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Comment by chmod600 | Hacker News Reader

Does anyone have plans to land on Venus? Is that way more difficult or something?

The USSR did back in the day. It is much more harder, not to necessary land, but for your lander to survive more than a couple of hours.

It is hot like an oven, with 400F temperatures, and multiple ATM pressures. It is much a more challenging environment.

Russians landed 10 probes successfully and took pictures and did the science. Venera 13 lander survived for 127 minutes.

You can shield the probes from sulfuric acid and pressure, but it's hard to keep electronics cool for longer than few hours. Mean surface temperature is 464 °C. (867 °F). Doing science experiments is even harder.

You could use active cooling but the energy requirements would be immense, as you would need to make the heat sink even hotter than the 464+ C atmosphere.

You would basically have to use a crazy high temperature reactor like those envisioned for project Pluto, but setup to somehow produce useful work instead of propulsion, to get the necessary power needed to reach sane cold side temperatures on your heat pump.

NASA has been soliciting lander designs[1], as well as coming up with their own[2].

[1] https://www.nasa.gov/feature/jpl/nasas-venus-rover-challenge...

[2] https://ntrs.nasa.gov/citations/20190034042

See the Venera missions:

https://en.m.wikipedia.org/wiki/Venera

Not that I know of, Venus is kinda crazy. 90 ATM pressure, -1 pH acid rain, about 700 K temperatures at night, it's pretty absurd. Unless you want to make a probe out of solid Tungsten, you're probably out of luck. And good luck getting that out of low earth orbit, that would be stupidly heavy.

Would it help to have a burrowing probe? What are the subterranean conditions like?

I believe an airship would have higher chances of survival. If the surface has been that hot for thousands/millions of years, why would the underground be different? Unless you go really deep (hundreds of KM?), which is impossible.

IIRC some designs have an airship with probe on a long cable. The airship stays in the relatively cool upper layers of the atmosphere and periodically lowers the probe to study the surface for a short while.

That way you can cool the probe down every time you reel it in instead of making it withstand the hellish temperatures for extended amounts of time.

What if you designed a probe like a medicine capsule, with an outer shell that's designed to melt, but a smaller rover inside that can survive the heat/acid/pressure?

Designing the rover that can survive the environment is the difficult part.

If the shell melts, then how does it help the rover

They are going for a fully mechanical automaton probe apparently, no electronics, very interesting approach. https://spectrum.ieee.org/automaton/robotics/space-robots/jp...

Apart from Venus which is quite interesting, indeed, but very challenging goal, I hope there will be better exploration of Mercury, since it's rich in iron and closest to the Sun. It is a perfect fit for systematic monitoring of Sun's activity. Moreover, such proximity would make the energy density a big advantage in terms of the mission lifetime.

BepiColombo is on the way! We will start getting data back in 2026.

There's a Mercury Flyby in October of this year!

https://solarsystem.nasa.gov/missions/bepicolombo/in-depth/

planetary.org/articles/every-picture-from-venus-surface-ever

Yes because the lander will melt quickly.

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