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

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

#161

Post by jpindar »

ravi-delia wrote: post #155
egeozcan wrote: post #122

Earlier quoted context omitted.

> 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/202…

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-...

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

#162

Post by willis936 »

justin66 wrote: post #139
WithinReason wrote: post #127

Earlier quoted context omitted.

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...

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

#163

Post by cronix »

wongarsu wrote: post #78
amelius wrote: post #73

Earlier quoted context omitted.

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.

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...

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

#164

Post by aitchnyu »

egeozcan wrote: post #122
Sharlin wrote: post #80

Earlier quoted context omitted.

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/202…

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

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

#165

Post by dr_orpheus »

PinkMilkshake wrote: post #3

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.…

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

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

#166

Post by chernevik »

s5300 wrote: post #58
EMM_386 wrote: post #9

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.

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 thin…

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.

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

#167

Post by bgirard »

willis936 wrote: post #162
justin66 wrote: post #139

Earlier quoted context omitted.

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)

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

#168

Post by scrumbledober »

s5300 wrote: post #58
EMM_386 wrote: post #9

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.

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 thin…

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.

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

#169

Post by sp332 »

PinkMilkshake wrote: post #3

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.…

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.

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

#170

Post by arcticfox »

raverbashing wrote: post #42
arcticfox wrote: post #33

Earlier quoted context omitted.

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

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