How Does The James Webb Telescope Phone Home?

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Of course, we know that NASA didn’t hit up eBay for an outdated Samsung EVO SSD to slap into their next-generation space observatory.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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Hackaday Links: March 27, 2022

Remember that time back in 2021 when a huge container ship blocked the Suez Canal and disrupted world shipping for a week? Well, something a little like that is playing out again, this time in the Chesapeake Bay outside of the Port of Baltimore, where the MV Ever Forward ran aground over a week ago as it was headed out to sea. Luckily, the mammoth container ship isn’t in quite as narrow a space as her canal-occluding sister ship Ever Given was last year, so traffic isn’t nearly as impacted. But the recovery operation is causing a stir, and refloating a ship that was drawing 13 meters when it strayed from the shipping channel into a muddy-bottomed area that’s only about 6 meters deep is going to be quite a feat of marine engineering. Merchant Marine YouTuber Chief MAKOi has a good rundown of what’s going on, and what will be required to get the ship moving again.

With the pace of deep-space exploration increasing dramatically of late, and with a full slate of missions planned for the future, it was good news to hear that NASA added another antenna to its Deep Space Network. The huge dish antenna, dubbed DSS-53, is the fourteenth dish in the DSN network, which spans three sites: Goldstone in California; outside of Canberra in Australia; and in Madrid, where the new dish was installed. The 34-meter dish will add 8% more capacity to the network; that may not sound like much, but with the DSN currently supporting 40 missions and with close to that number of missions planned, every little bit counts. We find the DSN fascinating, enough so that we did an article on the system a few years ago. We also love the insider’s scoop on DSN operations that @Richard Stephenson, one of the Canberra operators, provides.

Does anybody know what’s up with Benchy? We got a tip the other day that the trusty benchmarking tugboat model has gone missing from several sites. It sure looks like Sketchfab and Thingiverse have deleted their Benchy files, while other sites still seem to allow access. We poked around a bit but couldn’t get a clear picture of what’s going on, if anything. If anyone has information, let us know in the comments. We sure hope this isn’t some kind of intellectual property thing, where you’re going to have to cough up money to print a Benchy.

Speaking of IP protections, if you’ve ever wondered how far a company will go to enforce its position, look no further than Andrew Zonenberg’s “teardown” of an anti-counterfeiting label that Hewlett Packard uses on their ink cartridges. There’s a dizzying array of technologies embedded inside what appears to be a simple label. In addition to the standard stuff, like the little cuts that make it difficult to peel a tag off one item and place it on another — commonly used to thwart “price swapping” retail thefts — there’s an almost holographic area of the label. Zooming in with a microscope, the color-shifting image appears to be made from tiny hexagonal cells that almost look like the pixels in an e-ink display. Zooming in even further, the pixels offer an even bigger (smaller) surprise. Take a look, and marvel at the effort involved in making sure you pay top dollar for printer ink.

And finally, we got a tip a couple of weeks ago on a video about jerry cans. If that sounds boring, stop reading right now — this one won’t reach you. But if you’re even marginally interested in engineering design and military history, make sure you watch this video. What is now known to the US military as “Can, Gasoline, Military 5-Gallon (S/S by MIL-C-53109)” and colloquially known as the NATO jerry can, started life as the Wehrmacht-Einheitskanister, a 20-liter jug whose design addresses a long list of specifications, from the amount of liquid it could contain to how the cans would be carried. The original could serve as a master class in good design, and some of the jugs that were built in the 1940s are still in service and actively sought by collectors of militaria. Cheap knockoffs are out there, of course, but after watching this video, we’ve developed a taste for jerry cans that only the original will sate.

After Eight-Month Break, Deep Space Network Reconnects With Voyager 2

When the news broke recently that communications had finally been re-established with Voyager 2, I felt a momentary surge of panic. I’ve literally been following the Voyager missions since the twin space probes launched back in 1977, and I’ve been dreading the inevitable day when the last little bit of plutonium in their radioisotope thermal generators decays to the point that they’re no longer able to talk to us, and they go silent in the abyss of interstellar space. According to these headlines, Voyager 2 had stopped communicating for eight months — could this be a quick nap before the final sleep?

Thankfully, no. It turns out that the recent blackout to our most distant outpost of human engineering was completely expected, and completely Earth-side. Upgrades and maintenance were performed on the Deep Space Network antennas that are needed to talk to Voyager. But that left me with a question: What about the rest of the DSN? Could they have not picked up the slack and kept us in touch with Voyager as it sails through interstellar space? The answer to that is an interesting combination of RF engineering and orbital dynamics.

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It Came From Outer Space: Listening To The Deep Space Network

Ham radio operators love to push the boundaries of their equipment. A new ham may start out by making a local contact three miles away on the 2m band, then talk to somebody a few hundred miles away on 20m. Before long, they may find themselves chatting to fellow operators 12,000 miles away on 160m. Some of the adventurous return to 2m and try to carry out long-distance conversations by bouncing signals off of the Moon, waiting for the signal to travel 480,000 miles before returning to Earth. And then some take it several steps further when they listen to signals from spacecraft 9.4 million miles away.

That’s exactly what [David Prutchi] set out to do when he started building a system to listen to the Deep Space Network (DSN) last year. The DSN is NASA’s worldwide antenna system, designed to relay signals to and from spacecraft that have strayed far from home. The system communicates with tons of inanimate explorers Earth has sent out over the years, including Voyager 1 & 2, Juno, and the Mars Reconnaissance Orbiter. Because the craft are transmitting weak signals over a great distance (Voyager 1 is 14 billion miles away!), the earth-based antennas need to be big. Real big. Each of the DSN’s three international facilities houses several massive dishes designed to capture these whispers from beyond the atmosphere — and yet, [David] was able to receive signals in his back yard.

Sporting a stunning X-band antenna array, a whole bunch of feedlines, and some tracking software, he’s managed to eavesdrop on a handful of spacecraft phoning home via the DSN. He heard the first, Bepi-Colombo, in May 2020, and has only improved his system since then. Next up, he hopes to find Juno, and decode the signals he receives to actually look at the data that’s being sent back from space.

We’ve seen a small group of enthusiasts listen in on the DSN before, but [David]’s excellent documentation should provide a fantastic starting point for anybody else interested in doing some interstellar snooping.

NASA Making Big Upgrades To Their Big Dish DSS43

When it comes to antenna projects, we usually cover little ones here. From copper traces on a circuit board to hand-made units for ham radio. But every once in a while it’s fun to look at the opposite end of the spectrum, and anyone who craves such change of pace should check out DSS43’s upgrade currently underway.

Part of NASA’s Deep Space Network (DSN) built to communicate with spacecraft that venture far beyond Earth, Deep Space Station 43 is a large dish antenna with a diameter of 70 meters and largest of the Canberra, Australia DSN complex. However, the raw reflective surface area is only as good as the radio equipment at its center, which are now outdated and thus focus of this round of upgrades.

The NASA page linked above offers a few pieces of fun trivia about DSS43 and its capabilities. If that whets an appetite for more, head over to Twitter for a huge treasure trove. Whoever is in charge of Canberra DSN’s Twitter account has an endless fountain of facts and very eager to share them in response to questions, usually tagged with #DSS43. Example: the weight of DSS43 is roughly 8.5 million kilograms, 4 million of which is moving structure. They also shared time lapse video clips of work in progress, one of which is embedded after the break.

Taking the uniquely capable DSS43 offline for upgrades does have some consequences, one of which is losing our ability to send commands to distant interplanetary probe Voyager 2. (Apparently smaller DSN dishes can be arrayed to receive data, but only DSS43 can send commands.) Such sacrifices are necessary as an investment for the future, with upgrade completion scheduled for January 2021. Just in time to help support Perseverance (formerly “Mars 2020”) rover‘s arrival in February and many more missions for years to come.

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Clock Monitors Deep Space Network, Keeps Vigil Over Lost Mars Rover

It’s been a long, long time since we heard from Opportunity, the remarkable Mars rover that has shattered all expectations on endurance and productivity but has been silent since a planet-wide dust storm blotted out the Sun and left it starved for power. Right now, it’s perched on the edge of a crater on Mars, waiting for enough sunlight to charge its batteries so it can call home. All we can do is sit, and wait.

To pass the time until Opportunity stirs again, [G4lile0] built this Deep Space Network clock. Built around an ESP32 and a TFT display, the clock monitors the Deep Space Network (DSN) website to see if mission control is using any of the huge antennas at its disposal to listen for signals from the marooned rover. If the DSN is listening, it displays a special animation exhorting the rover to phone home; otherwise, it shows which of the many far-flung probes the network is communicating with, along with a slideshow of Mars mission photos to keep the spirits up. When the day finally comes that Opportunity checks in, an alarm will sound so [G4lile0] can pop the champagne and celebrate with the rest of us.

We realize that the odds that Opportunity will survive this ordeal are decreasing by the Sol. It’s an uphill battle; after all, the machine was 55 times its original 90-day design life when it went dark, so it’s an uphill battle. Then again, it has beaten the odds before, so there’s still hope.

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Serious DX: The Deep Space Network

Humanity has been a spacefaring species for barely sixty years now. In that brief time, we’ve fairly mastered the business of putting objects into orbit around the Earth, and done so with such gusto that a cloud of both useful and useless objects now surrounds us. Communicating with satellites in Earth orbit is almost trivial; your phone is probably listening to at least half a dozen geosynchronous GPS birds right now, and any ham radio operator can chat with the astronauts aboard the ISS with nothing more that a $30 handy-talkie and a homemade antenna.

But once our spacecraft get much beyond geosynchronous orbit, communications get a little dicier. The inverse square law and the limited power budget available to most interplanetary craft exact a toll on how much RF energy can be sent back home. And yet the science of these missions demands a reliable connection with enough bandwidth to both control the spacecraft and to retrieve its precious cargo of data. That requires a powerful radio network with some mighty big ears, but as we’ll see, NASA isn’t the only one listening to what’s happening out in deep space. Continue reading “Serious DX: The Deep Space Network”