Satellite Ground Station Upcycles Trash

While the term “upcycle” is relatively recent, we feel like [saveitforparts] has been doing it for a long time. He’d previously built gear to pick up low-Earth orbit satellites, but now wants to pick up geosynchronous birds which requires a better antenna. While his setup won’t win a beauty contest, it does seem to work, and saved some trash from a landfill, too. (Video, embedded below.)

Small dishes are cheap on the surplus market. A can makes a nice feedhorn using a classic cantenna design, although that required aluminum tape since the only can in the trash was a cardboard oatmeal carton. The tape came in handy when the dish turned out to be about 25% too small, as well.

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Putting Perseverance Rover’s View Into Satellite View Context

It’s always fun to look over aerial and satellite maps of places we know, seeing a perspective different from our usual ground level view. We lose that context when it’s a place we don’t know by heart. Such as, say, Mars. So [Matthew Earl] sought to give Perseverance rover’s landing video some context by projecting onto orbital imagery from ESA’s Mars Express. The resulting video (embedded below the break) is a fun watch alongside the technical writeup Reprojecting the Perseverance landing footage onto satellite imagery.

Some telemetry of rover position and orientation were transmitted live during the landing process, with the rest recorded and downloaded later. Surprisingly, none of that information was used for this project, which was based entirely on video pixels. This makes the results even more impressive and the techniques more widely applicable to other projects. The foundational piece is SIFT (Scale Invariant Feature Transform), which is one of many tools in the OpenCV toolbox. SIFT found correlations between Perseverance’s video frames and Mars Express orbital image, feeding into a processing pipeline written in Python for results rendered in Blender.

While many elements of this project sound enticing for applications in robot vision, there are a few challenges touched upon in the “Final Touches” section of the writeup. The falling heatshield interfered with automated tracking, implying this process will need help to properly understand dynamically changing environments. Furthermore, it does not seem to run fast enough for a robot’s real-time needs. But at first glance, these problems are not fundamental. They merely await some motivated people to tackle in the future.

This process bears some superficial similarities to projection mapping, which is a category of projects we’ve featured on these pages. Except everything is reversed (camera instead of video projector, etc.) making the math an entirely different can of worms. But if projection mapping sounds more to your interest, here is a starting point.

[via Dr. Tanya Harrison @TanyaOfMars]

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Sirius XM Satellite Failure A Reminder That Space Is Risky (And That Satellite Insurance Is A Thing)

It’s easy to imagine that once a spacecraft leaves Earth’s atmosphere and is in a stable orbit, the most dangerous phase of the mission is over. After all, that’s when we collectively close the live stream and turn our attentions back to terrestrial matters. Once the fire and fury of the launch is over with, all the excitement is done. From that point on, it’s just years of silently sailing through the vacuum of space. What’s the worst that could happen?

Unfortunately, satellite radio provider Sirius XM just received a harsh reminder that there’s still plenty that can go wrong after you’ve slipped Earth’s surly bonds. Despite a flawless launch in early December 2020 on a SpaceX Falcon 9 and a reportedly uneventful trip to its designated position in geostationary orbit approximately 35,786 km (22,236 mi) above the planet, their brand new SXM-7 broadcasting satellite appears to be in serious trouble.

Maxar Technologies, prime contractor for the SXM-7, says they’re currently trying to determine what’s gone wrong with the 7,000 kilogram satellite. In a statement, the Colorado-based aerospace company claimed they were focused on “safely completing the commissioning of the satellite and optimizing its performance.” But the language used by Sirius XM in their January 27th filing with the U.S. Securities and Exchange Commission was notably more pessimistic. No mention is made of bringing SXM-7 online, and instead, the company makes it clear that their existing fleet of satellites will be able to maintain service to their customers until a replacement can be launched.

So what happened, and more importantly, is there any hope for SXM-7? Neither company has released any concrete details, and given the amount of money on the line, there’s a good chance the public won’t get the full story for some time. But we can theorize a bit based on what we do know, and make some predictions about where things go from here.

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Japan To Launch Wooden Satellites

We may have wooden satellites in just a few years, according to an announcement this month by Kyoto University and Sumitomo Forestry, organizations whose combined roots go back 550 years.

Wood’s place in high-technology has a long track record. During World War 2, wooden boats were used for minesweepers, the Spruce Goose was designed to circumvent wartime material restrictions, and Britain’s plywood-built De Havilland Mosquito had a very low radar cross section. In this century, a man in Bosnia has even built a Volkswagen Beetle out of oak.

The newly-announced aerospace project, led by retired astronaut and engineer Prof Takao Doi, plans to launch satellites built from wood in order to reduce space debris and hazardous substances resulting from re-entry. We’re somewhat skeptical on the hazardous substances angle (and we’re not alone in this), but certainly as a way to help ensure complete burn up upon re-entry, wood is an interesting material. It also achieves a great strength to weight ratio and as a renewable resource it’s easy to source.

Prof Doi has been studying the use of wood in space for several years now. Back in 2017 he began basic research on the usability of timbers in space (pg 16), where his team experimented with coniferous (cedar and cypress) and hardwood (satinwood, magnolia, and zelkova) trees in vacuum environments. Based on successes, they predicted wooden satellite launches in the mid 2020s (their announcement this month said 2023). Sumitomo engineers have not released what kind of wood(s) will finally be used on the satellite.

You might remember Astronaut Doi from an experiment aboard the ISS where he successfully demonstrated flying a boomerang in space (video below), and he’s also discovered two supernovae in his spare time. We wish him good luck.

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Hackaday Links: November 15, 2020

Now that we drive around cars that are more like mobile data centers than simple transportation, there’s a wealth of data to be harvested when the inevitable crashes occur. After a recent Tesla crash on a California highway, a security researcher got a hold of the car’s “black box” and extracted some terrifying insights into just how bad a car crash can be. The interesting bit is the view of the crash from the Tesla’s forward-facing cameras with object detection overlays. Putting aside the fact that the driver of this car was accelerating up to the moment it rear-ended the hapless Honda with a closing speed of 63 MPH (101 km/h), the update speeds on the bounding boxes and lane sensing are incredible. The author of the article uses this as an object lesson in why Level 2 self-driving is a bad idea, and while I agree with that premise, the fact that self-driving had been disabled 40 seconds before the driver plowed into the Honda seems to make that argument moot. Tech or not, someone this unskilled or impaired was going to have an accident eventually, and it was just bad luck for the other driver.

Last week I shared a link to Scan the World, an effort to 3D-scan and preserve culturally significant artifacts and create a virtual museum. Shortly after the article ran we got an email from Elisa at Scan the World announcing their “Unlocking Lockdown” competition, which encourages people to scan cultural artifacts and treasures directly from their home. You may not have a Ming Dynasty vase or a Grecian urn on display in your parlor, but you’ve probably got family heirlooms, knick-knacks, and other tchotchkes that should be preserved. Take a look around and scan something for posterity. And I want to thank Elisa for the link to the Pompeiian bread that I mentioned.

The Defense Advanced Research Projects Agency (DARPA)has been running an interesting challenge for the last couple of years: The Subterranean (SubT) Challenge. The goal is to discover new ways to operate autonomously below the surface of the Earth, whether for mining, search and rescue, or warfare applications. They’ve been running different circuits to simulate various underground environments, with the most recent circuit being a cave course back in October. On Tuesday November 17, DARPA will webcast the competition, which features 16 teams and their autonomous search for artifacts in a virtual cave. It could make for interesting viewing.

If underground adventures don’t do it for you, how about going upstairs? LeoLabs, a California-based company that specializes in providing information about satellites, has a fascinating visualization of the planet’s satellite constellation. It’s sort of Google Earth but with the details focused on low-earth orbit. You can fly around the planet and watch the satellites whiz by or even pick out the hundreds of spent upper-stage rockets still up there. You can lock onto a specific satellite, watch for near-misses, or even turn on a layer for space debris, which honestly just turns the display into a purple miasma of orbiting junk. The best bit, though, is the easily discerned samba-lines of newly launched Starlink satellites.

A doorbell used to be a pretty simple device, but like many things, they’ve taken on added complexity. And danger, it appears, as Amazon Ring doorbell users are reporting their new gadgets going up in flame upon installation. The problem stems from installers confusing the screws supplied with the unit. The longer wood screws are intended to mount the device to the wall, while a shorter security screw secures the battery cover. Mix the two up for whatever reason, and the sharp point of the mounting screw can find the LiPo battery within, with predictable results.

And finally, it may be the shittiest of shitty robots: a monstrous robotic wolf intended to scare away wild bears. It seems the Japanese town of Takikawa has been having a problem with bears lately, so they deployed a pair of these improbable looking creatures to protect themselves. It’s hard to say what’s the best feature: the flashing LED eyes, the strobe light tail, the fact that the whole thing floats in the air atop a pole. Whatever it is, it seems to work on bears, which is probably good enough. Take a look in the video below the break.

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Tracking Satellites With A Commodore PET

A recent writeup by Tom Nardi about using the 6502-based NES to track satellites brought back memories of my senior project at Georgia Tech back in the early 80s.  At our club station W4AQL, I had become interested in Amateur Radio satellites.  It was quite a thrill to hear your signal returning from space, adjusting for Doppler as it speeds overhead, keeping the antennas pointed, all while carrying on a brief conversation with other Earth stations or copying spacecraft telemetry, usually in Morse code.

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Hackaday Links: September 27, 2020

Hardly a week goes by without a headline screaming about some asteroid or another making a close approach to Earth; it’s only by reading the fine print that we remember what an astronomer’s definition of “close” means. Still, 2020 being what it is, it pays to stay on top of these things, and when you do the story can get really interesting. Take asteroid 2020 SO, a tiny near-Earth asteroid that was discovered just last week. In a couple of weeks, 2020 SO will be temporarily captured into Earth orbit and come with 50,000 km near the beginning of December. That’s cool and all, but what’s really interesting about this asteroid is that it may not be a rock at all. NASA scientists have reverse-engineered the complex orbit of the object and found that it was in the vicinity of Earth in late 1966. They think it may be a Centaur booster from the Surveyor 2 moon mission, launched in September 1966 in the runup to Apollo. The object will be close enough for spectral analysis of its. surface; if it’s the booster, the titanium dioxide in the white paint should show up loud and clear.

Lasers are sort of forbidden fruit for geeks — you know you can put an eye out with them, and still, when you get your hands on even a low-power laser pointer, it’s hard to resist the urge to shine it where you shouldn’t. That includes into the night sky, which as cool as it looks could be bad news for pilots, and then for you. Luckily, friend of Hackaday Seb Lee-Delisle has figured out a way for you to blast lasers into the night sky to your heart’s content. The project is called Laser Light City and takes place in Seb’s home base of Brighton int he UK on October 1. The interactive installation will have three tall buildings with three powerful lasers mounted on each; a smartphone app will let participants control the direction, shape, and color of each beam. It sounds like a load of fun, so check it out if you’re in the area.

We got an interesting story from a JR Nelis about a quick hack he came up with to help his wife stay connected. The whole post is worth a read, but the short version of the story is that his wife has dementia and is in assisted living. Her landline phone is her social lifeline, but she can’t be trusted with it, lest she makes inappropriate calls. His solution was to modify her favorite cordless phone by modifying the keypad, turning it into a receive-only phone. It’s a sad but touching story, and it may prove useful to others with loved ones in similar situations.

We pay a lot of attention to the history of the early computer scene, but we tend to concentrate on computers that were popular in North America and the UK. But the Anglo-American computers were far from the only game in town, and there’s a new effort afoot to celebrate one of the less well-known but still important pioneer computers: the Galaksija. Aside from having a cool name, the Yugoslavian Z80 computer has a great story that will be told in documentary form, as part of the crowdsourced Galaksija project. The documentary stars our own Voja Antonic, who was key to the computer’s development. In addition to the film, the project seeks to produce a replica of the Galaksija in kit form. Check out the Crowd Supply page and see if it’s something you’re willing to back.

There’s an interesting new podcast out there: the Pick, Place, Podcast. Hosted by Chris Denney and Melissa Hough, it comes out every other week and is dedicated to the electronic assembly industry. They’ve currently got eight episodes in the can ranging from pick and place assembly to parts purchasing to solder paste printing. If you want to learn a little more about PCB assembly, this could be a real asset. Of course don’t forget to make time for our own Hackaday Podcast, where editors Mike and Elliot get together to discuss the week in hardware hacking.