James Webb Space Telescope (JWST)

[HVM]

Obviously needs my wife's packing skills

Impressive diagram, thanks. Did or does Falcon 9 have an enlarged nose cone for certain missions, or am I thinking of a different rocket?

Not yet. SpaceX asked quota from above-mentioned RUAG for larger nosecone. But ULA said; not in OUR factory. RUAG USA manufacturing is in ULA’s Decatur rocket factory in Alabama.

Also: "SpaceX received a $316 million contract to launch a National Reconnaissance Office satellite in fiscal year 2022...
SpaceX is however charging the government for the cost of an extended payload fairing, upgrades to the company’s West Coast launch pad at Vandenberg Air Force in California, and a vertical integration facility required for NRO missions."

SpaceX explains why the U.S. Space Force is paying $316 million for a single launch

SpaceX explains why the U.S. Space Force is paying $316 million for a single launch

spacenews.com

So no elongated nose before 2022...

 

[bxr140]

Interesting comments in that article. NASA was setting more strict standard for the A5 fairing (for JWST), and soon after RUAG (fairing manufacturer) and Arianespace started having problems with the fairing separation.

I didn't get that out of the SN article (could be missing it, or maybe that note is somewhere else?), but that would be a bummer if the off-nominal separations were induced by NASA's insistence that Ariane fix a problem that, up to that point, didn't exist.

Bad show on Ariane either way, of course. If it wasn't the result of NASA's request, what did they change, for what reason, and why didn't they get it right? If it was because of a NASA request, still, why couldn't Ariane get it right? Anomalies during a development campaign are expected. Anomalies two decades into service...

Impressive diagram, thanks. Did or does Falcon 9 have an enlarged nose cone for certain missions, or am I thinking of a different rocket?

Falcon currently only has one fairing.

Ariane and Atlas 5/Vulcan (both of which use similar Ruag fairings...at least for the 5m Atlas) each have a few different lengths. H3 does/will have multiple fairing options as well. Optionality is all about being able to fly edge case missions--almost always they're 'light' and tall (physics makes it hard to have a heavy and tall payload), and almost always those kinds of missions are one off gub'ment deals where there's big antennas or long . IMHO I'd prefer less optionality in favor of overall more efficiency ("you can have any color you want as long as its black", so to speak); evidence the $B/3 of taxpayer dollars being spent on a little bit bigger F9 fairing, a few more shacks on the beach at Vandy, and a stupid vertical integration facility because The Man doesn't understand physics.

 

[Grendal]

Obviously needs my wife's packing skills

Impressive diagram, thanks. Did or does Falcon 9 have an enlarged nose cone for certain missions, or am I thinking of a different rocket?

Not yet. One size for now. The military is paying for a larger fairing for the Falcon Heavy along with vertical integration. I'm sure that same fairing could be used for the F9 as well - maybe. F9 is a fine tuned machine with every key factor maximized. SpaceX engineers are pretty spectacular and maybe they can tweak a few things to make it work though.

 

[HVM]

I didn't get that out of the SN article (could be missing it, or maybe that note is somewhere else?), but that would be a bummer if the off-nominal separations were induced by NASA's insistence that Ariane fix a problem that, up to that point, didn't exist.

Bad show on Ariane either way, of course. If it wasn't the result of NASA's request, what did they change, for what reason, and why didn't they get it right? If it was because of a NASA request, still, why couldn't Ariane get it right? Anomalies during a development campaign are expected. Anomalies two decades into service...
...

I needed to be more clear; It's was comment on public comments section, and so it can be total BS. Although it's true that NASA required changes to the fairing:

“We’re preparing for James Webb, and we have introduced a slightly modified fairing which has an impact on the pressurization under the fairing for the requirement by NASA, and we worked out the solution and we will fly it,” said Daniel Neuenschwander, ESA’s director of space transportation."

"On an Ariane 5 launch earlier this year, engineers flew a payload fairing with the new vents, according to Eric Smith, NASA’s program scientist for JWST. That showed some improvement in the fairing’s internal air pressure, and Smith said the vents on the next Ariane 5 flight, scheduled for Friday, will test vents with a larger opening."

Ariane 5 to test modified fairing for JWST, hardware for new range safety system – Spaceflight Now

And if I read newer SN piece right, those were the missions with the problem...

 

[Grendal]

Another major reason for not even considering SpaceX is that the Arianne 5 launch is a significant part of Europe's contribution to JWST. JWST is a multi-national effort. So there are political implications involved.

 

[HVM]

Reading between lines, delay is (possibly) due RUAG manufacturing/design problem, and that change is made same times as NASA demanded vent upgrade. This has grounded both Ariane 5 and Atlas V (with that 5m nosecone)...

 

[Grendal]

JWST launch slips to November

American and European officials acknowledged June 1 that the launch of the James Webb Space Telescope will likely slip to at least mid-November.

spacenews.com

 

[Grendal]

JWST passes launch review

JWST is one step closer to launch after a review of its Ariane launch vehicle, while NASA continues a separate review of the name of the spacecraft itself.

spacenews.com

 

[Grendal]

Maybe...

JWST gets mid-December launch date

NASA’s James Webb Space Telescope is finally scheduled to launch Dec. 18 on an Ariane 5 from French Guiana after years of development delays.

spacenews.com

 

[bxr140]

JWST made it to Kourou!

Mostly just a picture of a boat.

 

[Grendal]

 

[Electroman]

Why is this not being launched through F9 or FH? and instead through French agency?

 

[bxr140]

Why is this not being launched through F9 or FH? and instead through French agency?

James Webb Space Telescope (JWST)

 

[bxr140]

***Also, JWST mass far exceeds F9 capability for L2 transfer, and the launch deal was done long before FH was a thing (maybe even done before SpaceX was a thing). There's also a bunch of ESA stuff on the vehicle, and I'm sure some deal was made at the time to also rack in a launcher. On a personal note, I can only hope that deal was to Dick Shelby's most extreme chagrin.

The low inclination Ariane pad at CSG also makes Ariane 5 more capable than even the biggest Atlas 5 for this mission, which would have been the only real American option at the time, and its not even clear whether or not the Big Atlas would be able to serve the mission. And while I suppose DH would have technically also been a viable option for this mission, I'm sure the powers that be looked at the 400-whatever $M price tag and thought "that costs too much". <Cue jokes about the 11 figure tag on JWST>

 

[Electroman]

Thanks.

Curious about the trajectory. In a typical GTO (or GEO) the rocket gives the satellite enough speed to go on a elliptical orbit and then the satellites own rocket propulsion circularizes it and increases the altitude as necessary. L2 is much further away, and so I am wondering how much does JWST's own propulsion is used to get to L2.

 

[Grendal]

Thanks.

Curious about the trajectory. In a typical GTO (or GEO) the rocket gives the satellite enough speed to go on a elliptical orbit and then the satellites own rocket propulsion circularizes it and increases the altitude as necessary. L2 is much further away, and so I am wondering how much does JWST's own propulsion is used to get to L2.

And Part 2 from my earlier post:

 

[bxr140]

In addition to the informative and definitely nothing can go wrong with this plan deployment video @Grendal linked above, here's an interesting one of the actual L2 orbit, which animates JWST orbiting the L2 point (orbiting L2 allows the sat to remain in constant sunlight, and so it doesn't need very big solar arrays or very big batteries). Both come from this page, which is a pretty useful read.

Curious about the trajectory. In a typical GTO (or GEO) the rocket gives the satellite enough speed to go on a elliptical orbit and then the satellites own rocket propulsion circularizes it and increases the altitude as necessary. L2 is much further away, and so I am wondering how much does JWST's own propulsion is used to get to L2.

Its the same general concept with JWST, and in fact JWST has smaller thrusters than a typical [chemical] GEO because its major propulsive maneuvers (and generally the total ∆V demand) are actually lower than an GEO after GTO separation. (Note: Certainly the launcher is inserting JWST into a higher energy orbit than a GTO). Kinda related, there's also a moon-assist, where JWST is getting launched "up" to the moon and then the moon is going to bend the trajectory "sideways" toward the heliocentric L2 position. (Its not dissimilar to how gravity bends the trajectory of a rocket launching from earth--that rocket starts going directly up and needs to end up going sideways).

Here's a cool graphic on ∆ V for various objects in the solar system.

The L2 orbit is unstable so there's constant orbital maintenance required, but its not a massively unstable geometry so the ∆ V demand to station-keep isn't untenable.

 

[Cosmacelf]

Why is this not being launched through F9 or FH? and instead through French agency?

Two reasons. One is that this project has literally been in the planning stages forever and FH wasn’t a viable option back then (takes a lot of time to integrate a payload to a specific launch vehicle, especially this payload), but the real reason is that this is an internationally funded mission and the French contribution was the rocket launch.

 

[Electroman]

Thanks to everyone for sharing some really exciting, very informative link. I spent the last day and half just reading through so many those pages, including Wiki pages about Lagrange points, L2 specifically and then wandered into escape velocity wiki and all the equations around that.

The Smarter Everyday interview with Dr. John Mather on JWST was fantastic. I have been watching Justin's videos for a long time, and I have to say some of his videos are better than sex .

My other favorite YouTuber is Blue1Brown. Brilliant and captivating graphics and animation to explain math. Veritasium is another brilliant youtuber.

 

[Grendal]