A brief service line in a recent space roundup for early October noted that NASA had completed thermal testing of an engineering model of the DAVINCI probe. They heated a capsule the size of a yoga ball to 465 °C six times in a ceramic chamber with scorched walls, and it held up. It looks like a routine engineering report, but behind it lies something that has not happened in nearly half a century.
DAVINCI is NASA’s upcoming Venus mission, consisting of a flyby spacecraft and a descent probe. The probe is meant to enter the atmosphere, fall through it for about an hour, collect data on its chemical composition, and photograph the surface in high resolution. The Solar System’s second planet, Earth’s nearest neighbor, is almost our twin in size and mass. And no spacecraft has descended to its surface since 1985.
That number snagged me. Venus is not some forgotten backwater that no one wants to visit. It is a planet humanity had explored more deeply than Mars before Viking landed on Mars. And then we simply stopped. Nearly half a century lies between the last Soviet landing and the future American one. What kind of pause lasts a human lifetime?
To understand why Venus dropped out of the plans, you first have to understand exactly where one would be landing. The planet’s surface is 465 °C at a pressure of around 92 Earth atmospheres. The temperature is above the melting point of lead (327 °C) and above the melting point of tin (232 °C). The pressure is like that at a depth of roughly a kilometer in the ocean. The atmosphere is almost pure carbon dioxide; the clouds are sulfuric acid, which dissolves nylon and, generally, anything made of ordinary polymers.
The thermodynamics are merciless and simple: the difference in temperature between the blazing outer shell and the spacecraft’s innards is hundreds of degrees, and heat always flows inward, from hot to cold. There is no such thing as “protection forever.” There is only delay. All Venus engineering is a struggle not to survive, but to avoid dying for as long as possible—and the countdown begins the moment of atmospheric entry.
The spacecraft need a reserve of cold before launch. The Soviet Venera probes carried blocks of lithium nitrate—a salt with a very high heat of fusion. As the salt melts, it absorbs heat and keeps the innards habitable, just as ice in a cooler keeps things cold. When the salt runs out, the instruments die. Everything else—insulation and radiative heat rejection—merely extends the working life of this “cold battery.”
The only photographs in history taken from Venus’s surface belong to the Soviet Venera program. Behind it stand eighteen launches from 1961 to 1984, thirteen successful atmospheric entries, and ten soft landings. The program ran for almost thirty years and tried everything: the first attempts in 1961 did not even leave Earth orbit; Venera 3, in 1966, became the first human-made object to reach the surface of another planet—albeit as wreckage. Venera 4, two years later, measured the atmosphere of another planet for the first time and transmitted its principal gas: carbon dioxide.
The first to survive down there was the Venera 7 descent vehicle in 1970. Its parachute tore almost at the surface, the impact flipped the craft over, and its radio antenna ended up pointed sideways. The signal was barely alive, but it continued for another 23 minutes. These were the first data transmitted from the surface of another planet.
Then came the cameras. Venera 9, in 1975, sent back the first panorama in history from the surface of another world—it worked for 53 minutes. Venera 10—65 minutes. But each lost one camera: the lens covers failed to eject. On Venera 11 and Venera 12, neither cover opened, and both missions returned with data but not a single photograph.
The high point was Venera 13 and Venera 14, launched in 1981. Each carried cameras, a microphone, a soil-sampling drill, and an X-ray spectrometer. Venera 13 landed on March 1, 1982, at 03:57 UTC, east of Phoebe Regio, and worked for 127 minutes—though its entire designed lifetime was 32 minutes. Venera 14 got 57 minutes. Both recorded the first “sound recording” in history from another planet: the howl of the Venusian wind, the craft striking the ground, and the drill at work.
The cameras shot through quartz portholes, and both drills bit into real Venusian basalt. Venera 13 found leucite basalt; Venera 14, tholeiitic basalt—the same kind that lies on the floor of Earth’s oceanic ridges. Not bad for a craft designed to work for half an hour in an oven.
There is a twist here that I did not expect and that deserves its own paragraph. Those famous Venera 13 and Venera 14 images everyone has seen are not high-quality originals. The raw data long existed in a form inconvenient to process: nine bits per pixel, logarithmic encoding, with the tenth bit as a checksum. What mostly circulated were analog copies, accumulating “generational losses.”
Years later, the task of extracting the raw telemetry fell to an enthusiast named Don Mitchell, who was connected to the Russian scientific community. He pulled out the original recordings, assembled several transmissions of the same panorama, manually aligned them, cleaned up bit errors, and rebuilt them. The work on these data is still unfinished—Mitchell wrote candidly that reconstructing the radiometric function and balancing the color still lay ahead.
So for a quarter-century we were looking at a photocopy of Venus. The originals lay in an archive, waiting for someone to bring them back to life. It happens more often than people like to think: raw data can outlive an era, but hands willing to decipher it do not always survive with them.
If the pause had been only about money and risk, it would not have lasted this long. Behind those forty years lies a deeper scientific turn: interest shifted from Venus to Mars. Mars is safer for spacecraft, farther from the Sun, and, above all, that is where people look for traces of life. Venus, meanwhile, posed questions whose answers came dearly: to understand anything, you had to go inside.
The central question all this time has been one: was Venus ever like Earth, and did it have oceans? The clue was sought in the atmosphere’s isotopic composition—above all, in the deuterium-to-hydrogen ratio. The logic goes like this: ordinary hydrogen is lighter, and when water breaks down in the upper atmosphere, the light isotope escapes into space faster while heavier deuterium accumulates. If Venus had lost a great deal of water, the deuterium-to-hydrogen ratio would be far higher than Earth’s.
In 1982, Thomas Donahue and colleagues measured that ratio and got a result dubbed “Venus was wet”: there was about a hundred times more deuterium there than on Earth. It looked like the signature of a global catastrophe.
But then comes the uncertainty that is annoying for the story. Over forty years, the interpretation of those numbers has been revised more than once. Different explanations proposed different physics for hydrogen escape: a thermal mechanism, impacts by hot oxygen atoms. Each version produced its own estimate of the original water supply. So the isotopic “signature” is more a key for reading different versions than a finished conclusion.
A 2024 paper in Nature complicated the picture further. Its authors, Eryn Cangi and Michael Chaffin of the University of Colorado, showed that the HCO⁺ ion—hydrogen, carbon, oxygen—is also responsible for water loss: in the upper atmosphere it reacts with electrons, breaks apart, and the hydrogen escapes. By their calculations, this makes the planet lose roughly twice as much water per day as previously thought. And there is a wonderful detail here: no one has ever observed HCO⁺ around Venus—the spacecraft simply did not have instruments suited to detecting it. The model says the ion should be among the most abundant in the atmosphere. Nobody was looking with the right eyes.
How dry the planet is today—the number is shocking. If all of Earth’s water were gathered up and spread in an even layer, it would make a film roughly 3 kilometers deep. On Venus, the same operation would yield 3 centimeters. It has about a hundred thousand times less water than Earth, despite almost identical size and mass. Two planets born alongside each other diverged so completely that one became ocean and life, the other a heated rock with 3 centimeters of moisture in the air.
Venus’s surface went unvisited for almost half a century not only because it is expensive. Flying there had ceased to make sense in its old form: spacecraft landed, gathered an hour of data, and died. To get more out of Venus, a different model was needed—not “get there and die,” but “collect everything on the way down.”
That is exactly how DAVINCI is designed. The flyby spacecraft first passes Venus twice, studying the clouds and terrain from above, then two years later releases a spherical probe. The probe is not meant to survive as a station—it is meant to make good use of its single hour of descent. Inside are four instruments: a mass spectrometer for noble and trace gases, an atmospheric-structure instrument for pressure, temperature, and wind, a camera, and another sensor to measure oxygen in the lower atmosphere. Titanium; a heat-resistant shell with inlet ports for hot gases; a sapphire window before the infrared camera. The parachute will have to be made from material five times stronger than steel: nylon would dissolve in sulfuric acid.
The descent will take 55–60 minutes. Launch: December 2030. Arrival at Venus and probe release: January 2033. If it works, these will be the first photographs of Venus’s surface in more than forty years—and the first detailed study in history of tesserae, mysterious highland regions fractured into blocks that exist only on Venus. Previous spacecraft spent years viewing them by radar from above, but none came close. Scientists want to know whether these most ancient rocks contain granite—a stone that on Earth forms in the presence of water.
One particular source of pride for the engineers: the current furnace tests showed that, for the second time in U.S. history—after the mid-1970s—an American team has tested a planetary-scale hardware component at Venusian temperatures.
While DAVINCI has yet to fly, several missions are approaching the planet from different directions at once.
America’s VERITAS is meant to map Venus from orbit and determine whether it has tectonics and active volcanism. Europe’s EnVision, whose construction began in 2025, will tackle the same thing from the European side; its launch window is no later than 2033, or the diverging planets will push the mission back by at least three years. This is where money enters the game: under the 2026 budget, NASA received around $2.54 billion for planetary science, roughly $200 million less than a year earlier. NASA planetary science division director Louise Prockter said outright in March 2026: “not everything can move forward or move forward in the way it has been.” DAVINCI received $99 million in that budget to continue, while VERITAS is picking up speed slowly. Of NASA’s three missions, it is confidently carrying one for now.
At the other end of the budget is a private venture. Rocket Lab and an MIT team are preparing Venus Life Finder: a capsule about 40 centimeters across and weighing 17 kilograms, carrying a single instrument of roughly one kilogram. It is meant to pierce the middle cloud layer and operate there for around 330 seconds—give or take five minutes—studying droplets of sulfuric acid with a laser at a wavelength of 440 nanometers. The stated cost is under $10 million, three orders of magnitude below an ordinary planetary mission.
I am skeptical here, and the reason is arithmetic: five minutes and one instrument mean the mission is physically incapable of answering “no” to the question of life on Venus. A negative result says only something about one patch of sky, one wavelength, and one instant in a rapidly circulating atmosphere. A positive one is merely a reason to send a more serious instrument.
The label “private mission” also conceals a loophole: NASA made and supplied the spacecraft’s heat shield, NASA supported ground testing of the instrument, and NASA will provide navigation and communications through the Deep Space Network. “Mostly private” would be more honest. But the project is honest in another respect: Rocket Lab does not name a specific launch date. Early targets—2023, early 2025, summer 2026—have all come and gone; the manifest now says TBC.
There is also an especially stubborn story inside the archive itself. In 2012, Leonid Ksanfomaliti, a veteran Soviet planetary scientist with a formidable reputation, published a paper claiming signs of life—“scorpions” and “disks” moving between frames—while examining old Venera 13 panoramas.
The planetary community took it apart piece by piece. The reason is simple: there really are many differences between two consecutive frames of the same panorama, but they are noise—the craft transmitted data using two different forms of signal modulation, which changed the structure of the interference. On top of that, the surface around the craft was kicked up and disturbed during landing; dust settles and is blown around by the wind; and the camera was compromised by a loss of bit synchronization. Ksanfomaliti insisted that Photoshop was “categorically excluded,” but immediately acknowledged adjusting contrast and brightness and using the “blur” and “sharpen” tools in a standard drawing program. One analysis ended with a short summary: “there’s nothing here, move along.”
So what closed the forty-year pause? A shift in priorities. Mars promised a story with hope for life and required only care; Venus promised hell and required getting inside—with an unclear payoff. Hence the budget arithmetic. Hence the silence. An indirect signature that the turn has finally happened is that very furnace in Pennsylvania: the temperature that kept the planet at arm’s length for almost half a century now appears as a separate line in the technical requirements.