A few months ago Starlink, the satellite broadband company founded by Elon Musk, launched 60 broadband satellites. Since that launch, we’ve learned a few more things about the secretive venture.

We now know more details about the satellites. Each one weighs about 500 pounds. They are thin rectangular boxes like a flat-panel TV. Much of the surface is a solar panel, and each satellite also extends a second solar panel.

Each satellite comes with a krypton-powered ion thruster to use to navigate the satellite into initial orbit and to avoid future debris when necessary. This may sound like a cutting-edge propulsion system, but it’s been around for many years and the tiny engines create a small amount of thrust by shooting out charged ions of the noble gas – not a lot of thrust is needed to move a 500-pound satellite.

It seems the satellites can’t detect nearby space debris, so Starlink instead connects to the Air Force’s Combined Space Operations Center, which tracks the trajectories of all known space debris. The company will direct satellites to avoid known debris.

Probably the most important announcement for readers of this blog is that the company is likely to only compete in rural areas where there are few other broadband alternatives. This was finally admitted by Musk. There has been hopeful speculation in some parts of the industry that the low-orbit satellites would provide a broadband alternative everywhere, thus supplying a new competitor for cable companies. Since widespread competition generally results in lower prices there was hope that satellite broadband would act to make the whole broadband market more competitive.

We already had an inkling that satellite broadband was going to be rural-only when OneWeb, one of the competitors to Starlink, told the FCC that they were likely going to ultimately need about like 1 million wireless licenses for receivers. While that might sound like a huge number, one million satellite connections spread across the US is not creating a major competitor. We also heard the same message when several of the satellite companies talked about eventually having tens of millions of customers worldwide at maturity. Even with multiple satellite companies competing for customers there probably won’t be more than 3 – 4 million satellite broadband customers in the US – that would make a dent but wouldn’t fix the rural broadband gap. This strategy makes sense for the satellite companies since they’ll be able to charge a premium price for rural customers who have no broadband alternative instead of cutting prices to compete with cable companies.

There has still been no discussion from Starlink or the other competitors on broadband speeds or broadband pricing. It’s been nearly impossible to predict the impact of the satellites without understanding data speeds and total download capacity. The physics suggest that backhaul to the satellites will be the critical limiting factor, so it’s possible that there will be monthly data caps or some other way to control consumption.

One of the most interesting unanswered questions is how the satellites will do backhaul. Landline ISPs of any size today control cost and control data volumes by directly peering with the largest sources of broadband demand – being mostly Netflix, Google, Amazon, and Microsoft. As much as 70% of the traffic headed to an ISP is from this handful of destinations. Engineers are wondering how Starlink will handle peering. Will there be backhaul between satellites or will each satellite have a dedicated link to the ground for all data usage? This is a key question when a satellite is passing over a remote area – will it try to find a place within sight of the satellite to connect to the Internet or will data instead be passed between satellite with connections only at a major hub?

Answering that question is harder than might be imagined because these satellites are not stationary. Each satellite continuously orbits the earth and so a given customer will be handed off from one satellite to the next as satellites pass out of the visible horizon. The company says the receivers are about the size of a pizza box and they are not aimed at a given satellite, like what happens with satellite TV – instead, each receiver just has to be generally aimed skyward. It’s hard to think that there won’t be issues for homes living in heavy wooded areas.

One last interesting tidbit is that the satellites are visible to the naked eye. When the recent launch was first completed it was easy to spot the string of 60 satellites before they were dispersed. Astronomers are wondering what this will mean when there are ten thousand satellites filling the sky from the various providers. Elon Musk says he’s working to reduce albedo (the reflection of sunlight) to reduce any problems this might cause with land-based astronomy. But for stargazers this means there will always be multiple visible satellites crossing the sky.