- This topic has 7 replies, 7 voices, and was last updated 1 week, 3 days ago by
.
-
Posts
-
Seems we ain’t seen nothing yet!
This is for orbital data centres and the business case seems pretty tenuous compared to comms systems like Starlink. The actual FCC application is here:
although you need to register to be able to download the details. As far as I can see this would be launching solar powered data centres to support AI so hopefully that bubble will burst well before this gets anywhere. The proposal would be to put most of the satellites in high (up to 2000 km) Sun Synchronous Orbits (SSOs) so that they remain illuminated most of the time. That would be a nightmare for astronomy within a few thousand km of the terminator where these things would be visible well beyond astro twilight.
I immediately read this news with interest, and I was delighted by it because I glimpsed in it a sort of great new discovery, somewhat similar to what the discovery of America must have been four centuries ago. Driven by strong enthusiasm for it, I wanted to do some calculations, done, so to speak, with a child’s abacus.
Data: Satellites N=10^6, orbiting at d=1000km above the ground and R=7350km from the center of the Earth.
Here are the results: surface area of the sphere centered on S = 4 * 3.14 * R^2 = 6.8 * 10^8 km2. Each satellite would have approximately S/N = 680 km2. The area is roughly square, with side L = 26 km. The hypothetical future tourist who will be on holiday in orbit approximately 1000 km above the surface will pass near a satellite every 2.5 seconds. This is a very short interval, similar to the frequency with which a driver encounters streetlights along a route in a city like Rome.
The worst is yet to come for us amateur astronomers. The angular distance between two nearby satellites is: 26km/1000km = 0.026 rad = approximately 1.5°. That is, between one false star (satellite) and the other closest to it, there would be only 3 lunar diameters. At 50x, we will see at least two satellites in the eyepiece field at the same time. Let’s hope they are invisible to the naked eye. If only each one had a magnitude of 1, it would be like having an almost full moon every night: goodbye to nebulae, clusters, and deep sky in general. This would lead to the bankruptcy of all telescope and accessory manufacturers. Thus, humanity will definitively lose a huge cultural heritage; no one will ever again look up at the starless sky; it will be pointless. Everyone, heads down, miserable, sad, and afflicted, will crawl on the ground almost like reptiles. In this state, I see no light, but black, the symbol of the famine emerging from the underworld: I see the apocalyptic Black Knight. A famine of natural stars, a famine of beautiful things. One side of his scale leans toward artificial light pollution, toward illusions, toward the falsehood that pushes everyone into the deepest corner of a Dantean Inferno.I wonder if that “brilliant” idea is a sign of pure madness, a carnival joke, or something truly serious.
And just to make sure we get a Kessler cascade….
China don’t want to be left out.
On a more positive note…If every satellite had an astro camera on it looking out it would be possible to image the entire sky continuously, 24/7. Imagine the possibilities…what would you do with a camera in space?
Time for the astronomical community, amateur and professional, to start working with the constellation builders. How can we use all these camera platforms in space to benefit everyone? It could open up imaging/photometry/spectroscopy in the UV and IR. Exo-planet hunting could be carried out over the entire sky. Anyone could ‘see’ the pristine night sky anywhere, anytime. Good for astronomy, great PR for tech firms. [The dawn of space-based amateur astronomy?].
I can see a headline sometime in the 2030’s…”AI Mega-constellation discovers first exo-planet: Musk-1a”…guaranteed immortality…!
If it’s going to happen why not take advantage of it…I guess it’s evolve or die.
Don’t just think outside the box, think outside the atmosphere…The current equivalent of ‘Don’t it always seem to go, that you don’t know what you’ve got ’til its gone – They paved paradise, and put up a parking lot.’ Include me out! (Thanks to Joni Mitchell for writing the song.)
Hi All,
There is no doubt that the application by SpaceX for a 1 million satellite strong mega-constellation has the potential to be a devastating blow to astronomy at all levels. Yet, the economics of such a venture are alot less clear and some within the industry are already casting doubt on orbital data centres as both uneconomical and a significant risk to data security.
Whether or not this ever becomes a reality remains to be seen, though, as we have seen before with Musk / SpaceX never underestimate their ability to make even the improbable possible.
There is however, another potentially serious threat looming in the sidelines in the form of the Earendil-1 prototype satellite from Reflect Orbital. Their application for launch is currently before the FCC. If you are not aware of Reflect Orbitals plans a very basic summary is that they intend to launch a satellite constellation that will provide “sunlight as a service” – basically large space mirrors that will sit in an orbital shell at 625 km. The purpose is to reflect sunlight onto the dark side of earth to provide near 24hr illumination on areas where subscriber’s to their service pay for it. These will track across the sky shining a beam of light on, for example a solar farm and its surrounding area. There is no clear method stated as to where this beam of light goes as the satellite reorientates onto its next target. This is of course a very short and simplistic overview of their project.
There are many impacts and risks to their proposal, the key ones for astronomy being the launch of intentionally bright satellites and the risk of retinal damage if you are unfortunate enough to be looking through a telescope or binoculars when one of these satellites passes directly into your FOV.There are of course other significant impacts on ecology, and atmospheric pollution, aviation and so on, and also its worth noting the US military have seen the potential applications and have gave the project financial resources to explore ‘novel uses’ of the technology.
I would like to encourage any and all within the BAA to have a look at this project and join in lodging objections to the FCC. I am happy to provide details as to how to do this, and you do not need to be a US citizen to lodge an objection. All objections are equally valid, whether from individuals or organisations.
Clear skies,
JimJames Verner
Director
Dark Sky UK
IAU-CPS Member
- You must be logged in to reply to this topic.