This image shows only a small fraction of the eventual Starlink constellation, which will dominate low-Earth orbit. Image credit: SpaceX
In June of last year, we published a story on the launch of a brand-new SpaceX mission, Starlink, an ostensible name really that has nothing to do with linking to the stars (whatever that means) rather, it would be more like eclipsing them. This is an update to that story and the news isn’t good for astronomers.
Amid the CoronaVirus pandemic currently gripping the entire globe, Elon Musk’s SpaceX will be launching the next round of Starlink Satellites this month, adding to the 360 already in low-earth orbit. In case anyone is unfamiliar with this latest brainchild of the eccentric billionaire entrepreneur, the project’s ultimate goal is to encircle the entire globe (with the exception of the Polar regions) with a continuous network of satellites in low-earth orbit, with 12,000+ the target number!
The ostensible purpose of this “Mega Satellite Constellation” (their terminology) is to provide broadband [5G] internet service to undeserved regions of the globe. At first this may seem like a noble endeavor but one needs to look at Musk’s other companies like Tesla and that SpaceX has been receiving a veritable king’s ransom in US Government contracts, funding and subsidies. So, now the US Government cares about the undeserved peoples of the world and, with their magnanimous heart wants to assist Musk in this noble cause? No, the main driver is to expand and enhance Tesla driverless car capability (along with Google) and the current security state with 5G capability!
For astronomers, Starlink is a nightmare; have a read of the latest update in Sky and Telescope to get a sense of the scope and scale of what a fully-deployed Starlink “Mega Constellation” would mean for ground-based astronomy (optical, radio, etc).
Quoting directly from the article
On March 18th, aerospace company SpaceX sent its sixth batch of 60 Starlink satellites into the sky. That brings the total number of Starlinks in low-Earth orbit to 360, putting SpaceX well on its way to having a working network of broadband internet-providing satellites. The company is staying on course to build a preliminary network of 1,584 satellites, and ultimately one that’s 12,000 or even 40,000 strong.
Those numbers throw many astronomers into despair. Satellites in our skies are nothing new — the number has been increasing steadily since the Space Age began. But for the first time, thousands of satellites will be reflecting sunlight from low orbits, making them bright enough to outshine the stars.
And this little gem
So What’s Next?
SpaceX is continuing to roll out its broadband internet plans, having just received Federal Communications Commission (FCC) approval for 1 million Starlink ground stations. And even amid the coronavirus pandemic, another Starlink launch is scheduled for April.
Aside from the obvious lack of forethought on the part of SpaceX executives (Elon Musk) and how their project would effect astronomy, there are other troublesome aspects to this dystopian Skynet:
1) That the FCC has granted an operating license to SpaceX for 1 million ground stations!
Where will they be located? A quick calculation of the surface density of 1,000,000 ground nodes and the approximate surface area of the continental US (9.6 M Sq Km), since the FCC’s jurisdiction ends at the borders, places one downlink receiver uniformly every 9.6 Km within the lower 48 states. Presumably, the downlink signal will be to support 5G surface broadband and, with the jury still out on the health effects of 5G, is this a good idea?
Starlink will be using both the Ku and Ka bands, presumably observing the conventional uplink and downlink frequency protocols. The uplink and downlink frequencies in the Ka band are 26.5 – 40 Ghz and 12 – 20 Ghz respectively, all in the microwave region of the spectrum! As an aside, 5G partially overlaps the Ka band at 28, 38, and 60 GHz.
The question begs asking: what is the beam width from each satellite at 550 Km altitude? It’s probably not that narrow, hence the need for 1 M ground nodes; thus will we be continuously bathed in low-level Ka/Ku microwave-band RF?
2) Radio Astronomy and the ALMA
If SpaceX’s proposed rollout is allowed to proceed as planned, the impact to Radio Astronomy could be more far-reaching and much worse than the impact Starlink would have on Optical Astronomy if the engineers at SpaceX don’t manage to solve the current satellite reflection problem, in whole or in part.
The data, research, images and results streaming out from ALMA are nothing short of spectacular! As we know, ALMA provides us with the ability to observe and explore the ‘Cold Universe’. SpaceX’s proposed worldwide coverage by Starlink is a frontal, full-on, direct threat to ALMA and our ability now to observe the universe in the millimeter and sub-millimeter wavebands.
As of now, the low-end of ALMA’s observing waveband (350 μm – 10 mm) of 10 mm overlaps the Ka uplink range of 11.1 mm – 7.5 mm.
With worldwide coverage, the ATACAMA Desert Plateau would be bathed in a continuous, low-level stream of Ka band downlink RF in the 12-20 Ghz range, that’s if SpaceX respects those constraints. As an aside, the Kepler Mission used the higher frequency range (11.1 mm – 7.5 mm) to downlink the science data collected by the telescope, so these frequency protocols are more of a convention than an enforceable rule. Whose to say what they could decide to do now or later and, with the currect political climate and virtually no government oversight, it’s a fools bet to hope that a huge corporation that continues to receive government contracts, funding and subsidies to develop low earth orbit like its a piece of real estate would do the right thing and play by the rules.
With Ajit Pai as head of the FCC, the 1 M-Station operating license is no surprise and any impediment to expanding or enhancing the Starlink project would be steamrolled, something not too hard to imagine given that they’ve greenlighted 5G rollout over the objections of hundreds of doctors and professionals worldwide from many scientific disciplines.
New observing programs and targets below the 10 mm cutoff would forever be impossible at ALMA, even if the low-end wavelength cutoff were extended below 10 mm as the array would be looking upward at a 10+ mm sky much in the same way the CMB looked to Penzias and Wilson.
Imagination is more important than knowledge
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