HorstG

I disagree. I really think doing an intentionally crappy job is acceptable. Not even pretend. I think it is okay to really half-arse it. Or break it. Or be lazy. Or whatever. Except maybe intentionally harm someone.

No. Just no. They may do so to the worst of their abilities. Thats their prerogative.

The only limit might be publishing something that is actively intended to do harm. But I can't imagine a plausible example of that...

GDPR binds an operator of a service. The developer can do as he likes.

Just as you shouldn't eat everything you just picked up from the sidewalk, you shouldn't just use any code thats available out there.

check, check and check again...

Security isn't a special license for being nasty. Criticism is fine, even with some urgency due to security being important.

But software done for free by volunteers carries no obligation of a legal or even a moral kind, whatsoever. This is completely different from selling software or doing work for hire or donations. There a moral and often even legal obligation exists.

Defense would actually be quite easy. Just undesirable. There are working antisat weapons in the major powers' arsenals. However, they would produce nasty debris clouds.

And then there is also the vulnerability of the lauch site and control center...

Launch capacity scaling isn't only possible through useless comsats.

And astronomy is still an extremely important component for becoming space-faring. No use in going somewhere blindly when you can have a look first. But if there is no-one looking because nothing to see, funding dried up, scientists demotivated,...

Theoretically yes, through interferometry. But that is really difficult when there is relative motion within the constellation such as with starlink.

one gets time signals from photomultipliers, but those are too bulky for traditional pixel sensors. And something as bright as a satellite flare might fry them at an unexpected moment. They are usually built and tuned to be able to observe few to single photons.

Well then, we should also have Elon pay rent for use of space...

Depending on the type of measureme t taken, a dark transient is also harmful. However, by far not as bad as a bright transient.

It will kill astronomy pretty good.

The key point is usable observation time. Our current handful of satellite telescopes provide 24h of time a day. Each terrestrial telescope provides maybe 8h. However, there are a magnitude more telescopes on Hawaii alone than in space. You would need to get a hundred satellite telescopes to begin to replace earthbased observation time.

And that doesn't even begin to talk about the possible instruments, mirror sizes, astronomical costs of buulding and running satellites, etc.

Modern astronomy works at the edges of whats possible, a single frame might take hours. Needing multiple frames would mean multiple days per observation. It would mean no longer seeing faint and distant objects, limiting us to younger, closer and frankly far more boring objects. It would make observing variability impossible for certain timescales.

You need old distant objects for cosmology, observing the structure if the universe, big bang and stuff. You need variability for finding exoplanets, measuring distance and observing transitions such as supernovae.

Oh, and then a huge part is taking spectra, which means bouncing the light directly off a grating. Filtering transients is hard to impossible there. You need spectra for relative motion, magnetic fields, composition of matter and radiation and of course temperature.

Needing such filters would set astronomy back a few decades

Yes, but stability against vibration and thermally induced warping is also important. So you could make the mirror thinner than on the ground, but not really thin.

Cherenkov telescopes for neutrinos do look down for reasons of schielding. Neutrinos can pass the earth, other particles not so much.

But those are a special case, air cherenkov telescopes are looking for "less weird" particles like photons or protons. Those can only be seen looking up, since the primary particles moving down focuses the cherenkov light down in a narrow cone.