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xoa 15 hours ago

Can't tell if you're joking or not, but SpaceX has indeed been collaborating with astronomical observatories to reduce the apparent magnitude (brightness) to ground for Starlink satellites. It's not as if the potential issues weren't apparent and reported on pretty early on, ie, [0] in summer 2020 before the network entered beta. It's not perfect and the period during orbit raising before the satellites enter operational orbits is more challenging, but very significant reductions have been achieved per recs, see for example "Starlink Gen 2 Mini Satellites Photometric Characterization" [1] in 2023 and "The Brightness of Starlink Mini Satellites During Orbit-Raising" [2] in 2024:

>When magnitudes are adjusted to a uniform distance of 1000 km the means are 4.58 and 7.52, respectively. The difference of 2.94 between distance-adjusted magnitudes above and below threshold implies that mitigation is 93% effective in reducing the brightness of orbit-raising spacecraft.

So there has been progress, though more may be possible particularly as Starship gives them more mass to work with for less money. That may bring new possibilities to spend mass on "cosmetic" purposes to shade and further reduce magnitude even if it contributes nothing to the core functionality. Same as more mass may allow regulators to feasibly require higher levels of redundancy and more margin for deorbiting in case of issues or at EOL.

Of course, that does leave older unmitigated working sats contributing to light pollution for the rest of their operational lifetimes, though worth noting that one of many major advantages for low-LEO/VLEO operation is that by design such lifetimes are much shorter, and in turn generation refresh will happen more quickly. Perhaps more importantly long term, there aren't as far as I know any actual international standards and agreements towards responsible brightness mitigation (or other issues like disposing of expended upper stages responsibly, standardized end-of-life deorbiting, etc). SpaceX has, for both PR and simple corporate self-interest reasons, been a pretty good actor so far even if they get a lot of attention for being the leading first mega constellation. But I really hope follow on efforts from other players can hit the ground running with magnitude reductions at least as good, and that SpaceX itself continues to improve (or at a bare minimum not backslide).

High bandwidth fully global comms is simply too valuable a capability to really imagine going back at this point. But that's no reason not to pursue reasonable compromise mitigations, and potentially some sort of funds to ultimately create far more orbital telescopes as well as part of the package taking full advantage of what upcoming cheap megalift will make possible.

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0: "Impact of Satellite Constellations on Optical Astronomy and Recommendations Toward Mitigations" | https://aas.org/sites/default/files/2020-08/SATCON1-Report.p...

1: https://arxiv.org/pdf/2306.06657

2: https://arxiv.org/pdf/2405.12007

defrost 11 hours ago | parent | next [-]

It's not just optical pollution, the same satellites visible in the article photo over the Pinnacles are leaking radio spectrum noise into the ostensibly "Radio Quiet Zone" of the nearby Murchison that's home to cosmic microwave sensors and one regional part of the developing global SKA radio telescope platform.

genewitch 7 hours ago | parent [-]

This would be real simple to prove, Starlink Satelites downlink on the same band as Satelite TV so you can use the receiver from a dish that downconverts it to something a cheap dongle can handle and put that all inside a grounded, metal box in the bed of a diesel and just record spectrum.

I was under the impression that actual space business people had ways of not leaking RF when flying over.

defrost 7 hours ago | parent [-]

It's been proven by several teams already, eg:

  In new research accepted for publication in Astronomy and Astrophysics Letters, we discovered Starlink satellites are also “leaking” radio signals that interfere with radio astronomy. Even in a “radio quiet zone” in outback Western Australia, we found the satellite emissions were far brighter than any natural source in the sky.
from: https://theconversation.com/starlink-satellites-are-leaking-...

referencing: Detection of intended and unintended emissions from Starlink satellites in the SKA-Low frequency range, at the SKA-Low site, with an SKA-Low station analog (Sep. 2023)

https://arxiv.org/abs/2309.15672

It's an ongoing issue in that Starlink v1.0 leaked and as I recall promises were made that the next generation of satellites would leak less and turn off when over radio quiet zones .. that second gen group have (IIRC) more noise and continuing transmitting over RQZ's.

WalterBright 15 hours ago | parent | prev [-]

> Can't tell if you're joking or not

Not. Often obvious simple solutions are overlooked. For example, NASA spent huge sums of money trying to design a gas gauge that will work in weightless conditions. Until an engineer suggested just having a "reserve" tank that has enough to bring the spacecraft out of orbit.

Another one was NASA spend a lot of money trying to figure out how to not have the Apollo capsule overheat from the sun. The trivial solution was to make it a rotisserie, i.e. slowly rotate it.

xoa 14 hours ago | parent [-]

>Not. Often obvious simple solutions are overlooked.

I'm not sure I'd say "often" has something like what you offered up been overlooked by SpaceX. We're long, long past the early eras when everything was first getting figured out, and the timescales and costs are totally different. Talking of "obvious", painting something black in orbit has clear enormous thermal implications, and there are aspects of the system that seem necessarily reflective as well (solar panels, optical links and so on) and in turn mitigation requires cascading design decisions. These aren't platinum plated Apollo era programs either. Like, gut check here: do you see ANY space stations or satellites in space, at all, where they "just painted them black"? I don't think it's actually trivial at all.

Anyway main point is yes, it's recognized and yes, it's getting worked on (successfully!), and I hope that will ultimately help pave the road for any other future megaconstellation efforts by showing what's possible.

WalterBright 11 hours ago | parent [-]

I've been designing things my entire professional life, and yes, engineers overlook the obvious all the time (me too!).

I always look for simpler ways, and often enough find them.