Not All SpaceX Software Goes To Space

June 1, 2021 by Roger Cheng 13 Comments

SpaceX has always been willing to break from aerospace tradition if they feel there’s a more pragmatic solution. Today this is most visible in their use of standard construction equipment like cranes in their Starship development facility. But the same focus on problem solving can also be found in their software parts we don’t see. Recently we got two different views behind the scenes. First, a four-part series about “software in space” published by StackOverflow blog, followed quickly by an Ask Me Anything (AMA) session on SpaceX Reddit.

Some of the StackOverflow series cover ground that has been previously discussed. Mostly in the first part dealing with their workhorse Falcon and Dragon vehicles, and some in the second part discussing Starlink whose beta program is reaching more and more people. Both confirmed that spaceflight software has to meet very stringent requirements and are mostly close to the metal bespoke C++ code. But we receive fascinating new information in part three, which focuses on code verification and testing. Here they leverage a lot of open source infrastructure more common to software startups than aerospace companies. The fourth and final component of this series covers software to support SpaceX hardware manufacturing, which had been rarely discussed before this point. (Unfortunately, there was nothing about how often SpaceX software developers copy and paste code from StackOverflow.)

The recent Reddit AMA likewise had some overlap with the SpaceX software AMA a year ago, but there were new information about SpaceX work within the past year. There was Crew Dragon’s transition from a test to an operational vehicle, and the aforementioned Starship development program. Our comments section had a lot of discussion about the practicality of touchscreen interfaces in real spacecraft, and here we learn SpaceX put a lot of study into building something functional and effective.

It also showed us that essentially every Sci-Fi Movie Interface was unrealistic and would be unreadable under extreme conditions.

In the course of this research, they learned a lot of pitfalls about fictional touch interfaces. Though to be fair, movie and television spacecraft UI are more concerned about looking cool than being useful.

If the standard AMA format is not to your liking, one of the contributors compiled all SpaceX answers alongside their related questions in a much more readable form here. And even though there’s an obvious recruiting side to these events, we’re happy to learn more about how SpaceX have continued to focus on getting the job done instead of rigidly conforming to aerospace tradition. An attitude that goes all the way back to the beginning of this company.

Starlink: A Review And Some Hacks

May 24, 2021 by Jonathan Bennett 129 Comments

I could probably be described as a SpaceX enthusiast. I catch their launches when I can, and I’ve watched the development of Starship with great interest. But the side-effect of SpaceX’s reusable launch system is that getting to space has become a lot cheaper. Having excess launch capacity means that space projects that were previously infeasible become suddenly at least plausible. One of those is Starlink.

Starlink is SpaceX’s satellite Internet service. Wireless and cellular internet have helped in some places, but if you really live out in the sticks, satellite internet is your only option. And while satellite Internet isn’t exactly new, Starlink is a bit different. Hughesnet, another provider, has a handful of satellites in geostationary orbit, which is about 22,000 miles above the earth. To quote Grace Hopper, holding a nearly foot-long length of wire representing a nanosecond, “Between here and the satellite, there are a very large number nanoseconds.”

SpaceX opted to do something a bit different. In what seemed like an insane pipe dream at the time, they planned to launch a satellite constellation of 12,000 birds, some of them flying as low as 214 mile altitude. The downside of flying so low is that they won’t stay in orbit as long, but SpaceX is launching them significantly faster than they’re coming down. So far, nearly 1,600 Starlink satellites are in orbit, in a criss-crossing pattern at 342 miles (550 km) up.

This hundred-fold difference in altitude matters. A Hughesnet connection has a minimum theoretical latency of 480 ms, and in reality runs closer to 600 ms. Starlink predicts a theoretical minimum of under 10 ms, though real-world performance isn’t quite that low yet. In the few weeks I’ve had the service, ping times have fallen from mid-60s down to 20s and 30s. The way Starlink works right now, data goes up to the closest satellite and directly back to the connected ground station. The long-term plan is to allow the satellites to talk directly to each other over laser links, skipping over the ground stations. Since the speed of light is higher in a vacuum than in a fiber-optic cable, the fully deployed system could potentially have lower latency than even fiber Internet, depending on the location of the endpoint and how many hops need to be made.

I got a Starlink setup, and have been trying out the beta service. Here’s my experience, and a bonus hack to boot.

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Google Loon’s Internet Balloons Come Back To Earth After A Decade In The Stratosphere

January 28, 2021 by Maya Posch 47 Comments

After a journey of a decade, what started as Project Loon by Google is no more. Promoted as a way to bring communications to the most remote parts of the globe, it used gigantic, high-altitude balloons equipped with communication hardware for air to ground, as well as air to air communication, between individual balloons. Based around LTE technology, it would bring multiple megabit per second data links to both remote areas and disaster zones.

Seven years into its development, Loon became its own company (Loon LLC), and would provide communications to some areas of Kenya, in addition to Sri Lanka in 2015 and Puerto Rico in 2017 after Hurricane Maria. Three years later, in January of 2021, it was announced that Loon LLC would be shutting down operations. By that point it had become apparent that the technology would not be commercially viable, with alternatives including wired internet access having reduced the target market.

While the idea behind Loon sounds simple in theory, it turns out that it was more complicated than just floating up some weather balloon with LTE base stations strapped to them.

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Starlink Satellite Dish X-Rayed To Unlock RF Magic Inside

January 11, 2021 by Tom Nardi 15 Comments

When [Kenneth Keiter] took apart his Starlink dish back in November, he did his best to explain the high-level functionality of the incredibly complex device in a video posted to his YouTube channel. It was a fascinating look at the equipment, but by his own admission, he wasn’t the right person to try and explain the nuances of how the phased array actually functioned. But he knew who could do the technology justice, which is why he shipped the dismembered dish over to [Shahriar Shahramian] of The Signal Path.

Don’t be surprised if you can’t quite wrap your head around his detailed analysis after your first viewing. You’ll probably have a few lingering questions after the second re-watch as well. But that’s OK, as [Shahriar] still has a few of his own. Even after cutting out a section of the dish and putting it under an X-ray, it’s still not completely clear how the SpaceX engineers managed to cram everything into such a tidy package. Though there seems to be no question that the $500 price for the early-access hardware is an absolute steal, all things considered.

The layered antenna works on multiple frequencies.

Most of the video is spent examining the stacked honeycomb construction of the phased antenna array, which as expected, holds a number of RF secrets if you know what to look for. Put simply, there’s no such thing as an insignificant detail to the trained eye. From the carefully sized injection molded spacer sheet that keeps the upper array a specific distance from the RF4-like radome, to the almost microscopic holes that have been bored through each floating patch to maintain equalized air pressure through the stack up, [Shahriar] picks up on fascinating details which might otherwise seem like arbitrary design decisions.

But a visual inspection will only get you so far. Eventually [Shahriar] has to cut out a slice of the PCB so he can fit it into the X-ray machine, but don’t feel too bad, the dish was long dead before he got his hands on it. While he hasn’t yet completed his full analysis, an initial examination indicates that each large IC and the eight chips surrounding it make up a 16 channel beam forming module. Each channel is further split into two RX and TX pairs, which provides the necessary right and left hand polarization. That said, he admits there’s some room for interpretation and that further work would be necessary before any hard conclusions could be made.

Between this RF analysis and the initial overview provided by [Kenneth], we’ve already learned a lot more about this device than many might have expected considering how rare and expensive the hardware is. While we admit it’s not immediately clear what kind of hijinks hardware hackers could get into once this device is fully understood, we’re certainly eager to find out.

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Literally Tearing Apart A SpaceX Starlink Antenna

November 25, 2020 by Tom Nardi 85 Comments

While SpaceX’s constellation of Starlink satellites is nowhere near its projected final size, the company has enough of the birds zipping around in low Earth orbit to start a limited testing period they call the Better Than Nothing Beta. If you’re lucky enough to get selected, you have to cough up $500 for the hardware and another $100 a month for the service. Despite the fairly high bar for getting your hands on one, [Kenneth Keiter] decided to sacrifice his Starlink dish to the teardown Gods.

We say sacrifice because [Kenneth] had to literally destroy the dish to get a look inside. It doesn’t appear that you can realistically get into the exceptionally thin antenna array without pulling it all apart, thanks in part to preposterous amount of adhesive that holds the structural back plate onto the PCB. The sky-facing side of the phased array, the key element that allows the antenna to track the rapidly moving Starlink satellites as they pass overhead, is also laminated to a stack-up comprised of plastic hexagonal mesh layers, passive antenna elements, and the outer fiberglass skin. In short, there are definitely no user-serviceable parts inside.

The dish hides many secrets under its skin.

Beyond attempting to analyze the RF magic that’s happening inside the antenna, [Kenneth] also takes viewers through a tour of some of the more recognizable components of the PCB; picking out things like the Power over Ethernet magnetics, a GPS receiver, some flash storage, and the H-Bridge drivers used to control the pan and tilt motors in the base of the dish.

It also appears that the antenna is a self-contained computer of sorts, complete with ARM processor and RAM to run the software that aims the phased array. Speaking of which, it should come as no surprise to find that not only are the ICs that drive the dizzying array of antenna elements the most numerous components on the PCB, but that they appear to be some kind of custom silicon designed specifically for SpaceX.

In short, there’s still plenty we don’t know about how this high-tech receiver actually works. While [Kenneth] does a respectable job of trying to make sense of it all, and we admire the dedication required to rip apart such a rare and expensive piece of kit, it’s still going to be awhile before the hacker community truly masters the tech that SpaceX is putting into their ambitions global Internet service.

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Hackaday Links: November 15, 2020

November 15, 2020 by Dan Maloney 13 Comments

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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Spacing Out: A Big Anniversary, Starlink Failures Plummet, Lunar Cellphones, And A Crewed Launch

November 11, 2020 by Jenny List 32 Comments

After a couple of months away we’re returning with our periodic roundup of happenings in orbit, as we tear you away from Star Trek: Discovery and The Mandalorian, and bring you up to date with some highlights from the real world of space. We’ve got a launch to look forward to this week, as well as a significant anniversary.

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