Colonization of Venus - AbsoluteAstronomy.com

The colonization of Venus
Venus
Venus is the second planet from the Sun, orbiting it every 224.7 Earth days. The planet is named after Venus, the Roman goddess of love and beauty. After the Moon, it is the brightest natural object in the night sky, reaching an apparent magnitude of −4.6, bright enough to cast shadows...

has been a subject of much speculation and many works of science fiction

Science fiction

Science fiction is a genre of fiction dealing with imaginary but more or less plausible content such as future settings, futuristic science and technology, space travel, aliens, and paranormal abilities...

since before the dawn of spaceflight

Spaceflight

Spaceflight is the act of travelling into or through outer space. Spaceflight can occur with spacecraft which may, or may not, have humans on board. Examples of human spaceflight include the Russian Soyuz program, the U.S. Space shuttle program, as well as the ongoing International Space Station...

, and is still much discussed. With the discovery of Venus' hostile surface environment, attention has largely shifted towards the colonization of the Moon

Colonization of the Moon

The colonization of the Moon is the proposed establishment of permanent human communities on the Moon. Advocates of space exploration have seen settlement of the Moon as a logical step in the expansion of humanity beyond the Earth. Recent indication that water might be present in noteworthy...

and the colonization of Mars

Colonization of Mars

The colonization of Mars by humans is the focus of speculation and serious study because the surface conditions and availability of water on Mars make it arguably the most hospitable planet in the solar system other than Earth...

Reasons for colonization

Space colonization is a step beyond space exploration

Space exploration

Space exploration is the use of space technology to explore outer space. Physical exploration of space is conducted both by human spaceflights and by robotic spacecraft....

, and implies the permanent or long-term presence of humans in an environment outside Earth

Earth

Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...

. Colonization of space is arguably the best way to ensure the survival

Space and survival

Space and survival is the relationship between outer space and the long-term survival of the human species and civilization. Its investigation is justified by the fact that space colonization and space science could prevent many human extinction scenarios...

of humans as a species. Other reasons for colonizing space include economic interests, long-term scientific research best carried out by humans, and sheer curiosity. Venus is the second largest terrestrial planet

Terrestrial planet

A terrestrial planet, telluric planet or rocky planet is a planet that is composed primarily of silicate rocks or metals. Within the Solar System, the terrestrial planets are the inner planets closest to the Sun...

and Earth's closest neighbour, which makes it a potential target.

Advantages

Venus has certain similarities to Earth

Earth

Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...

which, were it not for the hostile conditions, might make colonization easier in many respects in comparison with other possible destinations. These similarities, and its proximity, have led Venus to be called Earth's "sister planet".

At present it has not been established whether the gravity of Mars, 0.38 times that of the Earth, would be sufficient to avoid bone decalcification

Bone decalcification

Bone decalcification is the removal of calcium ions from the bone through histological process thereby making the bone flexible and easy for pathological investigation....

and loss of muscle tone experienced by astronauts living in an environment of microgravity (the probe Mars Gravity Biosatellite

Mars Gravity Biosatellite

The Mars Gravity Biosatellite was a project initiated in 2001 by the Mars Society and volunteer students and staff of MIT to build a spacecraft to study the effects of Mars-level gravity on mammals. On 24 June 2009, a status report was released declaring the end of this program, due to lack of...

was going to be the first probe to investigate this, however it has since been canceled due to lack of funding). In contrast, Venus is close in size and mass to the Earth, resulting in a similar surface gravity (0.904 g

G-force

The g-force associated with an object is its acceleration relative to free-fall. This acceleration experienced by an object is due to the vector sum of non-gravitational forces acting on an object free to move. The accelerations that are not produced by gravity are termed proper accelerations, and...

). Most other space exploration and colonization plans face concerns about the damaging effect of long-term exposure to fractional g or zero gravity on the human musculoskeletal system

Musculoskeletal system

A musculoskeletal system is an organ system that gives animals the ability to move using the muscular and skeletal systems...

. Humans born on Venus would probably have little difficulty adapting to Earth gravity should there be a reason to visit or return; contrasted to return trips from Mars where humans would likely need rehabilitation or the use of an exoskeleton

Exoskeleton

An exoskeleton is the external skeleton that supports and protects an animal's body, in contrast to the internal skeleton of, for example, a human. In popular usage, some of the larger kinds of exoskeletons are known as "shells". Examples of exoskeleton animals include insects such as grasshoppers...

.

Venus's relative proximity makes transportation and communications easier than for most other locations in the solar system. With current propulsion systems, launch window

Launch window

Launch window is a term used in spaceflight to describe a time period in which a particular launch vehicle must be launched. If the rocket does not launch within the "window", it has to wait for the next window....

s to Venus occur every 584 days, compared to the 780 days for Mars. Flight time is also somewhat shorter; the probe Venus Express

Venus Express

Venus Express is the first Venus exploration mission of the European Space Agency. Launched in November 2005, it arrived at Venus in April 2006 and has been continuously sending back science data from its polar orbit around Venus. Equipped with seven science instruments, the main objective of the...

that arrived at Venus in April 2006 spent slightly over five months en route, compared to nearly six months for Mars Express

Mars Express

Mars Express is a space exploration mission being conducted by the European Space Agency . The Mars Express mission is exploring the planet Mars, and is the first planetary mission attempted by the agency. "Express" originally referred to the speed and efficiency with which the spacecraft was...

. This is because at closest approach, Venus is 45 million km from Earth compared to 56 million km for Mars, making Venus the closest planet to the Earth.

Difficulties

Venus also presents several significant challenges to human colonization. Surface conditions on Venus are practically impossible to deal with: the temperature

Temperature

Temperature is a physical property of matter that quantitatively expresses the common notions of hot and cold. Objects of low temperature are cold, while various degrees of higher temperatures are referred to as warm or hot...

at the equator

Equator

An equator is the intersection of a sphere's surface with the plane perpendicular to the sphere's axis of rotation and containing the sphere's center of mass....

averages around 500 °C (932 °F), higher than the melting point

Melting point

The melting point of a solid is the temperature at which it changes state from solid to liquid. At the melting point the solid and liquid phase exist in equilibrium. The melting point of a substance depends on pressure and is usually specified at standard atmospheric pressure...

of lead

Lead

Lead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...

. The atmospheric pressure

Atmospheric pressure

Atmospheric pressure is the force per unit area exerted into a surface by the weight of air above that surface in the atmosphere of Earth . In most circumstances atmospheric pressure is closely approximated by the hydrostatic pressure caused by the weight of air above the measurement point...

on the surface is also at least ninety times greater than on Earth, which is equivalent to the pressure experienced under a kilometer of water. These conditions have caused missions to the surface to be extremely brief: the probes Venera 5 and Venera 6 for example were crushed by high pressure whilst still 18 km above the surface. Following landers such as Venera 7 and Venera 8 succeeded in transmitting data after reaching the surface, but these missions were brief as well, surviving no more than a single hour on the surface.

Furthermore, water

Water

Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...

, in any form, is almost entirely absent from Venus. The atmosphere

Atmosphere

An atmosphere is a layer of gases that may surround a material body of sufficient mass, and that is held in place by the gravity of the body. An atmosphere may be retained for a longer duration, if the gravity is high and the atmosphere's temperature is low...

is devoid of molecular oxygen

Oxygen

Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...

and is primarily carbon dioxide

Carbon dioxide

Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...

in poisonously high concentrations. In addition, the visible clouds are composed partly of corrosive sulfuric acid

Sulfuric acid

Sulfuric acid is a strong mineral acid with the molecular formula . Its historical name is oil of vitriol. Pure sulfuric acid is a highly corrosive, colorless, viscous liquid. The salts of sulfuric acid are called sulfates...

and sulfur dioxide

Sulfur dioxide

Sulfur dioxide is the chemical compound with the formula . It is released by volcanoes and in various industrial processes. Since coal and petroleum often contain sulfur compounds, their combustion generates sulfur dioxide unless the sulfur compounds are removed before burning the fuel...

vapor.

Methods of colonization and exploration

Given the hostile conditions on Venus, a colony on the Venusian surface is far beyond current technological capabilities.

This has not prevented some science fiction authors from speculating on ways of overcoming this by, for example, terraforming Venus

Terraforming of Venus

The terraforming of Venus is the hypothetical process of engineering the global environment of the planet Venus in such a way as to make it suitable for human habitation. Terraforming Venus was first seriously proposed by the astronomer Carl Sagan in 1961. The minimum adjustments to the existing...

– making the planet more earth-like. Outside of fiction, the energy requirements for all terraforming plans are daunting in the context of our current technology, and the time required could possibly span hundreds of years. Other authors speculate that, if a large portion or the entire planet could be shaded, Venus would cool to a useful temperature in mere decades. Such authors postulate cooling methods such as placing sails (Solar shades) between Venus and the Sun

Sun

The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...

at the Lagrange point between the two, controlled dust clouds in space, and a large number of other ideas.

Others suggest a different approach, however, claiming that rather than attempting to colonize Venus' hostile surface, humans might attempt to colonize the Venusian atmosphere (the most habitable known part of any planet outside Earth). This is because at an altitude of approximately 50 kilometers (in Venus's upper atmosphere

Atmosphere of Venus

The atmosphere of Venus is much denser and hotter than that of Earth. The temperature at the surface is 740 K , while the pressure is 93 bar. The Venusian atmosphere supports opaque clouds made of sulfuric acid, making optical Earth-based and orbital observation of the surface impossible...

), the pressure and temperature are Earth-like (1 bar and 0-50 degrees Celsius).

Exploration and research

Due to the planet's hostile environment, Venus has not been studied as much as objects such as the Moon

Moon

The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...

and Mars have, and it is extremely unlikely that research would be conducted with a view to a human mission to the planet. The probe Venus Express

Venus Express

is currently in orbit around the planet, but other low-cost missions have been proposed to further explore the planet's atmosphere, as the area 50 kilometres above the surface where air pressure is at the same level as Earth has not yet been explored.

It is possible to land a robot on the surface. The Soviet Venera program succeeded in doing so – the Venera 13 lander survived for 127 minutes, and the Venera 14 lander for 57 minutes. This survival time might be extended. Improved materials and technology designed to work at the high temperatures and pressures would be necessary. As the survival times of the robotic probes grow longer, enhanced missions might be feasible, including the establishment of a robotic base at locations where important (perhaps fissionable) compounds might be found. The technology for operating under such conditions is at the current time so exotic as to be difficult to conceive, and funding is likely to go elsewhere.

Aerostat habitats and floating cities

Geoffrey A. Landis

Geoffrey A. Landis is an American scientist, working for the National Aeronautics and Space Administration on planetary exploration, interstellar propulsion, solar power and photovoltaics...

of NASA's Glenn Research Center

Glenn Research Center

NASA John H. Glenn Research Center at Lewis Field is a NASA center, located within the cities of Brook Park, Cleveland and Fairview Park, Ohio between Cleveland Hopkins International Airport and the Cleveland Metroparks's Rocky River Reservation, and has other subsidiary facilities in Ohio...

has summarized the perceived difficulties in colonizing Venus as being merely from the assumption that a colony would need to be based on the surface of a planet:

“However, viewed in a different way, the problem with Venus is merely that the ground level is too far below the one atmosphere level. At cloud-top level, Venus is the paradise planet.”

Landis has proposed aerostat

Aerostat

An aerostat is a craft that remains aloft primarily through the use of buoyant lighter than air gases, which impart lift to a vehicle with nearly the same overall density as air. Aerostats include free balloons, airships, and moored balloons...

habitats followed by floating cities

Floating city (science fiction)

In science fiction, floating cities are settlements that strictly use buoyancy to remain in the atmosphere of a planet. However the term generally refers to any city that is flying, hovering, or otherwise suspended in the air via any means technological or even magical.-Earth:In Jonathan Swift's...

, based on the concept that breathable air (21:79 Oxygen-Nitrogen mixture) is a lifting gas

Lifting gas

Because of the Archimedes' principle, a lifting gas is required for aerostats to create buoyancy. Its density is lower than that of air . Only certain lighter than air gases are suitable as lifting gases.- Hot Air :...

in the dense carbon dioxide

Carbon dioxide

Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...

atmosphere, with over 60% of the lifting power that helium

Helium

Helium is the chemical element with atomic number 2 and an atomic weight of 4.002602, which is represented by the symbol He. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas that heads the noble gas group in the periodic table...

has on Earth. In effect, a balloon

Gas balloon

A gas balloon is any balloon that stays aloft due to being filled with a gas less dense than air or lighter than air . A gas balloon may also be called a Charlière for its inventor, the Frenchman Jacques Charles. Today, familiar gas balloons include large blimps and small rubber party balloons...

full of human-breathable air would sustain itself and extra weight (such as a colony) in midair. At an altitude of 50 km above Venusian surface, the environment is the most Earth-like in the solar system – a pressure of approximately 1 bar and temperatures in the 0°C–50°C range. Because there is not a significant pressure difference between the inside and the outside of the breathable-air balloon, any rips or tears would cause gases to diffuse at normal atmospheric mixing rates, giving time to repair any such damages. In addition, humans would not require pressurized suits when outside, merely air to breathe, a protection from the acidic rain; and on some occasions low level protection against heat. Alternatively, two-part domes could contain a lifting gas like hydrogen or helium (extractable from the atmosphere) to allow a higher mass density.

Cloud-top colonization also offers a way to avoid the issue of slow Venusian rotation. At the top of the clouds the wind speed on Venus reaches up to 95 m/s (approximately 212 mph), circling the planet approximately every four Earth days in a phenomenon known as "super-rotation". Colonies floating in this region could therefore have a much shorter day length by remaining untethered to the ground and moving with the atmosphere. While a space elevator

Space elevator

A space elevator, also known as a geostationary orbital tether or a beanstalk, is a proposed non-rocket spacelaunch structure...

extending to the surface of Venus is impractical due to the slow rotation, constructing a skyhook

Skyhook (structure)

Skyhooks are a theoretical class of cable based techniques intended to lift payloads to high altitudes and speeds. The name skyhook is a reference to an imaginary hook that hangs from the sky....

that extended into the upper atmosphere and rotated at the wind speed would not be difficult compared to constructing a space elevator on Earth. The cloud-top colonists would also enjoy the benefits of Venus' 0.9 g surface gravity just as they would at the surface.

Since such colonies would be viable in current Venusian conditions, this allows a dynamic approach to colonization instead of requiring extensive terraforming measures in advance. The main challenge would be using a substance resistant to sulfuric acid to serve as the structure’s outer layer; ceramics or metal sulfates could possibly serve in this role. Dyneema, Polyethene and Polypropylene

Polypropylene

Polypropylene , also known as polypropene, is a thermoplastic polymer used in a wide variety of applications including packaging, textiles , stationery, plastic parts and reusable containers of various types, laboratory equipment, loudspeakers, automotive components, and polymer banknotes...

would be well usable for the skin of the balloon.

Landis has suggested that as more floating cities were built, they could form a solar shield around the planet, and could simultaneously be used to process the atmosphere into a more desirable form. If made from carbon nanotubes (recently fabricated into sheet form) or graphene

Graphene

Graphene is an allotrope of carbon, whose structure is one-atom-thick planar sheets of sp2-bonded carbon atoms that are densely packed in a honeycomb crystal lattice. The term graphene was coined as a combination of graphite and the suffix -ene by Hanns-Peter Boehm, who described single-layer...

(a sheet-like carbon allotrope), the major structural materials can be produced using carbon dioxide gathered in situ from the atmosphere. The recently synthesised amorphous carbonia

Amorphous carbonia

Amorphous carbonia, also called a-carbonia or a-CO2, is an exotic amorphous solid form of carbon dioxide that is analogous to amorphous silica glass. It was first made in the laboratory in 2006 by subjecting dry ice to high pressures , in a diamond anvil...

might prove a useful structural material if it can be quenched to STP conditions

Standard conditions for temperature and pressure

Standard condition for temperature and pressure are standard sets of conditions for experimental measurements established to allow comparisons to be made between different sets of data...

, perhaps in a mixture with regular silica glass. According to Birch's analysis such colonies and materials would provide an immediate economic return from colonizing Venus, funding further terraforming efforts.

Terraforming

Terraforming of a planet, moon, or other body is the hypothetical process of deliberately modifying its atmosphere, temperature, surface topography or ecology to be similar to those of Earth, in order to make it habitable by terrestrial organisms.The term is sometimes used more generally as a...

(literally, "Earth-shaping") is the theoretical process of modifying a planet, moon, or other body to a more habitable atmosphere, temperature, or ecology. Venus has been the subject of a number of terraforming proposals. The proposals seek to remove or convert the dense carbon dioxide atmosphere, reduce Venus's 500 °C (770 K) surface temperature, and establish a day/night light cycle closer to that of Earth's.

Most proposals involve deployment of a solar shade and/or a system of orbital mirrors, for the purpose of reducing insolation

Insolation

Insolation is a measure of solar radiation energy received on a given surface area in a given time. It is commonly expressed as average irradiance in watts per square meter or kilowatt-hours per square meter per day...

and providing light to the dark side of Venus. Another common thread in most proposals involves some introduction of large quantities of hydrogen

Hydrogen

Hydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...

or water

Water

. Proposals also involve either freezing most of Venus's atmospheric CO₂, or converting it to carbonates, urea

Urea

Urea or carbamide is an organic compound with the chemical formula CO2. The molecule has two —NH2 groups joined by a carbonyl functional group....

or other forms.

Colonies in Venus Orbit

Another promising pathway to colonization is the use of near-Venus space for the orbital capture and development of comets and asteroids. Although Venus currently has no moons, in the near future it may be practical to nudge smaller bodies into orbit around the inner planets. Venus is especially good for this because aerobraking

Aerobraking

Aerobraking is a spaceflight maneuver that reduces the high point of an elliptical orbit by flying the vehicle through the atmosphere at the low point of the orbit . The resulting drag slows the spacecraft...

in its thick atmosphere can be used to slow these bodies down. Unlike near-Earth space where the danger of hitting the Earth

Impact event

An impact event is the collision of a large meteorite, asteroid, comet, or other celestial object with the Earth or another planet. Throughout recorded history, hundreds of minor impact events have been reported, with some occurrences causing deaths, injuries, property damage or other significant...

would have severe effects on the civilization, near-Venus space does not suffer from this problem. The available free solar energy from the Sun makes Venus a desirable location for industrial development.

It is also a likely precursor to any serious attempt to develop economic activity in the gravity well

Gravity well

A gravity well or gravitational well is a conceptual model of the gravitational field surrounding a body in space. The more massive the body the deeper and more extensive the gravity well associated with it. The Sun has a far-reaching and deep gravity well. Asteroids and small moons have much...

of Venus. Resources in Venus orbit would be used to extend activity downward. A space elevator

Space elevator

A space elevator, also known as a geostationary orbital tether or a beanstalk, is a proposed non-rocket spacelaunch structure...

would likely not be feasible, given Venus' slow rotation (243 Earth days), but a skyhook

Skyhook (structure)

Skyhooks are a theoretical class of cable based techniques intended to lift payloads to high altitudes and speeds. The name skyhook is a reference to an imaginary hook that hangs from the sky....

into the atmosphere is possible.

Exploitation of resources

The first economic project for a profitable exploitation of prospectively found resources on Venus, as far as the interests of human civilization are concerned, could consist in accumulating carbon dioxide

Carbon dioxide

Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...

and sulfuric acid

Sulfuric acid

from the planet's atmosphere

Atmosphere of Venus

with the help of accumulating space devices such as PROFAC that use a nuclear energy source. Accumulation of atmospheric substances becomes possible for the purpose of transporting tankers filled with frozen CO₂ and H₂SO₄ with the help of interplanetary tugboats to circumterrestrial orbits, with the goal of selling it to private and state aerospace companies; in CO₂'s case, as a working substance for the kinetic engine of Alexander Mayboroda.

In compliance with various international agreements, nuclear energy cannot be used to accumulate substances from the Earth's atmosphere. However, that is no impediment to using nuclear devices on Venus. In that way it is possible to create unlimited and inexpensive stocks of oxygen

Oxygen

, carbon

Carbon

Carbon is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds...

, nitrogen

Nitrogen

Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...

and argon

Argon

Argon is a chemical element represented by the symbol Ar. Argon has atomic number 18 and is the third element in group 18 of the periodic table . Argon is the third most common gas in the Earth's atmosphere, at 0.93%, making it more common than carbon dioxide...

. Exploitation of Mayboroda's kinetic engine provides an opportunity to use these stocks not only as a working substance of inter-orbital and interplanetary apparatus, but more importantly as a working substance for the engines of spacecraft launched from the Earth into space, reducing the cost of launching cargo and people 20-fold. Roughly speaking, every ton of atmospheric substances accumulated from the atmosphere of Venus and tugged to the Earth provides an opportunity to deliver about one ton of cargo (passenger capsules) from the Earth into space with the help of simple one-stage reusable apparatus like Boeing X-37, SpaceShipOne or Blue Origin New Shepard

Blue Origin New Shepard

The Blue Origin New Shepard reusable launch vehicle is a vertical-takeoff, vertical-landing , suborbital manned rocket that is being developed by Blue Origin, a company owned by Amazon.com founder and businessman Jeff Bezos, as a commercial system for suborbital space tourism.The New Shepard makes...

External links

A Floating City on Venus - article from The Space Monitor

The source of this article is wikipedia, the free encyclopedia. The text of this article is licensed under the GFDL.