Maybe interesting to others, he's the Mitchell in the popular Mitchell-Netravali image resampling filters. Wikipedia only has an article in German and Japanese it seems: https://de.wikipedia.org/wiki/Mitchell-Netravali-Filter
Seeing the Venus surface images taken by the Venera 9 et al still blows me away.
The US has a fantastic track record regarding Mars landings but the successful Russion Venus landings are equally awe inspiring pieces of human engineering.
Venera missions just blow my mind, more so, even, than the Moon landings. Not only did they land onto an incredibly inhospitable surface (and sent _digital_ pictures from there before digital cameras were invented), they also did multi-stage missions where they'd first fly to Venus, and from there do a Halley comet approach. Even today this would be pretty nuts to pull off, for anyone.
Yeah it's one of those space missions (there were several of them) that I look at and am amazed every time. Like the Curiosity landing - how awesome was that?
I've heard that Mars is tough because the gravity is high enough that you need a lot of braking to land, but it's not quite high enough to maintain a thick atmosphere, so you can't use drag (e.g parachutes) to help reduce work/weight. Venus has a thick atmosphere and the Venera probes were able to use parachutes to help land.
Well, you can use parachutes, and indeed every lander mission to Mars has done so, but they are not enough, necessitating complex EDL (entry/descent/landing) sequences.
There've been so few successful Mars landings, that this could be interpreted as "the Soviets lost a couple of dice throws", really; it's not clear how much of a success is down to doing it properly vs just luck. Everyone has failures with Mars.
Also, of course, they clearly put more resources into Venus. AIUI it was the first Venera landings that established once and for all just how harsh conditions on Venus are; before that it looked potentially less harsh, and more interesting than, Mars.
Mars is expensive to get to and getting there is the hard part whereas Venus is cheap to get to and existing once you're there is the hard part. This has big implications for probe design.
A successful Mars probe is very light for the amount of science bits it packs (mars is far away so each probe is expensive, gotta pack as much science as possible on each one). As long as your stuff works after touchdown you're basically in the clear since the environment is pretty tolerable and generally stable. It's an exercise in value engineering everything to within a hair of its life so that you can fit it within the weight budget and get it to Mars in the first place. This sort of compromise game is something American engineering and project management tends to excel in.
Venus on the other hand is an exercise in pruning down your science instrument wish list to just the bare essentials (Venus is decently close, no need to compromise things so your favorite instrument can make the cut, it can just catch a ride on the next probe) then packaging all that in a form factor that can operate and survive as long as possible as the nearly four digit outside temperatures slowly overwhelm the probe. It's an exercise in picking the bare essentials that you need to do the job and then building it ruggedly enough to do that job consistently in adverse conditions and even as conditions degrade beyond what the system is designed to work in is something Russian engineering and project management tends to excel in.
One reason I read about once was that with Soviet rockets it was much more easy and economically feasible to get to Venus than to Mars, due to less delta-V required for inner Solar system travel. Being able to successfully land is irrelevant if you never get into planet’s orbit in the first place.
True. Mars is a "cursed" planet though. European lander has failed there also. NASA really knocked it out of the park with the rovers. They're the only ones who know how to really do it properly.
Sure those failures were during NASA’s faster, better, cheaper era . I would argue that these failures led to cultural change at NASA that has led to their tremendous success during the last 20 years.
NASA has had many more missions overall and their success rate is quite good compared to other agencies.
Click on "Show this thread" to see more. The Twitter user posted more about it as well, click his name to see his postings. There is also a website linked from his profile thats contains information about the "Soviet Exploration of Venus".
My theory is that once the science data from the Venera probes was returned, it was confirmed that any further surface science missions would be VERY short lived.
The pressures and temperatures are not something we have the technology to deal with presently. Whereas rovers on Mars can be built with current technology to operate for many years.
The best modern technology wouldn't last any longer than the best Soviet technology of the '70s.
There are two problems.
1. Heat. This is the big one. Lots of technology we take for granted don't work at 900F. Semi conductors don't work, which rules out nearly all of the most interesting technological advances since the '60s.
2. Energy. There are a few types of semiconductors that would work, but none of them are practical for packaging in an IC and they all use relatively significant amounts of power. Unfortunately, the clouds are too thick for solar panels to work, and if you try to use an RTG to generate power, now you have two problems.
The most likely practical concepts for a long duration lander on Venus call for wind power and mechanical analog computers.
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.
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.
> 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.
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.
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?
Question: why has the US not attempted to land on Venus?
I'm glad the USA didn't. That left them more $$$ to spend on Mars and other projects.
For the most part the "space race" was over when the USA landed on the moon. So wouldn't it make more economic sense if the various space-faring nations did different things? E.g. it was the ESA that sent Rosetta to Comet Churyumov–Gerasimenko.
Money itself isn't the issue; copying from another website, NASA's budget for 2020 is $22 billion which represents 0.48% of all U.S. government spending (compare that to $705 billion for military spending combined).
Unfortunately the threadreader version does not load the images (at least in Firefox), which makes it useless for an image-heavy tweet thread like this.
I still think a Venus colony would be super cool and maybe more viable than mars given the available energy and gravity... this just seems so cool https://youtu.be/bcHkWKp9e4Y
5 vehicles, 4 (5?) crew transfers? Not to mention some "interesting" environmental conditions. Yeah, it's definitely cool, but wow would it be a complicated mission.
