Webb telescope launch date slips again

We "don't have a lot of reserve" left.

Read the whole story

 

[fl4Ksh]

"Development began in 1996 for a launch that was initially planned for 2007 and a 500-million-dollar budget"

For comparison, SpaceX didn't exist until 6 years after the start of this project - PayPal didn't exist until 2 years after the start of this project (where the SpaceX money came from). Yes, this is a hard thing, but it's been in progress for 25 years. Twenty. Five. Years.

Pardon my pessimistic outlook, but this whole thing seems doomed - it has had so many budget issues, has taken so long and slipped so many times that it just feels par for the course that the whole thing is going to blow up on the launch pad or fail to deploy. I will be very surprised if it actually works in the long run. I would like to be wrong.

My guess is that NASA and SpaceX have already roughed out a rescue plan using Starship if JWST has a problem anywhere between LEO and L2.

 

[Wickwick]

I feel like when they were dividing up the member countries contributions somebody should have pointed out that they could launch from just up the coast from it’s final construction location, and skip the whole “how are we going to ship our incredibly fragile space telescope half way across the world to launch”

How would that work? They need to launch on an Ariane 5 and they only fly out of Kourou in French Guiana. JWST was built in Los Angeles, the launch complex ``just up the coast'' from there is Vandenberg, and Ariane launch vehicles do not and can not launch from there.

WickWick noted the technical issues with my quip about “just launching from Vandy”, however what “need” did they have to use Ariane 5 other than it being part of the EU’s contribution to the program?

I'm going to guess it was a launch vehicle with a 5-meter fairing which could get a 6500 kg spacecraft on its way to the Earth-Sun L2 point. A Delta IV Heavy might be able to do that, but a Delta IV Heavy is very expensive, and the Ariane 5 would probably have been cheaper. Especially since NASA wouldn't have to pay for the launch.

DIVH has quite a bit more performance than Ariane 5 ECA. Going on DIVH would have helped that super-tight mass budget a bit, which might have reduced cost somewhat...

Scary when in retrospect you would have saved money launching on a DIVH. However, such a launch would have taken the entire original budget.

 

[Dvon-E]

... To the solar plane the optimal would be 23 deg. So Kourou is too far south but inside the direct orbit. VAFB is well North. Oh, and it can't launch east.

If only we knew someone near 25.6°N with a clear view to the east, a new launchpad under construction and a really big rocket to match.

 

[amarant]

If they are that concerned about piracy, why not send a couple of destroyers and frigates along to escort it? I mean, that's seriously a cheaper alternative to possible piracy/damage/destruction, and even more so could be a useful exercise/training for the vessels as well as real, serious protection.

I agree. Isn't protecting important American assets at sea one of the main reasons to have a navy?

No that's just the PR reason.

 

[NewCrow]

Piracy? For something this expensive can't we get an escort??

What would she be able to do to protect it?

/s

 

[matthewslyman]

The Ariane 5 is one of the most proven and reliable launch systems ever devised, but given the history of the James Webb Space Telescope I'm firmly in the camp of "check everything, check it again, then hire someone else to check it a third time... and maaaaybe just check it again after that".

Because the JWST is pretty much cursed, and everything that CAN go wrong WILL go wrong, so best make sure that NOTHING can go wrong. No tempting fate.

There's an argument in industry at least that TOO much inspection becomes counter productive.

Every inspection is an opportunity for the inspectors to introduce new defects.

 

[dio82]

some quick websearching hasn't yielded much other than reddit crap,
and so I'm very seriously wondering about
the multiple comments over the years about how
once JWST is on station its "unmaintainable/unserviceable"

This is, presumably, by design given that HST was built to be deployed by shuttle,
and periodically visited by shuttle, and no one figured that a spacecraft capable
of getting to the Lagrange point would exist to go service JWST.

With new spaceflight capabilities coming online (Starship, even Orion if we want to believe
that SLS flies more than once) is JWST still "doomed" if the insanely complex,
nearly 200 step deployment process fails?

The obvious caveats that come to mind:
* money to fly "tbd" spacecraft to JWST at the lagrange point
* money to train astronauts to do whatever servicing is required
* money and time to develop whatever repair tools, systems are needed
* TBD spacecraft being able to station keep with JWST? (presumably no Canadarm grapple fixture anywhere on JWST
* spacecraft needs an airlock for cycling while repair crew goes in and out
* rad hardening for 'tbd' spacecraft, EVA suits because in 'deep space'

That's the first order list that comes to mind: but I still ask the question because
for the stake of just how much $$$ was spent on JWST, if deploy step
154 fails, and all the remote troubleshooting fails, does it really
just get thrown away ? ( sunk cost fallacy enters the rambling here too I suppose)


Does a, say, $150M repair mission to get the multi-billion dollar JWST back online
come into the conversation?

Without a working heat shield it will be a very short race against to the clock for its stored liquid helium. :/

Without that cooling, its capabilities are very limited.

 

[i662i812r11]

If they are that concerned about piracy...

I agree. Isn't protecting important American assets at sea one of the main reasons to have a navy?

Wrong. The main purpose of the Navy is force projection.

You should call them to update their mission statement that begins:

'The United States is a maritime nation, and the U.S. Navy protects America at sea. Alongside our allies and partners, we defend freedom, preserve economic prosperity, and keep the seas open and free.'

https://www.navy.mil/About/Mission/

 

[Aufgehaben]

If they are that concerned about piracy, why not send a couple of destroyers and frigates along to escort it? I mean, that's seriously a cheaper alternative to possible piracy/damage/destruction, and even more so could be a useful exercise/training for the vessels as well as real, serious protection.

I agree. Isn't protecting important American assets at sea one of the main reasons to have a navy?

You're thinking of oil, not sciency stuff.

 

[shoe]

If the oopsie with Hubble had not happened, maybe JWST would not have been picked over so thoroughly. On the other hand, the Hubble blurred vision problem might have been a blessing since there is no way to go out to the JWST and fix any problems.

Hubble is also a far less technically challenging project. There are things to be unhappy with the contractor on about JWST, but part of it is just that you can't really get rid of the complexity without compromising the mission of the telescope.

There is just a lot more that could go wrong with the telescope.

Doesn't it seem like the mission goals were _too_ ambitious? My point of view is what if you had a telescope with 80% of the capability but half the cost and in operation 5 years sooner? And probably two of them.

 

[azazel1024]

The Ariane 5 is one of the most proven and reliable launch systems ever devised, but given the history of the James Webb Space Telescope I'm firmly in the camp of "check everything, check it again, then hire someone else to check it a third time... and maaaaybe just check it again after that".

Because the JWST is pretty much cursed, and everything that CAN go wrong WILL go wrong, so best make sure that NOTHING can go wrong. No tempting fate.

Yup. Also how it gets to expensive. Not that the technology isn't super impressive. But it is what I am deeply looking forward to SS+SH unlocking.

Something like James Webb could be launched on less than 10% of the budget. The launch services would be a small fraction of what Ariane is charging. The launcher could loft way more payload. And because all of that is cheaper, the space telescope isn't nearly as mass or space constrained. And guess what, if it fails, you are out perhaps a few hundred million. Not billions of dollars. Okay, launch a 2nd one. You don't want to just throw money at it, but if it is going to cost you $2 billion all up and there is a 0% chance of getting budget to try again, well invest $1 billion to make sure its right. And if you need to ask for some more to double check the double checkers. And while we are at it, lets ask for some more to double check them. And...

It is like the a large vehicle. It needs a heavier suspension. But that adds weight. So the engine needs to be more powerful. The brakes need to be bigger. The frame needs to accommodate this. Well, now all of that stuff has added weight, so the suspension needs to be beefier. Now all the other parts. Rinse and repeat. Small changes can make big impacts in the end.

But man I am so looking forward to JWST becoming operational. I am also really hoping within just a few years it is eclipsed by a significantly better and vastly cheaper space telescope(s).

 

[Wickwick]

If the oopsie with Hubble had not happened, maybe JWST would not have been picked over so thoroughly. On the other hand, the Hubble blurred vision problem might have been a blessing since there is no way to go out to the JWST and fix any problems.

Hubble is also a far less technically challenging project. There are things to be unhappy with the contractor on about JWST, but part of it is just that you can't really get rid of the complexity without compromising the mission of the telescope.

There is just a lot more that could go wrong with the telescope.

Doesn't it seem like the mission goals were _too_ ambitious? My point of view is what if you had a telescope with 80% of the capability but half the cost and in operation 5 years sooner? And probably two of them.

It depends on whether the sun shade was given a larger mass budget or not. At the start, the sun shade wasn't considered a technical pacing item. It was assigned a mass budget according to estimates at the time and design work began. That system has become a nightmare to test on the ground. If the less-capable telescope had only been reduced in the areas that were thought to be challenging, the problem with the sun shade would have still occurred.

 

[daveishereagain]

If the oopsie with Hubble had not happened, maybe JWST would not have been picked over so thoroughly. On the other hand, the Hubble blurred vision problem might have been a blessing since there is no way to go out to the JWST and fix any problems.

Hubble is also a far less technically challenging project. There are things to be unhappy with the contractor on about JWST, but part of it is just that you can't really get rid of the complexity without compromising the mission of the telescope.

There is just a lot more that could go wrong with the telescope.

Doesn't it seem like the mission goals were _too_ ambitious? My point of view is what if you had a telescope with 80% of the capability but half the cost and in operation 5 years sooner? And probably two of them.

Yeah, I think it comes down to Northrop being in way over their heads.
"Sure, we can do that."
"Can we do that?"
By now, there are plenty of lessons to add to the Don't Do It This Way book, but plans for the next round of space telescopes are already in the works.

 

[the-unknown]

I will be very surprised if there isn't some USN assets in place to keep an eye on the cargo ship.

It is probably not really going to cost anything, cos if a Destroyer at sea cost X dollars daily, it doesnt matter where at sea it is at, since it's still going to cost that much money.

And I don't think USN has all it's current ships on "must do active duty" whereby they can't just redeploy a ship at a different location for a couple of weeks or so without it being a security issue elsewhere.

 

[llanitedave]

Hubble is also a far less technically challenging project. There are things to be unhappy with the contractor on about JWST, but part of it is just that you can't really get rid of the complexity without compromising the mission of the telescope.

There is just a lot more that could go wrong with the telescope.

Hubble was basically a spy satellite that looked up instead of down. The spacecraft bus (Lockheed) and optics (Perkin-Elmer) were made by the same people as built the KH series spysats. Sure, there were some unique requirements (zero thermal expansion, replaceable instruments), but a large part of it was built by people with experience...

And they still screwed it up.

 

[HeraldOfDawn]

The Ariane 5 is one of the most proven and reliable launch systems ever devised, but given the history of the James Webb Space Telescope I'm firmly in the camp of "check everything, check it again, then hire someone else to check it a third time... and maaaaybe just check it again after that".

Because the JWST is pretty much cursed, and everything that CAN go wrong WILL go wrong, so best make sure that NOTHING can go wrong. No tempting fate.

Yup. Also how it gets to expensive. Not that the technology isn't super impressive. But it is what I am deeply looking forward to SS+SH unlocking.

Something like James Webb could be launched on less than 10% of the budget. The launch services would be a small fraction of what Ariane is charging. The launcher could loft way more payload. And because all of that is cheaper, the space telescope isn't nearly as mass or space constrained. And guess what, if it fails, you are out perhaps a few hundred million. Not billions of dollars. Okay, launch a 2nd one. You don't want to just throw money at it, but if it is going to cost you $2 billion all up and there is a 0% chance of getting budget to try again, well invest $1 billion to make sure its right. And if you need to ask for some more to double check the double checkers. And while we are at it, lets ask for some more to double check them. And...

It is like the a large vehicle. It needs a heavier suspension. But that adds weight. So the engine needs to be more powerful. The brakes need to be bigger. The frame needs to accommodate this. Well, now all of that stuff has added weight, so the suspension needs to be beefier. Now all the other parts. Rinse and repeat. Small changes can make big impacts in the end.

But man I am so looking forward to JWST becoming operational. I am also really hoping within just a few years it is eclipsed by a significantly better and vastly cheaper space telescope(s).

Ariannespace isn’t charging NASA anything for the launch, ESA bought it as their project contribution. Tough to beat free - SS wouldn’t actually help in that particular way.

 

[Bongle]

I believe it was Scott Manley that pointed out that the "fairing issue" was:
1) JWST realized that the sunshield might have trapped gases that could quickly escape during the pressure drop when the fairing gets jettisoned. Rapidly expanding gas trapped in 5 layers of mission-critical mylar makes them nervous.
2) The standard Ariane fairing pressure drop at jettison was too much. Note that this pressure drop was the same that it's been for like 25 years...
3) So they requested Arianespace do a better job getting rid of the air in the fairing pre-jettison just for them.
4) There have been two launches so far with modified bigly-vented fairings attempting to hit the new JWST requirements, and both had slight anomalies.

So it's not quite just some random mechanical engineering or QC issue with the fairing - it's yet another JWST requirement.

 

[JBELL37]

Arrrr I need a hobby

 

[fryhole]

NASA plans to ship the telescope to the launch site by boat late this summer. (NASA is keeping precise plans vague due to concerns about piracy at sea. Seriously.)

Piracy? For something this expensive can't we get an escort??

Yeah, no shit. You'd think a small Navy escort (a few destoyers and cruisers) wouldn't be messed with by pirates.

And that would really suck if after everything some pirates got a hold of the JWST and/or sank it.

 

[wagnerrp]

Arrrr I need a hobby

Best first post ever?

 

[Wickwick]

I believe it was Scott Manley that pointed out that the "fairing issue" was:
1) JWST realized that the sunshield might have trapped gases that could quickly escape during the pressure drop when the fairing gets jettisoned. Rapidly expanding gas trapped in 5 layers of mission-critical mylar makes them nervous.
2) The standard Ariane fairing pressure drop at jettison was too much. Note that this pressure drop was the same that it's been for like 25 years...
3) So they requested Arianespace do a better job getting rid of the air in the fairing pre-jettison just for them.
4) There have been two launches so far with modified bigly-vented fairings attempting to hit the new JWST requirements, and both had slight anomalies.

So it's not quite just some random mechanical engineering or QC issue with the fairing - it's yet another JWST requirement.

I guess the fairings aren't strong enough to be pulled to vacuum on the pad?

 

[grrrz]

yeah to make things worse there is a P1 covid variant wave hitting french Guyana; and the vaccine campaign there is not picking up (from lack of vaccines or willingness to be vaccinated; that's not clear but the population there is pretty poor and often lives in very remote places).
vaccination rate is about 14% of people with at least one dose; when it's 40% average in France as a whole.

 

[Bongle]

I believe it was Scott Manley that pointed out that the "fairing issue" was:
1) JWST realized that the sunshield might have trapped gases that could quickly escape during the pressure drop when the fairing gets jettisoned. Rapidly expanding gas trapped in 5 layers of mission-critical mylar makes them nervous.
2) The standard Ariane fairing pressure drop at jettison was too much. Note that this pressure drop was the same that it's been for like 25 years...
3) So they requested Arianespace do a better job getting rid of the air in the fairing pre-jettison just for them.
4) There have been two launches so far with modified bigly-vented fairings attempting to hit the new JWST requirements, and both had slight anomalies.

So it's not quite just some random mechanical engineering or QC issue with the fairing - it's yet another JWST requirement.

I guess the fairings aren't strong enough to be pulled to vacuum on the pad?

That makes me wonder if they could've tested it by pulling a vacuum chamber from sea-level to vacuum in ~5 minutes, but I bet a vacuum chamber big enough to contain the packaged sunshield is too big to be vacuum'd that fast.

Here's an article that goes into more detail (there aren't many details available) about the fairing issue: https://spacenews.com/jwst-launch-slips-to-november/

Note that Arianespace says the current issue is not actually pressure-venting-related, but it occurred on the trialed JWST-spec fairings, so it seems not-entirely-unrelated. They're also confident they've fixed it. So maybe not a problem!

 

[PaleRedDot]

My local CVS is practically begging people to come in for shots. How about NASA buy enough stock to vaccinate everyone at the launch facility and their families?

ESA, not NASA!

 

[Wickwick]

My local CVS is practically begging people to come in for shots. How about NASA buy enough stock to vaccinate everyone at the launch facility and their families?

ESA, not NASA!

ESA would have to buy them in Europe where the supply isn't so free-flowing. NASA could buy them in the States where we're shortly going to have more supply than demand.

 

[melgross]

My local CVS is practically begging people to come in for shots. How about NASA buy enough stock to vaccinate everyone at the launch facility and their families?

Why doesn’t the EU do it? It’s their spaceport after all.

The EU can't even vaccinate itself (plus France is one of the most anti-vax western nations in the world).

So what? This is a launch facility. Not in Europe. If they want vaccinations, they should do it. There aren’t that many people there compared to the EU. Expecting a customer who needs just one launch that the EU can’t even do on time, to manage this, at our expense, no doubt, isn’t the way to handle this.

 

[Imbrium]

If they are that concerned about piracy, why not send a couple of destroyers and frigates along to escort it? I mean, that's seriously a cheaper alternative to possible piracy/damage/destruction, and even more so could be a useful exercise/training for the vessels as well as real, serious protection.

I agree. Isn't protecting important American assets at sea one of the main reasons to have a navy?

Wrong. The main purpose of the Navy is force projection.

The main purpose of a navy is to protect a nation's shipping, while also posing a threat to enemy shipping in time of war. Projecting power is useless if your nation is starving because the ships bringing in the food are lying on the bottom of the ocean. Ask England about that.

England was a global superpower for centuries largely because of the force projection of its navy.

And yet, it was the protection of their own shipping and the destruction of enemy shipping that was the most important role for the RN. They attacked the Spanish treasure fleets returning from the New World with their cargoes of gold. The main role of frigates in the age of sail was commerce protection and commerce raiding. While the battlefleets got the most attention in WWI, it was the ships that protected convoys while sweeping the oceans of German merchant ships and blockading German ports that had the most significant impact on the conduct of the war, starving the German people, setting up communist unrest that eventually crippled the German war effort. In WWII, nothing was more important than protecting merchant ships carrying food, weapons, ammunition and troops to England.

Did they do force projection? Obviously, but it was only the most visible part of the navy. It was the use of the navy to protect English commerce while denying the seas to their opponents that was the key.

 

[Imbrium]

I will be very surprised if there isn't some USN assets in place to keep an eye on the cargo ship.

It is probably not really going to cost anything, cos if a Destroyer at sea cost X dollars daily, it doesnt matter where at sea it is at, since it's still going to cost that much money.

And I don't think USN has all it's current ships on "must do active duty" whereby they can't just redeploy a ship at a different location for a couple of weeks or so without it being a security issue elsewhere.

The USN will be watching that area very closely. Iran is sending a converted tanker loaded with 7 missile patrol boats to Venezuela at this very moment, and I'm sure the Navy is VERY interested in that particular ship and its cargo. They would be there irregardless of whether JWST is transiting the area.

 

[Galapadoc]

If the oopsie with Hubble had not happened, maybe JWST would not have been picked over so thoroughly. On the other hand, the Hubble blurred vision problem might have been a blessing since there is no way to go out to the JWST and fix any problems.

I bet Musk could get a repair team to it if it became necessary.

 

[Bongle]

If the oopsie with Hubble had not happened, maybe JWST would not have been picked over so thoroughly. On the other hand, the Hubble blurred vision problem might have been a blessing since there is no way to go out to the JWST and fix any problems.

I bet Musk could get a repair team to it if it became necessary.

It's unlikely - no grapple fixtures so your astronauts would have a very hard time turning bolts, pushing things, or remaining attached.

Also, to save weight basically everything is glued rather than bolted.
Also, no lenscap, so an approaching spacecraft would contaminate the optics with thruster firings.
Also, the cold side of the telescope is at about 50K, so touching it or installing spacecraft-temperature parts would be interesting.

So it's not really a "get the astronauts there" problem, it's a "there's not a whole lot you can do to it" problem with a bonus serving of "the few things you could do to it would probably wreck the optics anyway". Imagine fixing the screen on your iphone while wearing inflated gloves.

If SpaceX got starship/superheavy flying, SpaceX could contribute a monolithic-mirror JWST-equivalent. But building bigass near-perfect mirrors is still really hard, so it wouldn't be that cheap.

 

[hecksagon]

If the oopsie with Hubble had not happened, maybe JWST would not have been picked over so thoroughly. On the other hand, the Hubble blurred vision problem might have been a blessing since there is no way to go out to the JWST and fix any problems.

I have the feeling they could have screwed up and built a fixed version a few times over now. Sometimes this extreme caution and over-engineering is more expensive than “git ’er done”. (See: SLS vs SpaceX.)

That has been one of the more consistent complaints about the JWST program. NASA could have flown prototypes of the various systems in LEO and even gotten some useful IR data from them along with learning how best to deploy sunshields in microgravity, all for less than the current bloated mess cost.

Instead, they kept insisting that they didn't need no prototypes and spent much more on ensuring that the rig would work.

There is a reason that many astronomers refer to JWST as "The Telescope That Ate Astronomy"

Of course you could have also very easily heavily exceeded. the budget of the current telescope. Things like what SpaceX is doing works a lot better when you're not developing something fundamentally new.

Given my understanding of the solar shade there is no way to handle that besides being extremely careful prior to launch. The big challenge is that all the folding has to be done correctly for it not to get damaged during launch and to deploy correctly.

What SpaceX is doing involves a great deal that's fundamentally new, and is how the early exploratory work in rocketry is done. It excels at dealing with new problems that you don't initially know how to solve.

There's nothing about shielding against sunlight that innately requires a complex self-deploying structure that's on the verge of tearing itself apart. If we'd launched smaller telescopes with similar shades, we would have had a better idea of what would be required and we'd never have even tried to fit that functionality in that volume/mass allocation.

We know what is required to shade this spacecraft. That's how they ended up with this design. It's as large as it is because it has to block sunlight from hitting ANY part of the spacecraft. Its as thick as it is because it has to create a thermal gradient from -236°C to 110°C passively of the instruments will get too hot to make observations. Obviously a sunshade larger than the spacecraft itself needs to be able to fold up to fit inside the envelope of the spacecraft for launch.

 

[khalathur]

If the oopsie with Hubble had not happened, maybe JWST would not have been picked over so thoroughly. On the other hand, the Hubble blurred vision problem might have been a blessing since there is no way to go out to the JWST and fix any problems.

Hubble is also a far less technically challenging project. There are things to be unhappy with the contractor on about JWST, but part of it is just that you can't really get rid of the complexity without compromising the mission of the telescope.

There is just a lot more that could go wrong with the telescope.

Doesn't it seem like the mission goals were _too_ ambitious? My point of view is what if you had a telescope with 80% of the capability but half the cost and in operation 5 years sooner? And probably two of them.

This was discussed a little bit earlier in the thread. Any large science installation is designed with specifications intended to answer specific questions. Like, the LHC was designed to verify whether the HIggs boson exists or not. That dictated things like it's energy and beam current. A small degradation in capability might mean you can still get the answers but it will take longer. A significant downgrade means you can't ever answer the questions the facility was built to answer. You can still investigate other topics, and unexpected discoveries are always hoped for, but you couldn't do the fundamental mission.

In short, if your new gizmo can't do things your old gizmos fundamentally can't do, then why build it? We could do Hubble-class science faster with more Hubble's, but no number of copies of Hubble could do what a working JWST could do.

Only in hindsight can you answer questions like your 80/50 tradeoff. And 80% of the capability might or might not have turned out to be good enough.

 

[Christopher James Huff]

If the oopsie with Hubble had not happened, maybe JWST would not have been picked over so thoroughly. On the other hand, the Hubble blurred vision problem might have been a blessing since there is no way to go out to the JWST and fix any problems.

I have the feeling they could have screwed up and built a fixed version a few times over now. Sometimes this extreme caution and over-engineering is more expensive than “git ’er done”. (See: SLS vs SpaceX.)

That has been one of the more consistent complaints about the JWST program. NASA could have flown prototypes of the various systems in LEO and even gotten some useful IR data from them along with learning how best to deploy sunshields in microgravity, all for less than the current bloated mess cost.

Instead, they kept insisting that they didn't need no prototypes and spent much more on ensuring that the rig would work.

There is a reason that many astronomers refer to JWST as "The Telescope That Ate Astronomy"

Of course you could have also very easily heavily exceeded. the budget of the current telescope. Things like what SpaceX is doing works a lot better when you're not developing something fundamentally new.

Given my understanding of the solar shade there is no way to handle that besides being extremely careful prior to launch. The big challenge is that all the folding has to be done correctly for it not to get damaged during launch and to deploy correctly.

What SpaceX is doing involves a great deal that's fundamentally new, and is how the early exploratory work in rocketry is done. It excels at dealing with new problems that you don't initially know how to solve.

There's nothing about shielding against sunlight that innately requires a complex self-deploying structure that's on the verge of tearing itself apart. If we'd launched smaller telescopes with similar shades, we would have had a better idea of what would be required and we'd never have even tried to fit that functionality in that volume/mass allocation.

We know what is required to shade this spacecraft. That's how they ended up with this design. It's as large as it is because it has to block sunlight from hitting ANY part of the spacecraft. Its as thick as it is because it has to create a thermal gradient from -236°C to 110°C passively of the instruments will get too hot to make observations. Obviously a sunshade larger than the spacecraft itself needs to be able to fold up to fit inside the envelope of the spacecraft for launch.

And it doesn't reasonably fit in the payload mass and volume available on the Ariane 5. If we'd flown a less-ambitious intermediate instrument first, we'd know what's reasonable and we wouldn't have spent an order of magnitude more than originally planned trying to cram JWST into the available mass and volume. We'd have launched and deployed it years ago, at less risk due to the experience gained with its predecessor, and be planning its bigger-and-better replacement now.

 

[thohac]

If they are that concerned about piracy, why not send a couple of destroyers and frigates along to escort it? I mean, that's seriously a cheaper alternative to possible piracy/damage/destruction, and even more so could be a useful exercise/training for the vessels as well as real, serious protection.

I agree. Isn't protecting important American assets at sea one of the main reasons to have a navy?

Wrong. The main purpose of the Navy is force projection.

There is only a handful of nations with Naval capabilities of "force projection"
The U.S and its 9 Supercarrier groups and 14 ballistic-missile subs is on a league of its own.
France, U.K and Russia have limited capabilities with 1 aircraft-carrier and a few ballistic-missle subs, although Admiral Kuznetsov's mazut-burning trail, its frequent breakdowns and accidents make it the butt of endless jokes.
China has several ballistic-missile subs and currently has 1 aircraft-carrier (A Soviet model that was never completed and sold for scrap by Russia) and another one in construction.
The Charles de Gaulle is the only non-Us carrier with a catapult launch system although it is smaller then the Nimitz-class.
Japan has 2 really large helicopter-carriers that many suspect were specifically designed with the possibility of rapid-conversation into fixed-wing carriers.

 

[thohac]

And it doesn't reasonably fit in the payload mass and volume available on the Ariane 5. If we'd flown a less-ambitious intermediate instrument first, we'd know what's reasonable and we wouldn't have spent an order of magnitude more than originally planned trying to cram JWST into the available mass and volume. We'd have launched and deployed it years ago, at less risk due to the experience gained with its predecessor, and be planning its bigger-and-better replacement now.

Yes but that route also had its own risks the largest being Congress not appropriating a follow-up mission, especially if the first had even a quarter of the issues and cost-overruns the JST ended up having.

 

[jaminb]

I feel like when they were dividing up the member countries contributions somebody should have pointed out that they could launch from just up the coast from it’s final construction location, and skip the whole “how are we going to ship our incredibly fragile space telescope half way across the world to launch”

How would that work? They need to launch on an Ariane 5 and they only fly out of Kourou in French Guiana. JWST was built in Los Angeles, the launch complex ``just up the coast'' from there is Vandenberg, and Ariane launch vehicles do not and can not launch from there.

WickWick noted the technical issues with my quip about “just launching from Vandy”, however what “need” did they have to use Ariane 5 other than it being part of the EU’s contribution to the program?

I'm going to guess it was a launch vehicle with a 5-meter fairing which could get a 6500 kg spacecraft on its way to the Earth-Sun L2 point. A Delta IV Heavy might be able to do that, but a Delta IV Heavy is very expensive, and the Ariane 5 would probably have been cheaper. Especially since NASA wouldn't have to pay for the launch.

Knowing what we know now, the Delta IV Heavy sounds like a bargain.
Could have used thicker mylar on the sunshade, more robust deployment system, skipped the sea voyage, greatly simplified the cargo box. Any leftover mass budget could have been spent at the very end of design on larger tanks of helium.

Sadness...

 

[A_username]

My local CVS is practically begging people to come in for shots. How about NASA buy enough stock to vaccinate everyone at the launch facility and their families?

That's a good point. Divert a few 10s of thousands of doses for the launch site and local area. You've got enough time, assuming you get started _now_. Or even just the J&J, one and done.

One and permanently done for some.

 

[A_username]

If the oopsie with Hubble had not happened, maybe JWST would not have been picked over so thoroughly. On the other hand, the Hubble blurred vision problem might have been a blessing since there is no way to go out to the JWST and fix any problems.

Hubble is also a far less technically challenging project. There are things to be unhappy with the contractor on about JWST, but part of it is just that you can't really get rid of the complexity without compromising the mission of the telescope.

There is just a lot more that could go wrong with the telescope.

Doesn't it seem like the mission goals were _too_ ambitious? My point of view is what if you had a telescope with 80% of the capability but half the cost and in operation 5 years sooner? And probably two of them.

It was an utterly terribly designed mission, everyone involved should be sent to l2.

 

[azazel1024]

I will be very surprised if there isn't some USN assets in place to keep an eye on the cargo ship.

It is probably not really going to cost anything, cos if a Destroyer at sea cost X dollars daily, it doesnt matter where at sea it is at, since it's still going to cost that much money.

And I don't think USN has all it's current ships on "must do active duty" whereby they can't just redeploy a ship at a different location for a couple of weeks or so without it being a security issue elsewhere.

Much more likely would be a USCS cutter to escort it. If it needs anything, it would be protection against non-state pirates, not a state sanctioned and support seizure. Though in terms of size and crew, the WMECs are effectively the same size as a USNS frigate, though somewhat less capable in armament.

I don't think a pirate ship would mess with a USCS cutter with a 76mm deck gun, some 50s and a Dolphin or Jayhawk with a door gun.

Or honestly an armed US Coast Guard team or USMC team. That generally wouldn't be a concern even in pirate waters for the most part, but because of national restrictions, most ships don't sail with firearms on board or an armed security team. Less a cost prohibitive issue and some ships do sail with armed security details on them.

Most pirates are sailing real warships of any stripe. They are a few fast boats with AK-47s, RPKs and RPG-7. Which isn't going to seriously sink any real cargo ship, but can do some damage and of course if they can board...

But a security team with rifles and a GPMG or two is going to be some MASSIVE dissuasion for the pirates life choices. I might be wrong, but I am not aware of any civilian ships successfully seized by pirates in any waters that did have an armed security team onboard. And several instances where such ships successfully repelled pirates.

 

[thohac]

I will be very surprised if there isn't some USN assets in place to keep an eye on the cargo ship.

It is probably not really going to cost anything, cos if a Destroyer at sea cost X dollars daily, it doesnt matter where at sea it is at, since it's still going to cost that much money.

And I don't think USN has all it's current ships on "must do active duty" whereby they can't just redeploy a ship at a different location for a couple of weeks or so without it being a security issue elsewhere.

Much more likely would be a USCS cutter to escort it. If it needs anything, it would be protection against non-state pirates, not a state sanctioned and support seizure. Though in terms of size and crew, the WMECs are effectively the same size as a USNS frigate, though somewhat less capable in armament.

I don't think a pirate ship would mess with a USCS cutter with a 76mm deck gun, some 50s and a Dolphin or Jayhawk with a door gun.

Or honestly an armed US Coast Guard team or USMC team. That generally wouldn't be a concern even in pirate waters for the most part, but because of national restrictions, most ships don't sail with firearms on board or an armed security team. Less a cost prohibitive issue and some ships do sail with armed security details on them.

Most pirates are sailing real warships of any stripe. They are a few fast boats with AK-47s, RPKs and RPG-7. Which isn't going to seriously sink any real cargo ship, but can do some damage and of course if they can board...

But a security team with rifles and a GPMG or two is going to be some MASSIVE dissuasion for the pirates life choices. I might be wrong, but I am not aware of any civilian ships successfully seized by pirates in any waters that did have an armed security team onboard. And several instances where such ships successfully repelled pirates.

A stray bullet hitting the JWST would be a total disaster so a on-board security team is not a good idea. Ideally you would want to intercept would be pirates as far away from the cargo-ship as possible.