Mini Falcon 9 Uses NASA Software

July 26, 2022 by Bryan Cockfield 17 Comments

[T-Zero Systems] has been working on his model Falcon 9 rocket for a while now. It’s an impressive model, complete with thrust vectoring, a microcontroller which follows a predetermined flight plan, a working launch pad, and even legs to attempt vertical landings. During his first tests of his model, though, there were some issues with the control system software that he wrote so he’s back with a new system that borrows software from the Space Shuttle.

The first problem to solve is gimbal lock, a problem that arises when two axes of rotation line up during flight, causing erratic motion. This is especially difficult because this model has no ability to control roll. Solving this using quaternion instead of Euler angles involves a lot of math, provided by libraries developed for use on the Space Shuttle, but with the extra efficiency improvements the new software runs at a much faster rate than it did previously. Unfortunately, the new software had a bug which prevented the parachute from opening, which wasn’t discovered until after launch.

There’s a lot going on in this build behind-the-scenes, too, like the test rocket motor used for testing the control system, which is actually two counter-rotating propellers that can be used to model the thrust of a motor without actually lighting anything on fire. There’s also a separate video describing a test method which validates new hardware with data from prior launches. And, if you want to take your model rocketry further in a different direction, it’s always possible to make your own fuel as well.

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How Does The James Webb Telescope Phone Home?

July 25, 2022 by Tom Nardi 31 Comments

When it comes to an engineering marvel like the James Webb Space Telescope, the technology involved is so specialized that there’s precious little the average person can truly relate to. We’re talking about an infrared observatory that cost $10 billion to build and operates at a temperature of 50 K (−223 °C; −370 °F), 1.5 million kilometers (930,000 mi) from Earth — you wouldn’t exactly expect it to share any parts with your run-of-the-mill laptop.

But it would be a lot easier for the public to understand if it did. So it’s really no surprise that this week we saw several tech sites running headlines about the “tiny solid state drive” inside the James Webb Space Telescope. They marveled at the observatory’s ability to deliver such incredible images with only 68 gigabytes of onboard storage, a figure below what you’d expect to see on a mid-tier smartphone these days. Focusing on the solid state drive (SSD) and its relatively meager capacity gave these articles a touchstone that was easy to grasp by a mainstream audience. Even if it was a flawed comparison, readers came away with a fun fact for the water cooler — “My computer’s got a bigger drive than the James Webb.”

Of course, we know that NASA didn’t hit up eBay for an outdated Samsung EVO SSD to slap into their next-generation space observatory. The reality is that the solid state drive, known officially as the Solid State Recorder (SSR), was custom built to meet the exact requirements of the JWST’s mission; just like every other component on the spacecraft. Likewise, its somewhat unusual 68 GB capacity isn’t just some arbitrary number, it was precisely calculated given the needs of the scientific instruments onboard.

With so much buzz about the James Webb Space Telescope’s storage capacity, or lack thereof, in the news, it seemed like an excellent time to dive a bit deeper into this particular subsystem of the observatory. How is the SSR utilized, how did engineers land on that specific capacity, and how does its design compare to previous space telescopes such as the Hubble?

Continue reading “How Does The James Webb Telescope Phone Home?” →

A wall-mounted display made from 18 golden hexagonal mirrors

Peer Into Space Through This James Webb-Style Hexagonal Mirror

July 17, 2022 by Robin Kearey 2 Comments

The James Webb Space Telescope (JWST) generated considerable excitement when its first test images were released earlier this year: they proved that the instrument was working and helped its engineers to set up all systems for maximum performance. But the real proof of the pudding came last week, when the first batch of beautiful full-scale pictures was unveiled. If you thought those pictures were pretty enough to hang on your wall, you’re not the only one: [Fredrik], also known as [Cellar Nerd], built a wall-mounted display, shaped like the JWST’s main mirror, that cycles through images taken by the space telescope.

The frame holding the mirror is made of plywood. [Fredrik] designed it in Fusion 360, but decided to cut it by hand using a jigsaw; 3D printing the thing would have resulted in a large number of small pieces that might be hard to fit together with sufficient accuracy. After cutting the wood and painting it black, it was simply a matter of sticking the mirror tiles on top and the basic JWST design was done.

The set of eighteen golden hexagonal mirrors might seem to be the hardest bit to make, but was actually the easiest: [Fredrik] simply bought them ready-made on Amazon. The item’s description didn’t include any precise measurements, so he had to wait until the mirrors arrived before he could make the rest of the setup. The segments also don’t have the nanometer accuracy required for a real telescope: in fact, they’re not even flat enough to be useful as an everyday mirror. But that doesn’t really matter: the whole setup is pretty enough that [Fredrik]’s wife even wanted it to have pride of place in the hallway.

An old 15.6″ laptop display sits behind the frame and shows an image through the gap in the center. The display is quite a bit larger than necessary, so the images are always placed in the middle of the screen and scaled to obtain the correct size. A Raspberry Pi 2 is used to store the images and drive the display; it currently cycles through a fixed set of pictures, but [Fredrik] plans to have it automatically download the latest JWST images once a reliable online source is available.

If the basic design looks a bit familiar, you might have seen this static James Webb mirror that we featured before. We’ve also taken a deep dive into the fascinating engineering behind the JWST’s cryocooling system that gives it its spectacular infrared performance. Continue reading “Peer Into Space Through This James Webb-Style Hexagonal Mirror” →

NASA’s Flying Telescope Is Winding Down Operations

July 11, 2022 by Tom Nardi 13 Comments

NASA’s Hubble Space Telescope is arguably the best known and most successful observatory in history, delivering unprecedented images that have tantalized the public and astronomers alike for more than 30 years. But even so, there’s nothing particularly special about Hubble. Ultimately it’s just a large optical telescope which has the benefit of being in space rather than on Earth’s surface. In fact, it’s long been believed that Hubble is not dissimilar from contemporary spy satellites operated by the National Reconnaissance Office — it’s just pointed in a different direction.

There are however some truly unique instruments in NASA’s observational arsenal, and though they might not have the name recognition of the Hubble or James Webb Space Telescopes, they still represent incredible feats of engineering. This is perhaps best exemplified by the Stratospheric Observatory for Infrared Astronomy (SOFIA), an airborne infrared telescope built into a retired airliner that is truly one-of-a-kind.

Unfortunately this unique aerial telescope also happens to be exceptionally expensive to operate; with an annual operating cost of approximately $85 million, it’s one of the agency’s most expensive ongoing astrophysics missions. After twelve years of observations, NASA and their partners at the German Aerospace Center have decided to end the SOFIA program after its current mission concludes in September.

With the telescope so close to making its final observations, it seems a good time to look back at this incredible program and why the US and German space centers decided it was time to put SOFIA back in the hangar.

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DIY Low-Cost LoRa Satellite Ground Station

July 7, 2022 by Chris Lott 23 Comments

Embedded engineer [Alberto Nunez] has put together a compact LoRa satellite telemetry ground station that fits in your hand and can be built for around $40 USD.

The station receives signals from any of several satellites which use LoRa for telemetry, like the FossaSat series of PocketQube satellites. Even with a sub-optimal setup consisting of a magnetic mount antenna stuck outside a window, [Alberto] is able to receive telemetry from satellites over 2,000 kilometers distant. He also built a smaller variant which is battery powered for portable use.

The construction of this ground station makes use of standard off-the-shelf items with a Heltec ESP32-based LoRa / WiFi module as the heart. This module is one of several supported by the TinyGS project, which provides receiver firmware and a worldwide telemetry network consisting of 1,002 stations as of this writing. The firmware has a lot of features, including OTA updates and auto-tuning of your receiver to catch each satellite as it passes overhead.

The TinyGS project started out as a weekend project back in 2019 to use an ESP32 to receive LoRa telemetry from the FossaSat-1 satellite, and has expanded to encompass all satellites, and other flying objects, using LoRa-based telemetry. It uses Telegram to distribute data, with a message being sent to the channel anytime any station in the network receives a telemetry packet from a satellite.

If you’re interested in getting your feet wet receiving satellite signals, this is an easy project to start with that won’t break the bank.

Windows 98 For Spaceships? Not Quite!

July 6, 2022 by Jenny List 78 Comments

One of the news items that generated the most chatter among Hackaday editors this week was that ESA’s Mars Express mission is receiving a software update. And they’re updating the operating system to…Windows 98.

Microsoft’s late-90s consumer desktop operating system wouldn’t have been the first to come to mind as appropriate for a spacecraft, but ESA were quick to remind us that it was the development toolchain, not the craft itself, that depended upon it. It’s still quite a surprise to find Windows 98 being dusted off for such an unexpected purpose, and it’s led us to consider those now-almost-forgotten operating systems once more, and to question where else it might still be found. Continue reading “Windows 98 For Spaceships? Not Quite!” →

Reverse Engineering An Apollo-Era Module With X-Ray

June 29, 2022 by Dan Maloney 9 Comments

The gear that helped us walk on the Moon nearly 60 years ago is still giving up its mysteries today, with some equipment from the Apollo era taking a little bit more effort to reverse engineer than others. A case in point is this radiographic reverse engineering of some Apollo test gear, pulled off by [Ken Shirriff] with help from his usual merry band of Apollo aficionados.

The item in question is a test set used for ground testing of the Up-Data Link, which received digital commands from mission controllers. Contrary to the highly integrated construction used in Apollo flight hardware, the test set, which was saved from a scrapyard, used more ad hoc construction, including cards populated by mysterious modules. The pluggable modules bear Motorola branding, and while they bear some resemblance to ICs, they’re clearly not.

[Ken] was able to do some preliminary reverse-engineering using methods we’ve seen him employ before, but ran into a dead end with his scope and meter without documentation. So the modules went under [John McMaster]’s X-ray beam for a peek inside. They discovered that the 13-pin modules are miniature analog circuits using cordwood construction, with common discrete passives stacked vertically between parallel PCBs. The module they imaged showed clear shadows of carbon composition resistors, metal-film capacitors, and some glass-body diodes. Different angles let [Ken] figure out the circuit, which appears to be part of a square wave to sine wave converter.

The bigger mystery here is why the original designer chose this method of construction. There must still be engineers out there who worked on stuff like this, so here’s hoping they chime in on this innovative method.