Patrick Collins «Orbital Sports Stadium» 2000.

Patrick Collins, Lunar Surface Sports Center, 2000
Lunar Surface Sports Center
Figure: NASA

The idea of space tourism has gained considerably in credibility, with NASA, the AIAA and Japan's Federation of Economic Organisations (Keidanren) releasing reports endorsing its feasibility and recognizing it as the most promising commercial market in space. As the space hotel business matures, orbital facilities are expected to grow in size and sophistication. Various kinds of sports centers are expected to be popular with guests of space hotels. An Orbital Sports Stadium large enough to accommodate major sports events will be assembled in orbit from components launched in volumetrically efficient packages.

Patrick Collins, Orbital Sports Stadium draft 1, 2000
Patrick Collins, Zero G Gymnasium Design draft, 2000
Orbital Sports Stadium, 2000
Patrick Collins, with Takashi Fukuoka
and Tsuyoshi Nishimura

Although it is too early to know what will become a 'standard' size for orbital sports stadia in future, one likely requirement will be to accommodate flying races by participants using fabric wings. It has been estimated that humans flying in this way will have a turning-circle of some 50 m. Consequently a stadium size of 60 m. diameter, with hemispherical ends, and an overall length of 100m is selected. A facility of this size would tend to dominate attached hotel facilities. This would be particularly true if the stadium was designed to be used for popular sports events, with TV coverage and live spectators, in addition to enabling hotel guests to engage in sports activities.

Patrick Collins, Zero G stadium in rotating hotel, 2000
Patrick Collins, Zero Gravity Sports Centers 1, 2000
Patrick Collins, Zero Gravity Sports Centers 2, 2000

A further consequence is that orbital sports stadia may well be sited in an equatorial orbit, since this would achieve launch cost economies of some 10-20% over inclined orbits, and would also provide many launch and return flight opportunities every day (from near-equatorial launch sites). Use of an equatorial orbit would have the adverse consequence that the facility would offer guests relatively limited views of only a narrow band of land around the equator. However, it is believed that there will be a significant proportion of guests for whom sports will be a more important and continuing motivation for visiting orbit than viewing the whole Earth, and demand from these will drive the development and growth of orbital sports centers. It seems likely that there will be demand in future for both rotating and non- rotating sports stadia in orbit. Slow rotation would introduce an entertaining difference into sports and games, in particular the curved trajectory followed by a person or ball through the air. A major difference is that the direction of the axis of rotation will be fixed in space, as suggested for the case of a rotating swimming pool. It would be convenient to make such a stadium's axis of rotation parallel to its orbital axis. A rotating stadium would have the additional constraint that entries and exits would necessarily be restricted to the axis of rotation. It would be physically possible for a single stadium to be used in both rotating and non-rotating modes. This does not seem likely in practice due to the energy that would be used in spinning and de-spinning the structure. It will be necessary to accommodate several hundred spectators around the central sports zone of a stadium of this size. These will need positioning devices (though not a full seat) as well as catering, toilets and "people movers" to assist their movement into, out of and within the stadium. Economics: Using Eilingsfeld's estimate of the cost of capital for space tourism we can say the stadium must earn profits of $112 million/year in order to be commercially viable. If we assume annual maintenance costs of 3% of the initial manufacturing cost of $300 million, this will add $9 million/year. The cost of 40 dedicated staff at $100,000/year would be a further $4 million/year, and their orbital accommodation and transportation costs of perhaps $1 million/year would add an additional $40 million/year. The required annual revenue would then be some $165 million, or some $450,000/day. Like a stadium on Earth, operating an orbital stadium would be a specialised business activity. If we assume that 1/2 of the required revenue was earned from hosting sports and media events, then the remaining cost of such a stadium attached to a hotel accommodating 400 guests would add about $600 per guest per day. For a stay lasting a few days this would be about 10% of an overall trip cost of some $25,000.