Hubble telescope has new lease on life after computer swap appears to fix glitch

Regarding the bomb, we were trying to end a global conflict, so the comparison couldn't be further off base.

It’s simply how things are done around here these days.

[0] Currently at least. Starship could I guess but it was planned way ahead of Starship even being a glimmer in Musk's eye. Do they have any grapple points on it as insurance? I would at this point, just put one of the posts they use on the ISS for Canada Arm to grapple.

JWST costs upwards to 9 billion USD. An Ariane 5 launch maybe 200 million.

Just because the launch is cheaper doesn’t make the rest of the project less complicated and costly.

With what's left of your budget, which is now very, very negative. Better to redefine abject failure as success to minimize the chances of it ending your career if you're involved in firm purchasing in any way. It's not like boards of directors have a clue. The big consulting firms will assist pulling the wool and priming the press so they can move onto the next mark. It's impossible to by cynical enough.

It took our IT over 4 years to migrate away from Siebel to Salesforce and it's going on 3 years since. I just learned the other day we still have a Siebel DB lingering around as a dirty little secret.

We move away from Lotus Notes over 10 years ago and we still have some Notes Apps used by our Legal Department.

me: I think we can build something in-house here better than what the vendor will provide, I think the vendor's solution is likely to be a failure for us.

them: Yeah, but if do it in-house and it fails, it's our fault. If the vendor's solution fails, it's their fault -- plenty of very prestigious universities are using this vendor, nobody's going to blame us for choosing them. [Ie, "nobody got fired for picking IBM" basically].

My dad was on an Air Force Base when the base commander delegated to his wife picking out all the furniture for the base housing. Naturally, every serviceman's wife hated it.

The project I worked one was migrating data from their in house ticket tracking system to Jira. I was importing tickets from 1985 into Jira which obviously didn't exist at that time.

Though probably a "different world". It would be hard to retrain to do react development, for example.

I guess the worst thing you can fuck up in space fairing software is the boot loader. Mess that up and you can’t update the software.

Note: I have never designed software for space. I have no clue what I’m talking about.

NASA is well funded, not underfunded. It receives over three times the funding of ESA by comparison.

Why aren't the Europeans funding their scientific institutions better? Because the combination of soaring entitlement costs and stagnant growth robs them of the necessary tax revenue for that. Which is exactly what's happening in the US, and it's going to get a lot worse yet. The US has a bit less of an excuse, seeing as it could safely cut $200b off of its military. However, that $200b spread around to every squeaky wheel still won't go very far (it's equal to a mere ~2.3% of total government spending), you might be able to fairly boost NASA's budget by $3b per year if you slashed the military. Back in reality, that $200b in cuts should probably be entirely allocated to healthcare, which brings us right back to the central issue of priorities; and the Europeans know that quite well, which is why ESA is poorly funded.

But again, even though it was "visible" it did not have many pretty pictures because the mission was looking at brightness variations in particular stars (planet transients).

> There's also JWST

Which is 15 years late and still on the ground.

https://www.greatobservatories.org/about

The next Roman optical space telescope is slated for 2025.

(He also worked on the TEAL AMBER and TEAL BLUE satellite surveillance systems, and probably others that he never even talked about.)

I make telescope mirrors.

This problem was well understood since the time of Herschel. We just have better solutions now.

The fact that this is a space scope is irrelevant to the fact that gravity will cause issues. For any telescope, you have to account for differences in the way the mirror is deformed in manufacturing vs in actual usage, and the ways the deformation will change in usage as the scope is leaning at different angles. That is always a thing.

What is particular to the Hubble is that the load in usage is zero (which is unusual), so you have to think about it that way in manufacture. But deformations in manufacture are always an issue you have to account for somehow.

Look at it this way: there is an ideal shape that the mirror needs to have, usually a revolution surface of some conic section (parabola, hyperbola, ellipse, circle). The performance of the mirror will track the difference between the ideal surface and the actual mirror. The error allowance depends on the wavelength λ of the observed radiation.

Telescopes where the error is greater than λ/4 just suck, and are unusable. Good performance begins around λ/8. A great mirror may do better than λ/20.

For visible light, λ/4 is 100 nm, or 0.1 microns. That's 10 thousand times less than 1 mm. On that scale, the mirror is made of jelly. If you put it on a rough surface, it will deform. If you put your thumb on it, hold it for a minute so it heats up from your skin, then pull away, there will be a "mountain" left behind on the mirror, under your thumb, until it cools off again.

In many cases, the support structures for large mirrors are complex mechanisms that ensure the force is uniformly distributed across a large number of points on the back of the mirror. Even amateur telescopes built using the Dobsonian template use passive self-balancing support with 3, 6, 9, 18, or even more points, depending on the size / thickness ratio.

Also, the vision is that robots can build on Mars, for example.

“Simply” means fund the research. My comment was from 7 years ago.

We also need the robots here on earth for dangerous tasks

We’d make impressive progress over each decade with more effort.

What if the system that swaps parts fails?

The other thing to remember was that Hubble was designed in an era that the Space Shuttle was meant to make manned missions to repair / upgrade commonplace. My understanding is that this was actually done at least once to Hubble (maybe more? I forget); but unfortunately for Reasons, NASA turned out to be incapable of resisting cutting corners which put people's lives at risk (Challenger, Colombia). A system designed today would be designed assuming that it would be robots or nothing.

So the idea is that you don't need to specialize it to the thing it's meant to work on, because it works on whatever a human works on. A similar idea drove a lot of the DARPA Robotics challenge, with its emphasis on being able to drive a normalish vehicle, open a door, climb a ladder, use a regular power tool, etc.

Anyway, I think the state of the art for all this is still pretty far away, which is why the instinct is to assume we're talking about something specialized.

It was also never meant for humans with less limited dexterity.

I recall one of the Hubble servicing missions I watched on NASA TV, in which they had to bolt a special adapter plate over a cover, unscrew over a hundred tiny non-captive screws (which the adapter plate was designed to catch, so they wouldn't float away), and only then could they open that cover. That part of the telescope clearly wasn't designed to be serviced in space.

"Just" is being extensively overused in this thread.

When operating multiple devices to improve reliability, diversity is one point.