Martian Successes Reshape Sample Return Plans

August 8, 2022 by Tom Nardi 19 Comments

For as long as humans have been sending probes to Mars, there’s been a desire to return rock, soil, and atmosphere samples back to Earth for more detailed analysis. But the physics of such a mission are particularly demanding — a vehicle that could land on the Martian surface, collect samples, and then launch itself back into orbit for the return to Earth would be massive and prohibitively expensive with our current technology.

Instead, NASA and their international partners have been working to distribute the cost and complexity of the mission among several different vehicles. In fact, the first phase of the program is well underway.

The Perseverance rover has been collecting samples and storing them in 15 cm (6 inch) titanium tubes since it landed on the Red Planet in February of 2021. Considerable progress has also been made on the Mars Ascent Vehicle (MAV) which will carry the samples from the surface and into orbit around the planet, where they will eventually be picked up by yet another vehicle which will ultimately return them to Earth.

But there’s still some large gaps in the overall plan. Chief among them is how the samples are to be transferred into the MAV. Previously, the European Space Agency (ESA) was to contribute a small “fetch rover” which would collect the sample tubes dropped by Perseverance and bring them to the MAV launch site.

But in a recent press release, NASA has announced that those plans have changed significantly, thanks at least in part to the incredible success of the agency’s current Mars missions.

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Next Floor: Geosynchronous Satellites, Orbiting Laboratories

August 3, 2022 by Al Williams 40 Comments

On Star Trek, if you want to go from one deck to another, you enter a “turbolift” and tell it where you want to go. However, many people have speculated that one day you’ll ride an elevator to orbit instead of using a relatively crude rocket. The idea is simple. If you had a tether anchored on the Earth with the other end connected to a satellite, you could simply move up and down the tether. Sound simple, so what’s the problem? The tether has to withstand enormous forces, and we don’t know how to make anything practical that could survive it. However, a team at the International Space Elevator Consortium could have the answer: graphene ribbons.

The concept is not new, but the hope of any practical material able to hold up to the strain has been scant. [Arthur C. Clarke] summed it up in 1979:

How close are we to achieving this with known materials? Not very. The best steel wire could manage only a miserable 31 mi (50 km) or so of vertical suspension before it snapped under its own weight. The trouble with metals is that, though they are strong, they are also heavy; we want something that is both strong and light. This suggests that we should look at modern synthetic and composite materials. Kevlar… for example, could sustain a vertical length of 124 mi (200 km) before snapping – impressive, but still totally inadequate compared with the 3,100 (5,000 km) needed.

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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?

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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.