The Soviet Union knocked off a ton of firsts in the early days of the space race. The Venera program saw the first human-made objects flyby, impact, and land on the planet Venus, the closest planet to Earth in both distance and size. Of the four rocky planets, Venus arguably has the harshest environment, making the temporary survival of the later Venera probes quite the engineering feat.

The Venera (Венерa, Russian for Venus) program eventually saw the first ever color images of the Venusian surface, and resulted in the first-ever artificial landing on another planet. All in all there were 16 spacecraft branded as Venera missions along with numerous failed missions that were not labelled (early on the USSR tended to only announce successful missions). To this day, the only spacecraft to touch the surface of Venus intact were part of the Venera (And Vega) line of spacecraft.

Artist rendition of Venera lander on Venus
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Venus: Worst Rocky Planet in the Solar System

The surface of Venus is probably the most inhospital surface in the entire solar system (not counting the interiors of gas giants with no surface and the sun itself). Imagine the worst environmental conditions you can think of on Earth, and Venus is one hundred times worse.

Orbiting the sun slightly in a mostly circular orbit closer than Earth (0.7 AU vs 1 AU for Earth), Venus is very close to Earth in physical size - with a radius of 6051 kilometers as opposed to Earth's 6378 kilometers. This means that walking on the surface would feel very similar to walking on Earth in terms of gravity. But that is just about the only thing you'd find familiar and comfortable - in fact, it is Venus' similar size to Earth that makes it so terrible in general.

Locked to Venus' surface is an extremely dense atmosphere of mostly Carbon Dioxide and Nitrogen gas. This thick atmosphere conceals the surface from view. Venus is the brightest planet when viewed from Earth, and its spherical shape can easily be seen with a telescope, but you will see no surface details as you would on Mars - the entire planet is essentially covered in one massive cloud. This enormous atmosphere has a pressure on the surface of over 90 atmospheres.

Planet Venus, a literal hell
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If that number doesn't mean anything to you, imagine diving down to the bottom of a moderately deep pool, 10 meters down. The pressure you feel down at the bottom of that pool is easily noticeable, and amounts to about 2 atmospheres of pressure (1 atmosphere from Earth's atmosphere, 1 atmosphere worth from the 10m of water above you). The Venusian surface has a pressure just due to the surrounding gas that is 45 times this! 90 atmospheres is about equal to the pressure 1 kilometer under the ocean. If you stood on the surface without a pressurized suit, you would be crushed to death. Containers of Earth atmospheric gas would be destroyed by the immense pressure difference.

But that's not the only reason you don't want to be on Venus. The surface temperatures is, on average, over 450 degrees Celsius. Water boils at 100 degrees on Earth. The Venus surface temperatures usually observed can melt lead on Earth. Kitchen ovens can get to around 200 C ... just imagine what it is like on Venus.

Map of the surface of Venus. Due to the lack of oceans, there is about 4 times more land on Venus than on Earth.
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These massive temperatures, far to high to just be due to Venus' proximity to the sun, are caused by heat being trapped in the atmosphere by the dense atmosphere.

But Venus gets even worse: Higher up, sulfuric acid clouds drift above the thick underlayer, and back down on the surface, hundreds of volcanoes scar the landscape. Venus is truly about as close to hell as we can imagine.

The planet is also especially bad for exploration because its huge mass (close to Earth) and atmosphere makes it essentially impossible to land a rocket that could then get back into orbit, even if said rocket could survive the ridiculously bad surface conditions.

All of this description should help to give you an appreciation for how incredible it is that the machines we are about to discuss survived as long as they did.

Venera-1: First (Dead) Flyby

The first somewhat successful Venera mission was Venera-1. This was not actually the first Venera mission, but the USSR had the habit of not announcing failed launches, so Venera-1 was named after being the first spacecraft in the program to somewhat succeed. Launched in 1961, this half-ton spacecraft carried various sensors and successfully flew by Venus in May of that year. However, due to an onboard failure, no communications or data were received from the flyby, making this only a success in that it was the first spacecraft to pass by the planet Venus.

Venera-1
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Venera-1 along with most of the later Venera missions were carried onto their mission trajectories by various versions of the Molniya rocket. This rocket, like the rockets that put Sputnik-1, the Luna missions, and the Vostok manned mission into space, was based on the design of the R-7 ICBM developed to launch nuclear explosives.

These rockets used four side boosters and several central rocket stages to propel moderately sized payloads into low Earth orbit and beyond. Here's the Molniya-M, a later version of the Molniya rocket:

Molniya-M Launch Vehicle. The orange fairing at the tops conceals the payload.
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Venera-1 didn't exactly succeed, but it kicked off the beginning of a long line of Venus explorers, a list that becomes even longer when you count the NASA missions to this planet and the much, much more recent Japanese/JAXA Venus exploration missions.

Venera-3: To the surface?

The next milestone came with Venera-3, a later mission to Venus launched in 1965. Venera-3 once again experienced a loss of communication before reaching Venus itself, but this mission was meant to land on the planet itself rather than just fly by. Because the lander was put onto an impact trajectory before loss of communication, it is likely that this vehicle reached the surface, becoming the first object from Earth to touch down on another planet.

However, it is unlikely that Venera-3 would be recognizable when it hit the surface. Because the exact conditions of the Venusian surface were not as well understood at the time, Venera-3 was likely mangled and destroyed by the intense pressure and temperature even if it wasn't destroyed by re-entry. While most of the atoms in this spacecraft had to have ended up somewhere on the planet, what was left of Venera-3 when it touched the rocky soil was likely a twisted, destroyed chunk of various metals.

Venera-3 is probably somewhere on Venus right now, but you wouldn't recognize it. This is what it looked like when it left Earth.
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Venera-4: Into the atmosphere

Following Venera-3 in 1967, the Venera-4 vehicle was able to enter Venus' atmosphere and survive long enough to send sensor readings back to Earth, from within the atmosphere itself. This spacecraft showed the composition of Venus' atmosphere (almost all CO2). For almost an hour, Venera-4 returned readings from Venus' atmosphere before succumbing to the harsh environmental about 25 kilometers above the hard surface.

A larger than necessary parachute served to delay the landing due to the incredibly dense atmosphere, forcing the spacecraft to survive far too long before it would eventually touch down. Nevertheless, this spacecraft did indeed land on the surface - it just wasn't in working order when it did so, and as such no transmissions were sent. It is still there to this day, although I doubt much is left of it after sitting in the hellish oven that is the surface of Venus for 50 years.

What Venera-4 originally looked like. Only the bottom capsule descended to Venus.
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Venera-8: First Successful Landing on the surface of Venus

Finally, in 1972, a spacecraft landed on the surface of Venus in a working state (previous Venera-7 had landed, but had bounced and rolled over, making it overall unsuccessful). Venera-8, sent directly to the Venus atmosphere, managed to survive entry and the harsh descent to the surface thanks to a smaller parachute, which hastened the fall.

Venera-8 survived for just over 50 minutes on the surface of Venus, sending back the first data from this world. It verified previous measurements of the incredibly harsh atmospheric conditions and improved our knowledge of the Venusian surface. It was even able to measure different elements in the rock where it landed. However, with no camera, no images were returned for us to see, and what this hell looked like remained unknown.

This really should show how intense the surface of Venus is: After numerous tries, Venera-8 lasted 50 minutes after landing. Venus is truly the most intense pressure cooker you can imagine, and not even the best engineered vehicles can last long here.

Venera-8 Descent Capsule.
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Venera-9: First Image of the surface of Venus

In 1975, Venera-9 followed Venera-8 in landing on the Venusian surface. This time, a single image, taken by the only camera that had properly deployed, was sent back to Earth before the poor spacecraft ceased functioning after just 53 minutes on the surface.

This image was the first picture of the surface of another planet. It was the only picture returned from Venera-9.

The surface of Venus
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Venera-13: Color Images of Venusian Surface

Venera-13 arrived on the Venus surface in 1981, and survived for 127 minutes on the surface. The rest of the spacecraft back above the planet served as a relay for sending surface observations back to Earth. This mission resulted in the first color picture of the surface of Venus, shown below.

Venus in color
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Another Venus surface image from V-13
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Other Venus Missions

Of course, there were many other Venera missions, both successful and not. These missions, along with several NASA orbiters (and landers, which did not survive to the surface), the two Vega probes, ESA's Venus Express and several JAXA missions have changed what we know about Venus. I could not hope to cover all of these incredible machines in just one post.

Venus is arguably the most hell-like place in the inner solar system apart from the sun itself. The surface is harsh enough to kill huge landing craft specifically designed for this in under 2 hours, every time. And yet, many missions have been sent there, with more to come. I know that there will be improvements and future landers that will last longer, and perhaps one day, with the help of a lot of innovation, we can maintain a permanent presence down there.

For now, Venus remains mostly unaccessible. For now, it remains as a massive graveyard of the various spacecraft sent there, including the now likely unrecognizable Venera and Pioneer Venus landers and the vaporized remains of various Venus orbiters sent down to the planet at the end of their missions. The surface has been somewhat mapped using radar, but more landers will be necessary to really find out the most about what is actually down there.

Pictures of Venus surface from Venera-13 and Venera-14. These remain some of the best surface images we have.
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Remember what Venus is: A massive swath of unexplored land four times the size of Earth's continents, covered in inhospitable toxic atmosphere and immense heat. Despite this challenge, there is no reason that the various space programs of the world can't explore more of it in the future, as we've barely even scratched the surface. So, if this interests you, remember to support increases to your country's space program budget. NASA only gets a pitiful 0.5% of the USA budget, and it already does incredible things. Landing on Venus and staying functional for longer than 2 hours is a massive, absurd challenge, but it isn't technically impossible.

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Well, that was a long one. Thanks for sticking around - hopefully you learned something new! If I got something wrong, or you have questions, please don't hesitate to let me know!

Thanks for reading!

Artist rendition of what the landers could look like after landing.
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Sources for Additional Reading
NASA Venera-8 Page
Venera Program Wikipedia Entry
NASA Venera-13 Image Page
Venera-13 Wikipedia Entry
Venera-1 Wikipedia Entry
Venera-3 Wikipedia Entry
List of Artificial Objects on Venus
List of Missions to Venus
NASA Venus Page
NASA Overall Venera Page