The O'Neill cylinder (also called an O'Neill colony) is a space settlement concept proposed by American physicist Gerard K. O'Neill in his 1976 book The High Frontier: Human Colonies in Space. O'Neill proposed the colonization of space for the 21st century, using materials extracted from the Moon and later from asteroids. Building 100 Starships/year gets to 1000 in 10 years or 100 megatons/year or maybe around 100k people per Earth-Mars orbital sync — Elon Musk (@elonmusk) January 17, 2020.
Artist's depiction of a pair of O'Neill cylinders
The O'Neill cylinder (also called an O'Neill colony) is a space settlement concept proposed by American physicistGerard K. O'Neill in his 1976 book The High Frontier: Human Colonies in Space.[1] O'Neill proposed the colonization of space for the 21st century, using materials extracted from the Moon and later from asteroids.[2]
An O'Neill cylinder would consist of two counter-rotating cylinders. The cylinders would rotate in opposite directions in order to cancel out any gyroscopic effects that would otherwise make it difficult to keep them aimed toward the Sun. Each would be 5 miles (8.0 km) in diameter and 20 miles (32 km) long, connected at each end by a rod via a bearing system. They would rotate so as to provide artificial gravity via centrifugal force on their inner surfaces.[1]
Interior view, showing alternating land and window stripes
Background[edit]
Artist's impression of the interior of an O'Neill cylinder, showing the curvature of the inner surface
While teaching undergraduate physics at Princeton University, O'Neill set his students the task of designing large structures in outer space, with the intent of showing that living in space could be desirable. Several of the designs were able to provide volumes large enough to be suitable for human habitation. This cooperative result inspired the idea of the cylinder and was first published by O'Neill in a September 1974 article of Physics Today.[3]
O'Neill's project was not the first example of this concept. In 1954, the German scientist Hermann Oberth described the use of gigantic habitable cylinders for space travel in his book Menschen im Weltraum—Neue Projekte für Raketen- und Raumfahrt (People in Space—New Projects for Rockets and Space Travel). In 1970, science-fiction author Larry Niven proposed a similar, but larger scale, concept in his novel Ringworld. Shortly before O'Neill proposed his cylinder, Arthur C. Clarke used such a cylinder (albeit of extraterrestrial construction) in his novel, Rendezvous with Rama.[citation needed].
Islands[edit]
O'Neill created[when?] three reference designs, nicknamed 'islands':
Island One is a rotating sphere measuring one mile (1.6 km) in circumference (1,681 feet (512 m) in diameter), with people living on the equatorial region (see Bernal sphere). A later NASA/Ames study at Stanford University developed an alternative version of Island One: the Stanford torus, a toroidal shape 1,600 feet (490 m) in diameter.[4]
Island Two is spherical in design, 5,200 feet (1,600 m) in diameter.[citation needed]
The Island Three design, better known as the O'Neill cylinder, consists of two counter-rotating cylinders. They are five miles (8.0 km) in diameter and are capable of being scaled up to twenty miles (32 km) long.[5] Each cylinder has six equal-area stripes that run the length of the cylinder; three are transparent windows, three are habitable 'land' surfaces. Furthermore, an outer agricultural ring, twenty miles (32 km) in diameter, rotates at a different speed to support farming. The habitat's industrial manufacturing block is located in the middle, to allow for minimized gravity for some manufacturing processes.[citation needed]
To save the immense cost of rocketing the materials from Earth, these habitats would be built with materials launched into space from the Moon with a magnetic mass driver.[1]
Design[edit]
Artificial gravity[edit]
A NASA lunar base concept with a mass driver (the long structure that extends toward the horizon that is a part of the plan to build O'Neill Cylinders)
The cylinders rotate to provide artificial gravity on their inner surface. At the radius described by O'Neill, the habitats would have to rotate about twenty-eight times an hour to simulate a standard Earth gravity; an angular velocity of 2.8 degrees per second. Research on human factors in rotating reference frames[6][7][8][9][10]indicate that, at such low rotation speeds, few people would experience motion sickness due to coriolis forces acting on the inner ear. People would, however, be able to detect spinward and antispinward directions by turning their heads, and any dropped items would appear to be deflected by a few centimetres.[9] The central axis of the habitat would be a zero-gravity region, and it was envisaged that recreational facilities could be located there.
Atmosphere and radiation[edit]
The habitat was planned to have oxygen at partial pressures roughly similar to terrestrial air, 20% of the Earth's sea-level air pressure. Nitrogen would also be included to add a further 30% of the Earth's pressure. This half-pressure atmosphere would save gas and reduce the needed strength and thickness of the habitat walls.[1][4]
Artist's depiction of the interior of an O'Neill cylinder, illuminated by reflected sunlight
At this scale, the air within the cylinder and the shell of the cylinder provide adequate shielding against cosmic rays.[1] The internal volume of an O'Neill cylinder is great enough to support its own small weather systems, which may be manipulated by altering the internal atmospheric composition or the amount of reflected sunlight.[5]
Sunlight[edit]
Earth Space Colonies 1 00
Large mirrors are hinged at the back of each stripe of window. The unhinged edge of the windows points toward the Sun. The purpose of the mirrors is to reflect sunlight into the cylinders through the windows. Night is simulated by opening the mirrors, letting the window view empty space; this also permits heat to radiate to space. During the day, the reflected Sun appears to move as the mirrors move, creating a natural progression of Sun angles. Although not visible to the naked eye, the Sun's image might be observed to rotate due to the cylinder's rotation. Light reflected by mirrors is polarized, which might confuse pollinating bees.[1]
To permit light to enter the habitat, large windows run the length of the cylinder.[1] These would not be single panes, but would be made up of many small sections, to prevent catastrophic damage, and so the aluminum or steel window frames can take most of the stresses of the air pressure of the habitat.[1] Occasionally a meteorite might break one of these panes. This would cause some loss of the atmosphere, but calculations showed that this would not be an emergency, due to the very large volume of the habitat.[1]
Attitude control[edit]
The habitat and its mirrors must be perpetually aimed at the Sun to collect solar energy and light the habitat's interior. O'Neill and his students carefully worked out a method of continuously turning the colony 360 degrees per orbit without using rockets (which would shed reaction mass).[1]First, the pair of habitats can be rolled by operating the cylinders as momentum wheels. If one habitat's rotation is slightly off, the two cylinders will rotate about each other. Once the plane formed by the two axes of rotation is perpendicular in the roll axis to the orbit, then the pair of cylinders can be yawed to aim at the Sun by exerting a force between the two sunward bearings. Pushing the cylinders away from each other will cause both cylinders to gyroscopically precess, and the system will yaw in one direction, while pushing them towards each other will cause yaw in the other direction. The counter-rotating habitats have no net gyroscopic effect, and so this slight precession can continue throughout the habitat's orbit, keeping it aimed at the Sun. This is a novel application of control moment gyroscopes.
Design update and derivatives[edit]
In 2014, a new construction method was suggested that involved inflating a bag and taping it with a spool (constructed from asteroidal materials) like the construction of a composite overwrapped pressure vessel.[11]
In 1990 and 2007, a smaller design derivative known as Kalpana One was presented, which addresses the wobbling effect of a rotating cylinder by increasing the diameter and shortening the length. The logistical challenges of radiation shielding are dealt with by constructing the station in low Earth orbit and removing the windows.[12][13]
Proposal[edit]
At a Blue Origin event in Washington on May 9, 2019 Jeff Bezos proposed building O'Neill colonies rather than colonizing other planets.[14][15]
![Earth Space Colonies 1 0 Earth Space Colonies 1 0](https://i.ytimg.com/vi/u1wRJLoc88g/maxresdefault.jpg)
Image gallery[edit]
- A cylinder growing out from interconnected bolas[16]
- A NASA concept image of multiple habitat cylinders oriented towards the Sun
See also[edit]
- Centrifuge Accommodations Module, a cancelled ISS module
![Colonies Colonies](https://4.bp.blogspot.com/-OMWjuoRZpis/V6VYZqgoHJI/AAAAAAAAALQ/lin24LmFYgY_RepL2rXwAwFNm_iCDa2YwCLcB/s1600/2222.jpg)
- In fiction
- Babylon 5 (fictional space station), a fictional O'Neill cylinder
- 2312 - a novel featuring the use of O'Neill cylinders in hollowed-out asteroids called 'terraria'
- Mobile Suit Gundam - anime set in the future, where O'Neill cylinders are the primary human colonies in space
- Rama (spacecraft)
- Interstellar (film) Cooper station
- The Expanse (TV series) The Nauvoo/Behemoth, a rotating cylinder with engines but without radiation shielding (Interstellar ship)
References[edit]
- ^ abcdefghijO'Neill, Gerard K. (1977). The High Frontier: Human Colonies in Space. New York: William Morrow & Company. ISBN0-688-03133-1.
- ^'SPACE RESOURCES and SPACE SETTLEMENTS,1977 Summer Study at NASA Ames Research Center'. Retrieved October 20, 2012.
- ^O'Neill, Gerard K. (September 1974). 'The Colonization of Space'. Physics Today. 27 (9): 32–40. Bibcode:1974PhT..27i.32O. doi:10.1063/1.3128863. ISSN0031-9228.[permanent dead link]
- ^ abSpace Settlements: A Design Study (1977)Archived 2012-06-14 at the Wayback Machine. NASA SP-413. NSS.org. Retrieved September 12, 2012.
- ^ ab'O'Neill Cylinder'. Orbital Space Settlements. National Space Society. Archived from the original on February 21, 2009. Retrieved November 13, 2012.
- ^Beauchamp, G. T. (October–December 1961). 'Adverse Effects Due to Space Vehicle Rotation'. Astronautical Sciences Review. 3 (4): 9–11.
- ^Proceedings of the Symposium on the Role of the Vestibular Organs in Manned Spaceflight, NASA SP-77, 1965. See in particular: Thompson, Allen B.:Physiological Design Criteria for Artificial Gravity Environments in Manned Space Systems
- ^Newsom, B. D. (June 1972). 'Habitability factors in a rotating space station'(PDF). Space Life Sciences. 3 (3): 192–197. Bibcode:1972SLSci..3.192N. doi:10.1007/BF00928163. PMID5038187.
- ^ abProceedings of the Fifth Symposium on the Role of Vestibular Organs in Space Exploration, Pensacola, Florida, August 19–21, 1970, NASA SP-314, 1973
- ^Altman, F. (1973). 'Some Aversive Effects of Centrifugally Generated Gravity'. Aerospace Medicine. 44: 418–421.
- ^Third Tennessee Valley Interstellar Workshop, Nov 10-11, 2014, Oak Ridge, TN, Dr. Gordon Woodcock (Boeing/NSS) (2014-12-21), 10.0 A Construction Scenario for O'Neill Cylinder Space Settlement Habitats, retrieved 2018-10-26CS1 maint: multiple names: authors list (link)
- ^'Kalpana One Space Settlement'. settlement.arc.nasa.gov. Retrieved 2018-10-26.
- ^Globus, Al. 'The Kalpana One Orbital Space Settlement Revised'(PDF).
- ^Blitz, Matt; Orf, Darren (9 May 2019). 'Blue Origin Reveals the Blue Moon Lunar Lander'. Popular Mechanics. Retrieved 11 June 2019.
- ^'Going to space to benefit Earth (Full event replay)'. Blue Origin. Retrieved 11 June 2019.
- ^Curreri, Peter A. (2007). 'A minimized technological approach towards human self sufficiency off Earth' (PDF). Space Technology and Applications International Forum (STAIF) Conference, Albuquerque, NM, 11–15 February 2007.
Further reading[edit]
- T. A., Heppenheimer (2007) [1977]. Colonies in Space (online book ed.). National Space Society. ISBN978-0-8117-0397-0. Retrieved 2009-04-19.
External links[edit]
Wikimedia Commons has media related to O'Neill cylinders. |
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© JAXA/NASA The bacterial exposure experiment, run from 2015 to 2018, utilized the Exposed Facility located outside Kibo, the Japanese Experimental Module of the International Space Station.A type of bacteria that is highly resistant to radiation and other environmental hazards survived outside of the International Space Station for three years, according to a new study.
The Japanese Tanpopo mission involved including pellets of dried Deinococcus bacteria within aluminum plates that were placed in exposure panels outside of the space station.
Deinococcus bacteria is found on Earth and has been nicknamed Conan the Bacterium by scientists for its ability to survive cold, dehydration and acid. It's known as the most radiant-resistant life form in the 'Guinness Book of World Records.'
It can resist 3,000 times the amount of radiation that would kill a human and was first isolated in cans of meat subjected to sterilizing radiation.
This mission was designed to test the 'panspermia' theory, which suggests that microbes can pass from one planet to another and actually distribute life.
Tanpopo means dandelion in Japanese.
Study author Akihiko Yamagishi, who is the principal investigator of the Tanpopo space mission, and his team in 2018 used an aircraft and scientific balloons to find Deinococcus bacteria that was actually floating 7.5 miles above Earth's surface.
Earth Space Colonies
This caused Yamagashi, also a professor of molecular biology at Tokyo University of Pharmacy and Life Sciences, and his team to wonder if this bacteria, which was resistant to ultraviolet (UV) radiation, could actually survive in space and even the journey to other planets through extreme temperature fluctuations and even harsher radiation. Movist pro 2 1 360.
Deinococcus is known to form colonies larger than 1 millimeter. For the Tanpopo mission, samples of bacteria were prepared in pellets of various thickness and placed in the wells of aluminum plates. Data was collected on the plates after one, two and three years.
Then, the bacteria were tested to see how they fared.
The results entirely depended on the thickness of the bacteria. Those that were larger than 0.5 millimeters were able to partially survive, sustaining DNA damage. Although the bacteria on the surface of the aggregate, or colony formed by the bacteria, died, the researchers found a protective layer beneath it that ensured the colony survived.
'Collectively, these results support the possibility of pellets as an ark for interplanetary transfer of microbes within several years,' the authors wrote.
Earth Space Colonies 1 01
The study published Wednesday in the journal Frontiers in Microbiology.
The Deinococcus bacteria studied inside the space station didn't fare so well, where oxygen and moisture proved harmful to the bacteria, Yamagishi said.
Based on the scientists' estimates, bacteria pellets thicker than 0.5 millimeters could survive between 15 and 45 years outside of the space station in low-Earth Orbit. The team predicted that colonies of this bacteria more than 1 millimeter in diameter could survive as long as eight years in outer space.
'The results suggest that radioresistant Deinococcus could survive during the travel from Earth to Mars and vice versa, which is several months or years in the shortest orbit,' Yamagishi said.
Previous studies have suggested that bacteria could survive longer in space if it was shielded by rock, known as lithopanspermia, but this study has shown that bacteria aggregates, or colonies, can survive in space, which is called massapanspermia.
Based on the research team's results, Yamagashi believes that 'it is very important to search for life on Mars before human missions to Mars.' Bacteria from Earth could present a false negative for life on Mars or act as a contaminant on Mars.
The NASA Perseverance Rover, which is currently en route and due to land on Mars in February after launching in July, went through rigorous cleaning from assembly to prelaunch. The rover will collect samples, returned to Earth in the next 10 years, that could contain proof of ancient life that once flourished on the red planet.
The team is also considering how microbial pellets could end up in space. Yamagashi and his team suspect that bacteria could potentially be launched from Earth by the electric field generated in thunderstorms, landing the way that micrometeorites do in the atmosphere of Earth.
'Tens of millions of kilograms of micrometeorites are reaching to the Earth's surface every year,' Yamagashi said. '(A) similar landing process may be present in the thin atmosphere of Mars.'
Next, Yamagashi and his team are interested in conducting more exposure experiments for microbes on NASA's Lunar Gateway.
The Lunar Gateway will act as an outpost orbiting the moon that provides support for the sustainable, long-term human return to the lunar surface, as well as a staging point for deep space exploration, according to NASA. It's a critical component of NASA's Artemis Program, which aims to land the first woman and next man on the lunar surface by 2024.
Earth Space Colonies
'The origin of life on Earth is the biggest mystery of human beings,' Yamagashi said. 'Scientists can have totally different points of view on the matter. Some think that life is very rare and happened only once in the Universe, while others think that life can happen on every suitable planet. If panspermia is possible, life must exist much more often than we previously thought.'