Monday, February 14, 2022

SpaceX Versus the Astronomers: Starlink In the Telescope Crosshairs

 

Elon Musk, who no one has accused of being shy and retiring in his corporate ventures, is engaged in deploying what he hopes will be some 40,000 low-earth-orbit satellites to form what he calls a Starlink system to provide internet service to underserved areas of the globe, and also presumably to make money.  So far, several thousand of the mass-produced satellites have been launched in batches of dozens at a time, although a recent geomagnetic storm caused an early demise for some of the newest ones as the resulting denser atmosphere at their orbital heights dragged them to a fiery death.

 

The satellites are comparatively small—about 500 pounds (220 kg) and about the size of a table—and burn up completely when they de-orbit, so we don't have to worry about pieces of them falling on our heads.  But the folks who are worried about the ones staying in orbit are astronomers, who are already seeing little bright Starlink satellite dots streak through their telescope fields of view, especially when they try to observe close to the horizon near dusk or dawn.

 

For some time now, the astronomers have been trying to garner attention for their plight, which only promises to get worse as other commercial space firms compete with SpaceX, Musk's company, to gain low-earth-orbit communications satellite market share.  Last week, the International Astronomical Union (IAU), a sort of United Nations of astronomy, announced the organization of the Center for the Protection of the Dark and Quiet Skies from Satellite Constellation Interference.  For once, the name of the new organization doesn't form a cute acronym, which perhaps bespeaks the seriousness of the endeavor.

 

The reason they call it both dark and quiet is that communications satellites, by nature, emit electromagnetic waves, usually in the microwave radio spectrum.  And although astronomers are provided with protected bits of the electromagnetic spectrum in which no radio emissions are allowed, these tend to be fairly narrow slices surrounded by wide bands where communications-related emissions are permitted.  Radiotelescopes use the most sensitive and delicate radio receivers on the planet, and they are not designed to reject nearby out-of-band interference very well.  If one of the Starlink satellites happens to sweep through the narrow beam of a radiotelescope, the satellite's emissions are likely to mess up the astronomy receiver in an unpredictable way.

 

And of course, visible-light telescopes pick up the Starlink satellites easily, even if the satellites are painted black.  One recent report in The Independent (UK) says that astronomers are seeing their visible-light exposures messed up with Starlink tracks an average of once every ten days.

 

So far, the problem is at a manageable annoyance level.  But multiply it by ten or more, and just the Starlink satellites will interfere seriously with a lot of astronomical projects, including the search for killer meteorites that might bring a premature end, not only to Starlink, but to everybody who could use it as well. 

 

It's an interesting problem in engineering ethics, if you want to view the situation through that lens.  In this corner, you have the public that would presumably like Internet access but lives too remotely for it now, and SpaceX wanting to provide that service with Starlink.  And in that corner, you have the IAU saying that what Starlink and similar firms are doing could raise havoc with a large portion of their activities.  

 

Historically, when you have a conflict between an entire industry and another popular institution such as astronomy, a third party such as government or an international organization has to get involved.  This is the way that radioastronomers obtained their reserved slices of the electromagnetic spectrum, by pleading with the International Telecommunications Union (ITU) for them and making effective arguments, possibly together with a little political diplomacy. 

 

Now that the commercialization of space has been going on for at least a couple of decades, we are seeing the kinds of conflicts that led to the formation in former years of the ITU for radio.  Although nobody "owns" the low-earth-orbit region of space in an exclusionary sense ("this is my two quadrillion cubic meters and you can't send your satellite into it"), it is clearly a limited resource, just like the electromagnetic spectrum, and we are now seeing an increasing need for some kind of global regulatory body to adjudicate issues such as the one that has arisen between SpaceX and the astronomers, represented by the IAU.

 

Something similar came about when transoceanic flights became routine and different countries had to arrange for protocols of using flight routes and standards for international airports.  The International Civil Aviation Organization (ICAO), whose present embodiment dates back to 1947, arose as a part of the United Nations to perform these duties. 

 

The UN currently has a couple of branches dealing with space: the UN Office for Outer Space Affairs and a registry of objects launched into orbit.  But neither of these outfits appears to have the regulatory clout needed to deal with disputes between a brash private firm bent on networking the Earth with 40,000 satellites, and a bunch of scientists who have little money for lobbying and whose main argument is that if you clutter up our telescopes too much, there's a teeny little chance that we'll miss seeing a meteor that will creep up on us and destroy civilization.

 

So far, the astronomers are just having to deal with the problems that Starlink causes them on a case-by-case basis.  And ultimately, it's quite possible that most cutting-edge observational astronomy will move to outer space anyway, as the recently launched James Webb Space Telescope promises to beat anything you can do with earth-based telescopes.  As a global culture, we may find that turning the night skies into shimmering collections of satellites and ruining them for astronomy is a reasonable price to pay for letting the most remote tribe in the world livestream SuperBowl C (100, if you're rusty on your Roman numerals).  But if that happens, I think we will have lost something that will be hard to get back.

 

Sources:  I referred to a report on The Independent's webpage at https://www.independent.co.uk/space/astronomers-elon-musk-satellites-asteroids-b2009163.html, a BBC report at https://www.bbc.com/news/world-60317806 about satellites lost to a geomagnetic storm, and the Wikipedia articles on the ICAO and the UN Office for Outer Space Affairs. 

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