TheStanford torus is a proposedNASA design[1] for aspace settlement capable of housing 10,000 permanent residents.[2] It is a type ofrotating wheel space station, consisting of a ring with a diameter of about 1.8 km (1.1 mi), its rotation providing about 1.0g ofartificial gravity.[3]
The Stanford torus was proposed during the 1975 NASA Summer Study,[1] conducted atStanford University, with the purpose of exploring and speculating on designs for futurespace colonies, with the conclusions and the detailed proposal being published in 1977 inSpace Settlements: A Design Study book, by Richard D. Johnson andCharles H. Holbrow[4] (Gerard O'Neill later proposed his Island One orBernal sphere as an alternative to the torus[5]). "Stanford torus" refers only to this particular version of the design, as the concept of aring-shaped rotating space station was previously proposed byKonstantin Tsiolkovsky ("Bublik-City", 1903),[6]Herman Potočnik (1923)[7] andWernher von Braun (1952),[8] among others.
The Stanford torus (the proposed 10,000 people habitat described in the 1975 Summer Study, to be distinguished from other rotating wheel space station designs) consists of atorus, ordoughnut-shaped ring, that is 1.8 km (1.1 mi) in diameter and rotates once per minute to provide between 0.9g and 1.0g ofartificial gravity on the inside of the outer ring viacentrifugal force.[9]
Sunlight is provided to the interior of the torus by a system ofmirrors, including a large non-rotating primary solar mirror.[10]
The ring is connected to a hub via a number of "spokes", which serve as conduits for people and materials travelling to and from the hub. Since the hub is at the rotational axis of the station, it experiences the least artificial gravity and is the easiest location forspacecraft to dock.Zero-gravity industry is performed in a non-rotating module attached to the hub's axis.[11]
The interior space of the torus itself is used as living space, and is large enough that a "natural" environment can be simulated; the torus appears similar to a long, narrow, straightglacial valley whose ends curve upward and eventually meet overhead to form a complete circle. The population density is similar to a dense suburb, with part of the ring dedicated to agriculture and part to housing.[11]
The Stanford Torus design was not conceived for a single, isolated space settlement, but as part of a system for the colonization of space. Part of the people living in the colony would work in the construction of satellite solar power stations and new colonies, so that the habitat would be capable of self-replication, with a full system of multiple Stanford toruses being eventually built.[12][13]
The 1975 NASA Summer Study evaluated several options for the space habitat design, including spherical and cylindrical shapes, in addition to the toroidal one. The torus was chosen as the best option, among other reasons, because it minimized the amount of mass required to have the same area and radius of rotation.[3]
The circumference of the torus proper (about 5,600 m (18,400 ft) in all) would be divided into 6 sections of equal length. 3 of the sections would be used for agriculture and the remaining 3 for residential uses. Agricultural and residential sections would alternate. A central plain would run through the full length of the torus. To gain space, structures would be terraced over the curved walls of the torus, while many commercial facilities (such as large shops, light industry or mechanical facilities) would be below the level of the central plain. According to the figures included in the study, the plain's floor would be about 1/4 of tube's diameter over the torus bottom, and each spoke would connect at the center of one of the 6 sections.[3]
| Use[3] | Used land area | Number of levels | Total usable area[Note 1] | Height per level | Volume | Notes |
|---|---|---|---|---|---|---|
| Residential | 120,000 m2 (1,300,000 sq ft) | 4 | 490,000 m2 (5,300,000 sq ft) | 3 m (9.8 ft) | 1,470,000 m3 (52,000,000 cu ft) | Including dwelling units (37 m2 (400 sq ft)/person), private exterior space and pedestrian access space (12 m2 (130 sq ft)/person of total exterior space). Modular housing, allowing for one- or two-level clustered homes, as well as grouped apartment buildings with 4 or 5 stories, and terraced homes taking advantage of the edges of the central plain that runs through the torus |
| Shops | 10,000 m2 (110,000 sq ft) | 2 | 23,000 m2 (250,000 sq ft) | 4 m (13 ft) | 92,000 m3 (3,200,000 cu ft) | The authors of the study determined the space use from recommendations that call for 10 shops per 1000 people |
| Offices | 3,300 m2 (36,000 sq ft) | 3 | 10,000 m2 (110,000 sq ft) | 4 m (13 ft) | 40,000 m3 (1,400,000 cu ft) | |
| Schools | 3,000 m2 (32,000 sq ft) | 3 | 10,000 m2 (110,000 sq ft) | 3.8 m (12 ft) | 38,000 m3 (1,300,000 cu ft) | With community multimedia center. The authors of the study calculated the space use for a student population of 10% of total population |
| Hospital | 3,000 m2 (32,000 sq ft) | 1 | 3,000 m2 (32,000 sq ft) | 5 m (16 ft) | 15,000 m3 (530,000 cu ft) | 50-bed hospital with all the different needed facilities |
| Assembly (churches, community halls, theaters) | 15,000 m2 (160,000 sq ft) | 1 | 15,000 m2 (160,000 sq ft) | 10 m (33 ft) | 150,000 m3 (5,300,000 cu ft) | |
| Recreation and entertainment | 10,000 m2 (110,000 sq ft) | 1 | 10,000 m2 (110,000 sq ft) | 3 m (9.8 ft) | 30,000 m3 (1,100,000 cu ft) | All commercial entertainment, including indoor activities and restaurants |
| Public open space | 100,000 m2 (1,100,000 sq ft) | 1 | 100,000 m2 (1,100,000 sq ft) | 50 m (160 ft) | 5,000,000 m3 (180,000,000 cu ft) | Parks, zoo, outdoor recreation (swimming, golf, playgrounds) |
| Service industry | 20,000 m2 (220,000 sq ft) | 2 | 40,000 m2 (430,000 sq ft) | 6 m (20 ft) | 240,000 m3 (8,500,000 cu ft) | Light service industry of personal goods, furniture, handicrafts, etc. |
| Storage | 10,000 m2 (110,000 sq ft) | 4 | 50,000 m2 (540,000 sq ft) | 3.2 m (10 ft) | 160,000 m3 (5,700,000 cu ft) | Wholesaling and storage |
| Transportation | 120,000 m2 (1,300,000 sq ft) | 1 | 120,000 m2 (1,300,000 sq ft) | 6 m (20 ft) | 720,000 m3 (25,000,000 cu ft) | 15 m (49 ft) width for typical streets. Ring road around the torus, at the edge of the central plain. Mass transport system consisting of a moving sidewalk, monorail, and minibus |
| Communication switching equipment (for 2800 families) | 500 m2 (5,400 sq ft) | 1 | 500 m2 (5,400 sq ft) | 4 m (13 ft) | 2,000 m3 (71,000 cu ft) | Communication and telephone distribution |
| Waste and water treatment and recycling | 40,000 m2 (430,000 sq ft) | 1 | 40,000 m2 (430,000 sq ft) | 4 m (13 ft) | 160,000 m3 (5,700,000 cu ft) | Including water supply, return and recycling, and sewage treatment |
| Electrical supply and distribution | 1,000 m2 (11,000 sq ft) | 1 | 1,000 m2 (11,000 sq ft) | 4 m (13 ft) | 4,000 m3 (140,000 cu ft) | Including transformer substations |
| Miscellaneous | 10,000 m2 (110,000 sq ft) | 2 | 29,000 m2 (310,000 sq ft) | 3.8 m (12 ft) | 112,000 m3 (4,000,000 cu ft) | |
| Total | 466,000 m2 (5,020,000 sq ft) | - | 942,000 m2 (10,140,000 sq ft) | - | 8,233,000 m3 (290,700,000 cu ft) |
| Use[3] | Used land area | Number of levels | Total usable area[Note 1] | Height per level | Volume | Notes |
|---|---|---|---|---|---|---|
| Plant growing areas | 147,000 m2 (1,580,000 sq ft) | 3 | 440,000 m2 (4,700,000 sq ft) | 15 m (49 ft) | 6,600,000 m3 (230,000,000 cu ft) | List of crops:
Each of the three agricultural areas inthe colony grows the same crops. Part of the plant production is used to feed livestock. Sorghum is used to obtain sugar. Fruit trees are grown in parks and residential areas, providing 250 grams (8.8 oz) of fruit per person each day, and also serving as ornamentation. |
| Animal areas | 17,000 m2 (180,000 sq ft) | 3 | 50,000 m2 (540,000 sq ft) | 15 m (49 ft) | 750,000 m3 (26,000,000 cu ft) | Stable herd of animals:
Each one of the three agricultural sections holds around a third of the animals of each species. Flexibility is allowed for other animals to replace parts of these numbers (for example, pigs would have area requirements between those of rabbits and cattle). |
| Food processing, collection, storage, etc. | 13,000 m2 (140,000 sq ft) | 3 | 40,000 m2 (430,000 sq ft) | 15 m (49 ft) | 600,000 m3 (21,000,000 cu ft) | |
| Agriculture drying area | 27,000 m2 (290,000 sq ft) | 3 | 80,000 m2 (860,000 sq ft) | 15 m (49 ft) | 1,200,000 m3 (42,000,000 cu ft) |
| Used land area | Total usable area | Volume | Notes[3] |
|---|---|---|---|
| 670,000 m2 (7,200,000 sq ft) | 1,552,000 m2 (16,710,000 sq ft) | 17,383,000 m3 (613,900,000 cu ft) | Only part of the 678,000 m2 (7,300,000 sq ft) of land area and 69,000,000 m3 (2.4×109 cu ft) of volume available in the torus are used. The total land area is the result of multiplying the length of the torus at its center (5,215 m (17,110 ft)) by the width at that same point (130 m (430 ft)). |
The torus would require nearly 10 million metric tons (9.8 million long tons; 11 million short tons) of mass. Construction would use materials extracted from theMoon and sent to space using amass accelerator. Amass catcher atL2 would collect the materials, transporting them toL5 where they could be processed in an industrial facility to construct the torus. Only materials that could not be obtained from the Moon would have to be imported from Earth.Asteroid mining is an alternative source of materials.[14]
The 2012 paperWorld Ships – Architectures & Feasibility Revisited proposed ageneration ship (also called a world ship) based on the Stanford torus. The Stanford torus was chosen over O'Neill colony designs because of its detailed design that covers in-depth aspects such as life support systems and wall thickness.
Four Stanford torus colonies would be stacked together, each with a population of 25,000 (bigger than the population of 10,000 for the original Stanford torus, while keeping the original general design and dimensions, and almost the same mass, that is increased by only 10% to 11 million tonnes), for a total population of 100,000, the minimum population size that the paper considers for a world ship.
For the propulsion system, an upscaled version of the one designed inProject Daedalus was chosen. A single Daedalus-based system, with a mass of around 500,000 tonnes, would be attached to the centers of the four toruses. Daedalus would provide other additional features, such as power generation (solar energy, as used in the original Stanford Torus, is not available in theinterstellar medium through which a world ship travels) and a dust shield to protect the toruses from interstellar dust impacts.
The world ship would also need a fully automatic fail detection and self-repair system, to prevent failures from having catastrophic effects.[15]
![Stanford Torus-based generation ship, proposed by Project Hyperion[15]](/mt/?noimg=&dark=on&url=https%3a%2f%2fen.wikipedia.org%2fwiki%2fFile%3aStanford_Torus-based_generation_ship.png)
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Notes: † Never inhabited due to launch or on-orbit failure, ‡ Part of theAlmaz military program, ° Never inhabited, lacks docking mechanism. | |||||||||
