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by ibrault 2301 days ago
Not a lander but NASA has 2 potential Venus missions in their proposed Discovery missions! [0]

In regards to why not a lander: I would guess it's because it's not really necessary? Orbiters (like the proposed ones above) can gather all of the science that's really necessary to study a planet like Venus. Landers are useful to study more micro-scale science to, for example, search for life (see the Mars rovers/landers and the proposed Europa lander). And orbiters are significantly cheaper and easier to make. Landing on Mars is really really really hard! I can assume it would only be harder on Venus.

[0] https://www.nasa.gov/press-release/nasa-selects-four-possibl...
2 comments
skykooler 2301 days ago
Landing on Venus is actually fairly easy; the atmosphere is so thick that even with a minimum of parachutes, a lander will touch down at a comfortably slow velocity. The hard part is keeping it cool enough to function; all the Soviet landers used a phase-change material to cool them, which worked for a little while until it had all changed phase at which point they rapidly overheated. Keeping a lander operating for more than a couple hours is a very difficult engineering challenge for that reason.
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ryandrake 2301 days ago
> Landing on Venus is actually fairly easy; the atmosphere is so thick that even with a minimum of parachutes, a lander will touch down at a comfortably slow velocity.

Doesn’t the thick atmosphere also mean a lot more mass to slam into at orbital speed when starting to enter it? Seems like it’s a double edged sword.

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crubier 2301 days ago
The upper layer of the atmosphere are not denser than the upper layer of the earth atmosphere, so it does not make aerocapture more difficult. It’s just that the atmosphere is “deeper”: going down, it starts thin, and then gradually densifies until reaching earth conditions at around 50km, then you keep going down in thicker and thicker atmosphere, which means you don’t need big parachutes.
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crispyambulance 2301 days ago
There were a number of Soviet missions that deployed a balloon-based probe to Venus. These were called the "Vega" missions (https://en.wikipedia.org/wiki/Vega_program).

I think that's more practical. At a high enough altitude, one doesn't have to deal with extreme pressure and temperature-- just sulfuric acid as rain?

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