Seems like the Soviets managed to get a lot of probes to Venus and the probes did relatively well.
The Soviets, US and Europe keep sending probes to Mars and other than successfully making it into orbit, they don’t survive long. Seems like Mars would be a lot easier on probes than Venus, plus we’re using the latest technology and materials. What is it about Mars that keeps thwarting us?
The martians just want to be left in peace!!
Seriously though, I think Venus’s atmosphere is more like earth’s. Maybe that has something to do with it–more conducive to machinery, etc, working like it’s supposed to.
I dunno. Just a WAG. <are WAGs permitted in GQ?>
WAG backed up by data would be better - you’re completely and totally wrong. 
Venus has a surface temp of 400-750K (lead meltingly hot), a surface pressure 90x that of earth sea level, as well as clouds of sulphuric acid that whip by at 350kmh.
Venus surface pics, Soviet lander info.
As to why, I’ve been wondering that myself. Chance? Older, simpler landers being way overbuilt? Who knows. I think surface winds might play a part too. In a brief search, Venus has slower winds than Mars, which makes the last bit before touchdown far easier, whether you’re using landing rockets, bouncing balls, or whatever.
Venus has an extremely thick atmosphere. The pressure at the surface is 90 times that on Earth at sea level. However, this actually makes landing there a little easier, provided you build a strong enough lander to survive that pressure. The Soviet Venera landers didn’t float down on parachutes all the way to the surface or rely on well timed retro-rocket firings. They jettisoned the chutes high in the atmosphere and then just floated down, letting the atmosphere do the work of slowing them down. When they landed they were only going about 7-8 m/s, which is probably the same as if they were dropped from 10 feet or so here on Earth.
The Soviet Venera’s were pretty successful, but only because they made a lot of attempts at it and managed to get it right. http://www.astronautix.com/project/venera.htm
Fiddlesticks has it right- the thick atmosphere of Venus simplified the landing process by providing all the deceleration the lander required. No retro rockets or airbags needed. The bottom part of the Venera landers was a simple circular metal frame which absorbed much of the landing impact.
It’s worth noting that the Venera landers only survived for about an hour on the surface. This is no criticism of the Soviet space program- this was the expected operational life, given the conditions.
By comparison, the US Viking landers remained operational on the surface of Mars for over three years (c. 1200 days in the case of one of the landers, IIRC).
But wait, there’s more - there were only 2 Venera landers, as I recall. They did send back pics, but (as hammos1 says) probably melted within the hour. That said, I’ve always thought it’s a testament to Soviet ingenuity that they landed on Venus successfully. Pretty cool.
The reason why there haven’t been any more sent is that there’s really no reason to. As other posters have said, the Venusian climate is exceedingly harsh: incredibly high pressures, unsurvivable heat, and lots of acid rain. It’s so inhospitable that Venusian mountains are said to be similar to silly putty - because temperatures and pressures are so high, the mountains flow and squish downhill and suffer much more from gravitational relaxation than those on Earth. Yes, Venus seems superficially similar to Earth (nearly the same size and all), but it’s a pretty hellish place.
Think about it - what’s the latest excitement surrounding the recent Mars activity centered around? The idea that one day, humans might go there. The idea that someday, humans might have to go somewhere. There’s been a big revival of the “we gotta be able to go somewhere else if Earth becomes uninhabitable” mindset lately, and everyone seems to want to put humans in semi- or permanent bases located somewhere off-planet. To do that, you’ve gotta find a place where humans can survive. We can survive on Mars or the Moon, with a lot of technical support. We simply can’t on Venus, regardless of technology.
I’m willing to bet that if Venus was more hospitable, if we or our rovers could last there, we’d have sent everything we could at it, just as we’re doing to Mars now. And there would probably be a very similar success/failure rate. After all, we don’t go because it is easy, but because it is hard.
Snicks
I have nothing to add except “Wow” - I never realised that we had pictures that good of the surface of Venus. I find it incredible to look at these ordinary looking boulders and think that they are on another planet. Really cool.
As for the problems with Mars landers… I saw a cartoon explaining this very issue a couple of weeks back. Can’t find it online, but imagine a couple of little green guys with spanners, springs flying everywhere, etc…
THEY DON’T WANT US THERE! 
A couple of things not mentioned yet.
[ul][li]Venus is a lot closer than Mars. This means that much more of the mission is taken up with just getting there. There is also a much larger time gap in sending signals, etc.[/li][li]Even if Venus didn’t have the thick atmosphere, it rotates so slowly that basically you would be dealing with one hot side and one freezing side. It is the atmosphere that keeps the heat spread out over the entire surface more evenly.[/ul][/li]
There are microbes that can convert some of the gases on Venus into more people friendly substances, such as oxygen. These microbes could be introduced to the upper layer of the atmoshere and allowed to do their thing. The reasons this isn’t done is that it’ll take a very long time; we’d be messing with mother nature; and there are other places we can go to instead.
I have no idea why I haven’t seen those pics before.
Wow amazing shots (assuming of course they are not actually from somewhere in Siberia
So landings on Venus are softer. If you consider hitting solid rock at 17 mph “softer.”
The Spirit lander had to freefall from a height of about four stories and then possibly bounce along the surface at freeway speeds, but was protected by airbags.
I guess I can see how landing on Mars might be a little trickier.
So why is our stuff malfunctioning once it successfully lands? Low temperatures and high winds? I wonder how much of an effect the high winds have in such a low density atmosphere?
I found this article that discusses Mars probe failures a bit.
It states:
So the most complicated mission ever flown was in the 1970’s, thirty years ago. Seems like the 60’s and 70’s were the golden age of space success?
It basically concludes, “luck of the draw,” to which I say, hmm.
Here’s a thought…
Technological advancement is much quicker nowadays than it used to be. The older techs had an longer life cycle and so were more robust than the newer techs. Of course we can do much more with the newer techs but we’ve sacrificed reliability.
note to self: no more WAGs on subjects you know jack about…
Anyone who has read the text by John Gray understands the concept. Mars will be explored and understood when it wants to be. Venus is willing to accept all the missions we’re willing to send, and will tell us more than we ever wanted to know. [Venutian]* So there was another mission, and we gave them everything, and did they write or call? No! So here we are, waiting for another probe, and it never arrives, and by the way, does this blue suit make me look fat? Anyway, …*[/Venutian] 