Search This Blog

Thursday, November 22, 2018

Space stations and habitats in fiction

From Wikipedia, the free encyclopedia

The concepts of space stations and habitats are common in modern culture. While space stations have become reality, there are as yet no true space habitats. Writers, filmmakers, and other artists have produced vivid renditions of the idea of a space station or habitat, and these iterations can be categorized by some of the basic scientific concepts from which they are derived.

Space stations

Space stations in science fiction can employ both existing and speculative technologies. One of the earliest images was the rotating wheel space station (such as the Stanford torus), the inertia and centripetal force of which would theoretically simulate the effects of gravity. Stations using artificial gravity are still purely speculative.

Space stations allow characters a relatively constrained setting, serving either as plot site or as safe refuge to which one can retreat. Since they are literary devices, there is no scientific imperative for their evolution to have followed the logical succession of scientific progress as it exists in reality; they may contain any artifact or device demanded by the plot, and can be provided by design or mere happenstance.

Space stations are often used as headquarters for organizations, which are thus linked to, but independent of, their place of formation, as research facilities in which experiments too dangerous for planetary settings can be carried out, and as the relics of lost civilizations, left behind when other things are removed.

Space stations rotating for pseudogravity

  • The film (and novel) 2001: A Space Odyssey is set in part on Space Station V, built as an 1,836-foot (560 m) partially completed double ring, revolving to produce one-sixth gravity. This station model is one of the most familiar designs from science fiction films.
  • Various stations in the 1996 Japanese anime Cowboy Bebop used torus space stations, although a number of the space colonies ignore physics and gravity laws behaving as Earth would. The ship Bebop itself also had an artificial gravity segment that slowly rotated as a cylinder inside of the fuselage, separate from the flight deck and hangar.
  • The 2003 Japanese anime Planetes has one of its main sets in the ISPV-7 (Seven), the 7th orbital station around the Earth while the 9th is under construction by the year 2075. It depicts accurately the zero-gravity zone around the axis, the microgravity service ring and the 1-g gravity external ring. The elevators have g-force indicators and harnesses for the passengers. Handles and grips are ubiquitous out of the 1-g area. The space station ISPV-7 serves as the base for the recovery ship DS-12 "Toybox".
  • Space Station One is the home of the Space Family Robinson. It is mobile, capable of planetary descent, and large enough for the family, with hydroponic gardens and two small shuttle crafts ("Spacemobiles"). Their ship functions as a habitat while attempting to return to earth.
  • Venus Equilateral Relay Station, from the 1940s Venus Equilateral series by George O. Smith, is a communications hub set in Venus' L4 point.
  • Earth II was a 1971 pilot (released theatrically outside North America), for a television series about a rotating colony established in orbit around the Earth.
  • The 1979 James Bond film Moonraker features a space station used as a base to launch attacks on Earth.
  • The television series Babylon 5 is set on a space station of that name in the years 2258–2262.
  • One book of the Outlanders series is set on a station called Parallax Red, supposedly launched by the United States, located at one of the Lagrangian points.
  • In the Command & Conquer series, the GDI faction has most of their command staff on a space station named Philadelphia.
  • Mystery in Space and Strange Adventures, the two most popular science fiction comic books of the 1950s, often depicted wheel-shaped space stations on their covers and in their stories.
  • In the Sonic the Hedgehog series, the Space Colony ARK is a near-Earth colonization ship, on which a secret research program has given birth to the Ultimate Life-form, Shadow the Hedgehog.

Space stations using artificial gravity

  • The Star Trek franchise features several space station designs that all use artificial gravity. UFP Deep Space Station K7, Earth Station McKinley, and the Federation Spacedocks are examples, as is Jupiter Station, a research and development facility, and Deep Space Nine (aka DS9 or Terok Nor), the primary setting of Star Trek: Deep Space Nine.
  • The Death Star and the Death Star II from the Star Wars series are mobile space stations designed to destroy entire planets. They are capable of travelling interstellar distances, and are the size of moons or small planets. Artificial gravity, not rotation, is used to counter weightlessness.
  • In the space role-playing game EVE Online, most actions besides mining, travelling and combat take place in space stations orbiting moons and/or planets.
  • Many episodes of Doctor Who take place on space stations, including StationFive / the Gamestation and Platform One, built five billion years in the future to witness Earth's destruction in the episode "The End of the World".
  • The Disney television film Zenon: Girl of the 21st Century and its two sequels Zenon: The Zequel and Zenon: Z3 are set on a space station in the 2050s.
  • In Stargate Atlantis, a "Stargate bridge" links the Milky Way and Pegasus galaxies. Because of differences between the Milky Way and Pegasus Stargates, there is a space station linking the two "gates" midway between the galaxies.
  • Space Station 76 is a 2014 dark comedy film that deconstructs seemingly idyllic relationships, set against the backdrop of Omega 76, a 1970s retrofuturistic space station.
  • The space station Perma One is a primary setting of the science fiction sitcom Quark.
  • In The Outer Limits episode "Specimen: Unknown", the research space station Adonis is in orbit of Earth.

Other space stations

Habitats

Spherical habitats

Dyson spheres

Bernal spheres

The Bernal sphere is a rotating sphere housing tens of thousands of people.

Toroidal or annular habitats

Illustration of a ring, with no apparent hub

Tori

A rotating torus sometimes quite large in diameter makes possible extensive artificial worlds.
  • One of the earliest portrayals of a torus station is shown in 1957 Soviet docufiction film Road to the Stars by Pavel Klushantsev.
  • Earth-orbiting Space Station V invented by Arthur C. Clarke and Stanley Kubrick and depicted in Kubrick's 1968 movie 2001: A Space Odyssey.
  • The short film L5: First City in Space is set on a Stanford torus at L5.
  • The novels of the Gaea Trilogy by John Varley are set on an unusual organic satellite of Saturn that is shaped as a Stanford Torus.
  • In the anime series Mobile Suit Gundam Wing, most of the many space colonies in Earth orbit are based on the Stanford torus. The anime series Mobile Suit Gundam 00 also depicts Stanford tori-type space stations. The Laplace Residence in Gundam Unicorn is also an example of a Stanford torus.
  • In the anime series Planetes, the main action also takes place in a Stanford torus-type space station around Earth.
  • Hideo Kojima's PlayStation 2 video game Zone of the Enders is set aboard a Stanford torus-type space station orbiting Jupiter called Antillia Colony.
  • The video game Startopia is set aboard a series of Stanford tori.
  • The video game Mass Effect features the Citadel, resembling a small Stanford torus with multiple arms attached. Arcturus Station, the Alliance capital, is also a Stanford torus, although it is never seen in-game.
  • Saturnalia and A Lion on Tharthee by Grant Callin features SpaceHome, a group of toroid space stations connected in a pinwheel fashion.
  • James P. Hogan wrote several novels that included a Stanford torus, including The Two Faces of Tomorrow, Endgame Enigma, and Voyage From Yesteryear.
  • FreeMarket Station, in the FreeMarket RPG, is a large Stanford Torus in stationary position near Saturn and home to over 85,000 transhuman individuals. Similar but smaller structures in this setting include Liberty (Earth L5) and Garuda (Mars).
  • The titular space station in Elysium, the 2013 science fiction film written and directed by Neill Blomkamp, strongly resembles a Stanford torus. However, it has an open atmosphere which make it more akin to a Bishop Ring. The lack of enclosure allowed the immigrant shuttles to land on Elysium.
  • The X game series has the planet encompassing Earth Torus which serves as a high orbital space dock for Terrans.
  • The French animated series Once upon a time... Space also featured a planet encompassiong Earth Torus, serving as space port as well as power supply station for the entire Earth.
  • In the 2004 Battlestar Galactica TV series the Zephyr, is a ship with a Stanford torus centered around a long cylindrical center.
  • In C. J. Cherryh's Alliance-Union universe most stations are described as rotating tori. The inside cover art for Downbelow Station shows the internal divisions of Pell station, a torus.

Bishop rings

The Bishop ring design is a ring 1,000 kilometres (620 mi) in radius and 500 kilometres (310 mi) thick, capable of supporting populations into the tens of billions. It requires mastery of carbon nanotubes.
  • Bishop Rings are a common type of habitat in the universe of the Orion's Arm world-building project, where the width of individual rings can vary from as little as 100 kilometres (62 mi) to as much as 500 kilometres (310 mi).

Other rings

Cylindrical habitats

NASA artist Rick Guidice's depiction of a pair of O'Neill cylinders

O'Neill cylinders

O'Neill's Island Three design, commonly called an O'Neill cylinder, consists of a pair of counter-rotating cylinders, each 3.2 kilometres (2.0 mi) in radius and 32 kilometres (20 mi) long, housing a population of up to 10 million.
  • In the SF-artwork book Mechanismo: An Illustrated Manual of Science Fiction Hardware (1978), edited by Harry Harrison, an illustration of Island Three is shown with technical notes.
  • Jerry Pournelle and John F. Carr edited an anthology of SF stories set in O'Neill cylinders or other types of space colonies, published in 1979 as The Endless Frontier volumes 1 and 2.
  • In the various Gundam anime series, O'Neill cylinders are common – especially in the Universal Century, where nine billion human beings live in these colonies. The Gundam series space colony design is usually portrayed with a rotational speed much faster than the original O'Neill design. This is in part for visual effect. All Gundam series involve space, and most are about conflicts between Earth and humans living in space colonies.
  • Vonda McIntyre's Starfarers series of novels is set on the Starfarer, a classic O'Neill double-cylinder space colony adapted to make faster-than-light interstellar jumps.
  • Alexis A. Gilliland's Rosinante novels feature a "dragon scale mosaic mirror", consisting of a large number of small mobile mirrors mounted on a cone around each habitat. These provide illumination, generate power, and defend the habitat. The array is much larger than the mirrors of O'Neill's design, but does not rotate with the habitat and so does not need as much structural strength.
  • An O'Neill cylinder similar to those found in the Gundam series provides the setting for a stage in the game Tekken 5. The arena consists of a glass platform mounted near the axis at one end of the habitat, with the rotating cylinder providing the backdrop. The stage is called "The Final Frontier", and the exterior can be seen in a cutscene. The view through the window would suggest that the facility is much nearer to the earth than the typical scenario. The same cylinder is also featured in Tekken 6, in a stage called "Fallen Colony", where the habitat has crashed down to Earth.
  • Hideo Kojima's adventure game Policenauts takes place in an O'Neill space colony located at the L5 Lagrange Point. These structures can also be seen in shooting games like Axelay (stage 2), Zone of the Enders, Super Earth Defense Force (stage 4), R-Type Final (stage 1), Thunder Force IV (Ruin stage), GG Aleste (stage 1), and Vanquish.
  • The Neyel, a race in the Star Trek novel The Sundered (by Andy Mangels and Michael A. Martin), were originally Earth humans who lived on Vanguard, an O'Neill-type habitat constructed inside an asteroid. (The name 'Neyel' is itself derived from O'Neill.)
  • The conclusion of Interstellar reveals that an O'Neill Cylinder has been built above Earth, with Earth's population migrating to it.
  • The Galactic Whirlpool, a Star Trek novel written by David Gerrold, focused on an O'Neill-style space station that had been retro-fitted as a generational interstellar ship.
  • Gene Wolfe's series The Book of the Long Sun take place on a generation ship, essentially a massive O'Neill cylinder, where the inhabitants have long forgotten that they are on a ship or journey. The series is followed by The Book of the Short Sun and is also linked to Wolfe's master work, The Book of the New Sun.
  • In the Italian comic book Nathan Never, Earth has spawned a number of space colonies in the form of O'Neill cylinders.
  • The anime series Sora wo Kakeru Shojo features an Island Three type space colony controlled by a narcissistic AI named Leopard as a major character.
  • David J. Williams' The Burning Skies features an O'Neill cylinder attacked by terrorists.
  • The miniseries L5 (2012) features an abandoned O'Neill cylinder.
  • In the Warhammer 40K books, it is mentioned that before Mankind mastered artificial gravity and Warp travel, "Ohnyl Cylinders" were used as habitats and generation ships.

McKendree cylinders

The McKendree cylinder design is a scaled-up O'Neill cylinder with a radius of 460 kilometres (290 mi) and a length of 4,600 kilometres (2,900 mi), capable of supporting populations in excess of 100 billion. This design requires mastery of carbon nanotubes.
  • McKendree cylinders are a type of habitat in the universe of the Orion's Arm world-building project, but scaled up to the theoretical limits of carbon nanotubes: 1,000 kilometres (620 mi) in radius and 10,000 kilometres (6,200 mi) long, containing 63 million square kilometres (24 million square miles) of living space—greater than the continent of Eurasia.

Other cylinders

  • Robert A. Heinlein, in his 1963 novelisation Orphans of the Sky (compiling two stories published in 1941), introduced revolving cylinders to emulate gravity. In this case there were many concentric levels, at which gravity stepwise-decreased towards the centre of the structure, resulting in zero gravity at the very centre.
  • In the Rama series of books by Arthur C. Clarke, gigantic alien spacecraft similar to O'Neill cylinders are explored by astronauts. Perhaps due to its design for interstellar travel, Rama lacks the mirrors and windows of an O'Neill cylinder, but does have lights arranged in three strips along its length, paralleling the placement of the windows. Note that Rendezvous with Rama was published (1973) in the period between O'Neill running the classes in which his cylinder design was produced and his publication, therefore the designs are likely entirely independent.
  • The television series Babylon 5 concerned an O'Neill-style space station 8.0 kilometres (5 miles) long. While the single cylinder Babylon 5 did not feature a counter-rotating section, its predecessor Babylon 4 did. Like Rama, Babylon 5 lacks the mirrors and windows of an O'Neill cylinder, but does have a fixed central light source. Day and night are simulated as the landscape below revolves around the light source.
  • In Ken Macleod's Learning the World, the 'Sunliner' Slow interstellar travel vessel But the Sky, My Lady! the Sky!, is based around an O'Neil cylinder with a central artificial 'sunline' (a miniature star strung out like an oversized tubular fluorescent bulb) that is simply activated and deactivated on a 24‑hour cycle, rather than relying on windows. On either end is a 'cone' together containing a bridge, maintenance systems, spare reaction fuel and propulsion/power grid systems.
  • Peter F. Hamilton's The Night's Dawn trilogy makes several references to an O'Neill halo orbiting Earth. The books aren't specific, but imply that it is constituted of a multitude of asteroids orbiting Earth. Also the Edenist culture of the books are said to inhabit huge Habitats that are slight variation on the O'Neill cylinder, though they are a gigantic living being. These habitats have a central light tube running through the centre of the structure rather than the mirror panels proposed in the original design. His Commonwealth Saga books also describe the character Ozzie Isaacs' home, which is an O'Neill cylinder located within an asteroid.
  • Orson Scott Card's novel Ender's Game concerns mostly the events taking place on Battle School, a short O'Neill cylinder, which houses the all-important Battle Room in the center of its rotation, which keeps it at null gravity.
  • The Citadel space station in the video game Mass Effect resembles an O'Neill cylinder, although there are no windows and atmosphere is only kept to around seven metres. The "land" sections are made up mostly of large buildings reminiscent of a city. Its head section is a Stanford torus, housing the headquarters of political and strategic decision-making. A second station, "Jump Zero", is mentioned but not yet seen in the franchise, and is described as a Bernal Sphere.
  • The French writer Bernard Werber in his novel Le papillon des étoiles described a generation ship under the form of a long rotating cylinder with central lightning tube. This ship is described to be privately constructed.
  • The 2001 novel Chasm City by Alastair Reynolds features a spindle-shaped variant, with higher gravity at the center and low gravity at the points. This is mentioned to be cheaper to build than cylindrical colonies.

Lunar Orbital Platform-Gateway

From Wikipedia, the free encyclopedia

Lunar Orbital Platform-Gateway
Lunar Orbital Platform-Gateway.jpg
Artist's concept of Lunar Orbital Platform-Gateway orbiting the Moon. The Orion MPCV is docked on the left.
Station statistics
Crew4 (proposed)
Carrier rocketSpace Launch System
Commercial vehicle
Proton-M
Angara

The Lunar Orbital Platform-Gateway (LOP-G) is a proposal for a lunar-orbit space station intended to serve as an all-in-one solar-powered communications hub, science laboratory, short-term habitation module, and holding area for rovers and other robots.

The science disciplines to be studied on the Gateway are expected to include planetary science, astrophysics, Earth observations, heliophysics, fundamental space biology and human health and performance.

The Gateway is designed to be developed, serviced, and utilized in collaboration with commercial and international partners. It will also serve as the staging point for crewed and robotic lunar exploration and a staging point for NASA's proposed Deep Space Transport craft to perform a 300-400 day shakedown mission prior to NASA's first crewed Mars mission. Deep Space Transport is a concept of a reusable vehicle that uses electric and chemical propulsion and would be specifically designed for crewed missions to destinations such as Mars.

The development is led by the International Space Station partners: ESA, NASA, Roscosmos, JAXA and CSA for construction in the 2020s. The International Space Exploration Coordination Group (ISECG), which comprises 14 space agencies participating with NASA, have concluded that LOP-G will be critical in expanding human presence to the Moon, Mars and deeper into the solar system. Formerly known as the Deep Space Gateway, the station was renamed in NASA's proposal for the 2019 United States federal budget. The omnibus spending bill passed by Congress in March of 2018 provided NASA with $504 million for the development of LOP-G in fiscal year 2019.

Overview

LOP-G advances NASA's goals of sustaining human space exploration and serves as a platform to further cislunar operations, lunar surface access and missions to Mars.

Originally, NASA had intended to build the Gateway as part of the now cancelled Asteroid Redirect Mission. An informal joint statement on cooperation between NASA and Roscosmos was announced on 27 September 2017. Traveling to and from cislunar space (lunar orbit) will help gain the knowledge and experience necessary to venture beyond the Moon and into deep space. The LOP-G would be initially placed in a highly elliptical near-rectilinear halo orbit (NRHO) around the Moon which will bring the station within 1,500 km (930 mi) of the lunar surface at closest approach and as far away as 70,000 km (43,000 mi) on a six-day orbit. This orbit would allow lunar expeditions from the Gateway to reach a polar low lunar orbit using 730 m/s of delta-v in half a day and also allow less than 10 m/s of delta-v to be required per year in stationkeeping. The Gateway could conceivably also support in-situ resource utilization (ISRU) development and testing from lunar and asteroid resources. The Gateway would offer the opportunity for gradual buildup of capabilities for more complex missions over time. Various components of the Gateway are to be launched on a commercial launch vehicle and on the Space Launch System as Orion co-manifested payloads on the flights EM-3 through EM-8. According to Roscosmos, they may also use Proton-M and Angara-A5M heavy launchers to fly payloads or crew.

The Power and Propulsion Element (PPE) for the LOP-G will have a mass of 8-9 t and be capable of generating 50 kW of solar electric power for its ion thrusters system for maneuverability, which can be supported by chemical propulsion. NASA stated that the most likely ion engine to be used on the PPE is the 14 kW Hall thruster called Advanced Electric Propulsion System (AEPS) still being developed by Glenn Research Center, the Jet Propulsion Laboratory, and Aerojet Rocketdyne. Four identical AEPS engines would consume the 50 kW generated.

Patrick Troutman serves as the lead for strategic assessments for the Deep Space Transport and the Lunar Orbital Platform-Gateway.

Studies

On 1 November 2017, NASA commissioned 5 studies lasting four months into affordable ways to develop the Power and Propulsion Element (PPE), hopefully leveraging private companies' plans. These studies had a combined budget of $2.4 million. The companies performing the PPE studies are Boeing, Lockheed Martin, Orbital ATK, Sierra Nevada and Space Systems/Loral. These awards are in addition of the ongoing set of NextSTEP-2 awards made in 2016 to study development and make ground prototypes of habitat modules that could be used on the Lunar Orbital Platform-Gateway as well as other commercial applications, so the LOP-G is likely to incorporate components developed under NextSTEP as well.

On 7 November 2017, NASA asked the global science community to submit concepts for scientific studies that could take advantage of the Gateway's location in cislunar space. The Deep Space Gateway Concept Science Workshop was held in Denver, Colorado from February 27th to March 1st 2018. This three-day conference was a workshop where 196 presentations were given for possible scientific studies that could be advanced through the use of the Gateway.

An earlier NASA proposal for a cislunar station had been made public in 2012 and was dubbed the Deep Space Habitat. That proposal had led to funding in 2015 under the NextSTEP program to study the requirements of deep space habitats. In February 2018 it was announced that those NextSTEP studies and other ISS partner studies would help to guide the capabilities required of the Gateway's habitation modules.

NASA has also initiated a Revolutionary Aerospace Systems Concepts Academic Linkage (RASC-AL) competition for universities to develop concepts and capabilities for the Gateway. The competitors are asked to employ original engineering and analysis in one of the following areas:
  • Gateway Uncrewed Utilization & Operations
  • Gateway-Based Human Lunar Surface Access
  • Gateway Logistics as a Science Platform
  • Design of a Gateway-Based Cislunar Tug
Teams of undergraduate and graduate students were asked to submit a response by January 17, 2019 addressing one of these four themes. NASA will select 20 teams to continue developing proposed concepts. Fourteen of the teams will be invited to present their projects in person on June 2019 at the RASC-AL Forum in Cocoa Beach, Florida and will receive a $6,000 stipend to participate in the Forum.

Proposed components

The Gateway will serve as an all-in-one solar-powered communications hub, science laboratory, short-term habitation module, and holding area for rovers and other robots.

The early concept for the LOP-G is still evolving, and may include the following component modules:
  • The Power and Propulsion Element (PPE) will be used to generate electricity for the space station and its solar electric propulsion. It is targeting launch on a commercial vehicle in 2022.
  • The European System Providing Refuelling, Infrastructure and Telecommunications (ESPRIT) module will provide additional xenon and hydrazine capacity, additional communications equipment, and an airlock for science packages. It would have a mass of approximately 4 tons, and a length of 3.91 m.
  • The U.S. Utilization Module is a small pressurized space that would enable a crew ingress on the very first mission to the Gateway assembly sequence. It will initially store additional food and will be launched along with ESPRIT on EM-3.
  • The International Partner Habitat and the U.S. Habitat are the two habitation modules. These will be launched on EM-4 and EM-5 and together will provide a minimum of 125 m3 of habitable volume to the station.
  • The Gateway Logistics Modules will be used to refuel, resupply and provide logistics on board the space station. The first logistics module sent to LOP-G will also arrive with a robotic arm, which will be built by the Canadian Space Agency.
  • The Gateway Airlock Module will be used for performing extravehicular activities outside the space station and will be the berth for the Deep Space Transport.

Surface missions

  • HERACLES (Human-Enhanced Robotic Architecture and Capability for Lunar Exploration and Science) is a proposed ESA-JAXA-CSA robotic lander and sample-return mission utilising the station. It involves dispatching a 11,000 kg lunar lander from Earth aboard an Ariane 64 which would land on the Moon before an ascent module returns to the Gateway station. The ascent modules (labelled I on the diagram above) are reusable and would be paired at Gateway with a fresh lander module dispatched from Earth. The rovers would land on the first and fourth lander missions collecting samples and loading them on the ascent module then traversing the hundreds of kilometres between landing sites on the lunar surface to rendezvous and load the next lander. The ascent module would return each time to the Gateway where it would be captured by the Canadian robotic arm and samples transferred to an Orion craft for transport to Earth with returning astronauts while the 2nd and 3rd landings would each have 500 kg payload available for alternate uses. The aim of the project is the development by ESA of a reusable lunar ascent engine, four of which could be clustered to power a wholly reusable crewed or robotic lander in the future, alongside the development of Gateway telecommunication command and control technology. ESA envisages that HERACLES would be subject to ministerial approval in 2019, and could allow a sample-return on the fourth or fifth Orion flight in the 2026-2030 timeframe, generating an early scientific return for the station and robotic surveying of the conditions that will be encountered at future crewed landing sites several years in advance.

Proposed timeline

Year Vehicle assembly objective Mission name Launch vehicle Human/robotic elements
September 2022 Start of the Lunar Orbital Platform-Gateway assembly by launching the Power and Propulsion Element (PPE) TBD Commercial launch vehicle Uncrewed
2024 ESPRIT and the U.S. Utilization Module launch and are mated to PPE in a L2 Southern Near Rectilinear Halo Orbit (NRHO) EM-3 Space Launch System, Block 1B Crewed
No Earlier Than 2024 Delivery of International Partner Habitat EM-4 Space Launch System, Block 1B Crewed
No Earlier Than 2025 Delivery of U.S. Habitat EM-5 Space Launch System, Block 1B Crewed
No Earlier Than 2024 Delivery of the first logistics module and the robotic arm EM-6 Space Launch System, Block 1B Crewed
2026 Orion capsule (crew 4) delivers the Airlock Module to the Gateway EM-7 Space Launch System, Block 1B Crewed
2027 Deep Space Transport (DST) to the Lunar Gateway EM-8 Space Launch System, Block 1B Uncrewed
2027 DST checkout mission EM-9 Space Launch System, Block 1B Crewed
2028 DST Cargo logistics and refuelling EM-10 Space Launch System, Block 1B Uncrewed
2029 DST one year cruise test (shakedown cruise) in cislunar space EM-11 Space Launch System, Block 2 Crewed
2030 Cargo DST logistics and refuelling mission EM-12 Space Launch System, Block 2 Uncrewed
2033 DST cruise for injection into Mars orbit EM-13 Space Launch System, Block 2 Crewed

Criticisms

The Deep Space Gateway has received numerous criticisms from several space professionals for lacking a proper scientific goal. Former NASA Astronaut Terry Virts, who was a pilot of STS-130 aboard Space Shuttle Endeavour and Commander of the International Space Station on Expedition 43 wrote in an Op-ed on Ars Technica that the Deep Space Gateway would "shackle human exploration, not enable it". Terry stated that there is no concrete human spaceflight goal with the Deep Space Gateway and that he cannot envision a new technology that would be developed or validated by building another modular space station. Terry further criticized NASA for abandoning its safety dictum of separating the crew from the cargo which was put in place following the Space Shuttle Columbia accident in 2003.

Mars Society founder Robert Zubrin, who has been one of the staunchest advocates for a human mission to Mars, called the Deep Space Gateway "NASA's worst plan yet" in an article on the National Review. Robert went on to say "We do not need a lunar-orbiting station to go to the Moon. We do not need such a station to go to Mars. We do not need it to go to near-Earth asteroids. We do not need it to go anywhere. Nor can we accomplish anything in such a station that we cannot do in the Earth-orbiting International Space Station" and that "there is nothing at all in lunar orbit: nothing to use, nothing to explore, nothing to do". Robert also stated that "If the goal is to build a Moon base, it should be built on the surface of the Moon. That is where the science is, that is where the shielding material is, and that is where the resources to make propellant and other useful things are to be found."

Retired aerospace engineer Gerald Black stated that the "LOP-G is useless for supporting human return to the lunar surface and a lunar base." He added that it is not even planned to be used as a rocket fuel depot and that stopping at LOP-G on the way to or from the Moon would serve no useful purpose and it would actually waste rocket fuel.

Pei Zhaoyu, deputy director of the Lunar Exploration and Space Program Center of the China National Space Administration, concludes that, from a cost-benefit standpoint, the gateway would have "lost cost-effectiveness." Pei said the Chinese plan is to focus on a research station on the surface.

Colonization of the Moon

From Wikipedia, the free encyclopedia

1986 artist concept of a lunar colony

Colonization of the Moon is the proposed establishment of a permanent human community or robotic industries on the Moon.

Discovery of lunar water at the lunar poles by Chandrayaan-1 has renewed interest in the Moon. Locating such a colony at one of the lunar poles would also avoid the problem of long lunar nights – about 354 hours long, a little more than two weeks – and allow the colony to take advantage of the continuous sunlight there for generating solar power.

Permanent human habitation on a planetary body other than the Earth is one of science fiction's most prevalent themes. As technology has advanced, and concerns about the future of humanity on Earth have increased, the vision of space colonization as an achievable and worthwhile goal has gained momentum. Because of its proximity to Earth, the Moon is seen as the best and most obvious location for the first permanent off-planet colony. Currently, the main problem hindering the development of such a colony is the high cost of spaceflight.

There are also several projects that have been proposed for the near future by space tourism startup companies for tourism on the Moon.

Proposals

Concept art from NASA showing astronauts entering a lunar outpost

The notion of a lunar colony originated before the Space Age. In 1638 Bishop John Wilkins wrote A Discourse Concerning a New World and Another Planet, in which he predicted a human colony on the Moon. Konstantin Tsiolkovsky (1857–1935), among others, also suggested such a step. From the 1950s onwards, a number of concepts and designs have been suggested by scientists, engineers and others.

In 1954, science-fiction writer Arthur C. Clarke proposed a lunar base of inflatable modules covered in lunar dust for insulation. A spaceship, assembled in low Earth orbit, would launch to the Moon, and astronauts would set up the igloo-like modules and an inflatable radio mast. Subsequent steps would include the establishment of a larger, permanent dome; an algae-based air purifier; a nuclear reactor for the provision of power; and electromagnetic cannons to launch cargo and fuel to interplanetary vessels in space.

In 1959, John S. Rinehart suggested that the safest design would be a structure that could "[float] in a stationary ocean of dust", since there were, at the time this concept was outlined, theories that there could be mile-deep dust oceans on the Moon.[11] The proposed design consisted of a half-cylinder with half-domes at both ends, with a micrometeoroid shield placed above the base.

Project Horizon

Project Horizon was a 1959 study regarding the United States Army's plan to establish a fort on the Moon by 1967. Heinz-Hermann Koelle, a German rocket engineer of the Army Ballistic Missile Agency (ABMA) led the Project Horizon study. It was proposed that the first landing would be carried out by two "soldier-astronauts" in 1965 and that more construction workers would soon follow. It was posited that through numerous launches (61 Saturn Is and 88 Saturn C-2s), 245 tons of cargo could be transported to the outpost by 1966.

Lunex Project

Lunex Project was a US Air Force plan for a manned lunar landing prior to the Apollo Program in 1961. It envisaged a 21-airman underground Air Force base on the Moon by 1968 at a total cost of $7.5 billion.

Sub-surface base

In 1962, John DeNike and Stanley Zahn published their idea of a sub-surface base located at the Sea of Tranquility. This base would house a crew of 21, in modules placed four meters below the surface, which was believed to provide radiation shielding on par with Earth's atmosphere. DeNike and Zahn favored nuclear reactors for energy production, because they were more efficient than solar panels, and would also overcome the problems with the long lunar nights. For the life support system, an algae-based gas exchanger was proposed.

Recent proposals

In 2007, Jim Burke, of the International Space University in France, said people should plan to preserve humanity's culture in the event of a civilization-stopping asteroid impact with Earth. A Lunar Noah's Ark was proposed. Subsequent planning may be taken up by the International Lunar Exploration Working Group (ILEWG).

In 2016, Johann-Dietrich Wörner, the Chief of ESA, proposed the International Moon Village as a non-governmental organization (NGO), and in November 2017, the Moon Village Association was created. This organization aims to promote international discussions to foster the implementation of a permanent human settlement near the lunar south pole.

Moon exploration

Exploration through 2017

Exploration of the lunar surface by spacecraft began in 1959 with the Soviet Union's Luna program. Luna 1 missed the Moon, but Luna 2 made a hard landing (impact) into its surface, and became the first artificial object on an extraterrestrial body. The same year, the Luna 3 mission radioed photographs to Earth of the Moon's hitherto unseen far side, marking the beginning of a decade-long series of robotic lunar explorations.

Responding to the Soviet program of space exploration, US President John F. Kennedy in 1961 told the US Congress on May 25: "I believe that this nation should commit itself to achieving the goal, before this decade is out, of landing a man on the Moon and returning him safely to the Earth." The same year the Soviet leadership made some of its first public pronouncements about landing a man on the Moon and establishing a lunar base.

Crewed exploration of the lunar surface began in 1968 when the Apollo 8 spacecraft orbited the Moon with three astronauts on board. This was mankind's first direct view of the far side. The following year, the Apollo 11 Apollo Lunar Module landed two astronauts on the Moon, proving the ability of humans to travel to the Moon, perform scientific research work there, and bring back sample materials.

Additional missions to the Moon continued this exploration phase. In 1969, the Apollo 12 mission landed next to the Surveyor 3 spacecraft, demonstrating precision landing capability. The use of a manned vehicle on the Moon's surface was demonstrated in 1971 with the Lunar Rover during Apollo 15. Apollo 16 made the first landing within the rugged lunar highlands. However, interest in further exploration of the Moon was beginning to wane among the American public. In 1972, Apollo 17 was the final Apollo lunar mission, and further planned missions were scrapped at the directive of President Nixon. Instead, focus was turned to the Space Shuttle and crewed missions in near Earth orbit.

In addition to its scientific returns, the Apollo program also provided valuable lessons about living and working in the lunar environment.

The Soviet manned lunar programs failed to send a manned mission to the Moon. However, in 1966 Luna 9 was the first probe to achieve a soft landing and return close-up shots of the lunar surface.  Luna 16 in 1970 returned the first Soviet lunar soil samples, while in 1970 and 1973 during the Lunokhod program two robotic rovers landed on the Moon. Lunokhod 1 explored the lunar surface for 322 days, and Lunokhod 2 operated on the Moon about four months only but covered a third more distance. 1974 saw the end of the Soviet Moonshot, two years after the last American manned landing. Besides the manned landings, an abandoned Soviet moon program included building the moonbase "Zvezda", which was the first detailed project with developed mockups of expedition vehicles and surface modules.

In the decades following, interest in exploring the Moon faded considerably, and only a few dedicated enthusiasts supported a return. However, evidence of lunar ice at the poles gathered by NASA's Clementine (1994) and Lunar Prospector (1998) missions rekindled some discussion, as did the potential growth of a Chinese space program that contemplated its own mission to the Moon. Subsequent research suggested that there was far less ice present (if any) than had originally been thought, but that there may still be some usable deposits of hydrogen in other forms. However, in September 2009, the Chandrayaan probe of India, carrying an ISRO instrument, discovered that the lunar soil contains 0.1% water by weight, overturning hypotheses that had stood for 40 years.

In 2004, US President George W. Bush called for a plan to return crewed missions to the Moon by 2020 (since cancelled – see Constellation program). On June 18, 2009, NASA's LCROSS/LRO mission to the moon was launched. The LCROSS mission was designed to acquire research information to assist with future lunar exploratory missions and was scheduled to conclude with a controlled collision of the craft on the lunar surface. LCROSS's mission concluded as scheduled with its controlled impact on October 9, 2009.

In 2010, due to reduced congressional NASA appropriations, President Barack Obama halted the Bush administration's earlier lunar exploration initiative and directed a generic focus on crewed missions to asteroids and Mars, as well as extending support for the International Space Station.

Planned crewed lunar missions 2021 - 2036

As of 2016, Russia is planning to begin building a human colony on the moon by 2030. Initially, the Moon base would be crewed by no more than 4 people, with their number later rising to maximum of 12 people. Japan also has plans to land a man on the moon by 2030, while the People's Republic of China is currently planning to land a human on the Moon by 2036 (see Chinese Lunar Exploration Program).

The United States currently (2017) has plans to send a crewed space mission to orbit (but not to land on) the Moon in 2021. While the US Trump administration has called for a return of crewed missions to the Moon, it has currently (2018) not authorized any funding for any such lunar missions in the next 20 years. The current administration has focused funding on Mars missions. What President Trump requests is the development of a lunar orbiting station called Lunar Orbital Platform-Gateway. A stated goal of aerospace company SpaceX is to enable the creation of a colony on the Moon using its upcoming BFR launch system. Billionaire Jeff Bezos has outlined his plans for a lunar base in the next decade.

Lunar water ice

File:LRO Peers into Permanent Shadows.ogv 
Play media
Beginning with a full-frame Moon in this video, the camera flies to the lunar south pole and shows areas of permanent shadow. Realistic shadows evolve through several months.

On 24 September 2009, Science magazine reported that the Moon Mineralogy Mapper (M3) on the Indian Space Research Organization's (ISRO) Chandrayaan-1 had detected water on the Moon. M3 detected absorption features near 2.8–3.0 μm (0.00011–0.00012 in) on the surface of the Moon. For silicate bodies, such features are typically attributed to hydroxyl- and/or water-bearing materials. On the Moon, the feature is seen as a widely distributed absorption that appears strongest at cooler high latitudes and at several fresh feldspathic craters. The general lack of correlation of this feature in sunlit M3 data with neutron spectrometer H abundance data suggests that the formation and retention of OH and H2O is an ongoing surficial process. OH/H2O production processes may feed polar cold traps and make the lunar regolith a candidate source of volatiles for human exploration.

The Moon Mineralogy Mapper (M3), an imaging spectrometer, was one of the 11 instruments on board Chandrayaan-1, whose mission came to a premature end on 29 August 2009. M3 was aimed at providing the first mineral map of the entire lunar surface.

Lunar scientists had discussed the possibility of water repositories for decades. They are now increasingly "confident that the decades-long debate is over" a report says. "The Moon, in fact, has water in all sorts of places; not just locked up in minerals, but scattered throughout the broken-up surface, and, potentially, in blocks or sheets of ice at depth." The results from the Chandrayaan mission are also "offering a wide array of watery signals."

On November 13, 2009, NASA announced that the LCROSS mission had discovered large quantities of water ice on the Moon around the LCROSS impact site at Cabeus. Robert Zubrin, president of the Mars Society, relativized the term 'large': "The 30 m crater ejected by the probe contained 10 million kilograms of regolith. Within this ejecta, an estimated 100 kg of water was detected. That represents a proportion of ten parts per million, which is a lower water concentration than that found in the soil of the driest deserts of the Earth. In contrast, we have found continent sized regions on Mars, which are 600,000 parts per million, or 60% water by weight." Although the Moon is very dry on the whole, the spot where the LCROSS impactor hit was chosen for a high concentration of water ice. Dr. Zubrin's computations are not a sound basis for estimating the percentage of water in the regolith at that site. Researchers with expertise in that area estimated that the regolith at the impact site contained 5.6 ± 2.9% water ice, and also noted the presence of other volatile substances. Hydrocarbons, material containing sulfur, carbon dioxide, carbon monoxide, methane and ammonia were present.

In March 2010, NASA reported that the findings of its mini-SAR radar aboard Chandrayaan-1 were consistent with ice deposits at the Moon's north pole. It is estimated there is at least 600 million tons of ice at the north pole in sheets of relatively pure ice at least a couple of meters thick.

In March 2014, researchers who had previously published reports on possible abundance of water on the Moon, reported new findings that refined their predictions substantially lower.

In 2018, it was announced that M3 infrared data from Chandrayaan-1 had been re-analyzed to confirm the existence of water across wide expanses of the Moon's polar regions.

Advantages and disadvantages

Placing a colony on a natural body would provide an ample source of material for construction and other uses in space, including shielding from cosmic radiation. The energy required to send objects from the Moon to space is much less than from Earth to space. This could allow the Moon to serve as a source of construction materials within cis-lunar space. Rockets launched from the Moon would require less locally produced propellant than rockets launched from Earth. Some proposals include using electric acceleration devices (mass drivers) to propel objects off the Moon without building rockets. Others have proposed momentum exchange tethers (see below). Furthermore, the Moon does have some gravity, which experience to date indicates may be vital for fetal development and long-term human health. Whether the Moon's gravity (roughly one sixth of Earth's) is adequate for this purpose, however, is uncertain.

In addition, the Moon is the closest large body in the Solar System to Earth. While some Earth-crosser asteroids occasionally pass closer, the Moon's distance is consistently within a small range close to 384,400 km. This proximity has several advantages:
  • A lunar base could be a site for launching rockets with locally manufactured fuel to distant planets such as Mars. Launching rockets from the Moon would be easier than from Earth because the Moon's gravity is lower, requiring a lower escape velocity. A lower escape velocity would require less propellant, but there is no guarantee that less propellant would cost less money than that required to launch from Earth. Asteroid mining, however, may prove useful in lowering various costs accrued during the construction and management of a lunar base and its activities.
  • The energy required to send objects from Earth to the Moon is lower than for most other bodies.
  • Transit time is short. The Apollo astronauts made the trip in three days and future technologies could improve on this time.
  • The short transit time would also allow emergency supplies to quickly reach a Moon colony from Earth, or allow a human crew to evacuate relatively quickly from the Moon to Earth in case of emergency. This could be an important consideration when establishing the first human colony.
  • If a long-term base were to be built on the Moon, the exposure would show the effects of low gravity on humans over an extended period of time. Those results could likely inform the viability of attempting a long-term base or a Mars colony.
  • The round trip communication delay to Earth is less than three seconds, allowing near-normal voice and video conversation, and allowing some kinds of remote control of machines from Earth that are not possible for any other celestial body. The delay for other Solar System bodies is minutes or hours; for example, round trip communication time between Earth and Mars ranges from about eight to forty minutes. This, again, could be particularly valuable in an early colony, where life-threatening problems requiring Earth's assistance could occur.
  • On the lunar near side, the Earth appears large and is always visible as an object 60 times brighter than the Moon appears from Earth, unlike more distant locations where the Earth would be seen merely as a star-like object, much as the planets appear from Earth. As a result, a lunar colony might feel less remote to humans living there.
  • Building observatory facilities on the Moon from lunar materials allows many of the benefits of space based facilities without the need to launch these into space. The lunar soil, although it poses a problem for any moving parts of telescopes, can be mixed with carbon nanotubes and epoxies in the construction of mirrors up to 50 meters in diameter. It is relatively nearby; astronomical seeing is not a concern; certain craters near the poles are permanently dark and cold, and thus especially useful for infrared telescopes; and radio telescopes on the far side would be shielded from the radio chatter of Earth. A lunar zenith telescope can be made cheaply with ionic liquid.
  • A farm at the lunar north pole could provide eight hours of sunlight per day during the local summer by rotating crops in and out of the sunlight which is continuous for the entire summer. A beneficial temperature, radiation protection, insects for pollination, and all other plant needs could be artificially provided during the local summer for a cost. One estimate suggested a 0.5 hectare space farm could feed 100 people.
There are several disadvantages to the Moon as a colony site:
  • The long lunar night would impede reliance on solar power and require that a colony exposed to the sunlit equatorial surface be designed to withstand large temperature extremes (about 95 K (−178.2 °C) to about 400 K (127 °C)). An exception to this restriction are the so-called "peaks of eternal light" located at the lunar north pole that are constantly bathed in sunlight. The rim of Shackleton Crater, towards the lunar south pole, also has a near-constant solar illumination. Other areas near the poles that get light most of the time could be linked in a power grid. The temperature 1 meter below the surface of the Moon is estimated to be near constant over the period of a month varying with latitude from near 220 K (−53 °C) at the equator to near 150 K (−123 °C) at the poles.
  • The Moon is highly depleted in volatile elements, such as nitrogen and hydrogen. Carbon, which forms volatile oxides, is also depleted. A number of robot probes including Lunar Prospector gathered evidence of hydrogen generally in the Moon's crust consistent with what would be expected from solar wind, and higher concentrations near the poles. There had been some disagreement whether the hydrogen must necessarily be in the form of water. The 2009 mission of the Lunar Crater Observation and Sensing Satellite (LCROSS) proved that there is water on the Moon. This water exists in ice form perhaps mixed in small crystals in the regolith in a colder landscape than people have ever mined. Other volatiles containing carbon and nitrogen were found in the same cold trap as ice. If no sufficient means is found for recovering these volatiles on the Moon, they would need to be imported from some other source to support life and industrial processes. Volatiles would need to be stringently recycled. This would limit the colony's rate of growth and keep it dependent on imports. The transportation cost of importing volatiles from Earth could be reduced by constructing the upper stage of supply ships using materials high in volatiles, such as carbon fiber and plastics. The 2006 announcement by the Keck Observatory that the binary Trojan asteroid 617 Patroclus, and possibly large numbers of other Trojan objects in Jupiter's orbit, are likely composed of water ice, with a layer of dust, and the hypothesized large amounts of water ice on the closer, main-belt asteroid 1 Ceres, suggest that importing volatiles from this region via the Interplanetary Transport Network may be practical in the not-so-distant future. However, these possibilities are dependent on complicated and expensive resource utilization from the mid to outer Solar System, which is not likely to become available to a Moon colony for a significant period of time.
  • It is uncertain whether the low (~ one-sixth g) gravity on the Moon is strong enough to prevent detrimental effects to human health in the long term. Exposure to weightlessness over month-long periods has been demonstrated to cause deterioration of physiological systems, such as loss of bone and muscle mass and a depressed immune system. Similar effects could occur in a low-gravity environment, although virtually all research into the health effects of low gravity has been limited to micro gravity.
  • The lack of a substantial atmosphere for insulation results in temperature extremes and makes the Moon's surface conditions somewhat like a deep space vacuum. It also leaves the lunar surface exposed to half as much radiation as in interplanetary space (with the other half blocked by the Moon itself underneath the colony), raising the issues of the health threat from cosmic rays and the risk of proton exposure from the solar wind. Lunar rubble can protect living quarters from cosmic rays. Shielding against solar flares during expeditions outside is more problematic.
  • When the Moon passes through the magnetotail of the Earth, the plasma sheet whips across its surface. Electrons crash into the Moon and are released again by UV photons on the day side but build up voltages on the dark side. This causes a negative charge build up from −200 V to −1000 V. See Magnetic field of the Moon.
  • The lack of an atmosphere increases the chances of the colony's being hit by meteors. Even small pebbles and dust (micrometeoroids) have the potential to damage or destroy insufficiently protected structures.
  • Moon dust is an extremely abrasive glassy substance formed by micrometeorites and unrounded due to the lack of weathering. It sticks to everything, can damage equipment, and it may be toxic. Since it is bombarded by charged particles in the solar wind, it is highly ionized, and is extremely harmful when breathed in. During the 1960s and 70s Apollo missions, astronauts were subject to respiratory problems on return flights from the Moon, for this reason.
  • Growing crops on the Moon faces many difficult challenges due to the long lunar night (354 hours), extreme variation in surface temperature, exposure to solar flares, nitrogen-poor soil, and lack of insects for pollination. Due to the lack of any atmosphere on the Moon, plants would need to be grown in sealed chambers, though experiments have shown that plants can thrive at pressures much lower than those on Earth. The use of electric lighting to compensate for the 354-hour night might be difficult: a single acre of plants on Earth enjoys a peak 4 megawatts of sunlight power at noon. Experiments conducted by the Soviet space program in the 1970s suggest it is possible to grow conventional crops with the 354-hour light, 354-hour dark cycle. A variety of concepts for lunar agriculture have been proposed, including the use of minimal artificial light to maintain plants during the night and the use of fast-growing crops that might be started as seedlings with artificial light and be harvestable at the end of one lunar day.
  • One of the less obvious difficulties lies not with the Moon itself but rather with the political and national interests of the nations engaged in colonization. Assuming that colonization efforts were able to overcome the difficulties outlined above – there would likely be issues regarding the rights of nations and their colonies to exploit resources on the lunar surface, to stake territorial claims and other issues of sovereignty which would have to be agreed upon before one or more nations established a permanent presence on the Moon. The ongoing negotiations and debate regarding the Antarctic is a good case study for prospective lunar colonization efforts in that it highlights the numerous pitfalls of developing/inhabiting a location that is subject to the claims of multiple sovereign nations.

Locations

Russian astronomer Vladislav V. Shevchenko proposed in 1988 the following three criteria that a lunar outpost should meet:
  • good conditions for transport operations;
  • a great number of different types of natural objects and features on the Moon of scientific interest; and
  • natural resources, such as oxygen. The abundance of certain minerals, such as iron oxide, varies dramatically over the lunar surface.
While a colony might be located anywhere, potential locations for a lunar colony fall into three broad categories.

Polar regions

There are two reasons why the north pole and south pole of the Moon might be attractive locations for a human colony. First, there is evidence for the presence of water in some continuously shaded areas near the poles. Second, the Moon's axis of rotation is sufficiently close to being perpendicular to the ecliptic plane that the radius of the Moon's polar circles is less than 50 km. Power collection stations could therefore be plausibly located so that at least one is exposed to sunlight at all times, thus making it possible to power polar colonies almost exclusively with solar energy. Solar power would be unavailable only during a lunar eclipse, but these events are relatively brief and absolutely predictable. Any such colony would therefore require a reserve energy supply that could temporarily sustain a colony during lunar eclipses or in the event of any incident or malfunction affecting solar power collection. Hydrogen fuel cells would be ideal for this purpose, since the hydrogen needed could be sourced locally using the Moon's polar water and surplus solar power. Moreover, due to the Moon's uneven surface some sites have nearly continuous sunlight. For example, Malapert mountain, located near the Shackleton crater at the lunar south pole, offers several advantages as a site:
  • It is exposed to the Sun most of the time; two closely spaced arrays of solar panels would receive nearly continuous power.
  • Its proximity to Shackleton Crater (116 km, or 69.8 mi) means that it could provide power and communications to the crater. This crater is potentially valuable for astronomical observation. An infrared instrument would benefit from the very low temperatures. A radio telescope would benefit from being shielded from Earth's broad spectrum radio interference.
  • The nearby Shoemaker and other craters are in constant deep shadow, and might contain valuable concentrations of hydrogen and other volatiles.
  • At around 5,000 meters (16,000 feet) elevation, it offers line of sight communications over a large area of the Moon, as well as to Earth.
  • The South Pole-Aitken basin is located at the lunar south pole. This is the second largest known impact basin in the Solar System, as well as the oldest and biggest impact feature on the Moon, and should provide geologists access to deeper layers of the Moon's crust.
NASA chose to use a south-polar site for the lunar outpost reference design in the Exploration Systems Architecture Study chapter on lunar architecture.

At the north pole, the rim of Peary Crater has been proposed as a favorable location for a base. Examination of images from the Clementine mission appear to show that parts of the crater rim are permanently illuminated by sunlight (except during lunar eclipses). As a result, the temperature conditions are expected to remain very stable at this location, averaging −50 °C (−58 °F). This is comparable to winter conditions in Earth's Poles of Cold in Siberia and Antarctica. The interior of Peary Crater may also harbor hydrogen deposits.

A 1994 bistatic radar experiment performed during the Clementine mission suggested the presence of water ice around the south pole. The Lunar Prospector spacecraft reported in 2008 enhanced hydrogen abundances at the south pole and even more at the north pole. On the other hand, results reported using the Arecibo radio telescope have been interpreted by some to indicate that the anomalous Clementine radar signatures are not indicative of ice, but surface roughness. This interpretation, however, is not universally agreed upon.

A potential limitation of the polar regions is that the inflow of solar wind can create an electrical charge on the leeward side of crater rims. The resulting voltage difference can affect electrical equipment, change surface chemistry, erode surfaces and levitate lunar dust.

Equatorial regions

The lunar equatorial regions are likely to have higher concentrations of helium-3 (rare on Earth but much sought after for use in nuclear fusion research) because the solar wind has a higher angle of incidence. They also enjoy an advantage in extra-Lunar traffic: The rotation advantage for launching material is slight due to the Moon's slow rotation, but the corresponding orbit coincides with the ecliptic, nearly coincides with the lunar orbit around Earth, and nearly coincides with the equatorial plane of Earth.

Several probes have landed in the Oceanus Procellarum area. There are many areas and features that could be subject to long-term study, such as the Reiner Gamma anomaly and the dark-floored Grimaldi crater.

Far side

The lunar far side lacks direct communication with Earth, though a communication satellite at the L2 Lagrangian point, or a network of orbiting satellites, could enable communication between the far side of the Moon and Earth. The far side is also a good location for a large radio telescope because it is well shielded from the Earth. Due to the lack of atmosphere, the location is also suitable for an array of optical telescopes, similar to the Very Large Telescope in Chile. To date, there has been no ground exploration of the far side.

Scientists have estimated that the highest concentrations of helium-3 can be found in the maria on the far side, as well as near side areas containing concentrations of the titanium-based mineral ilmenite. On the near side the Earth and its magnetic field partially shields the surface from the solar wind during each orbit. But the far side is fully exposed, and thus should receive a somewhat greater proportion of the ion stream.

Lunar lava tubes

High Sun view of a 100 meter deep lunar pit crater that may provide access to a lava tube

Lunar lava tubes are a potential location for constructing a lunar base. Any intact lava tube on the Moon could serve as a shelter from the severe environment of the lunar surface, with its frequent meteorite impacts, high-energy ultra-violet radiation and energetic particles, and extreme diurnal temperature variations. Lava tubes provide ideal positions for shelter because of their access to nearby resources. They also have proven themselves as a reliable structure, having withstood the test of time for billions of years.

An underground colony would escape the extreme of temperature on the Moon's surface. The average temperature on the surface of the Moon is about −5 °C. The day period (about 354 hours) has an average temperature of about 107 °C (225 °F), although it can rise as high as 123 °C (253 °F). The night period (also 354 hours) has an average temperature of about −153 °C (−243 °F). Underground, both periods would be around −23 °C (−9 °F), and humans could install ordinary heaters.

One such lava tube was discovered in early 2009.

Structure

Habitat

There have been numerous proposals regarding habitat modules. The designs have evolved throughout the years as mankind's knowledge about the Moon has grown, and as the technological possibilities have changed. The proposed habitats range from the actual spacecraft landers or their used fuel tanks, to inflatable modules of various shapes. Some hazards of the lunar environment such as sharp temperature shifts, lack of atmosphere or magnetic field (which means higher levels of radiation and micrometeoroids) and long nights, were unknown early on. Proposals have shifted as these hazards were recognized and taken into consideration.

Underground colonies

Some suggest building the lunar colony underground, which would give protection from radiation and micrometeoroids. This would also greatly reduce the risk of air leakage, as the colony would be fully sealed from the outside except for a few exits to the surface.

The construction of an underground base would probably be more complex; one of the first machines from Earth might be a remote-controlled excavating machine. Once created, some sort of hardening would be necessary to avoid collapse, possibly a spray-on concrete-like substance made from available materials. A more porous insulating material also made in-situ could then be applied. Rowley & Neudecker have suggested "melt-as-you-go" machines that would leave glassy internal surfaces. Mining methods such as the room and pillar might also be used. Inflatable self-sealing fabric habitats might then be put in place to retain air. Eventually an underground city can be constructed. Farms set up underground would need artificial sunlight. As an alternative to excavating, a lava tube could be covered and insulated, thus solving the problem of radiation exposure. An alternative solution is studied in Europe by students to excavate a habitat in the ice-filled craters of the moon.

Surface colonies

Variant for habitat creation on the surface or over lava tube
 
A NASA model of a proposed inflatable module
 
A possibly easier solution would be to build the lunar base on the surface, and cover the modules with lunar soil. The lunar soil is composed of a unique blend of silica and iron-containing compounds that may be fused into a glass-like solid using microwave energy. Blacic has studied the mechanical properties of lunar glass and has shown that it is a promising material for making rigid structures, if coated with metal to keep moisture out. This may allow for the use of "lunar bricks" in structural designs, or the vitrification of loose dirt to form a hard, ceramic crust.

A lunar base built on the surface would need to be protected by improved radiation and micrometeoroid shielding. Building the lunar base inside a deep crater would provide at least partial shielding against radiation and micrometeoroids. Artificial magnetic fields have been proposed as a means to provide radiation shielding for long range deep space crewed missions, and it might be possible to use similar technology on a lunar colony. Some regions on the Moon possess strong local magnetic fields that might partially mitigate exposure to charged solar and galactic particles.

In a turn from the usual engineer-designed lunar habitats, London-based Foster + Partners architectural firm proposed a building construction 3D-printer technology in January 2013 that would use lunar regolith raw materials to produce lunar building structures while using enclosed inflatable habitats for housing the human occupants inside the hard-shell lunar structures. Overall, these habitats would require only ten percent of the structure mass to be transported from Earth, while using local lunar materials for the other 90 percent of the structure mass. "Printed" lunar soil would provide both "radiation and temperature insulation. Inside, a lightweight pressurized inflatable with the same dome shape would be the living environment for the first human Moon settlers." The building technology would include mixing lunar material with magnesium oxide, which would turn the "moonstuff into a pulp that can be sprayed to form the block" when a binding salt is applied that "converts [this] material into a stone-like solid." Terrestrial versions of this 3D-printing building technology are already printing 2 metres (6 ft 7 in) of building material per hour with the next-generation printers capable of 3.5 metres (11 ft) per hour, sufficient to complete a building in a week.

Moon Capital

In 2010, The Moon Capital Competition offered a prize for a design of a lunar habitat intended to be an underground international commercial center capable of supporting a residential staff of 60 people and their families. The Moon Capital is intended to be self-sufficient with respect to food and other material required for life support. Prize money was provided primarily by the Boston Society of Architects, Google Lunar X Prize and The New England Council of the American Institute of Aeronautics and Astronautics.

3D printed structures

On January 31, 2013, the ESA working with an independent architectural firm, tested a 3D-printed structure that could be constructed of lunar regolith for use as a Moon base.

Energy

Nuclear power

A nuclear fission reactor might fulfill most of a Moon base's power requirements. With the help of fission reactors, one could overcome the difficulty of the 354 hour lunar night. According to NASA, a nuclear fission power station could generate a steady 40 kilowatts, equivalent to the demand of about eight houses on Earth. An artist's concept of such a station published by NASA envisages the reactor being buried below the Moon's surface to shield it from its surroundings; out from a tower-like generator part reaching above the surface over the reactor, radiators would extend into space to send away any heat energy that may be left over.

Radioisotope thermoelectric generators could be used as backup and emergency power sources for solar powered colonies.

One specific development program in the 2000s was the Fission Surface Power (FSP) project of NASA and DOE, a fission power system focused on "developing and demonstrating a nominal 40 kWe power system to support human exploration missions. The FSP system concept uses conventional low-temperature stainless steel, liquid metal-cooled reactor technology coupled with Stirling power conversion." As of 2010, significant component hardware testing had been successfully completed, and a non-nuclear system demonstration test was being fabricated.

Helium-3 mining could be used to provide a substitute for tritium for potential production of fusion power in the future.

Solar energy

Solar energy is a possible source of power for a lunar base. Many of the raw materials needed for solar panel production can be extracted on site. However, the long lunar night (354 hours or 14.75 Earth days) is a drawback for solar power on the Moon's surface. This might be solved by building several power plants, so that at least one of them is always in daylight. Another possibility would be to build such a power plant where there is constant or near-constant sunlight, such as at the Malapert mountain near the lunar south pole, or on the rim of Peary crater near the north pole. Since lunar regolith contains structural metals like iron and aluminum, solar panels could be mounted high up on locally-built towers that might rotate to follow the sun. A third possibility would be to leave the panels in orbit, and beam the power down as microwaves.

The solar energy converters need not be silicon solar panels. It may be more advantageous to use the larger temperature difference between Sun and shade to run heat engine generators. Concentrated sunlight could also be relayed via mirrors and used in Stirling engines or solar trough generators, or it could be used directly for lighting, agriculture and process heat. The focused heat might also be employed in materials processing to extract various elements from lunar surface materials.

Energy storage

Fuel cells on the Space Shuttle have operated reliably for up to 17 Earth days at a time. On the Moon, they would only be needed for 354 hours (14 ​34 days) – the length of the lunar night. Fuel cells produce water directly as a waste product. Current fuel cell technology is more advanced than the Shuttle's cells – PEM (Proton Exchange Membrane) cells produce considerably less heat (though their waste heat would likely be useful during the lunar night) and are lighter, not to mention the reduced mass of the smaller heat-dissipating radiators. This makes PEMs more economical to launch from Earth than the shuttle's cells. PEMs have not yet been proven in space.

Combining fuel cells with electrolysis would provide a "perpetual" source of electricity – solar energy could be used to provide power during the lunar day, and fuel cells at night. During the lunar day, solar energy would also be used to electrolyze the water created in the fuel cells – although there would be small losses of gases that would have to be replaced.

Even if lunar colonies could provide themselves access to a near-continuous source of solar energy, they would still need to maintain fuel cells or an alternate energy storage system to sustain themselves during lunar eclipses and emergency situations.

Transport

Earth to Moon

Conventional rockets have been used for most lunar explorations to date. The ESA's SMART-1 mission from 2003 to 2006 used conventional chemical rockets to reach orbit and Hall effect thrusters to arrive at the Moon in 13 months. NASA would have used chemical rockets on its Ares V booster and Lunar Surface Access Module, that were being developed for a planned return to the Moon around 2019, but this was cancelled. The construction workers, location finders, and other astronauts vital to building, would have been taken four at a time in NASA's Orion spacecraft.

Proposed concepts of Earth-Moon transportation are Space elevators.

On the surface

A lunar rover being unloaded from a cargo spacecraft. Conceptual drawing

Lunar colonists would need the ability to transport cargo and people to and from modules and spacecraft, and to carry out scientific study of a larger area of the lunar surface for long periods of time. Proposed concepts include a variety of vehicle designs, from small open rovers to large pressurized modules with lab equipment, and also a few flying or hopping vehicles.

Rovers could be useful if the terrain is not too steep or hilly. The only rovers to have operated on the surface of the Moon (as of 2008) are the three Apollo Lunar Roving Vehicles (LRV), developed by Boeing, the two robotic Soviet Lunokhods and the Chinese Yutu rover in 2013. The LRV was an open rover for a crew of two, and a range of 92 km during one lunar day. One NASA study resulted in the Mobile Lunar Laboratory concept, a crewed pressurized rover for a crew of two, with a range of 396 km. The Soviet Union developed different rover concepts in the Lunokhod series and the L5 for possible use on future crewed missions to the Moon or Mars. These rover designs were all pressurized for longer sorties.

If multiple bases were established on the lunar surface, they could be linked together by permanent railway systems. Both conventional and magnetic levitation (Maglev) systems have been proposed for the transport lines. Mag-Lev systems are particularly attractive as there is no atmosphere on the surface to slow down the train, so the vehicles could achieve velocities comparable to aircraft on the Earth. One significant difference with lunar trains, however, is that the cars would need to be individually sealed and possess their own life support systems.

For difficult areas, a flying vehicle may be more suitable. Bell Aerosystems proposed their design for the Lunar Flying Vehicle as part of a study for NASA, while Bell proposes the Manned Flying System, a similar concept.

Surface to space

Launch technology

A lunar base with a mass driver (the long structure that goes toward the horizon). NASA conceptual illustration

Experience so far indicates that launching human beings into space is much more expensive than launching cargo.

One way to get materials and products from the Moon to an interplanetary way station might be with a mass driver, a magnetically accelerated projectile launcher. Cargo would be picked up from orbit or an Earth-Moon Lagrangian point by a shuttle craft using ion propulsion, solar sails or other means and delivered to Earth orbit or other destinations such as near-Earth asteroids, Mars or other planets, perhaps using the Interplanetary Transport Network.

A lunar space elevator could transport people, raw materials and products to and from an orbital station at Lagrangian points L1 or L2. Chemical rockets would take a payload from Earth to the L1 lunar Lagrange location. From there a tether would slowly lower the payload to a soft landing on the lunar surface.

Other possibilities include a momentum exchange tether system.

Launch costs

  • Estimates of the cost per unit mass of launching cargo or people from the Moon vary and the cost impacts of future technological improvements are difficult to predict. An upper bound on the cost of launching material from the Moon might be about $40,000,000 per kilogram, based on dividing the Apollo program costs by the amount of material returned. At the other extreme, the incremental cost of launching material from the Moon using an electromagnetic accelerator could be quite low. The efficiency of launching material from the Moon with a proposed electric accelerator is suggested to be about 50%. If the carriage of a mass driver weighs the same as the cargo, two kilograms must be accelerated to orbital velocity for each kilogram put into orbit. The overall system efficiency would then drop to 25%. So 1.4 kilowatt-hours would be needed to launch an incremental kilogram of cargo to low orbit from the Moon. At $0.1/kilowatt-hour, a typical cost for electrical power on Earth, that amounts to $0.16 for the energy to launch a kilogram of cargo into orbit. For the actual cost of an operating system, energy loss for power conditioning, the cost of radiating waste heat, the cost of maintaining all systems, and the interest cost of the capital investment are considerations.
  • Passengers cannot be divided into the parcel size suggested for the cargo of a mass driver, nor subjected to hundreds of gravities acceleration. However, technical developments could also affect the cost of launching passengers to orbit from the Moon. Instead of bringing all fuel and oxidizer from Earth, liquid oxygen could be produced from lunar materials and hydrogen should be available from the lunar poles. The cost of producing these on the Moon is yet unknown, but they would be more expensive than production costs on Earth. The situation of the local hydrogen is most open to speculation. As a rocket fuel, hydrogen could be extended by combining it chemically with silicon to form silane, which has yet to be demonstrated in an actual rocket engine. In the absence of more technical developments, the cost of transporting people from the Moon would be an impediment to colonization.

Surface to and from cis-lunar space

A cis-lunar transport system has been proposed using tethers to achieve momentum exchange. This system requires zero net energy input, and could not only retrieve payloads from the lunar surface and transport them to Earth, but could also soft land payloads on to the lunar surface.

Economic development

For long term sustainability, a space colony should be close to self-sufficient. Mining and refining the Moon's materials on-site – for use both on the Moon and elsewhere in the Solar System – could provide an advantage over deliveries from Earth, as they can be launched into space at a much lower energy cost than from Earth. It is possible that large amounts of cargo would need to be launched into space for interplanetary exploration in the 21st century, and the lower cost of providing goods from the Moon might be attractive.

Space-based materials processing

In the long term, the Moon will likely play an important role in supplying space-based construction facilities with raw materials. Zero gravity in space allows for the processing of materials in ways impossible or difficult on Earth, such as "foaming" metals, where a gas is injected into a molten metal, and then the metal is annealed slowly. On Earth, the gas bubbles rise and burst, but in a zero gravity environment, that does not happen. The annealing process requires large amounts of energy, as a material is kept very hot for an extended period of time. (This allows the molecular structure to realign.)

Exporting material to Earth

Exporting material to Earth in trade from the Moon is more problematic due to the cost of transportation, which would vary greatly if the Moon is industrially developed (see "Launch costs" above). One suggested trade commodity is helium-3 (3He) which is carried by the solar wind and accumulated on the Moon's surface over billions of years, but occurs only rarely on Earth. Helium-3 might be present in the lunar regolith in quantities of 0.01 ppm to 0.05 ppm (depending on soil). In 2006 it had a market price of about $1,500 per gram ($1.5M per kilogram), more than 120 times the value per unit weight of gold and over eight times the value of rhodium.

In the future 3He harvested from the Moon may have a role as a fuel in thermonuclear fusion reactors. It should require about 100 tonnes of helium-3 to produce the electricity that Earth uses in a year and there should be enough on the Moon to provide that much for 10,000 years.

Exporting propellant obtained from lunar water

To reduce the cost of transport, the Moon could store propellants produced from lunar water at one or several depots between the Earth and the Moon, to resupply rockets or satellites in Earth orbit. The Shackleton Energy Company estimate investment in this infrastructure could cost around $25 billion.

Solar power satellites

Gerard K. O'Neill, noting the problem of high launch costs in the early 1970s, came up with the idea of building Solar Power Satellites in orbit with materials from the Moon. Launch costs from the Moon would vary greatly if the Moon is industrially developed (see "Launch costs" above). This proposal was based on the contemporary estimates of future launch costs of the space shuttle.
On 30 April 1979 the Final Report "Lunar Resources Utilization for Space Construction" by General Dynamics Convair Division under NASA contract NAS9-15560 concluded that use of lunar resources would be cheaper than terrestrial materials for a system comprising as few as thirty Solar Power Satellites of 10 GW capacity each.

In 1980, when it became obvious NASA's launch cost estimates for the space shuttle were grossly optimistic, O'Neill et al. published another route to manufacturing using lunar materials with much lower startup costs. This 1980s SPS concept relied less on human presence in space and more on partially self-replicating systems on the lunar surface under telepresence control of workers stationed on Earth.

Gene

From Wikipedia, the free encyclopedia https://en.wikipedia.org/wiki/Gene Chromosome ...