Hackaday Links: May 11, 2025

May 11, 2025 by Dan Maloney 6 Comments

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.

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Hackaday Links: May 4, 2025

May 4, 2025 by Dan Maloney 13 Comments

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.

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Dwingeloo telescope with sun shining through

Dwingeloo To Venus: Report Of A Successful Bounce

March 28, 2025 by Heidi Ulrich 14 Comments

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

October 26, 2024 by Danie Conradie 28 Comments

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

July 19, 2024 by Maya Posch 18 Comments

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

July 23, 2023 by Chris Lott 7 Comments

[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.

Hackaday Links: July 31, 2022

July 31, 2022 by Dan Maloney 12 Comments

Don’t look up! As of the time of this writing, there’s a decent chance that a Chinese Long March 5B booster has already completed its uncontrolled return to Earth, hopefully safely. The reentry prediction was continually tweaked over the last week or so, until the consensus closed in on 30 Jul 2022 at 17:08 UTC, give or take an hour either way. That two-hour window makes for a LOT of uncertainty about where the 25-ton piece of space debris will end up. Given the last prediction by The Aerospace Corporation, the likely surface paths cover a lot of open ocean, with only parts of Mexico and South America potentially in the crosshairs, along with parts of Indonesia. It’s expected that most of the material in the massive booster will burn up in the atmosphere, but with the size of the thing, even 20% making it to the ground could be catastrophic, as it nearly was in 2020.

[Update: US Space Command confirms that the booster splashed down in the Indian Ocean region at 16:45 UTC. No word yet on how much debris survived, or if any populated areas were impacted.]

Good news, everyone — thanks to 3D printing, we now know the maximum height of a dive into water that the average human can perform without injury. And it’s surprisingly small — 8 meters for head first, 12 meters if you break the water with your hands first, and 15 meters feet first. Bear in mind this is for the average person; the record for surviving a foot-first dive is almost 60 meters, but that was by a trained diver. Researchers from Cornell came up with these numbers by printing models of human divers in various poses, fitting them with accelerometers, and comparing the readings they got with known figures for deceleration injuries. There was no mention of the maximum survivable belly flop, but based on first-hand anecdotal experience, we’d say it’s not much more than a meter.

Humans have done a lot of spacefaring in the last sixty years or so, but almost all of it has been either in low Earth orbit or as flybys of our neighbors in the Sol system. Sure we’ve landed plenty of probes, but mostly on the Moon, Mars, and a few lucky asteroids. And Venus, which is sometimes easy to forget. We were reminded of that fact by this cool video of the 1982 Soviet landing of Venera 14, one of only a few attempts to land on our so-called sister planet. The video shows the few photographs Venera 14 managed to take before being destroyed by the heat and pressure on Venus, but the real treat is the sound recording the probe managed to make. Venera 14 captured the sounds of its own operations on the Venusian surface, including what sounds like a pneumatic drill being used to sample the regolith. It also captured, as the narrator put it, “the gentle blow of the Venusian wind” — as gentle as ultra-dense carbon dioxide hot enough to melt lead can be, anyway.

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