When I was asked to write an article for the New Year edition, I thought I should not be cynical, saying “I do not want to provide a story suitable for holiday chatter.” So, I begin this article with a deferential introduction: “Thank you for giving me the chance to write. I hope you find some hints for the future in this article.” I will discuss here ways to establish the next goal for rockets.
Current expendable rockets, which are all destroyed after launch, have enabled the world where information is distributed by radio waves, allowing a situation where businesses, such as communications, broadcasting and navigation, become possible. Satellites packages launched by rockets are, in a word, tools to distribute radio-waves or to collect and relay information. Technologies for information transmission and communications have made substantial progress today. However, when we “launcher men” are asked, “What progress have you made in the past 30 or 40 years,” we can only falter, ”Umm sorry.” All the market research on the satellite business says that demand for space transportation has peaked and no growth is expected for the next 15 years. Due to advances in performance and/or extension of the life of satellites, the market has been shrinking according to annual surveys. Naturally, in this situation we cannot see any chance for new launch systems to debut or for the initiation of a large investment in a new launcher. The Space Shuttle was expected to stimulate new demand for transportation by removing barriers to space. However, it flew a few times a year recently and is now on hold. Its repeat-flight potential is not utilized efficiently at all. Because of its intrinsic technological problems and lack of demand, the Space Shuttle has become an example of “an unusable reusable vehicle.”
So we must ask, is there no other demand for rockets than for launching satellites? Among the needs for rocket transportation that seem technically feasible and economically viable, the construction of solar-power satellites (SPS) and space travel for the general public have been justified by quantitative analysis. According to case studies of these projects, transportation costs must be reduced by two factors of ten. Borne from the social needs of solving the energy problem and conserving the global environment, SPS is a plan to deploy huge electricity-generating facilities in space and to transmit electricity to the ground. SPS features zero CO2-emissions, and is said to be competitive with other electricity-generating methods in terms of supply price. However, SPS transportation demand is decided in terms of the environmental impact caused by construction and/or transportation into orbit compared with other energy sources. For space travel, as a result of estimates of the number of passengers per year based on public surveys, and studies of methods to allow people to buy tickets and board rockets like regular airlines, we can guess that there are one million potential passengers per year. Therefore, a system to transport these travelers could become a trillion-yen business in annual income. Couldn’t the money to develop a new rocket for such a business be collected easily? A system to perform dozens of flights every day, like a transport convoy, is necessary in both cases. Rockets which are trashed every flight cannot support such a system. Coincidentally, the volume of transportation and cost of flights needed for both projects are almost the same, as shown in Table 1. Based on this table, I will discuss here a reusable vehicle with real commercial demand.
Fig. 1 shows the cost breakdown per flight for the present expendable rocket, the Space Shuttle, and a transportation vehicle for space tourism. Since the expendable rocket is new every flight, the major part of the cost is manufacture. The cost of the Space Shuttle is estimated based on 6 flights a year. About 10,000 people are involved in the Space Shuttle program. The cost is the same as that obtained by dividing personnel cost by the number of flights. Looking at the space-travel vehicle, if we assume (based on the survey results) that a ticket is 2 million yen and the number of passengers per flight is 50, the income for one flight becomes 100 million yen. According to airline-company balance sheets, amortization costs are about 10~15% of expenditure other than direct/indirect costs for operation. Since income per flight is 100 million yen and depreciation is about 10 million yen, we can estimate that, if the space vehicle costs tens of billions of yen, a thousand flights would be requested. This shows that the cost of development and fabrication of reusable vehicles has little significance. We can obtain an economic return by making a sufficiently large number of repeat flights.