For months before liftoff, the popular press had been hyping up the fact that the Polaris Dawn mission would include the first-ever private spacewalk. Not only would this be the first time anyone who wasn’t a professional astronaut would be opening the hatch of their spacecraft and venturing outside, but it would also be the first real-world test of SpaceX’s own extravehicular activity (EVA) suits. Whether you considered it a billionaire’s publicity stunt or an important step forward for commercial spaceflight, one thing was undeniable: when that hatch opened, it was going to be a moment for the history books.

But if you happened to have been watching the live stream of the big event earlier this month, you’d be forgiven for finding the whole thing a bit…abrupt. After years of training and hundreds of millions of dollars spent, crew members Jared Isaacman and Sarah Gillis both spent less than eight minutes outside of the Dragon capsule. Even then, you could argue that calling it a spacewalk would be a bit of a stretch.

Neither crew member ever fully exited the spacecraft, they simply stuck their upper bodies out into space while keeping their legs within the hatch at all times. When it was all said and done, the Dragon’s hatch was locked up tight less than half an hour after it was opened.

Likely, many armchair astronauts watching at home found the whole thing rather anticlimactic. But those who know a bit about the history of human spaceflight probably found themselves unable to move off of the edge of their seat until that hatch locked into place and all crew members were back in their seats.

Flying into space is already one of the most mindbogglingly dangerous activities a human could engage in, but opening the hatch and floating out into the infinite black once you’re out there is even riskier still. Thankfully the Polaris Dawn EVA appeared to go off without a hitch, but not everyone has been so lucky on their first trip outside the capsule.

A High Pressure Situation

The first-ever EVA took place during the Voskhod 2 mission in March of 1965. Through the use of an ingenious inflatable airlock module, cosmonaut Alexei Leonov was able to exit the Voskhod 3KD spacecraft and float freely in space at the end of a 5.35 m (17.6 ft) tether. He attached a camera to the outside of the airlock, providing a visual record of yet another space “first” achieved by the Soviet Union.

This very first EVA had two mission objectives, one of which Leonov had accomplished when he successfully rigged the external camera. The last thing he had to do was turn around and take pictures of the Voskhod spacecraft flying over the Earth — a powerful propaganda image that the USSR was eager to get their hands on. But when he tried to activate his suit’s camera using the trigger mounted to his thigh, he found he couldn’t reach it. It was then that he realized the suit had begun to balloon around him, and that moving his arms and legs was taking greater and greater effort due to the suit’s material stiffening.

After about ten minutes in space Leonov attempted to re-enter the airlock, but to his horror found that the suit had expanded to the point that it would no longer fit into the opening. As he struggled to cram himself into the airlock, his body temperature started to climb. Soon he was sweating profusely, which pooled around his body within the confines of the suit.

Unable to cope with the higher than anticipated internal temperature, the suit’s primitive life support system started to fail, making matters even worse. The runaway conditions in the suit caused his helmet’s visor to fog up, which he had no way to clear as he was now deep into a failure mode that the Soviet engineers had simply not anticipated. Not that they hadn’t provided him with a solution of sorts. Decades later, Leonov would reveal that there was a suicide pill in the helmet that he could have opted to use if need be.

With his core temperature now elevated by several degrees, Leonov was on the verge of heat stroke. His last option was to open a vent in his suit, which would hopefully cause it to deflate enough for him to fit inside the airlock. He noted that the suit was currently at 0.4 atmosphere, and started reducing the pressure. The safety minimum was 0.27 atm, but even at that pressure, he couldn’t fit. It wasn’t until the pressure fell to 0.25 atm that he was able to flex the suit enough to get his body back into the airlock, and from there back into the confines of the spacecraft.

In total, Alexei Leonov spent 12 minutes and 9 seconds in space. But it must have felt like an eternity.

Gemini’s Tricky Hatch

In classic Soviet style, nobody would know about the trouble Leonov ran into during his spacewalk for years. So when American astronaut Ed White was preparing to step out of the Gemini 4 capsule three months later in June of 1965, he believed he really had his work cut out for him. Not only had the Soviets pulled off a perfect EVA, but as far as anyone knew, they had made it look easy.

So it’s not hard to imagine how White must have felt when he pulled the lever to open the hatch on the Gemini spacecraft, only to find it refused to budge. As it so happens, this wasn’t the first time the hatch failed to open. During vacuum chamber testing back on the ground, the hatch had refused to lock because a spring-loaded gear in the mechanism failed to engage properly. Luckily the second astronaut aboard the Gemini capsule, James McDivitt, was present when they had this issue on the ground and knew how the latch mechanism functioned.

McDivitt felt confident that he could get the gear to engage and allow White to open the hatch, but was concerned about getting it closed. Failing to open the hatch and calling off the EVA was one thing, but not being able to secure the hatch afterwards meant certain death for the two men. Knowing that Mission Control would almost certainly have told them to abort the EVA if they were informed about the hatch situation, the astronauts decided to go ahead with the attempt.

As he predicted, McDivitt was able to fiddle with the latching mechanism and got the hatch open for White. Although there were some communication issues during the spacewalk due to problems with the voice-operated microphones, the EVA went very well, with White demonstrating a hand-held maneuvering thruster that allowed him to fly around the spacecraft at the end of his tether.

White was having such a good time that he kept making excuses to extend the spacewalk. Finally, after approximately 23 minutes, he begrudgingly returned to the Gemini capsule — informing Mission Control that it was “the saddest moment of my life.”

The hatch had remained open during the EVA, but now that White was strapped back into the capsule, it was time to close it back up. Unfortunately, just as McDivitt feared, the latches wouldn’t engage. To make matters worse, it took White so long to get back into the spacecraft that they were now shadowed by the Earth and working in the dark. Reaching blindly inside the mechanism, White was once again able to coax it into engaging, and the hatch was securely closed.

But there was still a problem. The mission plan called for the astronauts to open the hatch so they could discard unnecessary equipment before attempting to reenter the Earth’s atmosphere. As neither man was willing to risk opening the hatch again, they instead elected to stow everything aboard the capsule for the remainder of the flight.

Overworked, and Underprepared

At this point the Soviet Union and the United States had successfully conducted EVAs, but both had come dangerously close to disaster. Unfortunately, between the secretive nature of the Soviets and the reluctance of the Gemini 4 crew to communicate their issues to Mission Control, NASA administration started to underestimate the difficulties involved.

NASA didn’t even schedule EVAs for the next three Gemini missions, and the ambitious spacewalk planned for Gemini 8 never happened due to the mission being cut short due to technical issues with the spacecraft. It wouldn’t be until Gemini 9A that another human stepped out of their spacecraft.

The plan was for astronaut Gene Cernan to spend an incredible two hours outside of the capsule, during which time he would make his way to the rear of the spacecraft where a prototype Astronaut Maneuvering Unit (AMU) was stored. Once there, Cernan was to disconnect himself from the Gemini tether and don the AMU, which was essentially a small self-contained spacecraft in its own right.

But as soon as he left the capsule, Cernan reported that his suit had started to swell and that movement was becoming difficult. To make matters worse, there were insufficient handholds installed on the outside of the Gemini spacecraft, making it difficult for him to navigate his away along its exterior. After eventually reaching the AMU and struggling desperately to put it on, Mission Control noted his heart rate had climbed to 180 beats per minute. The flight surgeon was worried he would pass out, so Mission Control asked him to take a break while they debated if he should continue with the AMU demonstration.

At this point Cernan noted that his helmet’s visor had begun to fog up, and just as Alexei Leonov had discovered during his own EVA, the suit had no system to clear it up. The only way he was able to see was by stretching forward and clearing off a small section of the glass by rubbing his nose against it. Realizing the futility of continuing, Commander Thomas Stafford decided not to wait on Mission Control and ordered Cernan to abort the EVA and get back into the spacecraft.

Cernan slowly made his way back to the Gemini’s hatch. The cooling system in his suit had by now been completely overwhelmed, which caused the visor to fog up completely. Effectively blind, Cernan finally arrived at the spacecraft’s hatch, but was too exhausted to continue. Stafford held onto Cernan’s legs while he rested and finally regained the strength to lower himself into the capsule and close the hatch.

When they returned to Earth the next day, a medical examination revealed Cernan had lost 13 pounds (5.8 kg) during his ordeal. The close-call during his spacewalk lead NASA to completely reassess their EVA training and procedures, and the decision was made to limit the workload on all future Gemini spacewalks, as the current air-cooled suit clearly wasn’t suitable for long duration use. It wasn’t until the Apollo program introduced a liquid-cooled suit that American astronauts would spend any significant time working outside of their spacecraft.

The Next Giant Leap

Thanks to the magic of live streaming video, we know that the Polaris Dawn crew was able to complete their brief EVA without incident: no shadowy government cover-ups, cowboy heroics, or near death experiences involved.

With the benefit of improved materials and technology, not to mention the knowledge gained over the hundreds of spacewalks that have been completed since the early days of the Space Race, the first private spacewalk looked almost mundane in comparison to what had come before it.

But there’s still much work to be done. SpaceX needs to perform further tests of their new EVA suit, and will likely want to demonstrate that crew members can actually get work done while outside of the Dragon. So it’s safe to assume that when the next Polaris Dawn mission flies, its crew will do a bit more than just stick their heads out the hatch.

In an age where our gadgets allow us to explore the cosmos, we stumbled upon sounds from a future past: an article on historical signals from Mars. The piece, written by [Paul Gilster] of Centauri Dreams, cites a Times essay published by [Becky Ferreira] of August 20. [Ferreira]’s essay sheds light on a fascinating, if peculiar, chapter in the history of the search for extraterrestrial life.

She recounts an event from August 1924 when the U.S. Navy imposed a nationwide radio silence for five minutes each hour to allow observatories to listen for signals from Mars. This initiative aimed to capitalize on the planet’s close alignment with Earth, sparking intrigue and excitement among astronomers and enthusiasts alike.

Amid the technological optimism of the era, a dirigible equipped with radio equipment took to the skies to monitor potential Martian messages. The excitement peaked when a series of dots and dashes captured by the airborne antenna suggested a “crudely drawn face.” Some scientists speculated that this could be a signal from a Martian civilization, igniting a media frenzy. Yet, skeptics, including inventor C. Francis Jenkins, suggested these results were merely a case of radio frequency interference—an early reminder of the challenges we face in discerning genuine signals from the noise of our own planet.

As we tinker with our devices and dream of interstellar communication, the 1924 incident reminds us that the search for extraterrestrial intelligence is a blend of curiosity, creativity, and, often, misinterpretation.

The Voyager 2 spacecraft’s energy budget keeps dropping by about 4 Watt/year, as the plutonium in its nuclear power source is steadily dropping as the isotope decays. With 4 Watt of power less to use by its systems per year, the decision was made to disable the plasma spectrometer (PLS) instrument. As also noted by the NASA Voyager 2 team on Twitter, this doesn’t leave the spacecraft completely blind to plasma in the interstellar medium as the plasma wave subsystem (PWS) is still active. The PLS was instrumental in determining in 2018 that Voyager 2 had in fact left the heliosphere and entered interstellar space. The PLS on Voyager 1 had already broken down in 1980 and was turned off in 2007.

After saving the Voyager 1 spacecraft the past months from a dud memory chip and switching between increasingly clogged up thrusters, it was now Voyager 2’s turn for a reminder of the relentless march of time and the encroaching end of the Voyager missions. Currently Voyager 2 still has four active instruments, but by the time the power runs out, they’ll both be limping along with a single instrument, probably somewhere in the 2030s if their incredible luck holds.

This incredible feat was enabled both by the hard work and brilliance of the generations of teams behind the two spacecraft, who keep coming up with new tricks to save power, and the simplicity of the radioisotope generators (RTGs) which keep both Voyagers powered and warm even in the depths of interstellar space.

The International Space Station (ISS) might not be breaking news, but this February, National Geographic released a documentary that dives into the station’s intricate engineering. It’s a solid reminder of what human ingenuity can achieve when you put a team of engineers, scientists, and astronauts together. While the ISS is no longer a new toy in space, for hackers and tinkerers, it’s still one of the coolest and most ambitious projects ever. And if you’re like us—always looking for fresh inspiration—you’ll want to check this one out.

The ISS is a masterpiece, built piece by piece in space, because why make things easy? With 16 pressurized modules, it’s got everything needed to keep humans alive and working in one of the harshest environments imaginable. Add in the $150 billion price tag (yes, billion), and it’s officially the most expensive thing humans have ever built. What makes it especially interesting to us hackers is its life support systems—recycling water, generating oxygen, and running on solar power. That’s the kind of closed-loop system we love to experiment with down here on Earth. Imagine the implications for long-term sustainability!

But it’s not just a survival bunker in space. It’s also a global science lab. The ISS gives researchers the chance to run experiments that could never happen under Earth’s gravity—everything from technology advancements to health experiments. Plus, it’s our testing ground for future missions to Mars. If you’re fascinated by the idea of hacking complex systems, or just appreciate a good build, the ISS is a dream project.

Catch the documentary and dive into the world of space-grade hacking. The ISS may be orbiting out of sight, but for those of us looking to push the boundaries of what’s possible, it’s still full of inspiration.

Thanks a lot, Elon. Or maybe not, depending on how this report that China used Starlink signals to detect low-observable targets pans out. There aren’t a lot of details, and we couldn’t find anything approximating a primary source, but it seems like the idea is based on forward scatter, which is when waves striking an object are deflected only a little bit. The test setup for this experiment was a ground-based receiver listening to the downlink signal from a Starlink satellite while a DJI Phantom 4 Pro drone was flown into the signal path. The drone was chosen because nobody had a spare F-22 or F-35 lying around, and its radar cross-section is about that of one of these stealth fighters. They claim that this passive detection method was able to make out details about the drone, but as with most reporting these days, this needs to be taken with an ample pinch of salt. Still, it’s an interesting development that may change things up in the stealth superiority field.

Another week, another example of how the fine print on the EULA is never your friend. This time around it’s the popular Wyze security cameras, where there’s an unconfirmed report that a recent firmware update nerfed the “Recording Cooldown” setting menu, making the option to have no cooldown period between recording a paid feature. As we understand it, Wyze cameras previously had a cooldown feature, intended to keep the camera from overheating or killing the battery if the motion sensor detects a lot of continual movement. But it looks like earlier firmware revs allowed users to bypass the default five-minute period between recordings, a reasonable choice for anyone using these as security cameras. Now, bypassing the cooldown seems to require a paid subscription. We have to stress that we don’t know anything beyond this one unconfirmed report, but this enshittification is certainly something we’ve seen before, so it at least rings true, and it seems like another solid example of the fact that with cheap IoT appliances, you never truly own your stuff.

We hate to be the bearers of bad news — well, that might be a stretch given the two articles above — but this is really the kind of news we hate to hear. The Eugene Makerspace in Eugene, Oregon, suffered a major fire in their community shop on September 15. Judging by the pictures, the place was pretty thoroughly destroyed, and the fact that it was an early morning fire probably contributed to the lack of injuries. Their GoFundMe campaign is doing pretty well, but they could certainly use some help getting back on their feet. If you’re in a position to contribute, we’re sure they’d appreciate it.

When it comes to OpenAI’s newest AI model, you’d better watch what you think — or rather, you’d better not think too much about how the model thinks. Trying to get inside the model’s “head” is apparently against the terms of service, with users getting nastygrams from OpenAI warning them to step off. The “Strawberry” AI model has a feature that lets users have a glimpse into the “chain of thought” used to answer a question or complete a task, which on the face of it seems to be exactly what they don’t want users to do. But the chain of thought is only a hand-waving summary of the raw thought process, filtered through a separate AI model. This is what OpenAI doesn’t want people probing, and any attempts at engineering tricky prompts to reveal the raw chain of thought will potentially get you banned.

And finally, although motorsports aren’t really our thing, we have to admit a certain sense of awe at this video that exposes some of the extreme engineering that goes into top fuel drag racing. Specifically, this video concentrates on drag racing, where nitromethane-fueled engines-on-wheels scream down a quarter-mile track in less than four seconds. Everything about this sport is extreme, especially the engines, which run themselves almost to death for the few seconds they are under full power. The video is packed full of tidbits that boggle the mind, such as these engines burning out their sparkplugs about halfway through the course, with the engine continuing to run in diesel mode thanks to the high compression and temperatures. Drivers experience a brain-squishing 8 g of acceleration during a run, which consumes over 30 gallons of fuel and exerts so much force on the engine that the connecting rods get compressed. The supercharger alone takes 800 horsepower to run, and yet the engine still produces enough power that the car is going 60 miles per hour before it covers its own length. Oh, and that ridiculous exhaust plume? That’s raw fuel that is purposely left unburned until it escapes the exhaust tips, which are angled to provide additional down-force to make sure as much torque as possible gets from the tires to the track. Enjoy!

As anyone who’s looked at the sky just before dawn or right after dusk can confirm, for the last seventy years or so there have been all kinds of artificial satellites floating around in low-Earth orbit that are visible to the naked eye. Perhaps the most famous in the last few decades is the International Space Station, but there are all kinds of others up there from amateur radio satellites, the Starlink constellation, satellite TV, and, of course, various spy satellites from a few of the world’s governments. [Felix] seems to have found one and his images of it can be found here.

[Felix] has been taking pictures of the night sky for a while now, including many different satellites. While plenty of satellites publish their paths to enable use, spy satellites aren’t generally public record but are still able to be located nonetheless. He uses a large Dobsonian telescope to resolve the images of several different satellites speculated to be spy satellites, with at least one hosting a synthetic aperture radar (SAR) system. His images are good enough to deduce the size and shape of the antennas used, as well as the size of the solar panels on board.

As far as being concerned about the ramifications of imaging top-secret technology, [Felix] is not too concerned. He states that it’s likely that most rival governments would be able to observe these satellites with much more powerful telescopes that he has, so nothing he has published so far is likely to be a surprise to anyone. Besides, these aren’t exactly hidden away, either; they’re up in the sky for anyone to see. If you want to take a shot at that yourself you can get a Dobsonian-like telescope mostly from parts at Ikea, and use a bit of off-the-shelf electronics to point them at just the right position too.

NASA’s ACS3 (Advanced Composite Solar Sail System) is currently fully deployed in low Earth orbit, and stargazers can spot it if they know what to look for. It’s actually one of the brightest things in the night sky. When the conditions are right, anyway.

What conditions are those? Orientation, mostly. ACS3 is currently tumbling across the sky while NASA takes measurements about how it acts and moves. Once that’s done, the spacecraft will be stabilized. For now, it means that visibility depends on the ACS’s orientation relative to someone on the ground. At it’s brightest, it appears as bright as Sirius, the brightest star in the night sky.

ACS3 is part of NASA’s analysis and testing of solar sail technology for use in future missions. Solar sails represent a way of using reflected photons (from sunlight, but also possibly from a giant laser) for propulsion.

This perhaps doesn’t have much in the way of raw energy compared to traditional thrusters, but offers low cost and high efficiency (not to mention considerably lower complexity and weight) compared to propellant-based solutions. That makes it very worth investigating. Solar sail technology aims to send a probe to Alpha Centauri within the next twenty years.

Want to try to spot ACS3 with your own eyes? There’s a NASA app that can alert you to sighting opportunities in your local time and region, and even guide you toward the right region of the sky to look. Check it out!

With all the recent attention on Mars and the search for evidence of ancient life there, it’s easy to forget that not only has the Red Planet been under the figurative microscope since the early days of the Space Race, but we went to tremendous effort to send a pair of miniaturized biochemical laboratories there back in 1976. While the results were equivocal, it was still an amazing piece of engineering and spacefaring, one that [Marb] has recreated with this Earth-based version of the famed Viking “Labeled Release” experiment.

The Labeled Release experimental design was based on the fact that many metabolic processes result in the evolution of carbon dioxide gas, which should be detectable by inoculating a soil sample with a nutrient broth laced with radioactive carbon-14. For this homage to the LR experiment, [Marb] eschewed the radioactive tracer, instead looking for a relative increase in the much lower CO₂ concentration here on Earth. The test chamber is an electrical enclosure with a gasketed lid that holds a petri dish and a simple CO₂ sensor module. Glands in the lid allow an analog for Martian regolith — red terrarium sand — and a nutrient broth to be added to the petri dish. Once the chamber was sterilized, or at least sanitized, [Marb] established a baseline CO₂ level with a homebrew data logger and added his sample. Adding the nutrient broth — a solution of trypsinized milk protein, yeast extract, sugar, and salt — gives the bacteria in the “regolith” all the food they need, which increases the CO₂ level in the chamber.

More after the break…

[Marb]’s results are not surprising by any means, but that’s hardly the point. This is just a demonstration of the concept of the LR experiment, one that underscores the difficulties of doing biochemistry on another planet and the engineering it took to make it happen. Compared to some of the instruments rolling around Mars today, the Viking experiments seem downright primitive, and the fact that they delivered even the questionable data they did is pretty impressive.

Sometimes there’s nothing more rewarding than pulling apart an old piece of hardware of mysterious origin. [saveitforparts] does just that, and recently came across a curious satellite system from a surplus store. What else could he do, other than tear it down and try to get it humming? 

The device appeared to be satellite communication device for a tracking unit of some sort, complete with a long, thick proprietary cable. That led to a junction box with a serial port and an RJ45 port, along with some other interfaces. Disassembly of the unit revealed it contained a great deal of smarts onboard, including some kind of single-board computer. Comms-wise, it featured a cellular GPRS interface as well as an Orbcomm satellite modem. It also packed in GPS, WiFi, Xbee, Ethernet, and serial interfaces. It ultimately turned out to be a Digi ConnectPort X5 device, used as a satellite tracking system for commercial trucks.

What’s cool is that the video doesn’t just cover pulling it apart. It also dives into communicating with the unit. [saveitforparts] was able to power it up and, using the manufacturer’s software, actually talk to the device. He even found the web interface and tested the satellite modem.

Ultimately, this is the kind of obscure industry hardware that most of us would never come into contact with during our regular lives. It’s neat when these things show up on the secondary market so hackers can pull them apart and see what makes them tick. Video after the break.

After 47 years it’s little wonder that the hydrazine-powered thrusters of the Voyager 1, used to orient the spacecraft in such a way that its 3.7 meter (12 foot) diameter antenna always points back towards Earth, are getting somewhat clogged up. As a result, the team has now switched back to the thrusters which they originally retired back in 2018. The Voyager spacecraft each have three sets (branches) of thrusters. Two sets were originally intended for attitude propulsion, and one for trajectory correction maneuvers, but since leaving the Solar System many years ago, Voyager 1’s navigational needs have become more basic, allowing all three sets to be used effectively interchangeably.

The first set was used until 2002, when clogging of the fuel tubes was detected with silicon dioxide from an aging rubber diaphragm in the fuel tank. The second set of attitude propulsion thrusters was subsequently used until 2018, until clogging caused the team to switch to the third and final set. It is this last set that is now more clogged then the second set, with the fuel tube opening reduced from about 0.25 mm to 0.035 mm. Unlike a few decades ago, the spacecraft is much colder due energy-conserving methods, complicating the switching of thruster sets. Switching on a cold thruster set could damage it, so it had to be warmed up first with its thruster heaters.

The conundrum was where to temporarily borrow power from, as turning off one of the science instruments might be enough to not have it come back online. Ultimately a main heater was turned off for an hour, allowing the thruster swap to take place and allowing Voyager 1 to breathe a bit more freely for now.

Compared to the recent scare involving Voyager 1 where we thought that its computer systems might have died, this matter probably feels more routine to the team in charge, but with a spacecraft that’s the furthest removed man-made spacecraft in outer space, nothing is ever truly routine.

[Joe Barnard] made a solid propellant rocket motor, and as one does in such situations, he put it through its paces on the test stand. The video below is not about the test, nor is it about the motor’s construction. Rather, it’s a deconstruction of the remains of the motor in order to better understand its design, and it’s pretty interesting stuff.

Somewhere along the way, [Joe], aka “BPS.Space” on YouTube, transitioned from enthusiastic model rocketeer to full-fledged missile-man, and in the process stepped up his motor game considerably. The motor that goes under the knife — or rather, the bandsaw — in this video is his “Simplex V2,” a completely DIY build of [Joe]’s design. For scale, the casing is made from a 6″ (15 cm) diameter piece of aluminum tubing over a meter in length, with a machined aluminum forward closure and a composite nozzle assembly. This is a pretty serious piece of engineering.

The closure and the nozzle are the focus of the video, which makes sense since that’s where most of the action takes place. To understand what happened during the test, [Joe] lopped them off and cut them roughly in half longitudinally. The nozzle throat, which was machined from a slug of graphite, fared remarkably well during the test, accumulating only a little slag from the propellant, a combination of powdered aluminum, ammonium perchlorate, and HTBP resin. The lower part of the nozzle, made from phenolic-impregnated linen, did pretty well too, building up a pyrolyzed layer that acted much like a space capsule’s ablative heat shield would. The forward closure, whose sole job is to contain the inferno and direct the exhaust anywhere but up, took more of a beating but stood up to the challenge. Especially interesting was the state of the O-rings and the way that the igniter interfaced with the closure.

Post mortems like these are valuable teaching tools, and while it must be heartbreaking to destroy something you put so much work into, you can’t improve what you can’t measure. Hats off to [Joe] for the peek inside his world.

There was a time when building a telescope was a rite of passage for budding astronomers, much as building a radio was the coming age for electronics folks. These days, many things are cheaper to buy than build, even though we do enjoy building anything we can. Orion was a big name in telescopes for many years. Their parent company also owned Meade and Coronado, both well-known optical brands. A recent video from [Reflactor] brought it to our attention that Orion abruptly ceased operations on July 9th.

We always hate to hear when well-known brands that serve a big part of our community vanish. According to [Reflactor], people who have telescopes with the company for repair are likely to never see them again. [Dylan O’Donnell] also had a video about it (see below), and, as he notes, at that time, the website was still operating, but it’s gone now. To add further fuel to the fire Sky & Telescope ran an article on July 12th saying that Meade was also on the chopping block, although at the time of this writing, their site is still online.

You have to wonder what problems you might have selling telescopes today. Many people live where there is light pollution. We’d like to think there are still people who want to ponder the universe from their backyard, though.

There are still people selling telescopes, so presumably, one of them — maybe Celestron — will take up the slack. Or maybe we’ll see a resurgence in telescope homebrewing.

After all, if you have a 3D printer, you could make a 900 mm telescope on a tight budget. Or, try IKEA.

The European Space Agency (ESA) is showing 3D-printed metal parts made onboard the International Space Station using a printer and materials the agency sent earlier this year.  While 3D printing onboard the ISS is nothing new, the printing of metal parts in space is an important advancement. The agency’s goals are to be able to produce more tools and spares in situ rather than having to rely on resupply missions. An ambitious idea being pitched is to use captured space debris as input as well, which would further decrease the ISS’s dependence on Earth and expensive cargo runs from the bottom of the gravity well.

The 180 kg 3D printer lives in the European Drawer Rack Mark II inside ESA’s Columbus module. Controllers on Earth managed the printing process after installation. The printer ran for about four hours a day, with each layer inspected before continuing. This means the printing process took days, but running the machine continuously would, of course, cut printing time significantly.

The printer uses stainless steel wire that is fed to the printing location, where a laser melts it. As the pool of molten metal moves away from the laser-heated spot, it solidifies like plastic does in a regular FDM printer. Of course, with the melting point of stainless steel being around 1400 °C, it runs a lot hotter and thus requires that the printer to be inside a completely sealed box, with the atmosphere inside vented into space and replaced with nitrogen prior to starting the printing process. The presence of oxygen would totally ruin the print.

We badly want a practical metal printer for home use, but, so far, they remain out of reach. When you do get them, you might consider that there are different design rules for metal-printed parts.

We’re guessing most readers can cite things from their youth which gave them an interest in technology, and spurred on something which became a career or had a profound impact on their life. Public engagement activities for technology or science have a crucial role in bringing forth the next generations of curious people into those fields, and along the way they can provide some fun for grown-ups too.

A case in point is from NASA’s Landsat engagement team, Your Name In Landsat. Type in a text string, and it will spell it out in Earth features seen by the imaging satellites, that resemble letters. Endless fun can be had by all, as the random geology flashes by.

In itself, though fun, it’s not quite a hack. But behind the kids toy we’re curious as to how the images were identified, and mildly sad that the NASA PR people haven’t seen fit to tell us. We’re guessing that over the many decades of earth images there exists a significant knowledge base of Earth features with meaningful or just amusing shapes that will have been gathered by fun-loving engineers, and it’s possible that this is what informed this feature. But we’d also be curious to know whether they used an image classification algorithm instead. There must be a NASA employee or two who reads Hackaday and could ask around — let us know in the comments.

Meanwhile, if LANDSAT interests you, it’s possible to pull out of the air for free.

Imagine: you spent years training for a sojourn to the Moon, flew there on top of a Saturn V rocket as part of Apollo 16, to ultimately land on the lunar surface. You then spend the next few days on the surface, walking and skipping across the lunar regolith while setting up experiments and exploring per your mission assignments. Then, you pack everything up and blast off from the lunar surface to the orbiting command module before returning to Earth and a hero’s welcome. Then, decades later, you are told to your face that none of that ever happened. That’s the topic of a recent interview which [Jack Gordon] recently did with astronaut [Charles Duke].

None of these ‘arguments’ provided by the reality-denying crowd should be too shocking or feel new, as they range from the amount of fuel required to travel to the moon (solved by orbital mechanics) to the impossibility of lighting on the Moon (covered by everyone and their dog, including the Mythbusters in 2008).

Of course, these days, we have lunar orbiters (LRO and others) equipped with powerful cameras zoomed in on the lunar surface, which have photographed the Apollo landing sites with the experiments and footsteps still clearly visible. Like today’s crowd of spherical Earth deniers, skeptics will denounce anything that doesn’t fit their ill-conceived narrative as ‘faked’ for reasons that only exist in their fevered imaginations.

A common objection we’ve heard is that if we went to the moon back then, why haven’t we been back? The reason is obvious: politics. The STS (Shuttle) project sucked up all funding and the USSR collapsed. Only recently has there been a new kind of ‘space race’ in progress with nations like China. That doesn’t keep countless individuals from dreaming up lunar landing conspiracy theories to file away with their other truth nuggets, such as how microwaved and genetically engineered foods cause cancer, vaccines are another government conspiracy to control the population, and nuclear power plants can explode like nuclear bombs.

Perhaps the best takeaway is that even if we have not found intelligent life outside Earth yet, for at least a few years, intelligent life was the only kind on Earth’s Moon. We wish [Charles Duke] many happy returns, with maybe a casual return to the Moon in the near future as well, to frolic once more on the lunar surface.

Not that there hasn’t been a moon hoax, just not lately. If you want to watch the old Apollo video, it has been improved in recent years.

There may not be many radio astronomy printouts that have achieved universal fame, but the one from Ohio State University’s Big Ear telescope upon which astronomer [Jerry R. Ehman] wrote “WOW!” is definitely one of them. It showed an intense one-off burst that defied attempts to find others like it, prompting those who want to believe to speculate that it might have been the product of an extraterrestrial civilization. Sadly for them the Planetary Habitability Laboratory at the University of Puerto Rico at Arecibo has provided an explanation by examining historical data from the Arecibo telescope.

The radio signal in question lay on the hydrogen line frequency at 1420 MHz, and by looking at weaker emissions from cold hydrogen clouds they suggest that the WOW! signal may have come from a very unusual stimulation of one of these clouds. A magnetar is a type of neutron star which can create an intense magnetic field, and their suggestion is that Big Ear was in the lucky position of being in the right place at the right time to see one of these through a hydrogen cloud. The field would excite the hydrogen atoms to maser-like emission of radiation, leading to the unexpected blip on that printout.

There’s a question as to whether speculation about aliens is helpful to the cause of science, but in answer to that we’d like to remind readers that we wouldn’t be talking about magnetars now without it, and that the WOW! signal was in fact part of an early SETI experiment. Better keep on searching then!

Meanwhile readers with long memories will recollect us looking at the WOW! signal before.

Recently Canada’s Canadarm2 caught its 50th spacecraft in the form of a Northrop Grumman Cygnus cargo vessel since 2009. Although perhaps not the most prominent part of the International Space Station (ISS), the Canadarm2 performs a range of very essential functions on the outside of the ISS, such as moving equipment around and supporting astronauts during EVAs.

Officially called the Space Station Remote Manipulator System (SSRMS), it is part of the three-part Mobile Servicing System (MSS) that allows for the Canadarm2 and the Dextre unit to scoot around the non-Russian part of the ISS, attach to Power Data Grapple Fixtures (PDGFs) on the ISS and manipulate anything that has a compatible Grapple Fixture on it.

Originally the MSS was not designed to catch spacecraft when it was installed in 2001 by Space Shuttle Endeavour during STS-100, but with the US moving away from the Space Shuttle to a range of unmanned supply craft which aren’t all capable of autonomous docking, this became a necessity, with the Japanese HTV (with grapple fixture) becoming the first craft to be caught this way in 2009. Since the Canadarm2 was originally designed to manipulate ISS modules this wasn’t such a major shift, and the MSS is soon planned to also started building new space stations when the first Axiom Orbital Segment is launched by 2026. This would become the Axiom Station.

With the Axiom Station planned to have its own Canadarm-like system, this will likely mean that Canadarm2 and the rest of the MSS will be decommissioned with the rest of the ISS by 2031.

Top image: Canadarm2 captures Cygnus OA-5 S.S. Alan Poindexter in late 2016 (Credit: NASA)

One of the most sought after substances in the Universe is water – especially in its liquid form – as its presence on a planet makes the presence of life (as we know it) significantly more likely. While there are potentially oceans worth of liquid water on e.g. Jupiter’s moon Europa, for now Mars is significantly easier to explore as evidenced by the many probes which we got onto its surface so far. One of these was the InSight probe, which was capable of a unique feat: looking inside the planet’s crust with its seismometer to perform geophysical measurements. These measurements have now led to the fascinating prospect that liquid water may in fact exist on Mars right now, according to a paper published by [Vashan Wright] and colleagues in PNAS (with easy-read BBC coverage).

InSight’s mission lasted from November 2018 to December 2022 by which time too much dust had collected on its solar panels and communication was lost. During those active years it had used its seismometer (SEIS) to use the vibrations from natural marsquakes and similar to map the internals of the planet. Based on rock physics models and the data gathered by InSight, there is a distinct possibility that significant liquid water may exist in Mars’ mid-crust, meaning at a depth of about 11.5 to 20 km. Most tantalizing here is perhaps that at these depths, more liquid water may exist today than may have filled Mars’ past oceans.

Since we’re talking about just a single lander with a single instrument in a single location, it would be highly presumptuous to draw strong conclusions, and at these depths we would have no means to access it. Even so, it would offer interesting ideas for future Mars missions, not to mention underground Mars bases.