Venus Climate Orbiter Akatsuki’s Mission Has Ended

Japan’s Venus Climate Orbiter Akatsuki was launched on May 21, 2010, and started its active mission in 2015 after an initial orbital insertion failure. Since that time, Akatsuki has continuously observed Venus from orbit until issues began to crop up in 2024 when contact was lost in April of that year due to attitude control issues. Japan’s space agency, JAXA, has now announced that the mission has officially ended on September 18, 2025, after a period of trying to coax the spacecraft back into some level of functionality again.

The Akatsuki spacecraft in 2010 before its launch. (Credit: JAXA)
The Akatsuki spacecraft in 2010 before its launch. (Credit: JAXA)

The Akatsuki spacecraft had six instruments, consisting of cameras covering the visible spectrum, ultraviolet and infrared spectra, as well as an oscillator for radio occultation experiments.

All primary mission goals were successfully completed in April of 2018, but engineers determined Akatsuki was capable of lasting at least another few years. This puts it well past its original design lifespan, and has provided us with much more scientific data than we could have hoped for.

Unfortunately, the shutdown of Akatsuki represents the end of the last active Venus mission, with much uncertainty surrounding any potential upcoming mission to Earth’s near-twin planet. The next potential mission is the Venus Life Finder, as an atmospheric mission penciled in for a 2026 launch. It would take at least until 2028 for a potential orbiter mission to launch, so for the foreseeable future Venus will be left alone, without its artificial moon that has kept it company for a decade.

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Hackaday Links: May 11, 2025

Did artificial intelligence just jump the shark? Maybe so, and it came from the legal world of all places, with this report of an AI-generated victim impact statement. In an apparent first, the family of an Arizona man killed in a road rage incident in 2021 used AI to bring the victim back to life to testify during the sentencing phase of his killer’s trial. The video was created by the sister and brother-in-law of the 37-year-old victim using old photos and videos, and was quite well done, despite the normal uncanny valley stuff around lip-syncing that seems to be the fatal flaw for every deep-fake video we’ve seen so far. The victim’s beard is also strangely immobile, which we found off-putting.

Continue reading “Hackaday Links: May 11, 2025”

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Hackaday Links: May 4, 2025

By now, you’ve probably heard about Kosmos 482, a Soviet probe destined for Venus in 1972 that fell a bit short of the mark and stayed in Earth orbit for the last 53 years. Soon enough, though, the lander will make its fiery return; exactly where and when remain a mystery, but it should be sometime in the coming week. We talked about the return of Kosmos briefly on this week’s podcast and even joked a bit about how cool it would be if the parachute that would have been used for the descent to Venus had somehow deployed over its half-century in space. We might have been onto something, as astrophotographer Ralf Vanderburgh has taken some pictures of the spacecraft that seem to show a structure connected to and trailing behind it. The chute is probably in pretty bad shape after 50 years of UV torture, but how cool is that?

Parachute or not, chances are good that the 495-kilogram spacecraft, built to not only land on Venus but to survive the heat, pressure, and corrosive effects of the hellish planet’s atmosphere, will at least partially survive reentry into Earth’s more welcoming environs. That’s a good news, bad news thing: good news that we might be able to recover a priceless artifact of late-Cold War space technology, bad news to anyone on the surface near where this thing lands. If Kosmos 482 does manage to do some damage, it won’t be the first time. Shortly after launch, pieces of titanium rained down on New Zealand after the probe’s booster failed to send it on its way to Venus, damaging crops and starting some fires. The Soviets, ever secretive about their space exploits until they could claim complete success, disavowed the debris and denied responsibility for it. That made the farmers whose fields they fell in the rightful owners, which is also pretty cool. We doubt that the long-lost Kosmos lander will get the same treatment, but it would be nice if it did.

Continue reading “Hackaday Links: May 4, 2025”

Dwingeloo telescope with sun shining through

Dwingeloo To Venus: Report Of A Successful Bounce

Radio waves travel fast, and they can bounce, too. If you are able to operate a 25-meter dish, a transmitter, a solid software-defined radio, and an atomic clock, the answer is: yes, they can go all the way to Venus and back. On March 22, 2025, the Dwingeloo telescope in the Netherlands successfully pulled off an Earth-Venus-Earth (EVE) bounce, making them the second group of amateurs ever to do so. The full breakdown of this feat is available in their write-up here.

Bouncing signals off planets isn’t new. NASA has been at it since the 1960s – but amateur radio astronomers have far fewer toys to play with. Before Dwingeloo’s success, AMSAT-DL achieved the only known amateur EVE bounce back in 2009. This time, the Dwingeloo team transmitted a 278-second tone at 1299.5 MHz, with the round trip to Venus taking about 280 seconds. Stockert’s radio telescope in Germany also picked up the returning echo, stronger than Dwingeloo’s own, due to its more sensitive receiving setup.

Post-processing wasn’t easy either. Doppler shift corrections had to be applied, and the received signal was split into 1 Hz frequency bins. The resulting detections clocked in at 5.4 sigma for Dwingeloo alone, 8.5 sigma for Stockert’s recording, and 9.2 sigma when combining both datasets. A clear signal, loud and proud, straight from Venus’ surface.

The experiment was cut short when Dwingeloo’s transmitter started failing after four successful bounces. More complex signal modulations will have to wait for the next Venus conjunction in October 2026. Until then, you can read our previously published article on achievements of the Dwingeloo telescope.

Clockwork Rover For Venus

Venus hasn’t received nearly the same attention from space programs as Mars, largely due to its exceedingly hostile environment. Most electronics wouldn’t survive the 462 °C heat, never mind the intense atmospheric pressure and sulfuric acid clouds. With this in mind, NASA has been experimenting with the concept of a completely mechanical rover. The [Beardy Penguin] and a team of fellow students from the University of Southampton decided to try their hand at the concept—video after the break.

The project was divided into four subsystems: obstacle detection, mechanical computer, locomotion (tracks), and the drivetrain. The obstacle detection system consists of three (left, center, right) triple-rollers in front of the rover, which trigger inputs on the mechanical computer when it encounters an obstacle over a certain size. The inputs indicate the position of each roller (up/down) and the combination of inputs determines the appropriate maneuver to clear the obstacle. [Beardy Penguin] used Simulink to design the logic circuit, consisting of AND, OR, and NOT gates. The resulting 5-layer mechanical computer quickly ran into the limits of tolerances and friction, and the team eventually had trouble getting their design to work with the available input forces.

Due to the high-pressure atmosphere, an on-board wind turbine has long been proposed as a viable power source for a Venus rover. It wasn’t part of this project, so it was replaced with a comparable 40 W electric motor. The output from a logic circuit goes through a timing mechanism and into a planetary gearbox system. It changes output rotation direction by driving the planet gear carrier with the sun gear or locking it in a stationary position.

As with many undergraduate engineering projects, the physical results were mixed, but the educational value was immense. They got individual subsystems working, but not the fully integrated prototype. Even so, they received several awards for their project and even came third in an international Simulink challenge. It also allowed another team to continue their work and refine the subsystems. Continue reading “Clockwork Rover For Venus”

The Continuing Venusian Mystery Of Phosphine And Ammonia

The planet Venus is in so many ways an enigma. It’s a sister planet to Earth and also within relatively easy reach of our instruments and probes, yet we nevertheless know precious little about what is going on its surface or even inside its dense atmosphere. Much of this is of course due to planets like Mars getting all the orbiting probes and rovers scurrying around on its barren, radiation-blasted surface, but we had atmospheric probes descend through Venus’ atmosphere, so far to little avail. Back in 2020 speculation arose of phosphine being detected in Venus’ atmosphere, which caused both excitement and a lot of skepticism. Regardless, at the recent National Astronomy Meeting (NAM 2024) the current state of Venusian knowledge was discussed, which even got The Guardian to report on it.

In addition to phosphine, there’s speculation of ammonia also being detectable from Earth, both of which might be indicative of organic processes and thus potentially life. Related research has indicated that common amino acids essential to life on Earth would be stable even in sulfuric droplets like in Venus’ atmosphere. After criticism to the original 2020 phosphine article, [Jane S. Greaves] et al. repeated their observations based on feedback, although it’s clear that the observation of phosphine gas on Venus is not a simple binary question.

The same is true of ammonia, which if present in Venusian clouds would be a massive discovery, which according to research by [William Bains] and colleagues in PNAS could explain many curious observations in Venus’ atmosphere. With so much uncertainty with remote observations, it’s clear that the only way that we are going to answer these questions is with future Venus missions, which sadly remain rather sparse.

If there’s indeed life on Venus, it’ll have a while longer to evolve before we can go and check it out.

Amateur Estimates Of Venusian Day Using Arecibo Data

[Nathaniel Fairfield] aka [thandal] was curious about the actual rotation and axis tilt of Venus. He decided to spin up at GitHub Python repository to study the issue further, as one does. The scientific literature shows a wide range of estimates and variations for the planet’s rotation and axis tilt. He wondered if the real answer might be found in a publicly available set of uncalibrated delay-doppler images of Venus. These data were collected by the former Arecibo Observatory in Puerto Rico from 1988 through 2020.  [Thanda] observed that the planet’s rotation appears to be speeding up slightly, and furthermore, his estimates of the orbital axis were within 0.01 degrees of the International Astronomical Union’s (IAU) values. [Note: Venus is a bit confusing — one planetary rotation, 243 Earth days, is longer than its year, 225 Earth days].

Estimations of Venusian Orbital Period, [Thandal] Estimates in Green
Aligning and calibrating the raw data was no trivial task. You have to consider the radar’s (Earth’s) position and time, as well as Venus. Complicating the math even more, some times the radar was operated in a bistatic mode, with the Green Bank Telescope in West Virginia being the receiver.

There’s a lot of interesting signal processing going on here. The Doppler-delay data consists of images that are 8091×8092 array of complex values, has to be mapped onto the Venus geoid.  Then by using various surface features, one can compare their positions vs time and obtain an estimate of rotational speed and tilt. If these kinds of calculations interest you, be sure to check out [Thandal]’s summary report, and also take note of the poliastro Python astrodynamics library. Why is this important? One reason to better plan future missions.