Swarm Vs. Iridium: Which Satellite IoT Service Is Right For You?

In a world where it seems like everyone’s face is glued to a device screen, the idea that wireless service might be anything other than universal seems just plain silly. But it’s not, as witnessed by vast gaps in cell carrier coverage maps, not to mention the 70% of the planet covered by oceans. The lack of universal coverage can be a real pain for IoT applications, which is a gap that satellite-based IoT services aim to fill.

But which service is right for your application? To help answer that question, [Mike Krumpus] has performed the valuable work of comparing the services offered by Swarm and Iridium in a real-world IoT shootout. On the face of it, the match-up seems a little lopsided — Iridium has been around forever and has a constellation of big satellites and an extensive ground-based infrastructure. But as our own [Al Williams] discovered when he tested out Swarm, there’s something to be said for having a lot of 1/4U Cubesats up there.

[Mike] picked up the gauntlet and did head-to-head tests of the two services under real-world conditions. Using the same Swarm development kit that [Al] used for his test, alongside an Iridium dev board of his own design, [Mike] did basic tests on uplink and downlink times for a short message on each service. We couldn’t find specs on the test message length, but Swarm’s FAQ indicates that packets are limited to 192 bytes, so we assume they’re both in that ballpark. Iridium was the clear winner on uplink and downlink times, which makes sense because Swarm’s constellation is much smaller at this point and leaves large gaps in coverage. But when you consider costs, Swarm wins the day; what would cost over $1,500 with Iridium would set you back a mere $60 with Swarm.

The bottom line, as always, depends on your application and budget, but [Mike]’s work makes it easier to do that analysis.

DIY Low-Cost LoRa Satellite Ground Station

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.

South Korea’s KSLV-2 Rocket Delivers Payloads To Orbit

South Korea’s domestically developed KSLV-2 “Nuri” rocket successfully placed six payloads into low Earth orbit Tuesday, after lifting off from from Naro Space Center at 4 PM KST. This follows an earlier attempt in October which failed to reach orbit after the booster’s third stage engine shutdown prematurely. The flight followed an initial trajectory over the East China Sea, after which the upper stage steered out towards the Philippine Sea, finally placing the payload in the desired orbital inclination of 98 degrees. This less-than-ideal path wasted energy, but ensured that the first and second stages fell into the ocean and not onto people. Success was confirmed shortly after launch as the vehicle passed over South Korea’s King Sejong Station in Antarctica.

The payload on this test flight was primarily a mass simulator of 1.3 metric tons, but a small Performance Verification Satellite (PVSAT) was included, for a grand total of 1.5 metric tons. The PVSAT itself monitors vehicle performance, but also serves as a carrier for four CubeSats. These were developed by engineering teams at various local universities and will be deployed in the coming days.

If you’re inclined to track these, the launch has been given COSPAR ID 2022-065 and the first three objects (third stage, dummy mass, and PVSAT) have been assigned the NORAD catalog numbers 52894, 52895, and 52896. It’s too early to tell which is which at this point, but as more data about their respective orbits are collected, it should be possible to tell them apart. The next four catalog numbers, 52897 – 52900, have been reserved for the CubeSats once they are released.

With this launch, South Korea has become the 10th nation to put a payload into space using its own domestic technology, and the 7th to loft a payload of more than one ton to orbit — joining the ranks of the United States, Russia, Japan, China, France, and India.

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The Great Euro Sat Hack Should Be A Warning To Us All

Military officials and civilian security researchers have been warning us for years: cyberattacks are becoming a very real part of modern warfare. Far from being limited to military targets, cyberattacks can take out everything from vital public infrastructure to commercial and industrial operations, too.

In the early hours of February 24, as the Russian invasion force began raining missiles on Ukrainian cities, another attack was in progress in the digital realm. Suddenly, satellite terminals across Europe were going offline, with many suffering permanent damage from the attack.

Details remain hazy, but researchers and military analysts have pieced together a picture of what happened that night. The Great Euro Sat Hack prove to be the latest example of how vulnerable our digital infrastructure can be in wartime.

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Mercury Thrusters: A Worldwide Disaster Averted Just In Time

The field of space vehicle design is obsessed with efficiency by necessity. The cost to do anything in space is astronomical, and also heavily tied to launch weight. Thus, any technology or technique that can bring those figures down is prime for exploitation.

In recent years, mercury thrusters promised to be one such technology. The only catch was the potentially-ruinous environmental cost. Today, we’ll look at the benefits of mercury thrusters, and how they came to be outlawed in short order.

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Hacking An Experimental ESA Satellite

Hacking these days means everything from someone guessing your password and spamming your contacts with toxic links, to wide-scale offensive cyberattacks against infrastructure by sophisticated operators backed by nation states. When it comes to hacking satellites, though, [Didelot Maurice-Michel] found himself tangling with some hardware belonging to the European Space Agency. 

As part of an event called HackCYSAT, hackers were invited to attack the ESA’s OPS-SAT, a CubeSat intended to demonstrate improved techniques for mission control and more advanced satellite hardware. The computer hardware on board is ten times more powerful than other existing ESA satellites, and aims to take satellite technology on a new leap forward.

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Tune Your Dish Antenna Like A Pro

It’s a problem we all have at one time or another: your five-meter radio astronomy dish gets out of calibration and you don’t have a ridiculously expensive microwave holography rig on hand to diagnose it. OK, maybe this isn’t your problem, but when [Joe Martin]’s parabolic antenna got out of whack, he set out to diagnose and repair it, and then wrote up how he did it. You can download the PDF from his radio astronomy articles collection.

At the heart of the measurement rig is a laser rangefinder connected to a Porcupine Labs interface that passes the data on to a Pi 4. This is placed on the end of a two-degree-of-freedom servo gimbal that scans over the surface of the dish, measuring its shape. After measuring and math, [Joe] found out that it’s a little bit long here and short there, he attached two cables with turnbuckles to the front of the dish and pulled it back into shape — the sort of thing that you should probably only do if you’ve got a measurement rig already set up.

The Fluke rangefinder and Porcupine labs interface combo is pretty sweet, but it comes with a fairly hefty price tag. (Nothing compared to a professional dish measurement rig, we presume.) We’ve seen a few attempt at hacking into el-cheapo laser rangefinders, but other than [iliasam]’s heroic effort where he ended up writing his own firmware, it doesn’t seem like there are any successes. A shame, because applications like [Joe]’s prove that there’s a need for one. Let us know if there’s anything we missed?

Thanks [Ethan] for the tip!