Five Things to Consider Before Camping on Venus
Why can’t you camp on Venus?
Glacier national park; you hear the raindrops soothingly tap the fabric roof of your tent. Sun is slowly popping over the horizon, its rays just sneaking through the thick clouds. An hour, two at most, and you can put on your hiking shoes and share the path with the moose, who is on his daily commute to the darker part of the forest.
Here is an obvious question: why can’t you do that on Venus?
Venus is the second of the four inner rocky planets in our Solar system. Depending on its orbital position, it comes closest to the Earth (Mercury is closer most of the time). Since the old times, Venus has sparked the imagination of night-sky observers. It is one of the brightest spots in the sky, some nights appearing in the evening (as a so-called evening star), while on others in the morning (as the “morning star”); as such it has been sometimes recognized as two different bodies and often thought of as separate deities. Slavic mythology, for example, associated evening and morning star with two goddesses, Zoryas, who guarded the world against the destruction by Simargl, a winged dog leashed to Polaris star.
Volcanically active¹ Venus completes its journey around the Sun in 224.7 (Earth) days and its solar day lasts 116.75 (Earth) days — more than half of a Venusian year. This discrepancy in the day-night period just starts the list of striking differences between Earth and Venus. Let’s check why we can’t go camping on Venus!
1. There are currently no flights scheduled.
Going camping usually begins with an enjoyable ride towards some quiet part of nature. You might need to, however, hop on an airplane and whizz somewhere closer, if you are coming from afar. The distance to Venus does qualify as “afar,” unfortunately. While the title spoils the surprise a bit, there are in fact no flights scheduled to Venus. Since the trembling thunder of rocket engines has woken up Baikonur’s Гоферовые (gophers) in mid-June of 1967 when Soviet Venera 4 has left Baikonur, several fruitful missions have been launched to explore Venus.
Venera 4 was the first successful mission to provide an insight into the chemical composition of the planet’s atmosphere. Its siblings (Venera 5&6) followed the steps of the older sister as they conducted atmospheric observations; it was not until Venera 7 (first soft landing but partially failed to send useful data) and 8 (successful) that scientists got an objective insight into the Venusian world. The environment that awaited the probes there was even more hostile than imagined (more on that below). Yet, the Soviets soldiered on, launching more complex missions to explore the planet: the exploration of Venus was dominated by the Soviet missions. While NASA focused more on Mars, Soviets have landed ten missions on Mars. NASA has conducted several fly-by and atmospheric missions, which provided meaningful data.
Looking into the future, amongst more than a dozen proposed missions most promising are Indian Shukrayaan-1 and Russian Venera-D. Both are still under consideration and research objectives are being defined. Indian probe is supposed to explore Venus by deploying a balloon, while Venera-D aims to send the lander to study the interaction between the atmosphere and the surface, while the orbiter intent is to investigate the greenhouse effects and atmosphere as such. Both missions are still under considerations and no firm date has been set.
2. Your tent might not be suitable
Unless you embraced the retro-style to the fullest and went for old army cotton or linen tent, you are probably a proud owner of a polyester or nylon tent. While it served you well on the rainy weekend, its waterproofing is rendered meaningless on Venus. Clouds of sulphuric acid are hovering around 48 km above the surface and when acid rain droplets leave the mothership, they largely evaporate before reaching the surface. “But even if, polyester is resistant to sulphuric acid, so it could handle it,” you say. Indeed, but it is the surface temperature of ~470ºC that would melt your tent. In the case of going retro and taking a linen/cotton tent, the material would not ignite as there is no oxygen; however, it would turn into a char cloth due to pyrolysis. On a positive side, it now comes in a “midnight black” color.
3. Venusian cars should be made by submarine engineers
Even during the harshest of snowfalls, a car is an embassy of comfort; setting the temperature, maybe even some music and you can have a decent evening even if the weather is misbehaving. Yet, your favorite car manufacturer might not make the model that would withstand the Venusian conditions.
The pressure on the surface of Venus is more than ninety-times higher than on Earth; equivalent to the pressure at nearly a kilometer under sea-level. Are there any machines that can withstand such enormous pressures? Ohio-class of US ballistic submarines (that carry twenty-four Trident ballistic rockets, which can obliterate a significant number of cities), can reach a depth of around 240 m. Soviet-made submarine K-278, with an inner-hull made from titanium, could dive deeper than a kilometer; bathyscaphe Trieste has reached a whooping depth of 10,911 m, touching the ocean floor of Mariana Trench. These few examples demonstrate that submarine engineers know how to make sturdy machines capable of withstanding enormous pressures — sturdy machines withstanding Venusian atmospheric pressure can be engineered. So what is the problem?
While the sea is rather cold, high atmospheric pressure on Venus is accompanied by extreme temperatures, whose effects are detrimental to any equipment. When designing a probe, most common engineering assumptions have to be reconsidered. For example, the solder used to join the building blocks in electronics (resistors, transistors, etc) has a typical melting temperature between 90ºC-450ºC, requiring different materials and methods. Additionally, semiconductor properties of materials normally used in chipsets are temperature sensitive.
Some proposals resort to simpler designs: NASA’s AREE concept uses wind power to wind a spring, which in turn powers a mechanical computer (!) and propel the rover around Venus³.
4. You are not likely to see any life-forms (that you are used to)
Camping is a great way of learning more about Nature and wondering about the plethora of living beings, such as the hard-working moose mentioned above. Could life exist on Venus?
If you take a grain of sand on the beach, it can happen that it will be densely covered with microorganisms: for example, a study² showed that there can be between ten- to hundred-thousand bacterial cells on a single grain of the sea sediment. While there are certainly places devoid of life, terrestrial organisms prove again and again to be remarkably robust: high-temperature pools, freezing temperatures, high-salinity — name it, and life probably found its way there. Yet, even the harshest of conditions usually offer something that Venus is essentially devoid of: water. At current Venusian conditions, water cannot exist and with it, life as we know it is likely impossible. However, it might be that life can take another form — and as of yet, we do not have a widely accepted definition of what life even is⁴.
Philosophy aside, when leaving Earth, some expectation of what things are — including life — will have to be loosened; and as such, there might be a variant of life on Venus, that would consider our cozy Earth to be an icy and unwelcoming place, compared to plentiful carbon dioxide and warmth of Venusian home. So, barring the non-zero probability of tardigrades (presumably the toughest known Earth organism) ability to survive Venusian conditions, we should expect to be disappointed in search for familiar life; if recognized, an unknown variant of life could appear and surprise us.
5. The campsite might float in the air
This one is for the daredevils: as a kid, you probably played “floor is lava.” Well, you can contemplate experiencing it for real. NASA’s concept HAVOC⁵ (High Altitude Venus Operational Concept) proposes an establishment of a manned outpost in Venus atmosphere. That’s right, not on the hellish surface but rather above the clouds of sulphuric-acid at the altitude of 50 km. There, the pressure is nearly identical to the Earth’s surface pressure, while the atmosphere is still predominantly composed of carbon dioxide. Radiation shielding is similar to Earth’s one as well, thus making it a cozy outpost sporting a temperature of roughly 75ºC. While this might limit the astronaut selection to sauna-tempered Finnish nationals, with some decent cooling life could be possible.
The outpost would resemble a smaller version of zeppelins from the early twentieth century; HAVOC outpost would measure slightly more than thirty meters in length. High-speed winds would propel the outposts around the Venus every 110 hours, thus creating great conditions for observations of the planet. Mission profile would require a bit more than a hundred days for the crew to reach Venus, the stay was projected to last around 30 days and the return trip would last for three-hundred days. In total, the mission was estimated to last around 440 days — quite a bit of traveling for only a month of observation. However, later missions were assumed to take a year of residing above Venus, and could eventually lead to a permanent human habitat.
Since carbon, oxygen, and nitrogen could all be harvested from the atmosphere, the outpost could perform different chemical processing operations, including rocket fuel production. Such a mission would mostly serve a demonstration that humans can sustain themselves above (rather than on) a foreign planet.
For a second, imagine sleeping while being carried around Venus at roughly 350 km/h in an inflated airship, around two kilometers above the clouds of sulphuric acid, submarine-crashing pressures, and lead-melting temperatures. It sounds pretty badass; however, the project is currently noted as “archived.”
Next time when you observe this bright spot over the horizon and dream about taking the vacation there, maybe revisit these points. It is hellish, yet an incredibly interesting place that will remain challenging to visit, even for robotic probes. But it can also serve as a reminder that Venus might have started similar to our Earth and how a greenhouse runaway effect has made it unwelcoming, and the exploding amount of carbon dioxide has suffocated the hospitality of the planet. Yet, it will always pose a remarkable spot in our solar system, which is worthwhile exploring.
References:
¹Present-day volcanism on Venus as evidenced from weathering rates of olivine, Science Advances 6(2020)
²Microbial life on a sand grain: from bulk sediment to single grains, The ISME Journal 12 (2018)
³https://www.nasa.gov/feature/automaton-rover-for-extreme-environments-aree/
⁴Definning “Life”, Origins of Life and Evolution of the Biosphere 32 (2002)
⁵https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20160006329.pdf
