James Webb telescope reaches its final destination in space, million miles away | Hacker News Reader

James Webb telescope reaches its final destination in space, million miles away

npr.org

754 pointspseudolus342 comments

I'm a little embarrassed to say this and I don't know exactly what I pictured in my head, but I had no idea these telescopes were so big[1].

I guess I never saw one pictured next to a human. I've only seen pictures of satellites being worked on so I expected something more human sized? It seems so stupid now, especially since earth telescopes are huge.

[1] https://svs.gsfc.nasa.gov/vis/a010000/a013500/a013522/JWST_v...

The space shuttle blows my mind every time I see one. It's huge - the size of an airliner - and would glide back at Mach 25. It's a humbling level of accomplishment.

To show the comparison (737 for example here)

https://icdn2.digitaltrends.com/image/shuttle-948x1500.jpg?v...

Those size comparisons are super misleading. I've seen the shuttle and it's not that big. A 737 is pretty small. The shuttle can ride piggy-back on a 747--in fact it was designed to:

https://www.nasa.gov/centers/armstrong/news/FactSheets/FS-01...

Also, the comparison with the Statue of Liberty is also misleading. The Statue of Liberty is on a huge pedestal that makes it stand much, much higher; the orbiter and boosters wouldn't reach the top of the SoL.

The sum of your comment seems to be the subjective belief that the statue of liberty and 737s are "not that big"...

Not sure what size you'd expect the shuttles to be, but being in the same ballpark as the statue of liberty (without pedestal) seems a great deal larger than my expectations.

These are subjective things, sure. My personal feeling upon seeing the shuttle was that it was not that big, because I've seen big airliners all my life. I was expecting the shuttle to be bigger. So when I looked at the parent's infographic and saw a 737 and the Statue of Liberty there, they didn't seem right (I've also seen the SoL in-person). So the size comparisons I think are quite misleading in that graphic, and yeah, I was surprised how much smaller the shuttle is than what I expected.

Having never actually seen the statue of liberty my sense when seeing these comparisons is that it's much smaller in real life than the version in my imagination - no matter how many times I see the comparisons, the statue remains much bigger in my head

Well, the 737 is probably the worst aircraft to compare against, given it has been enlarged by 50% from the original 737-100 to the newer 737-900! https://upload.wikimedia.org/wikipedia/commons/b/bc/B737Fami...

original plan was smaller, but military had a mission in mind that required it be bigger, so they went bigger to get military buy in. And of course the imagined mission never happened. I wonder how much money would have been saved!

The space shuttle is a sad story. On the one hand the military’s money made it possible but they also influenced the design in a very bad way.

This is the case with almost all large scale human endeavors. To get things done with lots of people takes compromises. Apollo program was the same way. I assume the pyramids and roman roads and so on as well. Though to be fair at some point once the shuttle program got going someone could have aborted on it and said that really this doesn't make sense.

And the Mercury program, which launched on adapted Redstone ICBMs [0], themselves improvements on V-2s.

An unfunded project that never gets built is objectively worse than a military-funded project.

[0] https://en.m.wikipedia.org/wiki/PGM-11_Redstone#Redstone_der...

If the military-funded project creates $1M worth of value using $1B of funds, the unfunded project is objectively better.

That's what army mapping service essentially did with early radar distance measuring projects. Huge expensive fleet of 18-wheeler trucks failure. And classical surveying methods beat it in every way at the time.

But it was the direct predecessor to microwave communications. It was just portable military distance measuring equipment (like the model-99 dme w/ ~1cm @50km) that used a signal they found easy to piggyback voice and data on. And included that in the field units.

AND 2nd, after a dozen or so more hugely expensive projects (ranging from failure to moderate success to "achieves objectives"), it led to the Airforce NAVSTAR program, which you know as... GPS.

So the question becomes: What was the actual "objective" value provided by those expensive initial radar experiments, despite failing to achieve their direct objective?

It's difficult to say without access to the counterfactual world where GPS was invented based on civilian microwave communication which itself would have evolved from civilian radio communication. We live in a world where the DoD redistributes money away from private industry and towards another sector of private industry, and it is hard to say what would happen if R&D tax laws were changed to move that money back from private military industry R&D to industry-industry R&D.

Maybe microwave transmission, but the economics of GPS or GNSS in general would preclude civilian investment in such an expensive constellation without obvious revenue channels.

And it's moot for both these cases because the technology was needed for direct military applications anyway.

What's the practical or ideological benefit of industry-industry R&D when the military is going to be the only customer, or at least the only paying customer for the first years/decades of use?

I agree with you in general, with it being better for governments not picking the winners of markets or deciding who gets research money.

But military is such a unique (yet universally needed) type of market, that practicality here means treating them as a large customer with unique product needs ( products unlikely to be revenue generating on the public market), even if you don't treat it as direct government allocation or a fixed/manipulated market.

The only way I can think of to avoid that entirely would be some libertarian version of an all private, defense-by-contract type military.

And then you'd have concerns about whether that could hold up to peer adversaries, and dozens of other wildcard concerns.

And sweeping von Braun's Nazi complicity under the rug while others were hanging from the gallows at Nuremberg.

As A German this really bugs me. Von Braun and friends knew exactly what was going on in their production facilities, didn't care and never had to confront their role in this.

"Once the rockets are up who cares where they come down, that's not my department" https://www.youtube.com/watch?v=QEJ9HrZq7Ro

don't say that he's hyp-o-critical, say rather that he's a-po-litical

(For those who aren't familiar with 1967 humor: https://m.youtube.com/watch?v=QEJ9HrZq7Ro&t=17s )

Right, this is basically a "human politics" thing.

A pretty typical big government project to me. Lot's of power centers pulling in different directions, little focus on actual needs.

Space X does better work in part because it can make its own decisions and focus on long term goals.

That's the stereotype of government promoted by private business like SpaceX, so they can get the funding shifted from NASA to them. But no private business has accomplished in space anything approaching what government has. NASA has been spectacularly successful, orders of magnitude beyond any explorers in human history.

We're talking about just one of many successses on this page.

OTOH, they also influenced it in many good ways that you don't hear about.

E.g., my astronomy professor mentioned to me in a conversation that the original design for the Hubble was smaller due to expected budget, but that it got up-sized because it turned out that they could piggy-back off of other relevant military development, and iirc, that went beyond just the larger available size of the shuttle bay.

I thought the military money was promised but never ended being provided, making it doubly tragic.

>>the imagined mission never happened

The X37s would like a word. Also, "Rods from God" has something to say

https://en.wikipedia.org/wiki/Boeing_X-37

https://endwar.fandom.com/wiki/Kinetic_Strike

---

Rods from god may be the source of "jewish space lasers" <-- the comment by a senator on how the wild-fires have been started in US and AU, meaning that a tungsten rod from space rained down molten tungsten to start fires...

Fun stuff to speculate on.

The mission being referred to was capturing a Russian satellite in a polar orbit in the cargo bay and returning it to earth. The shuttle also needed big wings to provide the cross-range capability it would need to complete one polar orbit and land at the original launch point (Vandenberg) despite the earth having rotated, moving the airbase by many hundreds of miles since takeoff.

The original NASA spec had a smaller cargo bay and wings because it would have mainly been a crew ferry. As a result it would also have been launchable on top of a rocket instead of strapped to the side, giving better safety. Significant cargoes would have been launched independently.

Russians had the Buran, with more or less the same dimensions.

https://en.wikipedia.org/wiki/Buran_(spacecraft)

I've heard the (probably unfounded) story that the Soviets saw the Space Shuttle, couldn't figure out why the Americans would build it but figured there surely must be a good reason; so they copied it to also have whatever capability the Americans were after.

Buran was also superior in capabilities; greater lift capacity, ability to transport more people, and attain higher orbits. It could also perform a mission entirely autonomously.

The US Space Shuttle was the (heavy) inspiration, but the Soviets put their own spin on it.

That's the second mover advantage right?

That's part of it (with regards to rocket motor tech). The other is that the Soviet's designed the vehicle through a different process, versus the American's where it was design by committee (between NASA and the DoD [1]).

[1] https://en.wikipedia.org/wiki/Space_Shuttle_design_process

It had one test flight. Hardly comparable to a system which had (six?) models fully deployed and operational.

Five Shuttles flew to space - Columbia, Challenger, Discovery, Atlantis, Endeavour. And Buran - the one which flew (other Soviet spaceplanes would have different names, so Buran is like Columbia, not like Space Shuttle) - didn't have e.g. the life support system; it was rather a development flight, than a demonstration of a complete system. Still Buran (as a combined name, like Energiya-Buran program) had some better capabilities e.g. no toxic propellants onboard (Shuttle has to be chemically "pacified" after each landing) and longer orbital life (with cryogenics onboard).

> Buran (as a combined name, like Energiya-Buran program) had some better capabilities e.g. no toxic propellants onboard (Shuttle has to be chemically "pacified" after each landing) and longer orbital life (with cryogenics onboard).

My point is that they aren't capabilities, just specifications and promises for a cutting edge, developmental technology.

It didn't fail for any technical reason though, the whole government behind it was stumbling at the time on it's way to full collapse from a heady medley of internal and external forces.

According to a book cited on the Wikipedia page on the Buran program, the Soviets looked at the shuttle's payload capacity and concluded it could be used to deploy military weapons into orbit.

Any orbital rocket can deploy weapons into orbit. The Shuttle was unique in that it could theoretically capture a satellite and return to Earth with it.

It's not unfounded, and they knew about it before it ever flew once. A family member was in the CIA at the time (later at NSA and RAND) and played a role after they were sent to the USSR after graduating college to study Russian (paid for by CIA, they know 8 languages). They translated the technical Russian Buran plans/documents and decoded them for our scientists to compare to their own, as well as help slip design flaws into plans they knew would get stolen (because they knew who was stealing them from Nasa). They met with the president over the issue multiple times. True story. They were also involved in every stealth program until they retired in the early 2k's. They were in the pentagon when the plane struck on 9/11. I really wish I could get them to talk more or write a book lol. [Using "they" to avoid gendering family member]

The Soviets (at the time) didn't "copy" it. They stole the plans and made it from them, adding in a few alterations, although the plans they stole were purposefully flawed.

If you're up for it, you can visit the Buran's in their final resting place in Baikonur. They're just sitting there rotting away. Here's a video of some kids who broke in and had some fun exploring: https://www.youtube.com/watch?v=-q7ZVXOU3kM

Article about the Soviet's espionage to get the plans: https://www.19fortyfive.com/2021/12/buran-how-russia-stole-t...

In re the youtube vid, that's a flippin' huge hanger. Crazy that this stuff is sitting dormant.

There’s a fantastic book about the stealth program by the former director of the Skunk Works, Ben Rich

They told you about these highly classified operations?

It's not classified anymore (I linked to a story that gives more info than I did), and you can be sure they won't tell me most details of things I ask about. If you think they sit there and tell me state secrets, think again lol. They're quite frustrating to talk to about this kind of stuff with because they won't answer most questions, or answer vaguely, and give absolutely no visual or audio indication of what they're thinking or what the answer might be. No wink-wink nod-nod. Completely dead-pan. You don't get to the level they were at by not understanding what you can and can't talk about. They don't slip up when drinking. They're still active in the community in the public sector side post retiring.

What was the intended mission? I’ve read about the classified missions that went ahead, iirc one of them did use the full capacity.

Likely snatching enemy satellites in a single orbit (i.e. launch, snatch sattelite, land, all in the same orbit) before enemy can even detect that the shuttle is up there.

> What was the intended mission?

There were several. A couple of examples: the shuttle could delay release of a payload, maneuver while in orbit, release the payload, then maneuver again. So conceptually, you just put a satellite into an orbit and your enemy doesn't know exactly what orbit its in. I'm sure eventually they would find it, but the military still wants stuff like that.

Another example is the ability to grab a satellite and bring it back to Earth. To my knowledge, this was only ever used with the "long-duration exposure facility" because it'd probably be considered an act of war to steal another country's satellites but here again, it's the kind of thing the military would ask for.

Isn't the shuttle so big that it would be easy to track and see it?

yes, but no country can track a given object in LEO for its entire orbit (unless it's transmitting its position to another satellite).

So the idea is that the shuttle launches with a secret payload, and every 90 minutes you see it pass overhead. This goes on for days or weeks. Eventually it lands.

What happened? Well what you don't know is that on day 2, while it was over the Pacific and you weren't tracking it, it fired the OMS, deployed a payload, then fired the OMS again to return to it's previous orbit.

There's a whole other satellite out there and you don't know about it until you find it by some other means. And eventually you will find it. But the military is happy to pay for that short window of subterfuge.

No idea, but yes I assume other missions managed to use the full capabilities once it was big!

The one that had the biggest influence on the design of the shuttle was probably the plan to launch into a polar orbit, rendezvous with a satellite, capture it, and land as it swung around for the next orbit. This require massive cross-range capability, in order to be able to glide back to a suitable landing site in the US, putting lower limits on the size of the wings.

The classified autonomous X-37 [1] has a cargo bay [2] and there are (were?) plans to scale it up to double the size to accommodate larger payloads and crewed missions [3].

[1] https://en.wikipedia.org/wiki/Boeing_X-37

[2] https://www.thedrive.com/the-war-zone/36440/this-is-our-firs...

[3] http://www.spacesafetymagazine.com/aerospace-engineering/spa...

That X-37 photo in the wiki article had me go down the "payload fairing" rabbit hole. Still don't quite know what the "bubble wrap" is on the inside. I assume it is part insulation to protect from extreme heat and part, well, bubble wrap.

According to wikipedia those things cost around $6 million to manufacture and spacex was the first to ever bother retrieving them.

https://en.wikipedia.org/wiki/Payload_fairing

Gosh, the section on "Mission failures caused by payload fairings" is understandable but not something I've ever heard of before. The launch crew error of failing to remove two lanyards.. ugh. To be "that guy" must've sucked.

Scott Manley has a wonderful explainer on it "The Most Important Space Shuttle Mission Never Happened":

https://www.youtube.com/watch?v=_q2i0eu35aY

they spent a huge amount of money building a launch facility for it at Vandenberg that was never used. Got cancelled after the Challenger exploded.

https://www.thespacereview.com/article/1960/1

HEXAGON KH-9

> And of course the imagined mission never happened.

There were 11 classified (ten successful) DoD space shuttle missions:

https://www.space.com/34522-secret-shuttle-missions.html

That's roughly 8% of shuttle missions.

The mission I believe the parent comment was referring to was a foreign (Soviet) satellite recovery. It required a larger payload bay and as I recall a very aggressive launch profile that I believe also imposed some undesirable design constraints, but my memory is fuzzy.

My understanding was that the specific requirement was for a launch into polar orbit (southbound from Vandenberg AFB, just north of Los Angeles) and then a landing ~90 minutes later at Vandenberg, clearly to snatch something out of orbit.

Since the earth is rotating under the orbital plane of the shuttle, this requires a large amount of cross-range maneuverability on reentry so it could land back in California rather than ~22.5 degrees west of Vandenberg in the pacific ocean, and this required large wings.

I don't believe it's known for certain outside of classified circles what was to be brought back. One theory was that it was to snatch a Soviet spy satellite out of orbit, but it's entirely possible given the timelines that the classified requirement was to pull a film cartridge from a US spy satellite in polar orbit and return it quickly to earth for processing.

> I don't believe it's known for certain outside of classified circles what was to be brought back.

Given that many details of the keyhole program were recently declassified [1], is there any chance we'll get to know the true nature of the shuttle program? (And if so, when might it happen?)

[1] (a decade ago) https://en.wikipedia.org/wiki/KH-9_Hexagon

Unfortunately there would be no way for the USSR to know that they weren't going there to nuke Moscow from the south where there weren't any radars looking. I'm not sure if that was ever seriously considered on the US side but my sense is that the eventual realization that there was no way for the USSR to know and trust that is part of what stopped the shuttle from ever launching from there.

re military mission never using the size, there could always have been classified payload launches that ended up using it.

There were plenty, the military missions existence and classified nature weren't classified themselves. (Or at least plenty enough weren't. We wouldn't necessarily know of ones that were.)

So the "classified DOD project xyz" tasks are listed right there on the published official mission lists and schedules, and quite easy to look up on both Wikipedia and straight from NASA.

But the thing not achieved was Vandenberg launches, which would allow more N-S polar orbits that are often more useful to the military.

The less official but still obvious thing not achieved was the Airforce building a manned military space station (as far as we know...).

The shuttle had plenty of military missions, and most are still classified.

No, we never got the Vandenberg polar launches we were promised.

And I don't think anyone anticipated just how quickly miniaturization and automation were going to advance when it was designed in the 70's or even as missions began in the 80's.

Even autopilot was a controversial cutting edge technology that was excluded because of the focus on human centered missions.

But back to military- it's not a coincidence that Hubble fit so perfectly in the shuttle cargo bay.

(Hubble being a spare keyhole spy satellite body, with borrowed mirror fab tech.)

But it would be interesting to know just what else the military had in mind, besides their not-so-secret ambitions for militarized manned space stations.

> But back to military- it's not a coincidence that Hubble fit so perfectly in the shuttle cargo bay.

I assume Hubble was built that size because it would fit? No coincidence indeed. And what does that have to do with the military?

> what does that have to do with the military?

Hubble is a military spy satelite design.

Development of which presumably predated or coincided with setting the design parameters for the shuttle.

Not exactly, I think they just use a specific mirror design (2.4m dia.) because they are already manufacturing them to be used in spy satellites.

Actually one of the reason SS was not cost effective anymore because of the added complexities required by the DoD.

In perspective, you should keep in mind that the Space Shuttle was a failure as a launch vehicle, both in terms of safety and economics.

And yet it allowed capabilities that we have lost in 2022.

Reminds me of a video I came across last year about about landing the space shuttle and the complexities of it all. https://www.youtube.com/watch?v=Jb4prVsXkZU

You can actually go see Endeavor in real life at the L.A. Science Center. Admission is like $2. Regardless of the size, the spectacle is breathtaking.

I traveled to LA once just for the sole reason to see the space shuttle there. It was worth it!

I remember when it was decommissioned and flown to LA on the 747 transporter...definitely an event. They publicized the flight path and times, and did like 2 or 3 loops over LA and the west side. Everyone in the city was watching on the rooftops of all the office buildings and parking garages.

I'm sure it was! And more for your trouble you got to get really up close to a real SR-71 Blackbird out in the parking lot. The L.A. Science Center is one of the best hidden gems of Los Angeles and I used to love going there pre-COVID.

Standing next to a shuttle is a humbling experience. On TV it looks like, well, a plane, but in person, it's just massive. The exit hatch (I assume), the one you would expect an astronaut to exit while fully equipped and layered, looks like the size of a bottle opening.

https://californiasciencecenter.org/exhibits/endeavour-exper...

You can get really close to it, in the current temporary building. Wonderful. You can almost touch it, and you can smell it, and see the scuff and scorch marks. Go before they raise the money for a bigger building and stand it up.

Both Endeavor and Vasa[0] are super, super cool.

[0] https://i.redd.it/7zzqeyu5zyo71.jpg

Space shuttle was not that big. It was literally transported on an airliner and a fraction of the size.

The JWST at 6.5m is larger than the largest terrestrial telescope in my childhood.

Keck was the first one bigger - 1989.

The next one Keck 2 was 1997.

https://en.wikipedia.org/wiki/List_of_largest_optical_reflec...

The human is not to scale if that's the Webb telescope.

I measured the mirror - top to bottom - as 304 pixels and the human as 86 pixels. This makes the human 1.83 meters given a mirror diameter of 6.5 meters. So it is to scale.

I think the height is there, but the human seems otherwise out of proportion. He seems to wide, which gives the illusion that he is shorter. And his head is too big, which again makes him look younger/smaller, more cartoonish. I think this is from a stock cartoon character rather than a real person.

A human standing next to a full-size replica: https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2F...

It looks the same to me.

Where is this replica located? Is it open to the public?

I don't know where it is currently, but according to this 2008 article it was on a world tour at that time.

https://phys.org/news/2008-07-james-webb-space-telescope-ful...

I recall seeing a full-sized mockup of the James Webb at the South by Southwest about ten years ago. It was accompanied by a small traveling exhibit about the mission and some folks from a NASA (or Northrup?) education team to answer questions. They had been taking it to cities and museums across the country.

Not sure where it is now or if there are multiple full-sized mockups, but I wouldn't be surprised if one ends up in the public collection at Udvar-Hazy Smithsonian Annex where many big NASA toys end up.

6.5 m across 5 hexes. The human is maybe 1.25 hexes tall.

About 1.6m or 5'3". That's a dry short adult human.

It definitely is. 6.5m diameter of the mirror only on JSWT and 2.4 of Hubble.

Did you ever see images like these?

https://www1.udel.edu/udaily/2009/may/cool051509.html

Then it should not be surprising that a telescope is about that size.

just enjoy, if you have a disney+ account, the documentary "among the stars" where you can view the astronauts repairing the hubble telescope

May I please subscribe to the raw images of ANY space telescope...

I mean *WE* /paid/ for them... I would like to access the data provided in real-time.

Where can one get the raw images?

These images would not be your typical jpg taken in the visible part of the spectrum. I’m not sure it is cost effective to host these image data for random people to download without any post processing. If you are dedicated enough to understand and post process the data yourself you can probably get access to the data for free

Once they're taking images, you'll have access to them.

Hubble's all went up (in raw as well as processed form) at https://hla.stsci.edu/, http://hst.esac.esa.int/ehst/, and several other places. Expect the same for JWST.

(Same for any other NASA mission. Here's the Curiosity rover: https://mars.nasa.gov/msl/multimedia/raw-images/)

> Once they're taking images, you'll have access to them.

What you say is true but with an asterisk. They grant time limited exclusive access to the data to whatever science team is using the telescope. It's basically an embargo agreement. That way the science team gets the first chance to do their research and publish it. Not all missions fall under this and in some cases you'll see what is going on right away. Eventually all data will become public.

I'll just quote their policy[1]:

    Access to science data from most active missions is often limited to the Program Investigator Team during a period of exclusive access immediately following the observations. The duration of the exclusive access period ranges from a few months to as much as a year, depending upon the mission, the program category, and other factors. Some other data, such as those obtained during facility commissioning, or those that are found to duplicate concurrent observations by a Guaranteed Time Observer (GTO), may also be embargoed for a period of time. Data falling under exclusive access can be discovered via MAST public interfaces, but may not be retrieved except by authorized and authenticated persons. Following the expiration of the applicable exclusive access period, science data become available for public use without restriction.

There is a ton more [2] about how to apply to get time on the telescope. Dudes even have a standalone desktop application to help put together the proposal.

    [1] https://archive.stsci.edu/publishing/data-use
    [2] https://jwst-docs.stsci.edu/jwst-opportunities-and-policies

> I would like to access the data provided in real-time.

Telemetry is unencrypted. You have access to the data in real time. Have fun getting useful data out of it.

> Where can one get the raw images?

Online ,its all public. You might need a pHD to figure out how to make it useful to the mark 1 eyeball

I loved "Mark I Eyeball"

As noted elsewhere: um, yeah, all the data is available, for free.

But in regards to the James Webb: I don’t think you’re going to find the raw images to be particularly compelling. It is imaging in the infrared spectrum. So it’s going to require a fair bit of processing to get a reasonable monochrome image out of that data.

Give https://api.nasa.gov/ a look.

I tinkered around with the idea of building an app that would get daily images from the space telescopes and the Mars rovers, as it turns out - NASA has an API dedicated to them (search for it, really easy to find via your favorite search engine).

I never ended up building anything from it quite yet (maybe soon), but the possibility is there, and the data is free to obtain. You have to register for an API key, but again, it's still free. The photos are updated quite frequently if I remember correctly.

Same thing can be said about the National Weather Service. You can get your weather forecasts in nice JSON formats from NOAA, all whilst not having to sell your data to The Weather Channel, or whatever alternatives exist for weather apps on Android.

That animation seems right. Hubble space telescope is about the size and shape of a bus.

https://www.nasa.gov/audience/forstudents/k-4/stories/nasa-k...

https://www.sciencefocus.com/space/hubble-space-telescope-ho...

It’s really easy to get a wrong intuitive sense of the size of these things! I don’t understand why space agencies don’t always have human figures for reference in their visualizations. Or even a simple scale bar! We just get these silly “the size of a tennis court” type textual comparisons. Few people realize how big the Curiosity and Perseverance rovers are, as another example.

> Few people realize how big the Curiosity and Perseverance rovers are

To be fair, Perseverance looks as big as I imagined it would be, about the size of an SUV but wider (because even in 2020s, they still don't have streets in mars, what a bummer): https://www.nytimes.com/2020/03/05/science/mars-2020-rover-n...

Or did my googling fail me? :)

edit: direct image link around paywall: https://static01.nyt.com/images/2020/02/18/science/18mars202...

My mental image until I looked it up was around the size of a dog. No, I don't know why

The older ones were smaller.

https://earthlymission.com/size-comparison-generations-mars-...

But even Spirit and Oppy were… well, I guess they're roughly the size of a very large dog. At 185 kg, much heavier than even the largest dogs though.

Because it's called rover? :)

Stupid me thought its go kart sized like the one Howard Wolowitz in The Big Bang Theory brought to a baseball stadium.

https://archive.is/tpcRK for the article

I believe the banana is the Internet standard for visual scale.

Also radioactivity, which also suits a Mars rover comparison.

> Few people realize how big the Curiosity and Perseverance rovers are

… and how much larger they are than Sojourner from the Pathfinder mission. Perseverance was sent with a metal plate depicting profiles of all five Mars rovers to date: Sojourner, Spirit, Opportunity, Curiosity, and Perseverance. [1].

[1]: https://spaceplace.nasa.gov/mars-rovers/en/mars-rovers_metal...

Really sad that 30 years later we're only slightly larger. This is a major problem for telescopes since there are hard physical limits on resolution vs size.

Obviously it’s sad that we don’t have a larger Hubble-equivalent by now, but the Webb’s operating temperature makes it a completely different beast. It is massively expanding our capabilities in a way a larger Hubble wouldn’t. And I’m hopeful for the mid-term future, as the massive improvements in launch capability we’re seeing start to pay off.

It's 2.5 times the mirror diameter, which is 6.25 times the light collecting area.

They both look like they might be similar sizes in an illustration like that, but the Hubble mirror is 2.4 meters, whereas the JWST mirror is 6.5 meters, which has 7 times the light-gathering capability of Hubble.

SpaceX Starship may help with that, assuming it works as intended.

Maybe that video can also help:

https://svs.gsfc.nasa.gov/10776

I'm trying to find an article with the exact story, but during the building of some of the early large satellites (something like the MilStar satellites [0][1]) they realized it would be really handy to be to rotate the satellite to work on it from different angles. So the satellite manufacturers repurposed rotary train car dumpers [2] in order to rotate the giant satellites.

[0] https://external-content.duckduckgo.com/iu/?u=http%3A%2F%2Fc...

[1] https://en.wikipedia.org/wiki/Milstar

[2] https://en.wikipedia.org/wiki/Rotary_car_dumper

I think most satellites just unfurl solar panels. This one had to wrap up the big sun shield as well, and the lens pieces were kinda crammed together and then spaced out after deployment too. So the rocket couldn't fit something nearly as large as this as a payload going up.

The largest geostationary telecom satellites are also quite huge, if you were to stand next to one. In the range of 6500 kg weight and about the size of a school bus.

I marvel at how small they are. Why not add 20, 100, or 1000 more mirrors to JWT? Or launch 10 more of these and go full interferometry? Maybe I've just been playing to much Dyson Sphere Program, but it feels to me that NASA et al are committing the cardinal sin of making the production loop too small.

Probably because this project has been in development for decades and overran it’s timelines and budgets multiple times (to my knowledge). Congress already hates funding NASA, can’t imagine they were lining up to give them more money when I’m sure they had been asking when’s this thing even gonna come out?

Also, FWIW, this thing has 100+ points of failure along its route to being fully deployed and getting to the L2 spot. A lot of people thought for sure at least one area would malfunction, would have easily doomed the whole launch. After this successful launch, it’s possible we’ll see discussion on building another in this design, but there is already a telescope in the planning stages for a 2027 launch, as well as four other concepts being developed for the future.

https://en.m.wikipedia.org/wiki/Nancy_Grace_Roman_Space_Tele...

https://space.stackexchange.com/questions/57407/are-they-alr...

> Congress already hates funding NASA

? They seem to fund it quite a bit, for generations.

The nasa image[1] of employees with the scale model provides a better sense.

[1] https://www.astronomie.nl/upload/750x498/images/Telescopen/J...

I'm surprised that JWST isn't actually all that much bulkier than Hubble, despite the mirror(s) being so much larger. In retrospect I guess that makes sense, since much of Hubble's bulk is the long tube enclosing the mirror, which JWST lacks. Also, the size of things that can be reasonably launched into space is limited by the launch vehicles themselves. (Maybe NASA would have built it bigger if they knew exactly the launch vehicle specs that would be available at the end of 2021, or they might have waited for Starship, but obviously that couldn't have been predicted when work on JWST began.)

They're mostly limited by the size of the nose that goes on the rocket, which sadly hasn't advanced much in the past few decades. They were able to get a much larger mirror on there using a ton of clever engineering and folding, but the overall structure size is mostly limited by the payload size limit.

Starship would supposedly fit the unfolded mirror as a single piece. There has been discussion in actually using starship itself as the structure for a future telescope.

basically spaceships to capture photons!

I think Destin of the Smarter Every Day YT channel had an interview a couple years ago with Dr. John Mather, the senior project scientist of the JWST, where he asked something like "will you be nervous during the launch and deployments", and Dr. Mather replied " I don't get anxious about stuff I can't deal with", and that they've tested everything they thought of to test.

I was super impressed with Dr. Mather, not only that he seemed so wise, but also that this super busy man took the time to do an hour long interview with a random You-Tuber. I think the JWST project is in good hands.

Edit: I guess Destin is not a 'random' You-tuber, but someone that was well-placed to connect with Dr. Mather. Still, he's not CNN or BBC - he's a guy with a handheld camera that doesn't ask fluff question, but questions intended to help inform himself and his audience. Still think Dr. Mather thinking it was important to spend so much of his schedule with Destin was impressive.

Destin's channel is one of the older, best-known channels in the YT's educational sphere. Recently, the US Navy even let him on a multi-day tour of a nuclear submarine and tape classified information (later redacted). He himself worked in the military. I don't think that it's fair calling him a random youtuber, to me he seems like the perfect youtuber to interview such people (as Destin himself has a background in rocketry).

If I remember right, his dad was/is very involved in the JWST.

It's really amusing contrasting the brains going around in that family with them both goofing off with a lawn mower carburetor in the garage.

Funny, I wouldn't use the word contrasting, I thought it was cool that their goofing was was around smart stuff. (probably just because I didn't know much about how a carburetor works, and after watching the video, know much more)

Very true. Although not such an uncommon contrast in Huntsville, AL, where Destin lives.

Destin has also peaked (or very close to it) in importance of person interviewed, as he interviewed Obama during their presidency. Though, sadly not an hour long. https://youtu.be/GpWQHFzrEqc

Just out of curiosity, is it considered best practice these days to use the gender-neutral "their" even with a specific subject (Obama) who is known to use masculine pronouns for himself?

It doesn't matter

Definitely not.

I think it would be nice if English evolved to only ungendered pronouns. Eliminates accidental offense while also reducing everyone's cognitive load.

Also, you reminded me of a quote from yesterday: "The problem with defending the purity of the English language is that English is about as pure as a cribhouse whore."

I don't disagree with you, but I think it's worth pointing out that there is a pragmatic benefit to gendered pronouns.

You can think of pronouns as sort of like `$?` in bash or `_` in Python's interactive shell. They give you a short way to refer to a previously mentioned noun. When you have more than one of these "special variables", you can use them more often as long as they conveniently get uniformly distributed across the previously mentioned nouns.

So, in English, you can say:

"Blaine Wolfeschlegelsteinhausenbergerdorff Sr. gave Rhoshandiatellyneshiaunneveshenk Koyaanisquatsiuth Williams a sweater for Christmas. She liked his gift."

The second sentence can use two pronouns because they happen to be unambiguous. With only a single pronoun, that sentence ends up like:

"Rhoshandiatellyneshiaunneveshenk liked Wolfeschlegelsteinhausenbergerdorff's gift."

(This is obviously an extreme example for comedic effect.)

This is also why Romance languages have noun gender for inanimate objects where actual biological gender isn't meaningful. It's not about genitals, it's about scattering a few pronouns uniformly across the noun space.

Of course, one might rightly argue that gender is not a good mechanism to use for your pronoun distribution. We could do something like shells do where we assign pronouns based on recency of the mentioned noun. Or some other system.

But my point is that gendered pronouns aren't completely bananas. They serve a pragmatic function.

Interesting rationalisation for gendered inanimate nouns in romance languages, thanks. Also used in many/most other Germanic (and other language families?) right? Is your explanation a personal inspiration or established theory? For it to make sense they would need to (for example) refer to (say) a table as 'he' later in a sentence. Do they do that?

IMO grammatical gender in Indo European languages (of which the Germanic and Romance language families are a part of) reflect how nouns and their references (pronouns, adjectives etc) are semantically linked by modifying the word endings of the latter to better reflect those of the original noun - I like to think of it as the equivalent of type suffixes in assembly language.

Definitely not a personal inspiration, but I can't recall where I first heard the idea.

> For it to make sense they would need to (for example) refer to (say) a table as 'he' later in a sentence. Do they do that?

I don't speak any Romance languages beyond high school Spanish, but I assume that's the case.

> So, in English, you can say: "Blaine Wolfeschlegelsteinhausenbergerdorff Sr. gave Rhoshandiatellyneshiaunneveshenk Koyaanisquatsiuth Williams a sweater for Christmas. She liked his gift."

Actually in that example, you still don’t need gendered pronouns to resolve ambiguity: “they enjoyed the gift”.

It costs me absolutely zero cognitive load. You don't have to worry about that.

Now, trying to parse out if "they" is meant to refer to a group or an individual when used in place of s/he, that does take some work.

Politicizing this topic is what causes the cognitive load.

Persian and Chinese have, if I remember correctly, no gendered pronouns.

No effects on gender equality seem observable.

Chinese has gendered pronouns in written form. The characters for he and she are written differently, but they are both pronounced the same way - tā.

I assume that in some older form of Chinese the sounds must have been different, but they converged and people get by fine in spoken language.

It's actually the other way around. The 她 form was introduced in the relatively recent 1920s, partially to make it easier to translate Western texts.

As someone tuned in to queer twitter I can say that if you know someone’s pronouns you should use them, so ideally for Obama you would use he/him. But also we’re all using they/them a lot more for people when we’re not sure and that can bleed in to people even when we do know their pronouns, and generally that’s not a big deal. Only becomes a problem when a trans person has a clear preference for she/her or he/him (or anything else) and a person repeatedly and willfully uses they/them, as that can be used to deny recognition of someone’s gender identity. But it’s generally not a problem if you use they/them for a cis person once, that can just slip out. We’re more sensitive around pronouns for trans people, since they are much more likely to have trauma around that. They/them is cool for someone with unknown pronouns but it’s best to politely ask as soon as possible and begin to use the preferred ones.

OT: I use they/their by default, unless I know otherwise, but what to do with other common gendered terms such as Mr./Ms./Mrs, Sir/Madam/Ma'am/Miss?

These aren't avoidable problems: e.g., in the greeting for a business letter ('Dear ...'), or when getting the attention of a member of restaurant waitstaff whose name I don't know, etc.

Someone needs to come up with a plausible set of gender-neutral terms. They/their/them works for she/hers/her/he/his/him circumstances, but the needs are broader than that.

Mostly I’ve just stopped using gendered terms. In a business letter even if the person is not trans you can’t assume Mr/Mrs/Ms unless you know. If their name is gender neutral or ambiguous I would say “Dear First Last,” though that’s even US/western-centric as not all cultures do it that way. If it’s a really important business letter you should probably find out the persons gender using some other channel. Also if the person has a title like Dr or Professor you can use that.

Some people use Mx as a gender neutral but I don’t think that would fly with a more conservative minded person.

I think we can't avoid these issues and need to come up with solutions.

I've never seen Mx, so I think many people would wonder what it meant. Just "M." seems better and matches other usage (though outside contemporary English).

Sure. I would imagine there has been a lot of discussion around this in certain circles. Probably no shortage of good ideas. I think culturally we need to get to the point where most people accept gender as self identified, and the rest will shake out over time.

> If it’s a really important business letter you should probably find out the persons gender using some other channel.

Preferred form of address, not just gender, and this has been the rule for quite a long time. Even within the classical binary, there are all kinds of variations of status, preference, relationship with the sender, etc., that feed into that.

John Smith (a man) might be properly referred to in a salutation as any of:

“Mr. Smith”

”John”

“Dr. Smith”

“Your Excellency” (without the “Dear” that would prefer the others)

“Rev. Smith”

“Father Smith”

(And most of these correspond to one or more different forms that would be used in the main address, as well.)

Just noticed this. I'm puzzled why my comment attracted downvotes.

I typically lean towards gender neutral terms in my speech, but this actually wasn't one of those cases. I had originally used "his", but noticed it resulted in he/him/his referring to two different people. "Destin has also peaked [...], as he interviewed Obama during their presidency." vs "Destin has also peaked [...], as he interviewed Obama during his presidency."

Obviously, Obama was president and Destin wasn't, but the sentence still reads more weirdly with the grammatical implication that Destin was president.

He's also in the middle of a coast guard series he filmed last year. Pretty interesting stuff.

> the US Navy even let him on a multi-day tour of a nuclear submarine and tape classified information (later redacted)

They _paid_ him to tour it. It was a marketing event for the US Navy to drive recruitment.

They did? I am not disagreeing, just wondering if he disclosed that or how you found out.

In the first video in the series Destin himself says the Navy did not pay him.

https://youtu.be/5d6SEQQbwtU&t=2m47s

I do recall him mentioning his own biases and conflicts of interest at some point but I don’t recall what series that was a part of.

This might be it:

https://www.youtube.com/watch?v=qOTYgcdNrXE

From 2019: "For the last 15 years I have worked for the Army Test Evaluation Command."

They neither paid him nor had edit approval on his content besides redacting classified information.

He was covering sciene topics nothing controversial or political if i remember correctly it was about air circulation systems and the fail safes etc.

Beyond classified stuff , there is not much need for edit approval.

He's so creepily "wholesome" and obviously propaganda-adjacent in a Chris Pratt way it makes me not watch his videos.

Destin is far from a random YTer, he's a former Army Aerospace Engineer, worked with NASA if I'm remembering correctly, and has a VERY large audience. He would have been able to reach out to the right people and get the interview properly, not just random cold emailing like a real random YouTuber would.

Its a great interview and starts with his Dad, who also worked on the JWST... https://youtu.be/4P8fKd0IVOs

Well, Dr Mather surely had no idea who I was when I was researching my article on the JWST, but he was generous with his time and thoughts.

https://arstechnica.com/science/2016/03/meet-the-largest-sci...

I had the privilege of meeting Dr. Mather 10 years ago, when he spent a new years with my family, he booked a vacation with my parents company, and he is without a doubt the smartest person I have met in my life also very humble and interested.

One of the best experiences of my life.

If any of the James Webb team are here, Congratulations! A phenomenal achievement.

So excited to see first images and read about all the discoveries you are going to make. Exciting times!

My daughters (7yo) class have been talking about it, she keeps coming home from school excited to tell me about the latest update on its journey. I love the fact we have these exciting things happening in space science to experience together.

This animation, https://www.youtube.com/watch?v=6cUe4oMk69E&list=TLGG8tIphgp... is a nice visualization of the L2 orbit. It was different than what I expected.

For some reason I expected it to stay in Earth's shadow. L2 is probably too far from Earth for that.

An object at L2 absolutely could avoid the sun and stay in Earth's shadow. It would be problematical for this spacecraft, which is powered by a solar array.

Earth's umbra doesn't reach L2.

https://en.wikipedia.org/wiki/Umbra,_penumbra_and_antumbra

https://astronomy.stackexchange.com/questions/13585/does-ear...

I did some research here to understand this better: https://webb.nasa.gov/content/about/orbit.html

> This [L2] orbit (which takes Webb about 6 months to complete once) keeps the telescope out of the shadows of both the Earth and Moon.

>What is special about this orbit is that it lets the telescope stay in line with the Earth as it moves around the Sun.

and

> Webb's position out at L2 also makes it easy for us to talk to it. Since it will always be at the same location relative to Earth-in the midnight sky about 1.5 million km away - we can have continuous communications with it as the Earth rotates through the Deep Space Network (DSN)

As did I.

https://news.ycombinator.com/item?id=29859522

Ah, that stack exchange comment is super interesting.

"If Earth would be 9% larger in diameter, but with the same mass, its umbra would end almost exactly at L2."

They specifically avoid earth's shadow because they use solar panels (by shadow here, I mean penumbra, they're too far away to be in total shadow).

I've been wondering about that same issue and someone suggested that as a possibility. Do you know where NASA actually states it?

https://jwst-docs.stsci.edu/jwst-observatory-characteristics...

Muchas gracias! I've been looking for something like that. Another interesting bit I learned from the link:

> While orbits about the L2 point are inherently unstable, the orbit size is large and the orbital velocity is low (~1 km/s), so the orbit "decays" slowly. However, JWST's large sun shield, roughly the size of a tennis court, is subject to significant solar radiation pressure which results in both a force and a torque. The direction of solar force varies as the observatory's attitude changes from observation to observation. The solar torque is balanced by reaction wheels, but periodically, the accumulated momentum is dumped by firing thrusters.

If I understand correctly: JWST needs thrusters not to counteract a decaying orbit (too little energy), but to counteract accumulated momentum from solar radition (too much energy).

This simple 20 seconds video was far better than hundreds of those link. I mean I couldn't visualize the whole set up and orientation and this video made things crystal clear.

It's funny how the excellent job of the French Ariane launcher is nowhere to be seen in this (and others) article.

Ars Technica did a well-written story on it recently -- https://arstechnica.com/science/2022/01/all-hail-the-ariane-...

It got a lot of good press at the time, but agreed, it warrants a mention.

That is an interesting observation I never considered. If it were a SpaceX rocket, it would have been mentioned once per paragraph, minimum.

If it was a SpaceX rocket, it would be getting ready to fly again. Expendable rockets have been putting up payloads for 60 years at this point, SpaceX has been flying reusable rockets for less than a decade.

Not necessarily. Larger payloads (and maybe some trajectories) forego the reusability of the rocket (even Falcon Heavy)

Good point, but it's one major reason why SpaceX makes the news (also Crew Dragon) and Arianespace doesn't, even if it doesn't apply in every instance.

If SpaceX was simply doing the same thing as everyone else has for 60 yrs, no one would care, I don't understand why people think they're the same thing

You don't think it has something to do with Elon Musk's self-promotion and large cult? Quick, who is the CEO of Arianespace? Who is heading up the SLS project?

Somebody who'd lose if they try to get too much of a limelight? As both those organizations depend on governments way more than SpaceX.

Actually Hubble was put into space by a (mostly) reusable system the space shuttle STS-31. That was about 30 years ago.

Calling the Space Shuttle "mostly reusable" is laughable. It cost 1.5 billion dollars per launch[1] whereas a reused Falcon 9 costs 50 million to launch.

[1] https://en.wikipedia.org/wiki/Criticism_of_the_Space_Shuttle... [2] https://en.wikipedia.org/wiki/Falcon_9

I don't get the need to bag on the Shuttle program here. The Shuttle was designed nearly 50 years ago with drastically different requirements and stakeholders.

It's because people still defend it, or imply it was more worthy than it actually was. And because the same mistake is being repeated right now (SLS).

SLS isn’t the currently-in-development spacecraft that utilizes hundreds of ceramic tiles to aerobrake through the atmosphere. SLS is basically a modern Saturn V. A complete departure from the Shuttle, with the exception of-re-using the SRB design. On paper a very conservative choice.

Starship looks a lot like Shuttle 2.0 to me. Except the landing is somehow even more terrifying.

As far as I can tell the idea with Starship is to design a vehicle that can survive losing a few tiles because that’s inevitable.

The point of SLS is that it's a politically motivated boondoggle. This is also what the shuttle was. Nixon ok-ed it not because it was a good idea, but because of aerospace votes in California.

What is that based on?

Which part? The bit with Nixon is well known (see, for example, John Logsdon's book "After Apollo?"). As for SLS, it's called the "Senate Launch System" for a reason. Shelby in particular has saved it, to the extent that work on propellant depots was targeted for extermination (no one in NASA is to utter the "D" word.) Depots and propellant transfer render irrelevant the SLS's supposed advantage of large payload mass.

The Nixon bit isn't well known, but thanks for the reference. I've never heard the rest. Is there a source?

It's easy to attribute political reasons to whatever Congress does, because Congress is filled with politicians. But members have other motives too, and private businesses, despite the hype, have plenty of corrupt and political motives - throwing contracts to allies and friends, undermining enemies, etc. - though they are far less transparent and are unchecked by the public or other institutions.

https://arstechnica.com/science/2019/08/rocket-scientist-say...

which references

https://twitter.com/SciGuySpace/status/1156294287245660160

Quote:

> Digging through some old notes. Found this quote from a few years ago from a senior academic engineering source at the time.

> "Senator Shelby called NASA and said if he hears one more word about propellant depots he’s going to cancel the space technology program."

The evidence is someone (person A) on Twitter's old notes about a story someone else (person B) told them, about an event involving persons C and D (and potentially others), with no indication of person B actually witnessing it.

Aren't we supposed to start by considering the accuracy of the information?

That person is a very respected space journalist. If you are still dubious, that's a "you" problem, not a "me" problem, and I encourage you to expend your own effort to deal with it.

It's not that the Shuttle wasn't an absolutely astonishing display of engineering proficiency - it was - it's that if that money had gone into a Falcon-9 style rocket instead, we would all be much better off now in 2022.

The shuttle could cary 29,000kg to orbit, the Falcon 9 can only carry 22,000kg (30% more capacity) plus 8 astronauts (Falcon can only carry 3), and was designed and built in the 70s.

So yeah the Falcon is an improvement and I'm sure will be better one day, but the Space Shuttle was a huge achievement for its time, and as of today there is no lift system that can match it for both capacity and reusability.

At no point in the history of the Shuttle program would it have been a mistake to shut it down. By any metric, I'd call it a failure.

Slight nitpick - Crew Dragon currently carries 4 crew members and there's no particular reason it couldn't carry more (ie the rocket could handle it).

> The shuttle could cary 29,000kg to orbit

Sigh. Where did you get that number? Wikipedia lists 27,500 kg to LEO, but according to Guinness

"With a mass of 22,753 kg (50,161 lb), Chandra X-ray Observatory telescope launched on 23 July 1999 is the heaviest satellite the shuttle has ever launched."

And I suspect that if the flight required abort and won't reach orbit, the shuttle would have out-of-specification loads at landing, as the payload mass which is safe for landing is less than that.

> Sigh. Where did you get that number?

From NASA: https://www.nasa.gov/centers/johnson/pdf/584722main_Wings-ch...

Wonder if it was planned payload for some of Orbiters (they had different masses).

> the Space Shuttle was a huge achievement for its time

Agree.

> as of today there is no lift system that can match it for both capacity and reusability

Disagree. Falcon Heavy lifts higher payloads - you don't count the orbiter mass itself, do you, just like you don't count the mass of the last stage which actually gets to LEO, right?

Reusability was also lacking. SSME was made by Rocketdyne, not Pratt and Whitney, who had somewhat better hydrogen technology, so after each flight SSME had to be disassembled, tested and parts nearing faults (e.g. turbines) had to be replaced. The first stage modules, which dropped to the ocean, had to be cleaned from the sea water, which also isn't an easy rinsing. And of course thermal protection tiles had to be inspected and the broken ones replaced. X-37 is way better here.

It wasn't rapidly or cheaply reusable, but it was reusable yes ?

Reusable does not mean cheap . Usually you want reusable to make it cheaper but not always.

For example your standard AA/AAA batteries are much cheaper if they are one time use than reusable [1]

Reuse may be desirable in a product for environmental impact, turn around time, security or many other concerns.

Shuttle was mostly reusable even the booster components , not cheaply but reusable nonetheless.

[1] it is a crude example, overall cost being more expensive, TCO per cycle will be cheaper for rechargable batteries

The Space Shuttle was refurbishable. Its barely a valid comparison

This is absolutely true but entirely uninformative in this context. It's also a bit hilarious as it reinforces GP's suggestion that you can't involve or invoke SpaceX without a breathless-sounding shower of accolades stealing the show from the main payload / mission.

Because SpaceX made rocket launch interesting by having cameras on the rocket, did Ariane have cameras on their rockets?

If you go to https://jwst.nasa.gov/content/webbLaunch/whereIsWebb.html then there are repeated statements about how the rocket did such a good accurate job launching Webb onto its intended trajectory that the telescope hasn't had to use as much of its own rocket fuel as they expected, so the fuel is now expected to last 20 years instead of 10.

Shortly after launch there were quite a few articles talking about how well the launch went on the Ariane and how that allowed the mission to be extended to 20 years or so.

I'm not sure who it was anymore (possibly Scott Manley on youtube), but apparently ESA had been setting aside the components for the Ariane 5 that tested best to be used for the launch of JWST to lower the risk of failure and that might explain in part why it was able to launch it so precisely - it was not your average Joe's Ariane 5.

So they essentially binned the rocket parts much the same way a chip fab would?

No? This is a completely meaningless comparison

It’s the same idea. Instead of making a tighter spec and spending more resources making just the right number of parts meeting the specified tight tolerance, use a looser production tolerance and make a bunch of parts, and then (for an especially tricky use case) pick the parts satisfying a tighter tolerance after production, leaving the remaining parts for less demanding jobs.

They selected the parts that were the most up to spec (not necessarily the strongest, but the most faithful to spec).

Chip binning or most complex systems QC also works that way ?

If it doesn't behave as within parameters defined would the core/chip is binned.

Complex systems can break in unexpected ways if any one parameter is outside range even if it actually better (say more clock speed) , you want to stick to spec.

I also heard that for this launch, Arianespace made sure to make no innovation whatsoever to the launcher (usually each launch is used to test small improvements).

Source: podcast in French

Ariane 5 was cool in 1995

And now too, since it ~doubled the science/dollar output of the telescope by doubling the lifetime. I think that's cool

"doubled" the lower bound on what was surely an extremely conservative estimate meant to avoid a perception of failure if things didn't go perfectly. The Opportunity rover had a "90-day" expected lifetime and lived until 15 years old. It's great that Ariane performed superbly but this "doubling" calculation is pretty silly.

> The Opportunity rover had a "90-day" expected lifetime and lived until 15 years old. It's great that Ariane performed superbly but this "doubling" calculation is pretty silly.

Yeah, no. JWST has a limited lifetime because of the finite fuel, that's completely different from building a machine for a purpose and the machine not falling apart at the end of the initial mission.

When people say Ariane doubled the lifetime of JWST, they mean Ariane performed much better than the allowed margins, thus pushing the fuel efficiency to its limits.

Think this, a Toyota has a lifetime of 100K miles but many get 200K out of it. That's completely different from achieving 80mpg on a car rated 40mpg.

When someone tells you that they are driving so precisely that they are getting twice the milage, is it appropriate to say "So what, my car was supposed to last 100K miles but lasted 200K"?

I think, no.

There's really no telling how good Ariane was here though, without a lot more information. Maybe if it was perfect it could have "tripled" the lifetime.

Using your driving analogy, this is like you getting 80mpg on a car that needs to hit 40mpg or heads will roll. Maybe everyone driving it would get 80mpg. Maybe someone driving extremely precisely would get 120mpg.

There's not enough information here to say how well Ariane did other than public comments from the engineers which were vague but positive.

It's amazing that they pulled this off without node and electron, you mean?

This is one, among others, right after it was announced. Maybe you don’t follow space news as closely as you think you do?

https://arstechnica.com/science/2022/01/all-hail-the-ariane-...

I’ve seen it mentioned tons of times in articles. Especially in regards to how well it did which which leads to fuel savings which leads to a longer life.

Worse, journalists often compare Webb with Hubble, but they mostly ignore the https://en.wikipedia.org/wiki/Herschel_Space_Observatory, which had a larger primary mirror (for example, https://webb.nasa.gov/content/observatory/ote/mirrors/index....). It's a very subtle form of American exceptionalism.

I'm not sure it's American exceptionalism, just that Hubble has been around a long time and is much more prominent in the public conscience thanks to iconic images like the Hubble deep field.

If someone builds a big new ocean liner you know journalists are going to compare it to the Titanic. Same thing.

Yes, Herschel was a great project by the ESA. It certainly got short shrift within the US press despite significant contributions from NASA and JPL. I hope it got plenty of love from the European press. Great work.

> It's a very subtle form of American exceptionalism.

Oh, bullshit. NASA spends an awful lot of money and effort on promoting its projects to the English-language press. Does the ESA make a comparable amount of effort?

I am not sure where we disagree. I am talking about the (false) perception that the U.S. is the #1 among world nations. Maybe it is caused by comparatively higher marketing budget, but that doesn't ultimately matter, because the point is, the perception is still false, and ignoring Webb's predecessor contributes to it.

OTOH, I think Webb is amazing, and fairly, perhaps without the marketing it wouldn't even exist because of all the American deficit hawks.

> the (false) perception that the U.S. is the #1 among world nations

The #1 what? I wouldn't blame you for using some unkind phrases here, and I suspect you want to! But it's certainly not false that the U.S. does much more space exploration than any other nation, spends a lot more on it, achieves more in space, etc. None of that invalidates the work of other nations, and spaceflight and the production of scientific data seems like a very healthy form of competition (and cooperation!) between nations. If the U.S. isn't #1, I am curious how you are keeping score.

Herschel didn't just get less English-language press than American made space telescopes. It was less prominent in the public consciousness than short, much less expensive Japanese missions like Hayabusa and Hayabusa2. I doubt any of this is about American exceptionalism.

> OTOH, I think Webb is amazing, and fairly, perhaps without the marketing it wouldn't even exist because of all the American deficit hawks.

It's just like everything else in life. You can build the best product in the world but it won't make a damn bit of impact on people's lives unless you let them know it exists. Marketing your product is just as important to its success as the product itself.

Maybe because Herschel was active for only a few years while Hubble is still going? Hubble has also produced some of the most recognizable images of space. It's clearly a name with more awareness in the general public.

> It's funny how the excellent job of the French Ariane launcher is nowhere to be seen in this (and others) article.

US ego is already badly bruised that they've had to launch this highly visible project on a foreign rocket, and now you'd want them to sing the frenchies praises?

That's a huge ask.

Huh. I actually noticed the opposite: the ESA, and Ariane seemed to be featured much more prominently than I would have expected at the time around the launch.

This was an absurdly teeth-clenching deployment.

And no back-up, even if the Ariane launch failed. No back-up.

Congrats to everyone across the board for getting this amazing telescope right where it needs to be.

Now all we need is the mirror alignment and we're in for some seriously incredible science.

Mirror alignment was done in the days leading up to insertion, wasn't it?

Afaik, all that's left is testing and cooling- the cold side is still around 63K and needs to get down to 50K (-223C).

Mirror deployment was done before insertion, moving the 18 mirrors up from their locked position by 12.5 mm. Now, 3 months of mirror alignment will follow. They will align with a reference star having to first move one mirror a little bit to identify how the mirror affects the alignment, then calculate the alignment and move the mirror. Each mirror's position can be controlled at 10 nm resolution.

It's not only position, also deformation by pulling or pushing on the center of the mirror changing it's curvature.

Correct. And since the beryllium mirrors are 8 times harder than steel, it's probably a tough job.

Not really. They are quite thin and the deformation is minute, on the order of less than a micron at the largest point.

Edit: that should have been 10 micron.

I can't fathom how they have a servo, a linear actuator, or anything else, that can apply pressure to the mirror and keep it there, for years, in the most extreme environments.

Every component of this thing is mind bending.

Electromagnet with a constant current running through it would do the job nicely I would think? Keep in mind that with the sun always shining where Webb is that power is not really their first constraint.

"Cryogenic Nano-Actuator for JWST" https://www.esmats.eu/amspapers/pastpapers/pdfs/2006/warden....

Here's a good paper on the mirror actuators [1]. Skimming, they look like hexapod rotary stepper architecture that would not need power to hold a position, only to change position.

[1] https://www.esmats.eu/amspapers/pastpapers/pdfs/2006/warden....

Steppers make good sense for that application, what a beautiful design. 7 nm step size with a repeat accuracy of 1 nm is insane precision.

It is a beautiful design, isn't it?

I'll speculate that the engineers who designed this and other ground-breaking aspects of JWST feel the same euphoria that Beethoven might have felt on completing his 9th symphony.

I think beauty wears many masks, but she's in every human effort to bring something new into the world.

It’s really sad to think about how well NASA works when you consider how little funding they get and how hard they have to fight for it. It’s honestly quite ridiculous.

I know a lot of military industrial complex boils down to being nationwide jobs programs, e.g. everything to do with the F-35. But NASA? I don’t think they’re anywhere near as close to being a “jobs program”

Off the top of my head, I really can’t think of many things NASA as a whole has fucked up.

Challenger & Columbia. Challenger wasn’t a NASA problem, it was a Politicians & Bureaucracy problem. As I earlier mentioned… the people responsible for my initial statement of “how well NASA works” knew that disaster was highly likely with Challenger launch. But bureaucracy didn’t care. Haven’t read into Columbia so won’t comment.

So why the hell do they get so little funding… it’s depressing to think about. My cynicism doesn’t think James Webb success is going to bring in much more funding. SpaceX, understandably, is likely going to take more & more space related contracts.

I still think NASA deserves much, much better treatment.

I saw a study a few years ago where people were asked how much funding various agencies get, and the majority of people thought NASA was more than 10% of the federal budget; some even went as high as 25%. (It's less than half of 1%.)

What are you talking about Webb was build by contracting defense contractors, like for example Northrop Grumman (primary contractor if not mistaken) and Lockheed Martin who also build F-35, there is YouTube video where Lockheed does presentation about Webb telescope project complexity.

It’s true that Northrop Grumman was the prime contractor. You don’t want to keep all the skills to build this, and all the manufacturing steps, in-house.

But the project leadership and key pieces of the design were at GSFC and JPL.

Full list: https://webb.nasa.gov/content/meetTheTeam/team.html

Every large project is built by multiple partners. But in this case, the overall design and systems engineering was done by NASA/Goddard. Claiming otherwise is like saying that Foxconn makes iPads, not Apple.

I agree with your overall sentiment, but I have to disagree with this:

>Challenger & Columbia. Challenger wasn’t a NASA problem, it was a Politicians & Bureaucracy problem.

NASA managers overrode the recommendations of the engineers. That was absolutely a NASA problem. Sure they were under some political pressure, but they made the wrong call in the face of strong data. Columbia too was a management priorities problem.

That being said, NASA is doing great science. NASA is compromised of humans so they are therefore imperfect, but I would also love to see them get more support. Their $23 billion dollar budget is only 3% of the size of the DOD budget.

As far as SpaceX, they are a NASA subcontractor, executing goals specified by NASA. I don't understand your concern. (SpaceX also has a thriving private satellite business of course.) The entire Apollo program was executed by NASA paid subcontractors. That is how NASA operates. Their primary role is to spec, subcontract, and manage. SpaceX is doing things for less money than other subcontractors, so they are helping NASA's budget.

Parent comment: > It’s really sad to think about how well NASA works when you consider how little funding they get and how hard they have to fight for it. It’s honestly quite ridiculous.

Sibling comment (dmd): > I saw a study a few years ago where people were asked how much funding various agencies get, and the majority of people thought NASA was more than 10% of the federal budget; some even went as high as 25%. (It's less than half of 1%.)

Your comment: > [NASA’s] $23 billion dollar budget is only 3% of the size of the DOD budget.

NASA’s budget is about half a percent of total DoD budget, but that doesn’t tell an accurate story. Most people assume NASA is synonymous with the total or almost total US space budget, but its less than half. You can do the math in 2022 if you would like [0], but in 2013 NASA’s budget was $16.8B [1], and the total space budget was $39.3B [2]. According to that article, in 2013 every other nation was supposedly under a $10B space budget [2], but can’t really speak to the validity of that. I think it’s reasonable to say we spend a decent amount on space compared to others. All that said, not opposed to an increased space budget, more space is good in my book.

[0] https://comptroller.defense.gov/Portals/45/Documents/defbudg...

[1] https://en.m.wikipedia.org/wiki/Budget_of_NASA

[2] https://www.weforum.org/agenda/2016/01/which-countries-spend...

Thanks for the comment. Your reference [1] shows that NASA's budget is typically 0.5% of the total Federal budget in recent years, not the DOD budget. In 2020, NASA was about 23 billion and the DOD was about 766 billion, or about 3%. As to your other point, yes, some of the DOD budget is spent on space. That number will continue to increase.

Interesting tidbit: In constant 2020 dollars, peak NASA spending during Apollo was only twice today's budget.

https://en.m.wikipedia.org/wiki/Budget_of_NASA https://www.statista.com/statistics/264494/nasas-budget/ https://www.statista.com/statistics/272473/us-military-spend...

*The third link says 2012, but it covers through 2020.

...NASA is compromised [comprised/composed entirely] of humans...

Oops. Thanks. Yes, I meant comprised, although I suppose humans also lead to compromise...

This may or may not help your cynicism, but here's 2 fun facts:

* NASA doesn't even get the majority of the US government's space spending

* NASA's budget is still larger than every other country's civilian space program combined

NASA certainly has their share of "jobs programs." The SLS is a prime example. Not NASA's fault: when congress gives you money and tells you to work on something, you work on it.

https://en.wikipedia.org/wiki/Space_Launch_System

> I still think NASA deserves much, much better treatment.

This is certainly true.

It seems to me that there are two NASAs: The unmanned exploration programs, which do amazing things, and the manned exploration programs, which look very much like jobs programs.

I'm not an expert, but I haven't yet seen a good science rationale for returning to the moon. I'm not aware of what we've learned from the International Space Station. And the Space Shuttle was an expensive and needless boondoggle that killed fourteen people for no good reason. If someone can correct me on the science we gain from these programs I'd welcome it. Because it seems to me that we get precious little science from the treasure and blood dedicated to these programs.

The Apollo missions were a different thing, they taught a lot about the Moon and brought back crucial material like the Genesis Rock.

On the other hand the unmanned program does amazing things like Hubble, Voyager, Magellan, the Mars probes, and on and on. And soon, Webb. These have told us amazing things about our world, and we should be doing more of them.

> I'm not aware of what we've learned from the International Space Station

If you watch videos of the people on the space station you begin to be reminded of "remote hands" in a data center. The space station is like a colo-facility that houses science experiments instead of racks of computers. The people on board seem to exist as "remote hands" that maintain those science experiments for whatever science team is on the ground running them.

This is all conjecture, of course... but I've watched enough of "Hi I'm somebody on the space station, let's walk around" videos to draw this opinion. The ISS is a science lab that orbits the earth. The people on board are there to be remote hands.

Have there been any interesting breakthroughs or findings from the science done aboard the ISS?

I know you're asking specifically about results from on board the ISS but here's something more broad https://en.wikipedia.org/wiki/NASA_spinoff_technologies

Oodles. NASA puts out reports every once in a while detailing the benefits of the ISS.

Some of them are not too surprising. For example looking at hurricanes from space helps you predict where they will go.

I think the medical research is pretty interesting though. Of course a lot of the medical research is focused on the sorts of things that happen to people living in space for long periods of time. But there's also interesting experiments where microgravity has enabled medical advances that'll help people here on Earth.

On the "curing cancer" front, there's been a lot of exciting developments over the last few decades in immunotherapy, which tends to have milder side-effects than chemo. The monoclonal antibody Keytruda is used to treat a BUNCH of different cancers, but has some downsides: it's a pain to store (needs to be refrigerated, limited shelf life), and it has to be administered intravenously (takes more effort, leads to side-effects, not fun for patients). Thanks to lessons learned creating suspensions of the medicine in microgravity, Merck is currently testing a version of Keytruda that can be delivered as a quick shot.

As another example, TAS‐205 (a treatment for muscular dystrophy) is starting phase 3 trials after promising results in a smaller study. However if it eventually becomes an approved medicine, it'll probably be 20-30 years after the original protein experiments were done on the ISS

There's also the NICER mission (Neutron Star Interior Composition Explorer; https://heasarc.gsfc.nasa.gov/docs/nicer/nicer_about.html) which is a payload on the ISS that's mapped pulsar surfaces: https://www.youtube.com/watch?v=zukBXehGHas

> I'm not aware of what we've learned from the International Space Station.

We learned about the effects of microgravity on the human body for one. Useful for future trips to the Moon and/or Mars.

Plus we’ve had the benefit of a microgravity laboratory staffed by world class scientists for two decades.

Putting people back on the Moon is valuable just as a technology demonstration and test for more ambitious missions like Mars.

As you say, Apollo taught us a lot about the Moon. But it didn’t teach us everything. So if Apollo taught us something then clearly there is value in sending humans.

> And the Space Shuttle was an expensive and needless boondoggle that killed fourteen people for no good reason.

Without the Shuttle there is no ISS. So any benefit gained from the ISS is owed at least in part to the Shuttle.

definitely not as much of a jobs program, considering probably anyone smart enough and hard working enough to get a job at NASA could get a much easier and more high paying job elsewhere.

> It’s really sad to think about how well NASA works when you consider how little funding they get and how hard they have to fight for it.

I do agree with you, but have you maybe considered that you're looking at it the wrong way?

Isn't there a saying that armies that eat bad food win more battles?

Could it be that because NASA is not funded at the level they deserve, they have to be more efficient?

By the same logic we could conclude that the US Military is an efficient operation. After all I can find someone who will argue their funding needs to be increased.

I really can't wait until the have proper first light. They say June will be the earliest after phasing has completed, but it can't come soon enough.

That being said, I've waited 25 years so far, a few more months won't hurt

I'm sure there will be "test photos" that get published in the interim. I'd be seriously disappointed if there wasn't.

Yes does any one know when first light photos will appear? I know it is very unknown but I've seen many NASA employees live suggest there will be some interim first light photos to come and I am super excited to see them.

Amazing how a few meters of mirror can make out objects billions of light-years distant. Yes it's big - insofar as human-built telescopes have been - yet is so relatively minuscule per what it observes. Having gone from first flight to JWST in such a short time is staggering (Wright Bros 120 years ago - I've been alive nearly half that time); how soon will we achieve orders-of-magnitude bigger telescopes? say, multiple 100x-wider JWSTs operating from multiple LaGrange points? Think big!

In a slightly different vein, ESA's Gaia mission measured the distances to billions of stars by looking at how their position shifts as we orbit from one side of the sun to the other. Not taking highly detailed images like JWST, but in some ways you can think of it as a telescope the size of Earth's orbit.

https://www.esa.int/Science_Exploration/Space_Science/Gaia/P...

https://skyandtelescope.org/astronomy-news/gaia-makes-most-a...

The sky calls to us. If we do not destroy ourselves, we will one day venture to the stars.

-Carl Sagan

And that path currently goes thru an autist welding up rockets in tents on a beach.

I had no idea its final destination was a legrange point thats so cool!

I got confused though, I thought they were saying it was at the one between the sun and the earth (L1). But I guess its at the one behind the earth (L2)? Anyway so cool! Lagrange points always make me think of Liu Cixin :^)

> The L2 point of the Earth-Sun system was the home to the WMAP spacecraft, current home of Planck, and future home of the James Webb Space Telescope. L2 is ideal for astronomy because a spacecraft is close enough to readily communicate with Earth, can keep Sun, Earth and Moon behind the spacecraft for solar power and (with appropriate shielding) provides a clear view of deep space for our telescopes. The L1 and L2 points are unstable on a time scale of approximately 23 days, which requires satellites orbiting these positions to undergo regular course and attitude corrections.

https://solarsystem.nasa.gov/resources/754/what-is-a-lagrang...

^ cool lagrage point graphic and nasa explanation

How long until my new desktop wallpaper?

6 months

The NPR posting does now provide information as to how the image was taken and I wondered how this image came about. This page describes how the picture of JWST was taken. It was taken by the rocket after it separated.

https://www.flickr.com/photos/nasawebbtelescope/51775886252/...

>>Here it is: humanity’s final look at the James Webb Space Telescope as it heads into deep space to answer our biggest questions. Alone in the vastness of space, Webb will soon begin an approximately two-week process to deploy its antennas, mirrors, and sunshield. This image was captured by the cameras on board the rocket’s upper stage as the telescope separated from it. The Earth hover in the upper right. Credit: Arianespace, ESA, NASA, CSA, CNES

I'd be happier in a world where individual universities, or at least consortiums, could have their own space telescopes.

The JWT is famous for costing over 10b USD to develop. AFAIK it's the most expensive object ever to be launched into space.

I don't think universities should (or could) spend that kind of money on research equipment.

If launch costs are 1% or less per mass of the Ariane 5, mass budgets could be greatly increased, and engineering could become easier. I see no reason ultimately why space telescopes should be much different in cost than terrestrial telescopes. Ultimately I see telescopes being maintained and upgraded in space much as terrestrial telescopes are.

The Webb telescope didn't go several times over budget from growing several times heavier. Novel telescope are expensive because they must address unique engineering challenges with unforeseen costs. You can't just grab a sunshade off the shelf – everything's built bespoke.

Of course, the flip side here is that it would be cheaper to build a second Webb telescope. Maybe we could mass produce a hundred more for a tenth the cost, but it's not clear that would be a hundred times better for astronomy.

That's not what I was implying. I'm implying the mass (and volume, and especially servicability) constraints required expensive engineering. Those constraints are relaxed with much cheaper launch, especially if in-space assembly and maintenance (by astronauts!) becomes affordable.

Its nice to be able to design things around Sci-Fi. However, still in 2022, there is no spacecraft that allows EVAs anywhere.

The occupants of the ISS beg to differ.

http://spaceref.com/iss/eva.html

I was unaware that the ISS was a spacecraft. I was under the impression it was a space station.

Im also unaware that the ISS is able to reach L2 or really any orbit other than LEO roughly 400km in altitude.

> I was unaware that the ISS was a spacecraft.

I can't really help that, but here is a nice page from NASA:

https://www.nasa.gov/audience/forstudents/5-8/features/nasa-...

"The International Space Station is a large spacecraft in orbit around Earth."

> Im also unaware that the ISS is able to reach L2 or really any orbit other than LEO roughly 400km in altitude.

You can tow it wherever you want, provided you attach a suitable propulsion device. That's also how it stays in that orbit, every now and then they boost it back up to offset the orbital decay.

Also: in space assembly could take place in orbit and then when the device is complete it can be sent off to L2. The problem with such a scheme is when things break down after the transit to L2.

Exactly the same kind of snark could have been uttered about lower cost launch before SpaceX upset the apple cart. It would not require enormous changes for something like Hubble servicing to be done with a Crew Dragon.

I hear what you are saying--if launches were easy they could have dropped a bunch of expensive constraints. But consider that if launch costs were truly the bottleneck for JWST, they'd have just thrown more money at the launch budget and got a bigger / fancier rocket. I'm no rocket science person but I'd assume you can scale launch capacity by throwing more money at it--it's generally a solved problem whose risks are much better understood than whatever JWST is doing. It makes sense to throw money at things to reduce risk like larger launch vehicles, regardless of their cost.

JWST is expensive because it does stuff that has never been done before. Lots of "unknown unknowns" that you need to make "known unknowns" Anything like this will be expensive--same is true for software even. You are working in uncharted water--risks are everywhere.

If they could have dropped a bunch of their constraints and reduced program risk by throwing money at a fancier launcher, they'd have done it. The fact they didn't suggests that the cost & risk wasn't constrained by the launch.

Now maybe you could argue that "if there was only a way to make it serviceable using cheap rockets"--then yeah maybe they could drop some of the more expensive and risky constraints. But however many years ago when this project started, such a thing was not even on the horizon. Only in the last few years has such a thing even begun to seem feasible. Perhaps future missions can relax their constraints because suddenly technology makes repair "easy". But JWST didn't emerge in that environment.

With lowered launch costs, and more things launched into orbit, surely over time you’d have to handle these unique engineering challenges yourself less and less.

Why can't universities launch space telescopes that don't cost as much as the most expensive one ever?

The ISS has cost a combined total of 150b$. It's apples and oranges, of course, but it can considered to be the single most expensive item ever built.

It's one of the most expensive objects period

Cubesats fill that role, for when those groups need their own. JWST is from the consortium of half the first world, because they want to measure the same thing. It’s not an either-or.

Johns Hopkins University is playing a fairly large role in the JWST mission

Non-cookiewalled link:

https://text.npr.org/1075437484

Huge achievement, I can't wait to see what they find.

I know they're not reading HN but well done big congrats to all involved.

Amidst all the depressing news, this is a remider that humans can come together and do amazing things. Kudos to everyone involved.

I am quite relieved that all the deployment worked out and so looking forward to the first images. I hope, planning for a true Hubble successor (a telescope in the visual range) starts soon. Maybe a one-off Starship could be the telescope housing, it would enable an 8m mirror without any folding, just the tip of the Starship would open up once in orbit.

Why not go for a much larger folding mirror?

Price, simplicity. 8m mirror size would equal some of the largest telescopes currently on the ground. A lost of cost could be saved, if the whole teslescope could be completely assembled on ground. Later iterations could have larger mirrors, but just having a Hubble replacement with modern cameras would be a huge step, having a 4x larger mirror will be magnificient enough.

Question; why is the Where is Webb page saying current speed is .1255 miles/second? There's a blurb in the explainer that says that speed is Earth relative.

https://jwst.nasa.gov/content/webbLaunch/whereIsWebb.html?s=...

It's in orbit round L2, not stationary relative to Earth.

Video as linked by another comment: https://www.youtube.com/watch?v=6cUe4oMk69E&list=TLGG8tIphgp...

Watching that video it seems to me relative to earth the speed is Zero? Distance to the earth is not changing. Relative to other things sure it's moving around.

Maybe it’s zero relative to the earth-moon center of mass, and/or the rotation simply isn’t that exact for the relative speed to be zero.

I always find mentions of "speed" of spaceships in the press very strange: they never specify the reference frame.

Right? Sitting still we are 1,037 mph at the equator. And then you can consider relative to our sun, or galactic core, etc. https://www.space.com/33527-how-fast-is-earth-moving.html

We are all living vicariously through the good news of the James Webb space telescope successes. Some much needed good news that is based on the innovative push that humanity has. The good side of our human condition.

I have a dumb question. If the telescope is always moving in an orbit around L2 and then also around sun, how does it focus at a single area for long durations ?

Two parts to this answer. The short one is that this amount of orbital motion results in very very small differences in angle given the very long distance of the objects it's focused on and the relatively short exposure times (short with respect to the orbital period of the telescope).

The somewhat longer answer is that the spacecraft establishes an orientation using its Control Moment Gyros (CMGs). The ops team could use the CMGs to maintain pointing if this small amount of image smear ever became significant. But the CMGs would probably induce as much image smear as they removed, since they will induce structural vibrations in the spacecraft, so the utility of this approach would be questionable.

Thank you !

JWST will hear "GOD" Laughing (The Big Laugh).

No offence to anyone involved in this genuinely exciting and humbling project:

Please stop putting me on the edge of my seat until we’re just about to get our first images (many months from now)

I was excited about the launch, and happy to know it went better than expected so that there is extra fuel, but each milestone is burning me out. Let me know when the tests are done and we can view the images of distant objects.

Considering the number of times I've literally shed tears of joy since launch, I respectfully disagree. Keep those milestones coming, baby!

'Science' writing at its worst -> the tennis-court sized telescope made its way into a parking spot that's about a million miles away from Earth.

It would be better to try to explain concepts in a succinct way and, if it is not possible, to provide links to get the full information about a more detailed description. Also it is a good idea to use metric units for science articles.

> Also it is a good idea to use metric units for science articles.

It's not if you're writing for an American audience that's more familar with imperial units.

Then you can use football fields as measurement unit, following that argument. Or bananas.

There's a reason things like football fields are commonly used as measurements in science communication: it actually helps the average person to get a sense of scale.

But it also makes it impossible to compare things. A lot of these articles switch from tennis court to football field to school bus to width of a hair. I would be ok if they wrote something like “100m long which is about the size of a football field”. But I really hate that they omit the numbers. I have no idea how many tennis courts fit into an football field and how that translates to school buses. And I bet most people don’t know either. But I know that 30 meters fits 3.3 times into 100 meters. This kind of writing manipulates people and keeps them dumb.

The same happens in politics. They often omit that when they write that something costs 100 billion that this is actually over 20 years. Another time they bring up a number that’s over 5 years 1 year. Whatever is more convenient for the story.

All this writing seems designed not to educate and inform but to keep people dumb and to appeal to the emotions the author wants to effect.

Does it make a difference if it's 100m or 110m or 90m?? For a general audience? Obviously it does not, the point is to convey the scale/order of magnitude. Is it about the size of a person? An elephant? A bus? A football pitch? That's what is being communicated here.

'Football fields' seem particularly vague as there are half a dozen different sports called football, and each of these have different sized fields.

There are quite a few miles too: https://en.wikipedia.org/wiki/Mile_(disambiguation)

Yeah, and there used to be more. That's why people standardized the meter.

But tennis courts are very common in America. Every high school around here has at least 2. Many parks have them. The fitness center I go to has 2 external and 1 internal tennis courts.

They’re not “imperial” units, since those were set by the British Empire in the first part of the 1800s, and the Americans never adopted them.

We should just define that outer space uses metric units. The average american won't know the difference between "a million miles" and "a million kilometers", because they're both way beyond the realm of practical experience.

As an American, about 1.6.

600,000 kilometers is 1.5 times as far from Earth as the Moon. Interesting to think how much longer it took Webb to cover that distance than Apollo. A consequence of not being able to slow down under power.

JWST is around 1.5 million km, but that just illustrates my point. Being off by a factor of two makes no practical difference if you're not working on the mission.

Haha, I multiplied by 0.6 instead of 1.6. Good enough to crash a climate orbiter.

Pushes up glasses. Well, actually, the United States of America has never used Imperial Units. We have used US Customary Units which share some of the more common names. But the definitions and sizes are not the same, nor are all the names. Also, since 1893 US Customary Units have been defined in terms of SI units.

https://en.m.wikipedia.org/wiki/Mendenhall_Order https://en.m.wikipedia.org/wiki/Metric_Act_of_1866 https://en.m.wikipedia.org/wiki/Imperial_units

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