Japanese Rocket Society's Rocket Symposia 1995-2001

- With an Overview of Japanese Rocket Society's Space Tourism Study -

Abstract

The Japanese Rocket Society's Rocket Symposia were held on six occasions from 1995 to 2001, where new technical and other essential topics were discussed and ideas were exchanged from concerned communities of rocket engineers, civil aviation and others in order for making general public "space tourism" happen. The objective of the study was to identify the issues that were never taken into consideration in expendable launch vehicle's design and operation, and is to figure out the goal of space transportation architecture, particularly from the viewpoint of "real" commercialization and large scale transportation between the ground and low earth orbit. Considerations and assessments for achieving passenger safety, medical aspects, and regulations needed to allow civil airline-type operations, were made extensively together with necessary technical issues.

1. Introduction

There are two categories of people in the space community. One says "Space tourism? Such a fantasy world! I do not believe in it, and it is not my job." The other says "Why don't you think about how to make it happen?"

The Japanese Rocket Society ( JRS) started its "Space Tourism" study in 1993. Taking a look at the present status of the space transportation architecture based on expendable launch vehicles, the objective of the study was to identify what our next goal is. The expendable space launch architecture is well matured, however the launch success rate never reaches beyond ninety percent. The US STS has demonstrated its partly reusable system architecture, however the reality is far from what was expected at its planning phase in the 1970s. In the planning, it was expected to be reused much more frequently, such as once every ten days, and its turnaround operation was to be simpler and similar to that of aircraft operation.

One of the reasons for the lower launch rate and higher cost than expected is due to difficulties in reusing the spacecraft caused by its less engine reliability, poor durability of the thermal protection sub-system, and so on. Another reason to be pointed out is that there was not such a large transportation demand by which very frequent transport to and from the orbit was needed. As a result, the launch cost of the STS is more expensive than that of expendable vehicles.

Within the framework of present transportation demands, such as broadcasting, communication, navigation, space station logistics, and so on, a qualitative and drastic change in demand will never happen. This was the background idea why the JRS promoted studies for the tourism of general public. Since 1993, the JRS established several research committees under the coordination of the JRS's academic committee headed by Professor Makoto Nagatomo and his colleague at the Institute of Space and Astronautical Science (ISAS).

Starting from market research on the potential demand from passengers for tourism, figuring out the transportation vehicles needed to go from the ground to low Earth orbit and return to the ground. The study results were reported and published by the JRS. Based on these studies, the concept of the Kankoh-maru passenger carrier vehicle was established as shown in Fig.1. This is a single-stage-to-orbit ( SSTO) vehicle capable of carrying fifty passengers on-board to and from low Earth orbit. A fifty Kanko-maru fleet will carry a million passengers every year at a ticket price several times the monthly salary of average working people. Commercialization this venture in the business sector was assessed by the JRS Enterprising Committee which launched its business model and Regulatory Committee which studied the legal considerations of safety regulations as is done in the civil aviation community today. These studies pointed out many new topics and problems, such as procuring huge supplies of liquid hydrogen as fuel for Kankoh-maru fleets, the environmental impact of large numbers of launches as compared to the present launch frequency, and so on.

Fig.1 Kankoh-maru Passenger Carrier SSTO by JRS

It turned out that there were many difficulties to make such a totally different world than today, however it was meaningful in figuring out what our goal is, and in which direction our goal lies from the transportation architecture point-of-view.

Following these studies, aiming at establishing safety regulations for the vehicle design and operational aspect, a draft of so called "spaceworthiness" for this kind of space transportation vehicle was attempted, reflecting the "airworthiness" regulations of civil transports in the aircraft community. Since the JRS committees were originally composed of rocket engineers and researchers, the wide range of considerations presented above needed a wider variety of people to join in. The committees invited new members from the outside world, such as economist, aircraft manufacturers, airline people, travel agencies and so on. Unlike other space transportation studies conducted world-wide, those from out of the rocket community worked remarkably to establish new concepts and considerations. By discussion within the rocket community alone, such a new and extensive thought has never been achieved. These study results were summarized and published as Reports by the JRS. Although all the reports were published in Japanese, many topics were summarized in English journal published by the JRS [1-12], and in some other conference proceedings [13-16].

Throughout these studies, there were many new considerations and discussions in and outside the JRS committees.

The present "Rocket Symposia" were also coordinated and held by the JRS's Academic Committee to collect and discuss openly these new ideas and attempts at figuring out this totally different world. Starting from technical considerations for SSTO vehicles, discussions for new enterprises, regulatory issues, safety issues, opinions from airline people and travel agencies, and so on.

Table-1 Contents of Proceedings of JRS Rocket Symposia 1995-2001

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First Rocket Symposium: "Passenger Carrier Vehicle for Airline-Type Operation" (June 28. 1996)

1. Kanko-maru design and development cost estimate; Kohki Isozaki, Kawasaki Heavy Industry
2. Weight reduction of primary structure and TPS of Kanko-maru; Tomoko Maruyama, Fuji Heavy industry
3. Propulsion sub-systems of Kanko-maru; Hiroyuki Watanabe, Ishikawajima-Harima Heavy Industry
4. New structural layout for lighter weight SSTO; Takamichi Tanaka, Institute of Space and Astronautical Science
5. Landing Approach flight of vertical landing vehicle; Yoshifumi Inatani, Institute of Space and Astronautical Science
6. Landing gear for vertical landing SSTO vehicle; Yoshihiro Naruo, Institute of Space and Astronautical Science

Second Rocket Symposium: Passenger and Cargo Treatment (September 18. 1996)

1. Enterprising space tourism business and vehicle design; Patrick Collins, University of Tokyo
2. Cabin noise consideration for passenger carrier rocket; Tooru Ito, Kawasaki Heavy Industry
3. Ground Operation of Kanko-maru; Makoto Nagatomo, Institute of Space and Astronautical Science
4. Passenger's safety of Kanko-maru; Tsuruo Torikai Fuji, Aerospace Technology
5. Passenger seat for Kanko-maru; Patrick Collins, University of Tokyo

Third Rocket Symposium: Regulatory Issues As Public Transport (November 25. 1996)

1. Regulation for Space Flight; Yoshiyuki Funatsu, Aviation Consultant
2. Evacuation from passenger carrier aircraft; Yoshiyuki Funatsu, Aviation Consultant
3. Assured safety in civil aviation and space travel; Hideo Matsuoka, University of Tokyo
4. Operational Aspects of passenger carrier space vehicles; Patrick Collins, University of Tokyo

Fourth Rocket Symposium: Space Launch Vehicles Operated By Airline (march 28. 1997)

1. Looking back at Japanese rocket research; Kenjiro Kamijo, Tohoku University
2. Exterior engine noise and its reduction; Jun Kubota, University of Tokyo
3. Airline's request to space launch vehicle; Yoshiyuki Funatsu, Aviation Consultant
4. Utilization of non space-qualified parts and instruments for space vehicles; Teruo Fujiwara, Nossan Motor Co.
5. What is needed for commercial based development; Kouichi Suzuki, Ishikawajima-Harima Heavy Industry

Fifth Rocket Symposium: "Assuring Safety" (December 17. 1999)

1. Culture difference between rocket and aviation communities; Tsuruo Torikai, Fuji Aerospace Technology
2. Airworthiness and its goal; Tooru Miyashita, Ministry of Transport
3. Civil aviation and its safety concerns; Sadao Kondo, All Nippon Airways
4. Safety conscious design of aircraft and rocket launch reliability; Koichi Yonemoto, Kawasaki Heavy Industry
5. Space vehicle's structural safety margin; Kei Miyahara, Fuji Heavy Industry
6. Rocket engine independency considerations as aircraft design; Osamu Kitayama Mitsubishi Heavy Industry
7. Equipments to assure passengers' safety; Noboru Shinozaki, Nissan Motor Co.
8. Higher reliability rocket engine design; Kazutaka Iwama, Ishikawajima-harima Heavy Industry
9. "Spaceworthiness" regulation for passenger carrier space vehicle; Tsuruo Torikai, Fuji Aerospace Technology
10. Necessary medical data for space tourism; Makoto Nagatomo, Institute of Space and Astronautical Science

Sixth Rocket Symposium: "Airline's Viewpoint" (March 26. 2001)

1. Regulatory committee for civil space transport; Yoshiyuki Funatsu, Aviation Consultant
2. General specifications for cargo and passenger carrier space vehicle; Yoshiyuki Funatsu, Aviation Consultant
3. Basic specifications for civil space transport; Hitoshi Ohashi, All Nippon Airways
4. Guideline of medical science for space tourism; Shigeo Mori, Nagoya University

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Within the symposia, many discussions were collected from very preliminary thoughts to streamlined considerations. Some of these were directly reflected in the committee's Reports presented above, but some were not. However they were all helpful to deepen the thoughts in the reports published by each JRS research committee [17-22]. The present paper summarizes these talks and discussions in the symposia together with a brief overview and record of the JRS tourism study development.

2. Market Research and Kankoh-maru Technical Specifications

The concept of the Kankoh-maru SSTO vehicle was established based on market research. The market research basically asked "what amount of money out of your pocket will you pay for a return-flight to low Earth orbit?"

Transferring the result of this market research into annual demand with respect to the ticket price offered, it turned out that there is reason to assume a million potential passengers exist when we offer a ticket price of $15,000 per flight. Assuming that we do it as a business, this is $13 billion of annual revenue (Fig.2). Assuming fifty passengers on each vehicle and daily flights, it is a simple calculation how many vehicles we need, as if it is airliner marketing. Imagine fifty SSTO launches every day. It turned out to be a totally different world than today.

It is natural for us to ask questions how to handle so many launch vehicles as an airport operation, how much liquid hydrogen we need as a fuel, what is the good location of spaceport for attracting people, and how to assure safety. It is obvious that many totally new considerations were needed.

In the first "Rocket Symposium" in 1995, these topics were discussed primarily from the point-of-view of technical considerations. Daily flights were assumed in order to operate fifty vehicles of a Kankoh-maru fleet. A vertical lander SSTO with conventional rocket engines with liquid hydrogen as a fuel was selected, from the viewpoints of its SSTO performance consideration and potential simplicity of the flight and ground operation considerations. As discussed below, potential continuous intact abort capability was also taken into consideration.

In Table-2 the specification of Kankoh-maru is summarized based on these marketing and technical assessments. The total amount of liquid hydrogen required for a fifty Kankoh-maru fleet is more than ten times world production today. Therefore the study called for a new way to procure such a huge amount of fuel, and its production and transportation costs were outlined. If we operate this fleet from a single spaceport, a launch would take place every twenty minutes. Spaceport services and turn around operations needed to make it possible will be quite similar to those of airliner operations in the busy airport. Taking care of cryogenic fuel and oxidizer during its ground operation is one of the new and major concerns in dealing with these turnaround operations. Unlike today's launch vehicles, the fuel and oxidizer tanks and propulsion sub-systems need to maintain continually chilleddown condition by being in the loop with ground chilling-down facilities. Making space transportation vehicle as today's aircraft is also one of the major concerns, requiring eliminating toxic fuels for auxiliary propulsion sub-systems and on-board power generation. For the simplified vehicle systems and ground operations, even considering elimination of high-pressure helium for purging and actuation of many parts and valves of the propulsion sub-systems was attempted.

Number of Passenger	50
Annual No. of Flight	270
Fleet No. of Vehicle	52
Life of Vehicle	10 years
Vehicle price	$700M
Operation cost / Flight	$1.0M
Gross Lift Off Weight	550 ton
Vehicle Dray Weight	50 ton
Vehicle Height	22 m
Engine	LOX/ LH2 Rocket
No. of Engine	12

Table-2 Specification of Kankoh-maru based on Market Research [17,18]

3. Cost Estimates and Enterprise Considerations

Based on the preliminary design of the " Kankoh-maru" spaceship, the cost for development and production of the fleet was estimated. Similar to aircraft production and development, including R&D, proto-model manufacturing and production model manufacturing, the necessary costs for these phases were assembled. Aircraft industry people estimated them as $700 million for each vehicle's price assuming fifty Kankoh-maru fleet. Based on this estimate, business planning was assessed. It was still a hard task to estimate the way to establish a steady state with respect to market growth, and the transition phase from start of operating by a small number of vehicles to the final steady state would be a difficult task to develop.

Considering several models of the market growth were assumed. There are still many considerations needed for this kind of business planning, because the venture is totally for the first time and is aimed at a virgin market.

There is no question that a Kankoh-Maru fleet is to be operated by an operating company like today's airline companies. Based on a normal airline's balance sheet, depreciation of the vehicle purchase in the total balance sheet should be ten to fifteen percent. This requires that the vehicle should be operated for more than ten years before it is worn out. Thus the flight lifetime of a single vehicle should be in the order of one thousand to ten thousand times. This became one of the very important design specifications of the vehicle. As a result, the vehicle for the present tourism business from operation and maintenance aspect and number of reuses was specified as presented above. Many talks and discussions were made in the symposia, and it turned out that aircraft manufacturers and airliner people are much more knowledgeable than those from the rocket community on these issues related to turnaround and operational aspects of frequently flying vehicles. Rocket engineers learned that this is once again a totally different world. Thus the symposia was a very good opportunity for the people from both communities, and the discussion among them was very lively.

4. Safety and "Spaceworthiness" Regulation Considerations

Safety is the highest priority issue of transportation for the general public. No Japanese rocket engineer has experience in designing launch vehicles to carry passengers in the past or present. One of the goals of the JRS's tourism study is to identify the difference between expendable launch vehicles and passenger carriers in terms of design specification, qualification processes, and assuring safety for both people on-board and on the ground.

In aircraft transportation, there is an "airworthiness" standard that covers many topics to define the regulations for aircraft design from the safety point of view. In the symposia, starting from discussions for making difference between the passenger carrier and present launch vehicles, many safety related topics were pointed out one after another primarily by aircraft people. The rocket engineers realized that true safety-conscious design is totally different from that of present-day rockets. Normally when something happens to an expendable vehicle during its launch, the flight operator will make up his mind whether to continue the mission or to "abort" the mission with respect to the degree of the anomaly. Abort of the mission automatically results in the loss of the vehicle.

Although an emergency escape sub-system may be equipped for manned launch system or manned capsule on top of an expendable launcher, it is not always effective in all flight phases through launch and return flight. Therefore the design of such launch vehicles is made to reduce the probability of anomaly as much as possible. This is the only way to assure safety and reliability for expendable systems. On the other hand, aircraft are designed so as to accept the anomalies or incidents during flight. For example, for a certain degree of incident such as one-engine-out condition, "airworthiness" regulations describe that it must be designed to continue its flight or to come down to an alternative destination safely without losing prescribed flight quality and performance.

For mid-sized carrier passenger safety, all of passengers must be evacuated within ninety seconds when something dangerous happens to the vehicle on the ground.

There is no launch vehicle that was designed to cope with these incidents. Normally for the space community, the "three-sigma rule" is applied when we define whether the success probability is enough or not. For Kankohmaru operation, we have to carry a million of passengers a year, and so twenty thousand flights take place in the total fleet. It is obvious that the present reliability rule for space launch is far from sufficient for such a huge number of flights. A concept of continuous intact abort for space launch has been called for in designing next generation launch vehicles, however, it should be realized that the goal for the general public's space tourism is far beyond these vehicles in the next decade.

In the Transportation Committee, following the studies for technical assessment of the SSTO Kankoh-maru vehicle, "spaceworthniss" regulations for passenger launch vehicle or spacecraft was figured out. The study results were summarized and published in a report in 1999 [21].

A series of active discussions has been made through 3rd and 5th Rocket Symposia. The discussion pointed out many critical issues. Inevitable weight increase is anticipated from accommodating many safety related items and equipments such as independent fuel tanks and fuel feed systems from each tank as equipped in transport aircraft, auxiliary power generation and control subsystems, all of which endangers the weight limitation for assuring critical rocket SSTO performance. Although the normal rocket payload is positioned on the top of the vehicle, location of the passenger cabin for safe and quick evacuation as presented above was considered for passenger vehicles. Many ideas were presented, e.g. the cabin being located just beside the engines for easy and quick evacuation. Problems anticipated for such a lower cabin accommodation in terms of heating, noise and vibration related considerations were assessed. All possibilities should be allowed in the discussion, even if they are uncommon and strange in comparison with today's rocket.

That is the JRS policy. Even after finishing these discussion, there still remain many problems and contradictory issues unresolved in terms of accommodation of safety design and weight increase. However, through the symposia and the process to finalize the report, those pointed out in the discussion were meaningful and helpful to figure out what should be done and be taken into design considerations. These unresolved issues were also summarized in the report [21].

5. Medical Considerations for Passengers

For space tourist, the question of what medical conditions for passengers should be imposed, and what vehicle design meets these allowable medical conditions, arises and they are major concern for the rocket engineers.

For the relatively short time period of space travel offered by Kankoh-maru, the following five items to define the vehicle-derived environmental design issues were identified out of fifteen environmental measures normally prescribed for the relatively long time of space flight of Apollo and the Space Shuttle. These are conditions of temperature, linear acceleration, vibration, acoustics and pressure. Since there were no physicians and biomedical specialists in the JRS committees, JRS Transport Committee asked the Japanese Environmental Medicine Society to survey these five measures for the general public as potential passengers to allow space flight. The JRS's objective was to reflect these environmental conditions and limitations into the Kankoh-maru design. A report was issued by the society in 2000 [23].

The rocket symposia invited Proffesor Shigeo Mori from Nagoya University to present the survey and study results.

In addition to these survey results, proposals and considerations for designing orientation of passengers from the viewpoint of passenger seat layout and direction of acceleration both for launch and return, and lectures on the latest knowledge about the characterization of motion sickness due to weightlessness, were presented in the 6th Rocket Symposia. In the Japanese space community, part of these environmental concerns were relatively familiar to those working on International Space Station, but they were new to rocket engineers.These survey and study results would be reflected in further studies of Kankoh-maru and manned space transportation vehicle design.

6. Operator's Viewpoint

Airline people say that the most important things in airliner operation are first "operability", second "operability" and third "operability". Moreover, they say "keep the aircraft in the air as much as possible, because aircraft on the ground earn nothing." The world of airliners is like this, and business-based transportation operations are again far from the present status of the launch business in space today. The JRS committee named "Space Tourism Forum" headed by Prof. Yoshiyuki Funatsu, who was formerly an executive of one of the major airlines in Japan, was established in 2000. People from airlines and tourist agency were invited to talk about what kind of requirement should be imposed on the tourism vehicle from the operator's viewpoint. Lately in new passenger vehicle development in civil aviation, the so called "working together" policy is employed. It is a policy to reflect the operators' ideas and requirements into aircraft manufacturer in order to keep in close contact with each other from the beginning of the aircraft development. No vehicle can stand without taking operators' opinions about passenger's safety, convenience and comfortableness into design considerations. That is the present status of business aviation. On the other hand in today's launch services, the payload of the vehicle must be adjusted to meet tremendous numbers of constraints such as mechanical and thermal environment specification, access limitations, out-gassing and so on imposed from launch vehicle derived regulations. A thick manual or payload handbook is handed over to the payload manufacturer or passenger, and they honestly follow it. No deviation or wavier is in principle allowed. In this too, rocket engineers' culture must be changed in order to make truely businessbased transport or "space tourism" happen. Everything must be for passengers' benefit and their safety and comfort. It is an idea of "service" in the world of business.

In the fifth and sixth Rocket Symposia, many talks were made based on the discussions in the Space Tourism Forum.

For passengers' satisfaction, including safety and airline business viewpoints, a set of proposals were addressed and summarized in the last symposium. The idea for addressing the proposal is that the requirement from these operators will define a goal of vehicle design to the designer and manufacturer of the "space passenger carrier vehicle" like Kankoh-maru. In the address, proposals defined various items as follows: vehicle performance and flight configuration, safety, environmental issues, reliability, pilots, spaceports, profitability, cargo transportation, and operability. These were primarily based on airline operations regardless of the difficulties in designing an operational space launch vehicle; however, many essential things for rocket engineers to realize were addressed and summarized.

For example, they pointed out that in anycase the safety level achieved by present civil aviation must be reached, otherwise the general public will not pay for the service.

The operator's task is to offer a service without danger, and business transportation is not an adventure. Regulations established by government are precondition for business operators to operate, after licensing as is done in the civil air transport, and this should be a task of the ministry of Transport in the government. As for regulations such as airworthiness, international agreement or world standard must be established, because space flight is inherently an international concern. Concerning spaceport location, the address states that it should be convenient for passengers to access, on the other hand present space launch site is located in remote areas far from populated areas. Concerning spaceport facilities such as air traffic control, passenger boarding and vehicle maintenance, it is desirable to be used in common with aircraft operation.

Turnaround of the vehicle should be made within three hours. On-time operational rate should be 97%, and so on.

Many things addressed as above turned out to be nightmare for rocket engineers today. Returning to the original objective of the JRS studies for space tourism, it was to define and figure out the goal of our next space transportation architecture. The world of civil air traffic was established after lengthy efforts for commercialization and gaining reputation for safety. Taking a look back at aviation history, the JRS tourism studies should be regarded as trying to imagine the Jumbo jet, its operational state and air traffic networks at the time of the 1930. Could one imagine it properly or not at that time? Probably no one could do it correctly. Although the similarity between civil aviation development and space flight is not always true, this kind of study, which stimulates the present fossilized situation in space utilization development, and which shows the goal to the general public, will be beneficial to push the world forward and draw the future much closer.

7. Concluding Remarks

The JRS Rocket Symposia were precious opportunities not only for those from the space community but also those from aircraft manufacturers and the aviation community to talk about the future of space transportation architecture. An extensive discussion and exchange of ideas and background knowledge between the communities of rocket engineers, aircraft manufacturers, airline operators, and so on was conducted in the Rocket Symposia.

Topics were wide-ranging from technical assessment of passenger carrier SSTO vehicles to regulatory issues and the operator's viewpoint. Through the discussions in the Rocket Symposia, it was realized particularly by rocket engineers that the system architecture of passenger-carrying launch vehicles is totally different from that of the present expendable launcher system which is an extension of warhead launch or "ammunition type" of flying craft. Those from both communities realized that there is a tremendous culture difference between them. Through many discussions in and outside the symposia, concerning solution what our goal should be and toward what goal our culture should be changed into were sought. There are still many things unresolved and pending, however, so it will be meaningful for all of us to continue to discuss more widely, and even to criticize the image of the goal developed by JRS.

Acknowledgment

The author is deeply indebted to committee chairs Prof. M. Nagatomo of ISAS, Mr. K. Isozaki of Kawasaki Heavy Industry, Prof. P Collins of Azabu University, Mr. T Torikai of Fuji Aerospace Technology and Mr. Y Funatsu, for their intensive works with new venture of space tourism. Also special thanks are due to attendants of Rocket Symposia for their essential discussions.

References

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