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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

#301

Post by Symmetry »

bewaretheirs wrote: post #229
macintux wrote: post #186

Earlier quoted context omitted.

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…

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

#302

Post by zargon »

Buttons840 wrote: post #297
beerandt wrote: post #294

Earlier quoted context omitted.

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…

> 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.

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

#303

Post by avmich »

jedberg wrote: post #182
nexuist wrote: post #109

Earlier quoted context omitted.

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

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.

> 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.

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

#304

Post by _yoqn »

bdamm wrote: post #211
_yoqn wrote: post #203

Earlier quoted context omitted.

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'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.

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

#305

Post by avmich »

jedberg wrote: post #182
nexuist wrote: post #109

Earlier quoted context omitted.

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

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.

> 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.

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

#306

Post by thepasswordis »

bestouff wrote: post #4

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

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.

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

#307

Post by jedberg »

avmich wrote: post #303
jedberg wrote: post #182

Earlier quoted context omitted.

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.

> 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 a…

> Sigh. Where did you get that number?

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

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

#308

Post by avmich »

wolverine876 wrote: post #281
arcticfox wrote: post #170

Earlier quoted context omitted.

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.

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

#309

Post by dron57 »

BurningFrog wrote: post #243
Steltek wrote: post #151

Earlier quoted context omitted.

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."

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.

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

#310

Post by avmich »

jedberg wrote: post #307
avmich wrote: post #303

Earlier quoted context omitted.

> 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 a…

> 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).
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