Often referred to as Earth’s “evil twin”, Venus developed quite differently from our own planet due to its closer proximity to the Sun. It has a “runaway” greenhouse effect meaning that heat is completely trapped, a thick atmosphere rich in carbon dioxide, a surface hot enough to melt lead, and no magnetic field.
Several uncrewed scientific missions will examine how and why this happened over the next decade. But now some scientists want to send a crewed mission there for a flight, and it’s debated whether this is a good idea. But according to many experts, this is not a good idea at all.
Why is it so hard to go to Venus?
Venus, which has a slightly smaller diameter than Earth, orbits closer to the Sun. This means that any water on the surface will evaporate shortly after its formation, starting the greenhouse effect. Early and sustained volcanic eruptions created lava plains and increased carbon dioxide in the atmosphere. It started the runaway greenhouse effect, which raised the temperature to its current high of 475 °C, although it started only slightly higher than Earth’s.
Although Venus’s year (225 days) is shorter than ours, its rotation is very slow (243 days) and “backwards”, that is, in the opposite direction of Earth. The slow rotation is seen to be related to the lack of magnetic field causing a sustained loss of atmosphere, and Venus’ atmosphere is “super-spinning” faster than the planet itself. Images from several missions show V-shaped cloud patterns made of sulfuric acid droplets.
How did the idea to go to Venus come about?
Despite the harsh conditions, some scientists speculate that Venus’ clouds may harbor habitable conditions at some altitudes. Recent measurements that clearly show phosphine in the clouds of Venus, a potential sign of life as it is constantly produced by microbes on Earth, have sparked great controversy. So we need more metrics and research to find out where it’s coming from.
What we know about Venus comes from several different rovers in the past. In 1970-82, for example, the Soviet Venera 7-14 probes succeeded in landing on the rough surface of Venus, surviving for up to two hours, and returning their data and photos. But the question remains how Venus evolved so differently from Earth. These questions may also help us understand which planets orbiting other stars may have signs of life.
A very active period begins for Venus scientists in the next ten years. NASA has decided to launch Veritas and DaVinci+, two missions it selected in 2021, in 2028-2030. The European Space Agency plans to launch the EnVision mission in early 2030. These will be completely complementary missions and stand out as unmanned missions aimed at giving us more information about Venus’ environment and evolution.
Veritas will map the surface of Venus to try to determine the importance of its geological history, rock components and early water. DaVinci+ will include an orbiter, and a small probe will descend through the atmosphere to measure the structure of its atmosphere, study the formation and evolution of the planet, and see if it had an ocean in the past. EnVision will study the planet’s surface, subsurface and atmospheric trace gases. It will use radar to map the surface better than has been achieved in the past.
India is also planning a drone mission called Shukrayaan-1, and Russia is proposing a mission called Venera-D.
History of the manned mission idea
The idea of a manned mission near Venus was also proposed in the late 1060s and involved using an Apollo capsule to orbit humans around the planet. However, this idea was discontinued just as Apollo was finished. Now, with the Artemis project once again carrying the aim of a manned mission to the Moon, other manned mission ideas are coming to light again, and the idea of a manned mission to Venus is among these proposals.
The idea for this mission proposes to send a manned spacecraft that will return to Earth after orbiting Venus. Such a mission would allow scientists to test techniques they could use in manned deep space missions where there is a significant delay in communication. So this kind of mission could help us prepare for future more complex manned missions like Mars missions. However, the conditions on Venus are so harsh that the crew will not be able to land on the planet and do a real atmospheric survey.
The researchers proposing this mission also suggest that we can use Venus’ gravity to change the path of a vehicle to Mars and possibly save time and energy compared to going directly from Earth to Mars. This is because on a mission going directly to Mars, we would have to wait for the orbits of the two planets to align. In other words, we have to wait for the right launch moment, both on the outbound and on the way back. But since a mission to Mars would be very complex anyway, going directly helps keep the designs simple, even if we have to wait.
Also, a manned mission to Venus would add to the cost of the mission without contributing to the mission itself apart from the advantages mentioned above, as it could only stay around the planet for a few hours and not make an active contribution to research.
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