The NASA Langley Research Center has recently presented a proposal for a manned mission to Venus. The idea here is to explore the planet via a solar powered inflatable airship that floats 50 kilometers above the surface of Venus.
While temperatures at the surface are hot enough to melt lead and atmospheric pressure is 92 times that of Earth, the atmosphere of Venus would be surprisingly habitable. At an altitude of 50 kilometers the atmospheric pressure is the same as on Earth at sea level, the gravity is only slightly lower than Earth and the temperature up that high is 75 degrees Celsius, which is manageable.
Other advantages of a mission to Venus versus a manned mission to Mars include the protection against radiation and micrometeorites offered by Venus' atmosphere. On Mars, an astronaut would be exposed to 40 times as much radiation as on Earth, whereas in the atmosphere of Venus it would be about the same as on Earth. The round trip to Venus would be 440 days: 110 days out, a 30-day stay and then 30 days back, whereas a trip to Mars would require more than 500 days in space at a minimum and realistically anywhere from 650 to 900 days due to the need to wait for a favorable orbital alignment for the return journey..
The Langley concept for HAVOC points out a few ways in which Venus’ upper atmosphere is surprisingly hospitable. At that level, the atmospheric pressure is one atmosphere, which means we could test the airship design on Earth fairly easily. The temperature up that high is only 75 degrees Celsius, which is perfectly manageable.
Compared to Mars, Venus actually has several big advantages. Firstly, power would be no problem. With an array of solar panels on the airship, explorers would have all the power they’d need. Venus gets 40% more solar energy than Earth and 240 times more than Mars. Since there would be an atmosphere present, the airship could use electrical power to spin turbines for propulsion.
The NASA researchers argue that except not having something under your feet, the atmosphere of Venus is probably the most Earth-like environment in the solar system and would be a great chance of doing a practice run of going to Mars. However, it would take a substantial policy shift at NASA to consider this proposal ahead of one to Mars.
“Venus has value as a destination in and of itself for exploration and colonization,” says Jones. “But it’s also complementary to current Mars plans.…There are things that you would need to do for a Mars mission, but we see a little easier path through Venus.” For example, in order to get to Mars, or anywhere else outside of the Earth-moon system, we’ll need experience with long-duration habitats, aerobraking and aerocapture, and carbon dioxide processing, among many other things. Arney continues: “If you did Venus first, you could get a leg up on advancing those technologies and those capabilities ahead of doing a human-scale Mars mission. It’s a chance to do a practice run, if you will, of going to Mars.”
You can learn more about the High Altitude Venus Operational Concept (HAVOC) project at ExtremeTech and IEEE.