I assume because they knew they’d literally get only one shot. So imaging more of the nearby surface was the best use of that opportunity, for doing science.
The Soviets had already landed a probe on Mars, which sent back the top few lines of a picture of the sky and then stopped scanning down, and died. So they must have not wanted a repeat of that disappointment!
Probably, on Venus, the bandwidth and sensor tech just weren’t enough for it to be possible to get more pixels in the time available? So they concentrated the effort on the nearest rocks
Sadly that does make the photos visually sort of unimpressive, unlike all the splendid panoramic views America’s Viking probes took of Mars. (Where the lander wasn’t being pressure cooked and acid-etched in 20 minutes)
The rough numbers I can find are that the acid cloud layer is ~75km thick, which seems awfully long for any kind of tether that'll have to support its own weight. With the low pressure (~0.1 ATM) it'd also need to be a rather big balloon.
Further down, the ~100m/s (~220 mph) winds on the tether would likely try to drag everything sideways, scraping any probe across the landscape.
Acid's a solved problem; PTFE (Teflon) is a comprehensive solution to hot sulfuric acid, well validated in chemical engineering problems on Earth. It's versatile enough you can even coat balloons with it [0].
The hard part is keeping electronics cool. The balloon ideas offer a really elegant solution. You could cycle a balloon between altitudes—between the 500 °C surface, and cold layers of the high atmosphere, cooling off and refilling a thermal storage reservoir for the surface. On Venus, can find cool 20 °C air at a very reasonable, balloon-navigable, 0.5 bar pressure level [1].
Just wanna point out the obvious thing just in case: "article" is from 2021 but photos are from '75 and '82
http://mentallandscape.com/C_CatalogVenus.htm - here are few more; site may load really slowly.
https://youtu.be/UEmlOjKmL68 - Asianometry video covering topic of Soviet Venera program
Odd that none of them show the horizon. Does anyone know why they’re angled so low?
I assume because they knew they’d literally get only one shot. So imaging more of the nearby surface was the best use of that opportunity, for doing science.
The Soviets had already landed a probe on Mars, which sent back the top few lines of a picture of the sky and then stopped scanning down, and died. So they must have not wanted a repeat of that disappointment!
Probably, on Venus, the bandwidth and sensor tech just weren’t enough for it to be possible to get more pixels in the time available? So they concentrated the effort on the nearest rocks
Sadly that does make the photos visually sort of unimpressive, unlike all the splendid panoramic views America’s Viking probes took of Mars. (Where the lander wasn’t being pressure cooked and acid-etched in 20 minutes)
Hope that changes with RocketLab
Anything you send to Venus instantly fails; it would be tremendously expensive to try to collect more.
Balloon, long tether, hardened probe makes short trips to the surface. It could last for years.
The rough numbers I can find are that the acid cloud layer is ~75km thick, which seems awfully long for any kind of tether that'll have to support its own weight. With the low pressure (~0.1 ATM) it'd also need to be a rather big balloon.
Further down, the ~100m/s (~220 mph) winds on the tether would likely try to drag everything sideways, scraping any probe across the landscape.
Acid's a solved problem; PTFE (Teflon) is a comprehensive solution to hot sulfuric acid, well validated in chemical engineering problems on Earth. It's versatile enough you can even coat balloons with it [0].
The hard part is keeping electronics cool. The balloon ideas offer a really elegant solution. You could cycle a balloon between altitudes—between the 500 °C surface, and cold layers of the high atmosphere, cooling off and refilling a thermal storage reservoir for the surface. On Venus, can find cool 20 °C air at a very reasonable, balloon-navigable, 0.5 bar pressure level [1].
[0] https://robotics.jpl.nasa.gov/news/up-up-and-away-to-venus/
[1] https://en.wikipedia.org/wiki/Atmosphere_of_Venus?#/media/Fi...
I definitely would like to see that. The advantage with Venus is also that the turnaround times would be shorter compared to Jupiter or Saturn.
Still disappointed that it's not a swamp as promised by 20th C. sci-fi.
A dinosaur infested swamp, at that.