engine-throttling rather than gimballing; precision fuel management; selection of attractive orbital paths for Earth sight-seeing, and other topics.

Although it is believed that all the problems facing the establishment of a space tourism business are soluble, more detailed work is required on a number of subjects. These include both a range of technological issues relating to the vehicle and engines, and such ancillary matters as developing certification rules for passenger rocket vehicles, and revising space law (13). Resolving these issues satisfactorily will require collaboration of experts in a wide range of fields, and will be most effective if performed internationally. The proceedings of these meetings are to be published in book form, and are intended to help shift the paradigm of rockets from being seen as "missiles" to being seen as passenger-vehicles ("norimono" in Japanese).

Over the four years of the JRS study to date, the understanding of the potential of space tourism has advanced considerably both as a result of this study, and as a result of efforts elsewhere, as summarised in (13). The concept of space tourism is receiving increasing attention within a growing range of different organizations. Perhaps most significantly a joint study by NASA and the Space Transportation Association (STA) was initiated in 1995 (14), of which the Steering Committee reached the view in 1996 that the problems facing the establishment of a space tourism business could be overcome within 15 years (15). In Europe a preliminary feasibility study of the "Spacecab" low-cost spaceplane was commissioned by ESA, and subsequently confirmed by British government researchers (16). A development path for space tourism services was conceptualized at NASDA through four phases - low Earth orbit, highly elliptical orbits with apogees providing views of distant Earth, orbital accommodation, and lunar excursions (17). In 1997 researchers at the Aerospace Corporation published the design of a vehicle intended specifically for space tourism (18).

In consequence the JRS Transportation Research Committee is currently planning a 3rd phase of activity in which the design of the Kankoh-maru will be revised as a result of the technical analysis done to date, and more specifically in order to meet the requirements of certification for passenger carrying. In the initial design phase, this was considered too difficult a target. It would also have involved discussions with regulatory authorities at a time when the concept of commercial space tourism was still unfamiliar and its feasibility was still doubted. However, it is now considered both feasible and appropriate to tackle this next stage of design detail.

The Business Research Committee is considering a range of follow-on activities, although it is not yet decided in what format it will be most appropriate to continue. It is intended that the Business Research Committee should be followed by a Business Committee, chaired by a senior figure from the Japanese business community with the objective of raising the investment required to bring this project to fruition. However, prior to that it is felt desirable that further progress should be made in the following subjects.

Like aviation and other transportation systems, passenger space travel will need insurance, which in turn necessitates a range of appropriate new technical standards. In each of the fields of vehicle certification, airport accommodation of rocket vehicles, and design, construction and operation of orbital accommodation, various regulatory bodies both national and international have important roles to play. Work has begun on these issues in the USA. The Office of Commercial Space Transportation was moved into the FAA in 1995 and a panel was held in 1996 to consider regulation of reusable rocket operations (19). Proposals concerning regulation of commercial facilities in orbit have have also been made (20, 21). International participation in these discussions from as early a stage as possible could facilitate achieving harmonious international standards.

The environment for initiation of space tourism services today is much more regulated than the environment in which aviation services were initiated early this century. Consequently, unless existing regulatory bodies do the necessary research and create an accommodating environment, this new business cannot start. Creating an encouraging regulatory environment is as essential as the development of the necessary technology, and as the articulation of adequate market demand. Institutional and bureaucratic change are difficult, but countries in which government organisations resist these changes will fail in this new field of international economic competition. Countries which participate in a profitable space tourism industry will have a leading role in providing reliable, low cost access to space, and in the new commercial space activities that will arise.

Like other transport activities, the safety of commercial space tourism will depend ultimately on the demonstrated reliability of the vehicles, as measured by accumulated operating statistics.

In aiming at a passenger service it is therefore highly desirable to start to accumulate experience of reusable rocket operations as soon as possible. Although the concept of passenger-carrying rockets is unfamiliar today, during the 1950s Rocket-Assisted Take-Off ( RATO) aircraft employing reusable rocket engines were operated on a regular basis in the air forces of several countries', and a RATO version of the de Havilland "Comet" jet-liner was even certified for passenger carrying (22). From 1993 to 1996 the unpiloted DC-X and DC-XA re-usable VTOL rocket vehicles performed 15 rocket-powered flights in the USA. However, in order to achieve certification for passenger carrying, hundreds of flights of piloted vehicles will be required.

During 1995 and 1996 the Business Research Committee studied the possibility of cooperating with McDonnell Douglas Aerospace and partners to perform flights of the DC-X in Japan, possibly as part of a "world tour". This possibility disappeared with the accident that destroyed the DC-XA in 1996. However, the construction and operation of a piloted VTOL rocket test-vehicle is currently being considered. Operational experience of a piloted version, even with a sub-sonic flight envelope similar to the DC-X itself, would be very valuable in accumulating operating statistics. Once the reliability reached an acceptable level it would be possible to fly such a vehicle at air-shows. Some such activities might be sponsored commercially, and could have a beneficial influence in both publicising the concept of space tourism and demonstrating the maturity of the technology involved.

Another subject requiring further study is the design of orbital accommodation, or "space hotels". A few hundred thousand passengers per year staying in orbit for even 2 or 3 days on average will create a simultaneous orbital population of several thousand guests - and an additional population of more than 1000 hotel staff - a substantial scale of activity. To date, no reliable estimates have been published of the relative costs of a flight to orbit and of a stay in orbital accommodation, but as guests stay for longer and longer the growth potential is clearly substantial.

The basic technology required for accommodation in low Earth orbit has been available since the "Skylab" space station was in operation in 1973-74, because the technology needed for orbital accommodation is in many ways much simpler than that needed for a scientific research station such as the current international space station project. There is no need, for example, for advanced technology used in space research such as super-computers, high data-rate communications, high pointing accuracy, high power generation, and low-vibration centrifuges.

However there are new requirements since fare-paying guests require a higher level of both comfort and safety than the US and Soviet research facilities that have been operated in orbit to date. These new requirements include normal features of hotels such as private bedrooms with windows and bathrooms, communal dining-rooms, lounges, bars and "karaoke-boxes", rooms with large windows for looking outside, and entertainment facilities such as zero-gravity play-rooms. New construction standards will be needed to ensure guests' safety, as commercial buildings on Earth must comply with professional codes of practice and with government regulations. In these and other respects the development of orbital accommodation will be similar to real estate projects on Earth, as discussed by Lauer and colleagues in the USA (23).

The idea of space tourism is not yet widely known, and the fact that it is considered feasible within 15 years by senior NASA staff (15) is even less well-known. There are many obstacles to overcome, among them being the widespread misunderstanding that travelling to space is stressful, and so only unusually fit people can go to space. Japanese astronauts have been making valuable contributions towards overcoming this misunderstanding. Dr Mukai has explained that astronauts' long training is primarily needed for the busy work-schedule that they must achieve while in orbit, not because living in space is stressful, and has stated that "anyone can go to space" (24). Dr Mohri has explained that "space sickness" is a form of motion sickness and is cured by modern travel sickness medicines (24), and that the reason why many people who travel on the space shuttle are sick is that NASA staff ask them not to take medication before take-off, because they wish to collect data for research.

Fortunately the wide popularity of the concept of space tourism is helping this knowledge to spread. Both the Kankoh-maru reference vehicle design, and the idea that establishing a space tourism business is a feasible near-term objective are receiving growing attention in the media in Japan and abroad. The JRS's work has been the subject of substantial newspaper articles in the Asahi Shinbun and Yomiuri Shinbun; in magazines including Dagian, L5 and Aera in Japan, and Aerospace America in the USA (25); and also in books (24, 26). The 1/20 scale model of Kankoh-maru built by Kawasaki Heavy Industries has a full schedule of exhibition appearances, and has appeared on national television in Britain, on local television channels in Japan, and is due to appear on national US television. Separately from the JRS' work the concept of space tourism has been receiving increasingly serious attention world-wide, such as in the STA-NASA space tourism study started in September 1995 (14), and the announcement of the $10 million "X Prize" for the first private company to transport two people safely to an altitude of 100 km twice within one week (27).

The development of reusable launch vehicles capable of routine "airline like" operation can be justified only if they can serve a launch market many times larger than the market for satellite launches. Since 1993 the Japanese Rocket Society ( JRS) has been formally studying the establishment of a space tourism business, and has published a unique series of papers and reports clarifying the feasibility of developing space based on the popular support of the general public as customers rather than as taxpayers. Market estimates based on research in Japan, Canada, Germany and USA suggest that demand for space tourism flights to and from low Earth orbit could be large enough to justify the development of passenger launch vehicles in the near future. Following the first four years' work, further work is needed in a number of different fields in order to establish a commercial space tourism business. In what form this work continues in future is currently under discussion.

It will depend on several different factors, including the degree of interest shown by other countries in participating.

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