Considering the Factors Required to Colonize Venus
By: Jessica Frisky, Justin Larson, Brandon Louie, Austin Opekokew-Laliberte, Kale Scherger, and Katelyn Topp
In the future a need will likely arise for a new settlement somewhere other than Earth because of overpopulation and a lack of resources. Venus is one of the closest planets to Earth and is of a similar size, density, volume, and mass, making the possibility of creating a new human settlement on Venus in the future an area worth investigation. Creating a permanent settlement elsewhere in our solar system is an extremely difficult proposition. Humans, having evolved on Earth, are naturally attuned to a very specific environment. The difference in air pressure, atmospheric composition, temperature, and exposure to radiation that we would experience on other planets would prove fatal unless accounted for. Although Venus has several deadly characteristics, in the future, there may be technology developed that will allow for human life to be sustainable on Venus. Through investigating the physical evidence from past missions and analyzing the concepts behind technology that could be developed to sustain human life in the future, we will discuss the plausibility of colonizing Venus.
Figure 1: An overview of Venus’ characteristics. Credit to https://www.dreamstime.com/stock-illustration-earth-planet-technical-data-sheet-section-cutting-information-image45064179
Characteristics of Venus:
Here we investigate the multiple factors that could affect the ability to create a habitat on Venus and offer possible solutions to any uninhabitable characteristics:
Average Distance from Sun:
67 million miles (108 million km).1
This close proximity to the sun means that there would be high concentrations of solar power that can be harnessed for energy, but also an extreme average surface temperature of 464 degrees C.2 A solution to the extreme temperatures on Venus was suggested by a scientist named Paul Birch, who proposed a gigantic solar shade to block the Sun’s rays. 3 Currently, solar shades of much smaller scale have been created, and it would likely be difficult with today’s technology to create and place a shade large enough to block the Sun on Venus.
Rotation Period:
A year on Venus is roughly 225 Earth days, with a full orbital rotation taking 243 days (with the sun rising every 117 days), making the day length longer than the planet’s year. 4 Venus’s extremely long days and nights would likely prove difficult for humans to adapt to. Paul Birch suggested a solution to this as well, proposing the use of orbiting solar mirrors, to provide sunlight or shade depending on the need. 5
Gravity:
The strength of the gravitational pull on Venus’ surface is 91% that of Earth’s,This is one of the most appealing aspects of Venus in regards to colonization. Since the human body goes through bone decay under low gravity it would be beneficial not to have to contend with this issue on Venus. 6
Atmosphere:
-
96% Carbon dioxide
-
5% Nitrogen
-
0.015% Sulfur dioxide
-
0.007% Argon
-
0.002% Water vapor
-
0.0017% Carbon monoxide
-
0.0012% Helium
-
0.0007% Neon
Table 1: Table comparing the atmospheric components of Venus, Earth, and Mars. Credit to: https://www.ucar.edu/learn/1_1_2_1t.htm
As seen from Table 1, Venus has a drastically different atmosphere than Earth, which would make it difficult to create a liveable settlement. The major atmospheric component Venus lacks (especially for breathability) is oxygen, but CO2 is available in great quantity. Oxygen and carbon could be provided by separation of CO2. Scientists from the University of California have researched the ability to achieve this separation and found experimental evidence that CO2 could be dissociated to O2 and C using ultraviolet light specifically for the “abiotic oxygen production in CO2-heavy atmospheres of other planets.” 7
On Venus, what we consider breathable air acts as a lifting gas, so if we could create a “balloon” settlement filled with our breathable air it could actually float on Venus. Although the comparison is to a balloon, there is no risk of “popping” the settlement like a balloon, since the pressure inside and outside the balloon would be the same and therefore it would be more of a slow leak, with outside air leaking in, and inside air leaking out. “A one-kilometer diameter spherical envelope will lift 700,000 tons (two Empire state buildings). A two-kilometer diameter envelope would lift 6 million tons. So, if the settlement is contained in an envelope containing oxygen and nitrogen the size of a modest city, a huge amount of mass could be lifted. The result would be an environment as spacious as a typical city.” 8
Above the immense amount of carbon dioxide in the atmosphere, at an altitude of 50 km, the conditions are “as close to Earth’s as you’ll find anywhere in the solar system.” 9 Venus has a surface area of 3.1 times the land area of Earth, so there is much more room for expansion there. “A billion habitats, each one with a population of hundreds of thousands of humans, could be placed in the Venus atmosphere.” 10
Sulfuric acid is sometimes created from the sulfur dioxide in the atmosphere by photo-dissociation from the ultra-violet rays from the Sun. 11 The issue with the sulfuric acid droplets would be their potential to eat away at the outside of the proposed floating colony. This problem was solved as a by-product of the 1985 Vega 1 mission sent out by the USSR. The Vega 1 probe was sent to Venus to make use of its gravity to intercept Halley’s Comet. Since the probe was on Venus anyway, the USSR took advantage of this and also sent balloons floating into the atmosphere to record data. Since these balloons were made of Teflon, and withstood the atmospheric conditions present, it was discovered that Teflon is resistant to the acid in the atmosphere and therefore could be used to surround a floating settlement. 12
Past Missions:
In order to understand how we know so much about Venus it is important to study the past, current, and future missions that have shaped our understanding of the neighbouring planet. It has taken decades of scientific and technological breakthroughs to be able to learn so much about Venus’ relatively hostile environment and, through that process, we have been able to learn more about how to adapt to such an environment. If we are to investigate the possibility of a human colony on Venus, we must first examine the successes and failures of past missions.
In total there have been 20 spacecrafts that have flown on 16 missions to Venus since 1962. The first mission to reach the planet was Mariner 2, launched by NASA in August 1962 and arriving in December. Mariner 2 was the first spacecraft to successfully fly by the planet, detecting ground temperatures as high as 428C (800F). Radio contact was lost with the craft on January 3, 1963. Venera 4 was the first Soviet craft to reach Venus in October 1967, dropping several instruments into the atmosphere before descending itself. It revealed that the atmosphere is made up almost entirely of carbon dioxide, with extremely high temperatures and atmospheric pressure. NASA returned to Venus in October 1967 with Mariner 5, flying within 4000 miles (2,400 km) of the planet, measuring a surface temperature of 267C.13
Figure 3: A depiction of Mariner 2 in Space. Credit to NASA.
The Soviets were the first to send two crafts simultaneously to Venus, with Venera 5 & 6 arriving in May 1969. Venera 5 and 6 descended into the Venusian atmosphere, sending back data for just over 50 minutes before succumbing to the intense pressure. Venera 7 was the first Soviet probe to successfully land on the planet’s surface in December 1970, becoming the first spacecraft to return data from the surface of another planet. It reported surface temperatures of 475°C and atmospheric pressures 90 times greater than Earth’s. The Soviets repeated this feat in July 1972 with Venera 8, which also successfully landed on the planet’s surface. Venera 8 transmitted data for 50 minutes, again confirming a very high surface temperature and crushing atmospheric pressure.14
The next concurrent missions launched by the Soviets were Venera 9 & Venera 10, which arrived on Venus’s surface in October 1975. Venera 9 became the first spacecraft to transmit a picture from the surface of another planet. The two probes also sent back data on the Venusian clouds, atmospheric composition, and light levels.15
Pioneer Venus 1 & Pioneer Venus 2 marked NASA’s first mission with multiple crafts to Venus, as well as their first mission to the planet since 1967. Arriving in December 1978, Pioneer 1 used radar to map most of the planet. The spacecraft remained in orbit until August of 1992, when it used up all its fuel and burnt up in the atmosphere. Pioneer 2 consisted of four separate atmospheric probes. Each probe took atmospheric measurements as they descended through the cloud layer. One of the probes survived to transmit data for over an hour after it impacted with the surface.16
The Soviets next launched Venera 11 and 12 in September 1978, arriving in the same month as the Pioneer crafts. Both landers successfully touched down on the surface, sending back evidence of thunder and lightning as well as the presence of carbon monoxide. Venera 13 & 14 were the crafts involved in the next mission to the planet, launched by the Soviets in October 1981 and arriving in March 1982. Both Venera 13 and 14’s landers successfully touched down, neither one surviving for more than 2 hours before succumbing to the extreme heat and pressure. They each collected and examined samples with a mechanical arm, and sent back the fist colour images of the surface.17
Figure 4: Image taken by Venera 13, 1982.
Credit to: NASA.
The photo above was taken by Venera 13, featuring the right half of the panoramic view of the surface of Venus. Venera 15 and 16 were launched together in June 1983 and arrived in October. The crafts worked in cohesion to create a radar map of the planet over their joint mission lasting 8 months.
The final mission launched by the Russians before the fall of the Soviet Union was Vega 1, arriving in October 1984. Vega 1 deployed a probe into the planet’s atmosphere that measured temperature, pressure and wind velocity. NASA launched the Magellan craft in May 1989, arriving in August of the next year. By the end of its mission Magellan had mapped 98% of the planet using advanced radar techniques. The dissolution of the Soviet Union marked an end of NASA’s urgency to keep pace with the Russian space program, reducing the number of unmanned missions to nearby planets. The Venus Express was the next and latest craft to reach the planet, launched by the European Space Agency (ESA) in November 2005, and arriving to Venus in April 2006. Venus Express studied the atmosphere and surface of Venus over an 8 year period, and the data it gathered gave better insight into how its runaway greenhouse effect took hold. It was found that there are also indications that the planet is still volcanically active. 18
Current/Future Missions:
With NASA’s recent flyby mission to Pluto, there has been a growing fascination of the general public with interplanetary science, Venus being among them. There is currently one mission studying the planet. Launched in May 2010, the Venusian orbiter Akatsuki aims to study atmospheric dynamics. Using five cameras, Akatsuki can image Venus with wavelengths from ultraviolet (290nm) to mid-infrared (10μm).19 In December 2015, Akatsuki’s instruments recorded the presence of gravity waves. 20
Currently, there are no missions scheduled to study Venus in the near future. However, through international collaboration of both the European Space Agency (ESA) and the Japan Aerospace Exploration Agency (JAXA), the space craft BepiColombo will fly-by Venus twice in order to adjust its trajectory on its way to study Mercury; once in October 2020, and again in August 2021.21
There is one proposed future mission with an expected launch date of 2025, the Russian Federal Space Agency’s Venera-D. Venera-D is expected have a variety of elements, the first being an orbiter designed to relay data back to Earth from scientific instruments. The orbiter’s main goal is to research the circulation patterns and composition of Venus’ atmosphere. Venera-D is proposed to have two balloons that will be dropped at different altitudes to measure the acoustic and electrical properties of the atmosphere. Along with the balloons, up to four microprobes will be dropped to surface. During the descents, the microprobes will continuously measure the atmosphere. The final element of Venera-D is the lander, which would be dropped into a region called Tessera. With an expected lifespan of one-hour, the lander is designed to study the atmospheric composition during its descent. Once on the surface, the lander will analyze the soil composition; giving a new insight on the formation of the planet.22
Further Possible Solutions to Venus’ Uninhabitable Characteristics
As mentioned above, supplying oxygen to breathe could be achieved by dissociating CO2. Similarly, to compensate for the lack of water on Venus, the CO2 could again be reduced using hydrogen and a catalyst using the Bosch or Sabatier process. The Sabatier process is currently used by the International Space Station to create water and electricity. The additional product of electricity assists in solving yet another problem that would arise from colonizing Venus. The image below demonstrates the chemical equation used in the Sabatier process:
Figure 5: The chemical equation used in the Sebatier Process. Credit to: http://www.nss.org/settlement/nasa/teacher/course/h2o_gen.html
Using the same theory of being able to float systems filled with an Earth-like atmosphere, solar panels could be floated in the atmosphere if more energy was needed than was created from the Sabatier process. The solar panels could also be placed on the top of the floating settlement and would take advantage of the closeness of Venus to the Sun by the amount of solar energy they would receive.
Since the ground level on Venus is especially inaccessible to humans, there would need to be a way to grow food for the colony. The same logic that applies to the colony and the solar panels could apply and floating greenhouses could be built. The greenhouses would have to be regulated with respect to their atmosphere and the amount of sunlight they were receiving, as well as the temperature within.
Conclusion
Despite the difference of air pressure, atmosphere, and temperature on Venus from that of Earth, it was worthwhile to investigate past missions that had been sent to Venus in order to learn about technology that could be used to create a settlement on Venus in the future, should the need arise.
Figure 2: General data about Venus as compared to Earth. Credit to Kevin Tate, Space.com.
The missions that we studied have been partially unsuccessful due to the high air pressure, toxic atmosphere, excessive carbon monoxide, high temperatures, and thick cloud layers on Venus. There are dangerous chemicals that are found on Venus that would prevent a liveable level of air circulation such as carbon dioxide, nitrogen, carbon monoxide, argon, and sulphur dioxide. Another reason why Venus would be unfavourable for colonization is that water vapour makes up less than one percent of its atmosphere.
Suggestions were given as to ways technology could be used to create a liveable environment in the harsh conditions on Venus. The main solution found was to build a colony floating above the toxic, high-pressure environment closer to the surface. Oxygen and water could be separated from the large amount of C02 present in the atmosphere and the temperature and long days and nights could be managed using solar shades and solar mirrors. Currently, Venus is not a good candidate for settlement, because our technology is not advanced enough to implement the solutions available to us, but further investigation and research could provide potential technology to be able to build a settlement in the future.