Death of a Satellite Swarm

The SpaceX Starlink constellation now dominates low Earth orbit.

While the company eventually plans to launch up to 42,000 satellites to complete the constellation, with the launch of the 7,000th satellite earlier this week, Elon Musk now controls two thirds of the active satellites now in Earth orbit.

At least currently, however, just a few of those SpaceX satellites actually belong to a company called Swarm Technologies. Founded back 2016, Swarm built out a satellite constellation for VHF communications with Internet of Things (IoT) devices on the ground using a store-and-forward design.

The company became infamous in 2018 by being the first, and so far only, American company to illegally launch satellites in 2018 as the FCC refused the launch license to the then startup because they feared that their initial batch of 4 test satellites were too small to be tracked by space surveillance systems. Despite this, Swarm went ahead and launched them anyway onboard an Indian PSLV rocket. The violation cost the company $900,000 in fines.

By February 2021, Swarm had launched 9 test satellites and 72 of a planned 150 satellites in their low Earth orbit constellation, and began full commercial service to customers. They were acquired by SpaceX only a few months later, in July the same year.

Around the time they were starting to provide commercial service Swarm reached out to a lot of journalists, myself included, allowing us to test drive their new service for free.

The satellite modem that Swarm provided was called a Swarm Tile, it was small, low-powered, and relatively cheap. While the module itself was sold ready for integration into production devices, there was also maker-friendly units sold by well known vendors like Sparkfun.

Swarm stopped accepting new customers to their VHF platform just two years later, around the time of their final launch which completed their 150 satellite constellation, in June 2023.

But while you couldn't sign up for a new connection, users with an existing contract with Swarm have continued to enjoy service as normal. Recently, however, the company sent out the end of life notice for their VHF service.

Based on our current projections we expect the existing constellation to provide connectivity for the Swarm commercial service until March 2025. Latencies will gradually increase from now until the end of commercial service, with a significant jump in November 2024 that will approximately double current network latencies. Data plan renewals will not be charged for active devices going forward… we do not have any launches planned for the future to support the existing Swarm service. As such, we will continue to support the Swarm commercial service through the lifetime of the existing constellation.

The end of life notice is interesting, not necessarily because it affects a lot of people — I'm sure there can't be that many customers that are still heavily reliant on the platform, users will have seen the writing on the wall — but because it reminds everyone about the long term support burden of maintaining low Earth orbit constellations. Unlike geosynchronous satellites typically used for communications in the past, the new generation of low Earth orbit communications satellites won't stay in orbit forever.

While there is a sizable constellation of Starlink satellites in orbit now, that wouldn't always be the case if SpaceX were to stop launching tomorrow. Without active intervention, and a supply of replacement satellites, most estimates would have the last Starlink satellite deorbiting in around 5 years time due to atmospheric drag.

Going forward constellations like Starlink are going to need replacement satellites. That means that, while the frantic launch cadences we're seeing today won't need to be maintained forever, there will have to be replacement satellites. Of the 7,000 satellites launched to date, over 600 have now been deorbited. Low Earth orbit constellations rely on our ability to keep the rockets coming.

The idea that these new low Earth orbit constellations are ephemeral isn't something we've gotten used to, but SpaceX's Starlink shouldn't be your go to platform for a zombie apocalypse. The rapid decline in launch cadence due to zombies eating the ground crew is going to play havoc with your bandwidth.

For now though, Starlink's Direct-to-Cell service is almost ready to step in to replace the Swarm. There are now 181 Direct to Cell satellites on orbit, including 13 that were launched just last week.

Starlink's Direct to Cell service is a fascinating piece of technological progress. Unlike Swarm's store-and-forward model, Direct to Cell should eventually mean — not that long from now — that your cellphone will never be in a dead spot, no matter where you are on the planet. Then, eventually, your things can just assume they can talk to the network.

We've seen these sorts of step changes before, where something that used to be hard could just be assumed. O'Reilly Media ran a whole conference series around the last one, they called it Where 2.0. Today it is half-forgotten, but back in the mid-naughties a combination of GPS, Wi-Fi and cell triangulation, and the arrival of the then new smartphones, suddenly meant that you could assume you knew where you were all the time. It changed things, and all these years later your location is just another building block of most of the bits of software running on your phone. They can't live without it.

The idea that you won't need special equipment for your phone — the same phone that seventeen years ago changed everything — to be online all the time. Really all the time now, without dead zones, or holes in your coverage, will change everything again. Just watch out for the zombies. 🧟