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Comment by cryptonector | Hacker News Reader

Time to move the observatories to space. If only there was a launch platform for those.

The only problem there is cost, upfront and ongoing. JSW is super expensive. We were very lucky Hubble wasn't a complete write off and even then the fix was very expensive.

All that vs. laying down some concrete and a telescope in a remote location.

> The only problem there is cost

If only there were launch platforms that could put up smaller telescopes (optical and radio).

I mean you can do a lot with telescopes that are much smaller than Hubble Class or JSW. A lot of people are doing work with telescopes that are much smaller. Also, as long as frequencies and locations are published, much of this noise (not all!) can be removed. Sure, the VLA is going to have a major headache, but LIGO wouldn't exist if we didn't know how to remove noise (LIGO had to deal with noise from cars many miles away and all kinds of vibrations because it is ridiculously sensitive).

LIGO can isolate itself from seismic backgrounds, but it has no artificial gravitational-wave foregrounds. (Yes, Newtonian Noise is a concern for future generations, but it is expected to be modeled and subtracted well-enough.)

Arrays like Starlink are a persistent foreground for the big radio telescopes. SKA and the like are in the Outback for a reason, but for this there is no escape.

I'd expect that starlink could be disabled within a few hundred miles around green banks etc. Would that help?

Typically for high resolution images you actually take multiple images. So it would be more work, but you can definitely remove foreground objects. This is like how you can take a bunch of photos of a landscape with people moving around in it and remove all the people by just looking at what isn't changing in the images.

I'm not saying it is easy, but it is definitely possible.

> The only problem there is cost

If only there was a space launch company bringing orders of magnitude reduction in cost.

Not the launch cost, the cost of the satellite.

JWST is 6500kg. Quick googling shows SpaceX costs about $3k per kg, so the launch cost is about $20M.

The total project cost for JWST is $10bn according to wikipedia.

Having worked at NASA, let me tell you that number is 100% BS on all levels. You have to go out of your way to make a satellite cost that much, which they did.

Look at how, say, Planetary Resources was putting together their much smaller telescopes and you'd get an idea of how it could be done on the cheap. Then to scale up you'd focus on cost effectiveness instead of maximizing capability at all cost. Do multiple cheap launches ($100m each) instead of spending billions on a complicated automated unfurling mechanism, etc.

I bet SpaceX could assemble a huge telescope in space from smaller telescopes, and they could do it for much less than NASA ever could. NASA is a jobs program.

> NASA is a jobs program

NASA is first and foremost our nation's science program. Everything from the network card driver your AWS instance is using to the planes flying into hurricanes to determine how strong they will hit was built with major contributions from NASA engineers.

LASIK eye surgery, the nutritional supplements in baby formula, solar panels affordable for consumers, OpenStack, even the BowFlex were all developed by NASA or under NASA funding programs.

You could at best say NASA is a jobs program for HN readers. :)

It is correct to call NASA’s human space flight a jobs program. It is specifically engineered to maximize the number of jobs spread across key congressional districts and states. And unfortunately this makes it extremely wasteful.

With cheaper launches, you can throw up several simpler instruments per year, instead of a FANTASTIC one per generation.

Or with cheaper launches you can assemble it in space instead of using that crazy elaborate unfolding mechanism that accounts for much of the cost.

It only costs that much because launches are expensive. If you live in a world where your satellite costs $300m+ to launch your going to spend a lot on the satellite to make sure that it is reliable and has a long life.

If suddenly launches only cost $50m then you might build a cheaper and slightly less reliable satellite as you know you can always launch another for only $50m

The cost of JWST is way out of control. You could build 10 space telescopes for less if you actually cared about efficiency and didn't need everything to be perfect for the first and only launch. Especially since the crazy folding mechanism would be completely unnecessary if you just launched them on Starship, which is big enough to hold JWST's mirror unfolded and possibly even the sunshade.

If you built 10 space telescopes for the price of JWST, I believe that EACH one would still be more expensive than the most expensive terrestrial telescope ever

Giant Magellen and Thirty Meter Telescope are both $billion+ projects.

So, no.

I was only thinking of telescopes that currently exist, since it's hard to determine the cost of something before it's built. Inflation and such tends to make a direct comparison a bit trickier— it's not fair to compare JWST dollars spent in 2000 with dollars that won't be spent until 2025. Plus, even though these sorts of things typically end up being more expensive than the original budget, I'm being optimistic :)

I think it's mostly about funneling money to Northrop-Grumman.

I'm not sure switching launch vehicles is a realistic option for a project being in development for 24 years by now. Especially not to a not-yet-existing rocket.

Radio telescopes work better on the ground

How about a 1km diameter radio telescope on the far side of the moon? https://www.space.com/nasa-telescope-far-side-of-moon.html

That's just one though, meanwhile SpaceX is complicating all ground astronomy, you can't just replace all observatories on Earth with one big dish and expect things to be better than before.

Only if they are operating when they are in range of the telescope. The satellites know where they are in space, they could just shut off when passing over. Usually not many customers where these things are installed anyway.

According to a broad study of astronomical surveys[1], the impact of Starlink on the vast majority of observatories is quite minor. There were exceptions, like the upcoming Vera Rubin Observatory in Chile which uses a wide angle at twilight so is particularly impacted.

Starlink used that study to come up with the night shade idea to mitigate those impacts.

In that survey, radio telescopes were in the "minorly affected" list.

1: https://arxiv.org/abs/2003.07446

You must have pasted the wrong link, because the linked article mentioned "survey" 4 times and 3 of those was in a short sentence saying searches for near-Earth objects will loose all twilight...

The severity of the noise for radio was not graded in the slightest, and the word "minorly" is never used.

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