AI News, Robots Will Pave the Way to Mars

Robots Will Pave the Way to Mars

The first robot capable of building anything including a replica of itself, might cost a fortune to develop;

Send some of them into space and they could build new armies out ofplanetary rubble and dust, then go on to construct enough spaceships and refueling stations to carry the human race to other planets and, eventually, otherstars.

They envisioned robotic factories that would cover the moon and exploit the asteroid belt, extracting the resources needed to build more and better versions of themselves and also vast orbiting telescopes, space colonies, and other structures too big to launch from Earth.

It is now thought to contain a liquid ocean beneath its south pole, and it jettisons not just water but water rich with organic molecules into space.

And, crucially, there seems to be water, a multipurpose resource that can be purified for drinking, poured into containers to make radiation shielding, and split into hydrogen and oxygen to form rocket fuel.

The ice locked up in the moon’s north pole alone, Spudis says, is “enough to launch the equivalent of a space shuttle from the surface of the moon every day for 2200 years.” We could do far more in space if we make what we need out of what we can find, says Mason Peck, a professor of mechanical and aerospace engineering at Cornell and former NASA chief technologist.

For digging leverage against the moon’s reduced gravity, these drums are rotated in opposite directions, collecting lunar soil as they spin.

When full, the robot can drive to a processing station, fold up so as to place a drum above a collection spot, and rotate the drum in reverse to empty it.

Metzger and his colleagues have modeled how this might work, and they reckon that as little as 12 metric tons of equipment sent to the moon would be enough to jump-start the evolution of a self-sustaining robotic industry.

Because launch mass isn’t a concern, he says, “we can build a giant, clunky robot out of iron instead of a small, lightweight one out of titanium.” Truly advanced components, such as computer chips, could be shipped in batches and slotted into robots until they too could be manufactured in space.

For any harnessing of space resources to work, many experts say, the government will need to play a big role, creating infrastructure much as it might build a mail system or a network of highways or any other backbone of commerce.

The firm expects to extract it from some kinds of asteroids simply by using heat from concentrated sunlight, says Chris Lewicki, the company’s president and chief engineer.

The temperature can vary by hundreds of degrees in orbit, and large temperature gradients could prevent structures from properly cooling and hardening, causing wild deformations.

The team logged hundreds of hours on parabolic flights to perfect the technology, says lead engineer Michael Snyder, but he won’t disclose what sets it apart from typical 3-D printers.

Although the European Space Agency, NASA, and others have looked into building very crude structures—mostly human habitats and landing pads—out of lunar soil, at present there are no plans to try out these ideas in space.

“I’ve never seen such a screwed-up mess aswe now have.” NASA’s current plans call for sending humans to Mars in the 2030s, but any such trip is at least 60 years away, argues Ralph McNutt, a physicist at Johns Hopkins University’s Applied Physics Laboratory, in Laurel, Md.

“Theprice tags have come out to be so big that they’re just not palatable.” But Mars is easy for politicians to support, he says: They can advocate for the long-term goal without diverting enough funds today to make it happen.

“Ithink the worst case would be if we continue only with these occasional piecemeal, individual missions that are kind of designed to be self-sustaining, like Conestoga wagons full of all the supplies you’ll ever need,” says Mason Peck, a professor of mechanical and aerospace engineering at Cornell and former chief technologist at NASA.

Then we’ll never be able to get off the planet in a permanent way.” But even if the government does push aggressively to build space infrastructure, the effort could still falter.

Scott Pace, director of the Space Policy Institute at George Washington University, in Washington, D.C., phrases the problem like a riddle: “What’s the question,” he asks, “for which space is the answer?” There are also practical hurdles, such as the legality of claiming asteroids and lunar resources, says Henry Hertzfeld, a professor of space policy and international affairs at George Washington University.

Colonization of the Moon

Polar colonies could also avoid the problem of long lunar nights – about 354 hours,[3] a little more than two weeks – and take advantage of the Sun continuously, at least during the local summer (there is no data for the winter yet).[4] Permanent human habitation on a planetary body other than the Earth is one of science fiction's most prevalent themes.

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.[10] The proposed design consisted of a half-cylinder with half-domes at both ends, with a micrometeoroid shield placed above the base.

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[20] and surface modules.[21] 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,[22][23] as did the potential growth of a Chinese space program that contemplated its own mission to the Moon.[24] 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.[25] However, in September 2009, the Chandrayaan probe of India, carrying an ISRO instrument, discovered that the Lunar regolith contains 0.1% water by weight, overturning theories that had stood for 40 years.[26] In 2004, U.S. President George W.

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.[27] LCROSS's mission concluded as scheduled with its controlled impact on October 9, 2009.[28][29] 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 manned missions to asteroids and Mars, as well as extending support for the International Space Station.[30] As of 2016, Russia is planning to begin building a human colony on the moon by 2030.

Initially, the moon base will be manned by no more than 4 people, with their number later rising to maximum of 12 people.[31] Japan also has plans to land a man on the moon by 2030,[32] while the People's Republic of China is currently planning to land a human on the Moon by 2036 (see Chinese Lunar Exploration Program).[33] The United States currently (2017) has plans to send a manned space mission to orbit (but not to land on) the moon in 2021.[34] While the US Trump administration has called for a return of manned missions to the lunar surface, it has currently (2017) not authorized any funding for any such lunar missions in the next 20 years, and instead the current administration has actually reduced the NASA space exploration budget from earlier levels.[35][36] On 24 September 2009 Science magazine reported that the Moon Mineralogy Mapper (M3) on the Indian Space Research Organisation's (ISRO) Chandrayaan-1 had detected water on the Moon.[37] M3 detected absorption features near 2.8–3.0 μm (0.00011–0.00012 in) on the surface of the Moon.

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.[43] 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.[44] 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.

For example, Malapert mountain, located near the Shackleton crater at the Lunar south pole, offers several advantages as a site: NASA chose to use a south-polar site for the Lunar outpost reference design in the Exploration Systems Architecture Study chapter on Lunar Architecture.[67] At the north pole, the rim of Peary Crater has been proposed as a favorable location for a base.[68] 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).[68] As a result, the temperature conditions are expected to remain very stable at this location, averaging −50 °C (−58 °F).[68] This is comparable to winter conditions in Earth's Poles of Cold in Siberia and Antarctica.

1994[69] bistatic radar experiment performed during the Clementine mission suggested the presence of water ice around the south pole.[22][70] The Lunar Prospector spacecraft reported enhanced hydrogen abundances at the south pole and even more at the north pole, in 2008.[71] 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.[72] This interpretation, however, is not universally agreed upon.[73] A

The resulting voltage difference can affect electrical equipment, change surface chemistry, erode surfaces and levitate Lunar dust.[74] 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.[75] 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.

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.[76] The far side is also a good location for a large radio telescope because it is well shielded from the Earth.[77] 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.[47] To date, there has been no ground exploration of the far side.

The Lunar regolith is composed of a unique blend of silica and iron-containing compounds that may be fused into a glass-like solid using microwave energy.[84] 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.[85] This may allow for the use of 'Lunar bricks' in structural designs, or the vitrification of loose dirt to form a hard, ceramic crust.

Some regions on the Moon possess strong local magnetic fields that might partially mitigate exposure to charged solar and galactic particles.[88] 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.

Inside, a lightweight pressurized inflatable with the same dome shape will be the living environment for the first human Moon settlers.'[89] The building technology will include mixing Lunar material with magnesium oxide, which will 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.'[89] 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.[89] 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.

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

As of 2010[update], significant component hardware testing had been successfully completed, and a non-nuclear system demonstration test was being fabricated.[94][needs update] Helium-3 mining could be used to provide a substitute for tritium for potential production of fusion power in the future.

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.

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.

It is possible that large amounts of matter will 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.[82] In the long term, the Moon will likely play an important role in supplying space-based construction facilities with raw materials.[97] 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.

In the future 3He may have a role as a fuel in thermonuclear fusion reactors.[105] 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.[106] 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.[107] The Shackleton Energy Company estimate investment in this infrastructure could cost around $25 billion.[108] Gerard K.

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.[110] In 1980, when it became obvious NASA's launch cost estimates for the space shuttle were grossly optimistic, O'Neill et al.

Home On the Moon: How to Build a Lunar Colony (Infographic)

An outpost on the Earth’s moon has been a staple of science fiction since the 20th century.

One of the earliest practical proposals was the U.S. Army’s 1959 design for a nuclear powered fortress, built to establish a military presence on the moon before the Soviet Union could do the same.

A 1961 U.S. Air Force plan called for a 21-man underground lunar base, to be built by 1968.

A moon base must support its crew, either with supplies launched from Earth or by mining the resources ofthe moon itself.

One prime location for a moon base would be in the permanently shadowed deep craters near the moon's poles.

These very cold locations harbor vast quantities of water ice, which could be harvested relatively easily.

Space elevator

A space elevator is a proposed type of space transportation system.[1] The main component would be a cable (also called a tether) anchored to the surface and extending into space.

Carbon nanotubes (CNTs) have been identified as possibly being able to meet the specific strength requirements for an Earth space elevator.[2][4] Other materials considered have been boron nitride nanotubes, and diamond nanothreads, which were first constructed in 2014.[5][6] The concept is applicable to other planets and celestial bodies.

In 1966, Isaacs, Vine, Bradner and Bachus, four American engineers, reinvented the concept, naming it a 'Sky-Hook,' and published their analysis in the journal Science.[11] They decided to determine what type of material would be required to build a space elevator, assuming it would be a straight cable with no variations in its cross section, and found that the strength required would be twice that of any then-existing material including graphite, quartz, and diamond.

After the development of carbon nanotubes in the 1990s, engineer David Smitherman of NASA/Marshall's Advanced Projects Office realized that the high strength of these materials might make the concept of a space elevator feasible, and put together a workshop at the Marshall Space Flight Center, inviting many scientists and engineers to discuss concepts and compile plans for an elevator to turn the concept into a reality.

Edwards, suggested creating a 100,000 km (62,000 mi) long paper-thin ribbon using a carbon nanotube composite material.[13] He chose the wide-thin ribbon-like cross-section shape rather than earlier circular cross-section concepts because that shape would stand a greater chance of surviving impacts by meteoroids.

Supported by the NASA Institute for Advanced Concepts, Edwards' work was expanded to cover the deployment scenario, climber design, power delivery system, orbital debris avoidance, anchor system, surviving atomic oxygen, avoiding lightning and hurricanes by locating the anchor in the western equatorial Pacific, construction costs, construction schedule, and environmental hazards.[2][14][15][16] To speed space elevator development, proponents have organized several competitions, similar to the Ansari X Prize, for relevant technologies.[17][18] Among them are Elevator:2010, which organized annual competitions for climbers, ribbons and power-beaming systems from 2005 to 2009, the Robogames Space Elevator Ribbon Climbing competition,[19] as well as NASA's Centennial Challenges program, which, in March 2005, announced a partnership with the Spaceward Foundation (the operator of Elevator:2010), raising the total value of prizes to US$400,000.[20][21] The first European Space Elevator Challenge (EuSEC) to establish a climber structure took place in August 2011.[22] In 2005, 'the LiftPort Group of space elevator companies announced that it will be building a carbon nanotube manufacturing plant in Millville, New Jersey, to supply various glass, plastic and metal companies with these strong materials.

Although LiftPort hopes to eventually use carbon nanotubes in the construction of a 100,000 km (62,000 mi) space elevator, this move will allow it to make money in the short term and conduct research and development into new production methods.'[23] Their announced goal was a space elevator launch in 2010.

13 sheets of paper) thick, lifted with balloons.[24] In 2007, Elevator:2010 held the 2007 Space Elevator games, which featured USD500,000 awards for each of the two competitions, (USD1,000,000 total) as well as an additional USD4,000,000 to be awarded over the next five years for space elevator related technologies.[25] No teams won the competition, but a team from MIT entered the first 2-gram (0.07 oz), 100-percent carbon nanotube entry into the competition.[26] Japan held an international conference in November 2008 to draw up a timetable for building the elevator.[27] In 2008 the book Leaving the Planet by Space Elevator by Dr. Brad Edwards and Philip Ragan was published in Japanese and entered the Japanese best-seller list.[28] This led to Shuichi Ono, chairman of the Japan Space Elevator Association, unveiling a space-elevator plan, putting forth what observers considered an extremely low cost estimate of a trillion yen (£5 billion/ $8 billion) to build one.[27] In 2012, the Obayashi Corporation announced that in 38 years it could build a space elevator using carbon nanotube technology.[29] At 200 kilometers per hour, the design's 30-passenger climber would be able to reach the GEO level after a 7.5 day trip.[30] No cost estimates, finance plans, or other specifics were made.

This, along with timing and other factors, hinted that the announcement was made largely to provide publicity for the opening of one of the company's other projects in Tokyo.[31] In 2013, the International Academy of Astronautics published a technological feasibility assessment which concluded that the critical capability improvement needed was the tether material, which was projected to achieve the necessary strength-to-weight ratio within 20 years.

It was reported that it would be possible to operationally survive smaller impacts and avoid larger impacts, with meteors and space debris, and that the estimated cost of lifting a kilogram of payload to GEO and beyond would be $500.[32][33] In 2014, Google X's Rapid Evaluation RD team began the design of a Space Elevator, eventually finding that no one had yet manufactured a perfectly formed carbon nanotube strand longer than a meter.

Setting actual gravity equal to centrifugal acceleration gives:: Ref[35] page 126 On Earth, this distance is 35,786 km (22,236 mi) above the surface, the altitude of geostationary orbit.: Ref[35] Table 1 On the cable below geostationary orbit, downward gravity would be greater than the upward centrifugal force, so the apparent gravity would pull objects attached to the cable downward.

To maximize the usable excess strength for a given amount of cable material, the cable's cross section area would need to be designed for the most part in such a way that the stress (i.e., the tension per unit of cross sectional area) is constant along the length of the cable.[35][36] The constant-stress criterion is a starting point in the design of the cable cross section as it changes with altitude.

Other factors considered in more detailed designs include thickening at altitudes where more space junk is present, consideration of the point stresses imposed by climbers, and the use of varied materials.[37] To account for these and other factors, modern detailed cross section designs seek to achieve the largest safety margin possible, with as little variation over altitude and time as possible.[37] In simple starting-point designs, that equates to constant-stress.

is the ratio between the centrifugal force on the equator and the gravitational force.[35] To compare materials, the specific strength of the material for the space elevator can be expressed in terms of the characteristic length, or 'free breaking length': the length of an un-tapered cylindrical cable at which it will break under its own weight under constant gravity.

In an alternate concept, the base station could be a tower, forming a space elevator which comprises both a compression tower close to the surface, and a tether structure at higher altitudes.[9] Combining a compression structure with a tension structure would reduce loads from the atmosphere at the Earth end of the tether, and reduce the distance into the Earth's gravity field the cable needs to extend, and thus reduce the critical strength-to-density requirements for the cable material, all other design factors being equal.

An untapered space elevator cable would need a material capable of sustaining a length of 4,960 kilometers (3,080 mi) of its own weight at sea level to reach a geostationary altitude of 35,786 km (22,236 mi) without yielding.[39] Therefore, a material with very high strength and lightness is needed.

Nanoengineered materials such as carbon nanotubes and, more recently discovered, graphene ribbons (perfect two-dimensional sheets of carbon) are expected to have breaking lengths of 5000–6000 km at sea level, and also are able to conduct electrical power.[citation needed] For a space elevator on Earth, with its comparatively high gravity, the cable material would need to be stronger and lighter than currently available materials.[40] For this reason, there has been a focus on the development of new materials that meet the demanding specific strength requirement.

The challenge in using carbon nanotubes remains to extend to macroscopic sizes the production of such material that are still perfect on the microscopic scale (as microscopic defects are most responsible for material weakness).[40] [41] [42] As of 2014, carbon nanotube technology allowed growing tubes up to a few tenths of meters.[43] In 2014, diamond nanothreads were first synthesized.[5] Since they have strength properties similar to carbon nanotubes, diamond nanothreads were quickly seen as candidate cable material as well.[6] A

due to orbital rotation, of each part of the cable increases with altitude, proportional to distance from the center of the Earth, reaching low orbital speed at a point approximately 66 percent of the height between the surface and geostationary orbit, or a height of about 23,400 km.

With increasing release height the orbit would become less eccentric as both periapsis and apoapsis increase, becoming circular at geostationary level.[45][46] When the payload has reached GEO, the horizontal speed is exactly the speed of a circular orbit at that level, so that if released, it would remain adjacent to that point on the cable.

The overall effect of the centrifugal force acting on the cable would cause it to constantly try to return to the energetically favorable vertical orientation, so after an object has been lifted on the cable, the counterweight would swing back towards the vertical like an inverted pendulum.[44] Space elevators and their loads would be designed so that the center of mass is always well-enough above the level of geostationary orbit[47] to hold up the whole system.

Climbers would also need to maintain a minimum average speed in order to move material up and down economically and expeditiously.[citation needed] At the speed of a very fast car or train of 300 km/h (190 mph) it will take about 5 days to climb to geosynchronous orbit.[49] Both power and energy are significant issues for climbers—the climbers would need to gain a large amount of potential energy as quickly as possible to clear the cable for the next payload.

Using megawatt powered free electron or solid state lasers in combination with adaptive mirrors approximately 10 m (33 ft) wide and a photovoltaic array on the climber tuned to the laser frequency for efficiency.[2] For climber designs powered by power beaming, this efficiency is an important design goal.

Yoshio Aoki, a professor of precision machinery engineering at Nihon University and director of the Japan Space Elevator Association, suggested including a second cable and using the conductivity of carbon nanotubes to provide power.[27] Several solutions have been proposed to act as a counterweight: Extending the cable has the advantage of some simplicity of the task and the fact that a payload that went to the end of the counterweight-cable would acquire considerable velocity relative to the Earth, allowing it to be launched into interplanetary space.

The near side would extend through the Earth-Moon L1 point from an anchor point near the center of the visible part of Earth's Moon.[53] On the far side of the Moon, a lunar space elevator would need to be very long—more than twice the length of an Earth elevator—but due to the low gravity of the Moon, could also be made of existing engineering materials.[53] Rapidly spinning asteroids or moons could use cables to eject materials to convenient points, such as Earth orbits;[54] or conversely, to eject materials to send a portion of the mass of the asteroid or moon to Earth orbit or a Lagrangian point.

space elevator using presently available engineering materials could be constructed between mutually tidally locked worlds, such as Pluto and Charon or the components of binary asteroid 90 Antiope, with no terminus disconnect, according to Francis Graham of Kent State University.[55] However, spooled variable lengths of cable must be used due to ellipticity of the orbits.

One potential solution proposed by Edwards is to use a movable anchor (a sea anchor) to allow the tether to 'dodge' any space debris large enough to track.[2] Impacts by space objects such as meteoroids, micrometeorites and orbiting man-made debris pose another design constraint on the cable.

As of 2000, conventional rocket designs cost about US$25,000 per kilogram (US$11,000 per pound) for transfer to geostationary orbit.[60] Current space elevator proposals envision payload prices starting as low as $220 per kilogram ($100 per pound),[61] similar to the $5–$300/kg estimates of the Launch loop, but higher than the $310/ton to 500 km orbit quoted[62] to Dr. Jerry Pournelle for an orbital airship system.

Philip Ragan, co-author of the book Leaving the Planet by Space Elevator, states that 'The first country to deploy a space elevator will have a 95 percent cost advantage and could potentially control all space activities.'[63] The International Space Elevator Consortium (ISEC) was formed to promote the development, construction, and operation of a space elevator as 'a revolutionary and efficient way to space for all humanity'.[64] It was formed after the Space Elevator Conference in Redmond, Washington in July 2008 and became an affiliate organization with the National Space Society[65] in August 2013.[64] ISEC coordinates with the two other major societies focusing on space elevators: the Japanese Space Elevator Association[66] and EuroSpaceward.[67] ISEC supports symposia and presentations at the International Academy of Astronautics[68] and the International Astronautical Federation Congress[69] each year.

Topics that have concluded are: 2010 - Space Elevator Survivability, Space Debris Mitigation,[33] 2012 - Space Elevator Concept of Operations,[72] 2013 - Design Consideration for Tether Climbers,[73], 2014 - Space Elevator Architectures and Roadmaps.[74] 2015 - Design Characteristics of a Space Elevator Earth Port,[75] 2017 - Design Considerations for the Space Elevator Apex Anchor and GEO Node.[76] The conventional current concept of a 'Space Elevator' has evolved from a static compressive structure reaching to the level of GEO, to the modern baseline idea of a static tensile structure anchored to the ground and extending to well above the level of GEO.

This conventional type is a static structure fixed to the ground and extending into space high enough that cargo can climb the structure up from the ground to a level where simple release will put the cargo into an orbit.[77] Some concepts related to this modern baseline are not usually termed a 'Space Elevator', but are similar in some way and are sometimes termed 'Space Elevator' by their proponents.

For example, Hans Moravec published an article in 1977 called 'A Non-Synchronous Orbital Skyhook' describing a concept using a rotating cable.[78] The rotation speed would exactly match the orbital speed in such a way that the tip velocity at the lowest point was zero compared to the object to be 'elevated'.

The concept of a Tsiolkovsky tower combined with a classic space elevator cable (reaching above the level of GEO) has been suggested.[9] Other ideas use very tall compressive towers to reduce the demands on launch vehicles.[79] The vehicle is 'elevated' up the tower, which may extend as high as above the atmosphere, and is launched from the top.

Such a tall tower to access near-space altitudes of 20 km (12 mi) has been proposed by various researchers.[79][80][81] Other concepts for non-rocket spacelaunch related to a space elevator (or parts of a space elevator) include an orbital ring, a pneumatic space tower,[82] a space fountain, a launch loop, a Skyhook, a space tether, and a buoyant 'SpaceShaft'.[83]

Futuristic Moon Elevator Idea Takes Aim at Lunar Lifts

A moon-based elevator to space could radically reduce the costs and improve the reliability of placing equipment on the lunar surface.

LiftPort's concept for building the lunar space elevator infrastructure calls for using a climbing vehicle that scoots up and down a ribbon-shaped, tethered cable that's part of an anchor station secured to the airless moon.

The group envisions a rocket launched from Earth to a Lagrange Point PicoGravity Lab, where cargo is transferred to the robotic lifter and gently delivered to the moon's surface.

Using forecast models, backers of the LSEI see transport of three-dozen people to the moon per year as attainable in the early years of the elevator's operation.

He has been encouraged by NASA's newly announced Lunar Cargo Transportation and Landing by Soft Touchdown (Lunar CATALYST) program, which is intended to spur commercial cargo transportation capabilities to the surface of the moon.

Pearson said that the tough-to-do challenge list includes at least a few items: producing the vast quantities of high-strength carbon nanotube composites required;

"The lunar space elevator can be built of existing high-strength composites without waiting for suitable carbon nanotubes, and its dynamics can be tested on the moon, where it will not endanger satellites in low Earth orbit or geosynchronous Earth orbit,"

Additionally, the lunar space elevator can deliver enormous quantities of lunar regolith to high Earth orbit, Pearson said, where it could be used for the counterweight to the Earth space elevator.

"At our current rate of progress, EDDE could get rid of the dangerous low Earth orbit space debris by the middle of the next decade, and the lunar space elevator could be built at about the same time, as part of a return to the moon, Pearson said.

We believe that if we accept the waning of this nation's supremacy in space exploration, and if we ignore the moon, there will be profoundly adverse effects on U.S. economic growth and national security."

Among key talking points, the letter said that the moon has abundant resources "that can be used to dramatically reduce the cost of solar system exploration, and can also be used to stimulate new industries and technologies (i.e., creating new jobs) for mining, extracting, storing and using these resources to facilitate cislunar industry and exploration beyond the moon."

The Earth's moon is a treasure trove of mineral resources, such as precious metals, rare earth elements, helium-3 and oxygen for propellants,"

But by using modern fibers, space agencies could construct a lunar elevator that reduces the cost of lunar landing six-fold, he said.

Lunar mass driver: Why we should build a space gun on the Moon

This includes things like helium-3, an isotope of helium that some say could be used as fuel in future nuclear fusion power plants to provide a huge new source of energy.

Using magnetic levitation, the structure would accelerate a payload to the necessary speed required to escape the gravity of the Moon and return to Earth, or perhaps rendezvous with a cargo spacecraft in lunar orbit for transportation to Earth.

The idea of a mass driver is that when a payload is accelerated to a speed greater than the escape velocity of the Moon (2.4 kilometres or 1.5 miles per second), it will be released from the tube and travel into lunar orbit, where it can be picked up by a larger cargo spacecraft for use in space or transportation to Earth.

To reach and maintain low Earth orbit, for example, a spacecraft or payload needs to have a velocity of about 7.8 kilometres (4.8 miles) per second, or 28,000 kilometres (17,400 miles) per hour, and it would also have to contend with the Earth’s atmosphere and its relatively strong gravitational pull.