Certainly 30 meter telescopes in space are not possible now, and likely won't be until we get space based manufacturing capabilities.
We won't get space based manufacturing until we can put a ton of things in space - things that likely be much larger and a whole lot more visible than Starlink satellites.
I don't think requiring that we can put a 30M telescope in space be the requirement before we can put things into space.
Also, as very-much-an-amateur my understanding is that a single 30m element isn't necessarily the only way to get very large telescopes.
One approach is what JWST is using, using folding mirror segments, another is tying together multiple telescopes that are distant from each other, where the distance between them is the effective aperture.
Of course, I'm sure there's drawbacks and issues with those approaches too.
Your earlier comment seemed to suggest that astronomers should just put their telescopes in space. There are telescopes that simply cannot be put in space with current technology. Even for those that could theoretically be designed to be put in space, we're talking about increasing the cost of doing astronomy by orders of magnitude.
At the moment, the vast majority of telescopes are on Earth. There is a role for space telescopes, but the total number of them could be counted on a few hands. Space telescopes are an extremely precious and limited resource, used basically only for things that absolutely cannot be done from Earth.
We can sit here and dream about building 30-meter telescopes in space some day, but that day is a very long way off. My guess is that even far in the future, if you're given X amount of money to invest in astronomy, you will still want to invest a large percentage of it in ground-based telescopes, because your money goes a lot father on the ground for most problems.
> a single 30m element isn't necessarily the only way to get very large telescopes.
No existing or planned telescope uses a single 30-meter element. I think the largest primary mirror is 12m. All the planned 30-meter-class telescopes are segmented.
> Your earlier comment seemed to suggest that astronomers should just put their telescopes in space.
There's no "just" about it, I'm aware of that, and I know it's not a case of taking existing scopes and shoving them into space.
> There is a role for space telescopes, but the total number of them could be counted on a few hands. Space telescopes are an extremely precious and limited resource, used basically only for things that absolutely cannot be done from Earth.
This is, in large part, because of the cost of launching and maintaining them. Satellite launch prices have come down dramatically in the last 20 years. If Starship becomes a reality, then it'll come down even further.
If we're actually to ever get off this planet as a species, then dramatically lowering the cost of getting stuff into orbit is a necessity.
I sympathise with Astronomers who're concerned about the impact on their ability to do science today, but its a bit like people complaining about the first interstates highways being built. Yep, we're going to demolish some houses, and make some places a bit noisier.
I'm hoping that someone will decided to invest their billions of dollars into mining and manufacturing in space to demonstrate that it's actually possible, and likely incredibly profitable.
Once that happens, we can make really stupidly large telescopes in-orbit.
If we talk radio telescopes instead of visible/infrared light telescopes, we likeky already have such big radio telescopes in orbit now, they are just pointing the wrong way (downwards):
It is estimated the highly classified Orion signal inteligence satellites currently in geostationary orbit have radio reflecting dishes of more than 100 m in diameter.
We won't get space based manufacturing until we can put a ton of things in space - things that likely be much larger and a whole lot more visible than Starlink satellites.
I don't think requiring that we can put a 30M telescope in space be the requirement before we can put things into space.
Also, as very-much-an-amateur my understanding is that a single 30m element isn't necessarily the only way to get very large telescopes.
One approach is what JWST is using, using folding mirror segments, another is tying together multiple telescopes that are distant from each other, where the distance between them is the effective aperture.
Of course, I'm sure there's drawbacks and issues with those approaches too.