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Re:NASA says Webb’s excess fuel likely to extend its lifetim... by dahfizz on Tuesday January 11, 2022 @11:14AM (#29893328)
I didn't realize the JWT will need to burn fuel in its steady state. Its pretty disappointing that this took 20 years to build and we will only get 20 years of use out of it.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by verytrivial on Tuesday January 11, 2022 @11:23AM (#29893513)
Then you're going to be disappointed by all satellites I'm afraid. They all need to do station-keeping, and have a way to maintain orientation when they spin-down their reaction wheels. "Solar-powered" thrusters use fuel too but use an electric field to accelerate it.

20 years is still a rather long time. Expect something else fragile to fail before then. And that's still double the target life time! (And unless they've made it almost maliciously difficult to add fuel, I'm sure there will be some Space Bro who'll offer to refuel it for likes / tax reasons.)

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by dahfizz on Tuesday January 11, 2022 @11:29AM (#29893616)
> Then you're going to be disappointed by all satellites I'm afraid.

Except we launch well over 1000 satellites a year. The JWT is clearly a bigger deal than that. This has been advertised as NASA's magnum opus. The fact that it was only supposed to last 10 years makes it feel much less significant...

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by Fordec on Tuesday January 11, 2022 @11:36AM (#29893759)
And those satellites, by bulk, are in low earth orbit with a lifetime of usually 4 years, and a legally mandated reentry in 25 years.

JWTs location in L2 (a mathematically unstable location that requires energy to not roll back into a gravity well in any direction) is like putting it on the satellite equivalent of K2 and not coming down from the peak for 20 years and you compare it to the thousands of commuters that made it up the hill down the road from your house.

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by dotancohen on Tuesday January 11, 2022 @12:07PM (#29894227)

  > legally mandated reentry in 25 years.
What is this requirement?
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by Fordec on Tuesday January 11, 2022 @01:58PM (#29896029)
A few, but he one that is the closest rubber that hits the road is part of the FCC filing for radio spectrum access on satellite projects. Without which, you're not getting on most rockets.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by dotancohen on Tuesday January 11, 2022 @02:14PM (#29896271)
I am not aware of the FCC mandating satellite deorbit plans as a condition for receiving a transmission band.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by Fordec on Tuesday January 11, 2022 @02:21PM (#29896414)
Swarm breached the "Mitigation of Orbital Debris Second Report and Order" which has been in place since 2004[0], for their launch on an Indian rocket because their 0.5Us would breach this and their aerodynamics wouldn't comply because the satellites were so small and didn't have enough atmospheric drag to bring them down in time. The tracked by radar aspect was resolvable by Leo Labs radars, but not the atmospheric drag component.

FCC subsequently fined them $900k.

[0] https://docs.fcc.gov/public/attachments/DOC-363486A1.pdf

[1] https://www.reuters.com/article/us-usa-satellite-fine-idUSKC...

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by dotancohen on Tuesday January 11, 2022 @02:33PM (#29896591)
Fascinating, thank you very very much.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by jaywalk on Tuesday January 11, 2022 @12:57PM (#29895045)
There is no legal requirement of that sort that I'm aware of. However, it is recommended that LEO satellites should re-enter the atmosphere within 25 years of mission completion. This is to try and mitigate the ever-growing issue of space junk in LEO.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by K5EiS on Tuesday January 11, 2022 @01:21PM (#29895435)
I couldn't find any legal requirements, but the ESA recommends a reentry withtin 25 years of mission completion to reduce waste in orbit.

https://www.esa.int/Safety_Security/Space_Debris/Mitigating_...

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by dotancohen on Tuesday January 11, 2022 @02:12PM (#29896248)
I am aware of this, but it is not legally mandated as GP states.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by verytrivial on Tuesday January 11, 2022 @11:41AM (#29893841)
.. and 99% of those probably spend 100% of their time trying to sit utterly still in their orbit, staring down at Earth, maybe twitching around to point a bit if they're doing spy work.

JWST pivots the entire spacecraft to point the 6 meter mirror. I'm sure they've optimized the consumables on the schedule, but it simply 'costs resources' to do this sort of work. I assure you there are gruellingly dense and optimized observations plans afoot.

Compare to e.g. the very successful Herschel Space Observatory -- it too went out to L2(-ish), did everything it was meant to do in its three year mission, and managed to extend to four before (drum roll) running out of fuel, this time for cooling. JSWT solves this cooling issue by some incredibly funky mechanical resonance cooling. Herschel "only" cost about $1 billion, and it will be interesting to compare the science results.

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by Fordec on Tuesday January 11, 2022 @11:48AM (#29893941)
Also don't forget it at no point can it turn around and face the earth or sun or the light coming from the suns direction will burn out the optics. If it does it once, and it's mission over. All the while essentially driving most of the way up out of the gravity well and letting it get pulled back to earth a little and repeating. If it goes too far over the peak of the hill it will go over the other side with no way to reverse even if the rocket has the fuel.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by hoseja on Wednesday January 12, 2022 @08:57AM (#29906322)
No no no, it's circling the top of the "hill".
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by hnaccount_rng on Tuesday January 11, 2022 @01:55PM (#29895959)
I think you are misinterpreting where the fuel consumption comes from. It isn't the reoriantation. That you can do with internal reaction wheels. All you want is rotation, not movement. Turn something inside in one direction and the outside will turn the other way. The only problem is movement for that you need to eject stuff the opposite way you want to go. And that is needed because L2 is unstable. I.e. you roll down over time. Which needs to be counteracted by station keeping. I'm pretty sure they'll use the fuel usage to measure the local gravitational field around L2 and from that update mass distribution estimates around the inner solar system.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by verytrivial on Tuesday January 11, 2022 @05:21PM (#29899004)
Station keeping, yes, is probably going to need the lion's share, but I have no idea by what factor. I have read that dealing with reaction wheel saturation is also another fuel consumer though. Perfect reaction wheels attached to a spherical cow would use no fuel. As would perfectly balanced solar pressure engineering etc. It basically all ends up nibbling some fuel.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by easton_s on Tuesday January 11, 2022 @11:37AM (#29893782)
10 years of operation, but hundreds of years of data to analyze. We are still analyzing data captured from terrestrial telescopes that haven't operated in decades.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by _joel on Tuesday January 11, 2022 @12:21PM (#29894435)
Is that due to the format or availability of the data?
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by slenk on Tuesday January 11, 2022 @12:33PM (#29894638)
The sheer amount of data. The black hole that was imaged recently alone was four petabytes of data

https://www.hpcwire.com/2019/06/24/a-behind-the-scenes-look-...

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by smallerfish on Tuesday January 11, 2022 @12:56PM (#29895028)
Are there any interesting private companies / startups in this space?
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by _joel on Wednesday January 12, 2022 @08:13PM (#29915469)
No idea, but if it's difficult for acedemia to get hold of this then how could startups? More to the point, what would be the value add to make the commercials viable? Interested to hear if you think there could be?

Perhaps there's some altrusitic archive.org style site that needs to exist for science, that features datasets of multiple PB in magnitude and allows anyone to pull the full archive.

Maybe in the future, but still, people still have access to source imagery and they regularly make spectacular images and material from public domain data from space agencies and interest groups. You don't need 4PB unless doing something like, well, imaging a black hole.

It's fun, not sure how much there is run a business from it, unless you plan on taking the data and creating spectrographs for some future mining mission way in the future? :D

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by FourHand451 on Tuesday January 11, 2022 @11:34AM (#29893715)
I mean, is there something you'd suggest they should have done differently? I'd imagine they gave it as much fuel as they possibly could while meeting all of the other design goals. Is is possible you're more disappointed with the advertising than the observatory itself?
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by dahfizz on Tuesday January 11, 2022 @11:38AM (#29893803)
My real concern was the difficulty we had getting the JWT ready. If JWT's successor will also take 20 years to produce, then we better start working on it tomorrow. A 10-20 year lifespan on the telescope would be perfectly fine if we could launch a new one every 5-10 years.

I'm worried that NASA has spent all its money and political will (and then some) getting JWT over the finish line.

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by mlyle on Tuesday January 11, 2022 @11:54AM (#29894035)
Maybe a big infrared space telescope isn't the highest priority to build next compared to other instruments we could put in orbit.

I mean, we'll still have some big terrestrial infrared 'scopes. And we'll be coming off 20 years of very good space infrared scope data... And we'll have had the smaller Nancy Grace Roman Space Telescope up in L2 also (launching in 2027, nominal life 5 years).... ESA is launching an exoplanet-focused infrared scope to L2 in a similar timespan... Presumably other "smaller" infrared scopes will fly by 2042. So...

There's so many wavelengths and different possible space telescope missions. Let's not replace JWST (assuming it gets a normal mission life)-- let's keep some infrared capability and do something else.

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by baq on Tuesday January 11, 2022 @02:23PM (#29896442)
'terrestrial' is an issue in the context of JWST... as the wavelengths that it observes are absorbed by Earth's atmosphere.

wonder if we could put a telescope on the moon for $10B though.

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by mlyle on Tuesday January 11, 2022 @02:43PM (#29896744)
Yes, infrared scopes on earth have challenges and are not equally viable for all wavelengths. But VISTA, UKIRT, IRTF, etc, cover a substantial amount of the near and intermediate infrared-- the latter two are high enough to reach into a reasonable amount of the far infrared.

Most of JWST's wavelength coverage is energies that terrestrial telescopes can do (just less well). It's not like Herschel which went into the far, far infrared (and had its life limited by liquid He as a result).

Re: Moon-- Why put a telescope down a gravity well?

Most of the discussion of telescopes on the moon I've heard has been about radio telescopes, where a huge hunk of rock between you and Earth can be a feature.

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by mattkrause on Tuesday January 11, 2022 @12:10PM (#29894262)
There are a bunch in the pipeline!

Roman is slated for launch in 2027 (and survived the JWST overruns!), LISA in the 2030s, and there are a few competing proposals that haven't totally firmed up for the next decade too: LUVOIR, HabEx, and a few others

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by dredmorbius on Tuesday January 11, 2022 @12:21PM (#29894436)
There are at least four major proposals in the works, including another two IR telescopes, one with an even larger reflector, another with a wide-angle field of view; an x-ray observatory; and an optical + starshield pair (operating at 100k+ km separation) planet-finder. I've just posted in another top-level comment (https://news.ycombinator.com/item?id=29894335)

Further optical and gravitational observatories are amongst further options.

Trust that plans are in process.

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by jimkleiber on Tuesday January 11, 2022 @11:43AM (#29893863)
I'd be surprised if other NASA programs weren't nearly as long. Maybe not that long, but heck, I've heard to design a new car at a major car company normally takes 6 years or so, I would imagine a brand new type of one-off space project may take at least 10.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by btbuilder on Tuesday January 11, 2022 @11:50AM (#29893969)
Cost-wise and time-wise the JWST is inline with Hubble.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by jimkleiber on Tuesday January 11, 2022 @11:40AM (#29893829)
The Mars Opportunity rover was planned to last only 92 days but lasted about 5200 (~14 years). I think many NASA programs have short expected timelines and then hopefully outlast them.

https://en.m.wikipedia.org/wiki/Opportunity_(rover)

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by nindalf on Tuesday January 11, 2022 @12:33PM (#29894645)
The Spirit rover did very well too - https://xkcd.com/695/
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by jimkleiber on Tuesday January 11, 2022 @06:31PM (#29900005)
Ahhh XKCD, my heart! I hadn't seen this one, thank you for sharing.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by CrazyStat on Tuesday January 11, 2022 @11:50AM (#29893974)
10 years was not quite worst case but definitely a conservative estimate.

L2 is an unstable orbit and needs constant corrections to not drift away, so JWST has much more significant fuel needs than if it were in say Hubble's orbit. How much fuel it would have left for these maneuvers depended on how precise the launch was (i.e. how much fuel it needed to spend on corrective burns just to get to L2). This was obviously uncertain until after the launch, but ten years was a lower bound above which the launch would not be considered a major issue--if it only had say 5 years of fuel left after the launch that would be an indication that the launch was flubbed some how.

TLDR: JWST was not "supposed" to last only 10 years. It was designed and built to last much longer, that was just a lower bound assuming nothing went very wrong.

cf. Mars rovers operating long past the "planned" mission length, e.g. Opportunity's "planned" 90-day mission turning into over 5,000 days. It is vastly unfair to the people who designed and built Opportunity to say it was "supposed" to last only 90 days. It was built to last much longer; 90 days was a lower bound for the mission to be considered a success.

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by anonymousab on Tuesday January 11, 2022 @11:56AM (#29894071)
The scale and intensity of the problem is much bigger though.

This one is hundreds to thousands of times further out than any of those satellites, for instance. It also has a far longer lifetime compared to the average, even before this news. Four times the distance of the moon from Earth. There's no luxury of being able to repair, service and refuel such a thing without approaching or exceeding the costs of just making a new, better one with the learnings and savings from before.

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by shagie on Tuesday January 11, 2022 @12:00PM (#29894138)
The site https://www.jwst.nasa.gov/content/webbLaunch/whereIsWebb.htm... is neat. Change the scale from Time to Distance to get an idea of how far out it is.

(edit - the "earth moon" distance isn't to scale with respect to planetary diameters... the distance from the earth to the moon is about the same as the sum of all the diameters of all the planets - that's a long way itself)

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by tomr_stargazer on Tuesday January 11, 2022 @01:54PM (#29895953)
The primary deliverable isn't the satellite; it's the scientific data (and associated breakthroughs) the satellite will deliver.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by kiriberty on Tuesday January 11, 2022 @11:31AM (#29893657)
Space Bro, I like it
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by echelon on Tuesday January 11, 2022 @11:54AM (#29894040)
Is Elon Musk the very first space bro, followed by Bezos?

Or do we get to go all the way back to Shuttleworth, Tito, and Branson?

Surely Branson is the first space bro.

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by flipflipper on Tuesday January 11, 2022 @12:57PM (#29895061)
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by WJW on Tuesday January 11, 2022 @12:43PM (#29894807)
Was Youri Gagarin not a bro?
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by oofabz on Tuesday January 11, 2022 @01:27PM (#29895528)
Gagarin was a cosmonaut. The Russian equivalent to those mentioned would be Sergei Korolev.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by unzadunza on Tuesday January 11, 2022 @12:26PM (#29894509)
Nope, Han Solo is the first space bro.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by musesum on Tuesday January 11, 2022 @11:34AM (#29893728)
> some Space Bro who'll offer to refuel it for likes / tax reasons

Maybe a new kind of blockchain: https://news.ycombinator.com/item?id=26117587

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by mongol on Tuesday January 11, 2022 @11:43AM (#29893868)
From the Wikipedia page of the Large Hadron Collider

"After some years of running, any particle physics experiment typically begins to suffer from diminishing returns: as the key results reachable by the device begin to be completed, later years of operation discover proportionately less than earlier years"

Perhaps the same applies to space telescopes too?

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by dotancohen on Tuesday January 11, 2022 @12:13PM (#29894306)

  > Perhaps the same applies to space telescopes too?
Not really. The amount of targets that can be explored with JWST would take far longer than 20 years to image. And many targets, such as exoplanets or expanding novas, benefit from periodic reimaging with the same instrument.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by dredmorbius on Tuesday January 11, 2022 @12:36PM (#29894695)
Those targets themselves represent varying levels of interest and returns. The distribution of these is all but certainly a power law or Zipf function itself.

That's not to say we'll run out of interesting things to look at. Only that there is in fact a case of diminishing returns and interest.

But yes, space is big. And there's much in it.

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by enkid on Tuesday January 11, 2022 @11:26AM (#29893557)
We probably will have even cooler stuff up there in twenty years. Also, with the accessibility of space opening up, a refueling mission may become possible.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by anovikov on Tuesday January 11, 2022 @11:35AM (#29893742)
Most likely not refueling, but docking with a spacecraft that will provide propulsion. Has been tried with MEV-1 spacecraft docking Intelsat 901 a couple years back. JWST has a docking ring for that purpose.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by enkid on Tuesday January 11, 2022 @12:46PM (#29894852)
That's cool. Do you have a link with more info?
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by anovikov on Tuesday January 11, 2022 @11:47PM (#29902444)
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by FredPret on Tuesday January 11, 2022 @11:53AM (#29894025)
If I were a 100-billionaire, I’d finance several of these. There was a fashion among the very rich 100+ years ago to finance ground-based telescopes and have it named after themselves
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by ricardobeat on Tuesday January 11, 2022 @11:53AM (#29894019)
You should be disappointed that it took 20 years to build, period. Anything that runs for 20 years unattended is a massive technological achievement.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by 2OEH8eoCRo0 on Tuesday January 11, 2022 @11:21AM (#29893473)
I was planned to last 10 years.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by me_me_me on Tuesday January 11, 2022 @11:44AM (#29893885)
Weird nobody mentioned yet, JWST is at L2 (permanently shielded from sun by earth). L2 is not a stable and need correction burns to stay there that's the reason for life time of 20 years.

Only stable - self correcting - are L4 and L5 points .

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

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by carl_dr on Tuesday January 11, 2022 @11:54AM (#29894047)
JWST isn’t in Earth’s shadow - it orbits around L2 (approximately perpendicular to the Sun-Earth axis) at a radius comparable to the Earth-Moon distance. JWST has a huge solar array used to power the electronics on-board.

Even if it was stationary at L2, Earth wouldn’t completely shield it from the Sun - the point is too far from Earth/the Sun so large for it to.

There is a nice animation on https://webb.nasa.gov/content/about/orbit.html

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by me_me_me on Tuesday January 11, 2022 @01:14PM (#29895316)
You are absolutely correct, it even has a massive sun-shield for that :D
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by willis936 on Tuesday January 11, 2022 @11:35AM (#29893741)
Think about what the craft is doing. It isn't just sitting out staring at one location. It orbits the Sun but doesn't want to ever see the sun. I bet if we wanted to get extra clever we could do flip maneuvers to preserve fuel, but if JWST hasn't met its goals in 20 years then messing about with time wasting tricks won't help it.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by CabSauce on Tuesday January 11, 2022 @11:17AM (#29893401)
Hopefully we'll have cooler stuff in place by then. I'm assuming it can also be serviced, like Hubble.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by WJW on Tuesday January 11, 2022 @11:21AM (#29893478)
Nothing is impossible, but L2 is much further away than humans have ever been. AFAIK, we do not have any human rated spacecraft even remotely capable of going that far (and, hopefully, coming back).
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by btmiller on Tuesday January 11, 2022 @11:20AM (#29893448)
Current plans are for it not to be serviced. Considering that it’s sitting way beyond the moon at L2, it’d have been out of each even for the shuttles when they were still in service.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by Sharlin on Tuesday January 11, 2022 @11:28AM (#29893586)
However, hopefully it’s not out of reach of the hardware we’ll have in 20 years. Even though right now our capability is actually less than 20 years ago…
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by nzach on Tuesday January 11, 2022 @11:26AM (#29893558)
JWST will be so far away from earth that is unlikely any human will ever get near him. Also, Hubble was designed to be serviceable during its lifetime. This isn't the case for JWST.

Maybe technology will develop enough to allow us to send drones to work on JWST, but today this is still just a dream.

PS: I'm just a random code monkey on the internet, so take these comments with a grain of salt.

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by bpodgursky on Tuesday January 11, 2022 @11:29AM (#29893615)
20 years is a long time, and space is moving fast these days. I wouldn't bet on it not being serviced (although I do agree that we'll have something better by then).
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by jagger27 on Tuesday January 11, 2022 @11:49AM (#29893964)
If I were to bet on something it would be a simpler but bigger design that takes advantage of Starship’s much wider fairing.

Let’s say we wanted a constellation of telescopes to do full sky surveys of small objects in our system for asteroid detection. Do those need to be kept at near absolute zero to be effective at that task?

Webb has a specific mission of imaging deeply redshifted space. I would hope in 20 years we’ll be able to launch bigger, simpler, and cheaper designs for more “pedestrian” missions.

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by nisegami on Tuesday January 11, 2022 @11:21AM (#29893471)
The JWST was not designed to be serviceable. It's not impossible, but it's not in the plans right now.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by delecti on Tuesday January 11, 2022 @11:23AM (#29893505)
It's unlikely anything at L2 could be serviced until we have significant infrastructure in space (like something for refuelling). Hubble orbits about 400 miles up, JWST is about 1 million miles away.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by toomuchtodo on Tuesday January 11, 2022 @11:28AM (#29893589)
JWST was designed for future refueling capabilities (there is a docking target and an externally accessible port for access to propellant storage), and this mission is well within existing launch vehicle capabilities (if a robotic refueler is lifted as payload). At launch, JWST was fueled with ~301 kg of propellant, so subtract that from launch vehicle payload to get an idea how heavy your refueling vehicle can be (assuming roughly 4k-5k kg depending on launch vehicle), and some margin for the refueler to separate and propel itself over the gravity edge JWST balances itself on from L2 into deep space post refueling.

https://space.stackexchange.com/a/38415

https://time.com/6127003/webb-space-telescope-discoveries/

> Webb faces other operational challenges, however. Hubble has been kept alive in part through maintenance and servicing runs done by astronauts. Webb’s great distance from Earth makes that kind of house call impossible. What’s more, in order to remain stable at its gravity-balanced Lagrange point, Webb needs a thruster system, and a thruster system requires fuel. The telescope will launch with a full tank, but that will be only enough to keep it operating for a minimum of five years and a maximum of 10. In theory, a refill ought to be possible, and the telescope is actually equipped with a docking target to accommodate an incoming spacecraft that could conduct a refueling and extend the JWST’s life. It’s an appealing idea, especially considering the telescope’s dizzying price tag. That spacecraft, however, does not yet exist, though it could within the next decade.

To be honest, sounds like a cool project to start working on, with the idea that it becomes an off the shelf capability for future space observatories. SpaceX's Dragon can carry a 6000 kg payload, and already supports autonomous docking with the ISS, for example.

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by delecti on Tuesday January 11, 2022 @11:51AM (#29893992)
By "servicing" I actually meant more "repair". The initial burns left enough fuel that JWST is likely to wear out before it runs out of fuel. The refuelling I meant was for craft to get people there and back, because repair is significantly more difficult than refuelling.

https://blogs.nasa.gov/webb/2021/12/29/nasa-says-webbs-exces...

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by toomuchtodo on Tuesday January 11, 2022 @04:29PM (#29898229)
My mistake. In that case, it'd likely be more reasonable to get a vehicle to the observatory, boost it back to Earth orbit, and then attempt to return it to L2 after on orbit servicing. I don't know what that Delta-v budget looks like, although I'm happy to throw coffee money someone's way if they want to do the math in this thread.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by wpasc on Tuesday January 11, 2022 @11:21AM (#29893474)
its L2 point takes about a month to reach, much different orbit than Hubble which is why the flawless launch is so important and the unpacking.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by paxys on Tuesday January 11, 2022 @12:19PM (#29894400)
Think about the state of technology 25 years ago. Are you disappointed that things built back then are obsolete now? Why should satellites be any different?

Rather than lament its lifespan, I am hopeful that a couple decades from now we will build and launch something that is exponentially better.

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by Buttons840 on Tuesday January 11, 2022 @11:16AM (#29893380)
Hopefully the time limit will serve as a kick in the pants to build an even better telescope.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by Sharlin on Tuesday January 11, 2022 @11:31AM (#29893660)
LUVOIR: https://en.wikipedia.org/wiki/Large_Ultraviolet_Optical_Infr... (basically a bigger JWST but for UV/optical/NIR observations à la Hubble).
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by stjohnswarts on Tuesday January 11, 2022 @02:34PM (#29896612)
Sorry this is a one off unique device. 20 years is a great life in the history of NASA, plus they will most likely have robots that can refuel it in 20 years easily if it's even worth doing with 20 years of advancement in astronomy by then.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by JaimeThompson on Tuesday January 11, 2022 @11:17AM (#29893384)
Currently we can only lift so much mass into orbit which limits such things drastically.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by lanewinfield on Tuesday January 11, 2022 @11:18AM (#29893411)
leave it to hn to be disappointed about such a monumental achievement
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by dang on Wednesday January 12, 2022 @12:13PM (#29909672)
"Please don't sneer, including at the rest of the community." - https://news.ycombinator.com/newsguidelines.html.

We have that guideline because putting down your peers like this is reliably the marker of a bad comment, and leads to significantly poorer threads. We all love to feel superior to others, or (probably the same thing) to ward off feeling inferior, but this is a low-grade mechanism and never a source of interesting conversation. It also pretty much dominates the internet and we're trying for something different from those defaults here.

HN comments have been overwhelmingly positive about the JWT and it is currently one of the most popular topics that appears here.

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by unsui on Tuesday January 11, 2022 @12:43PM (#29894808)
agreed.

This was, and continues to be, a momentous accomplishment.

The fact that it happened at all is a herculean task in constraints management, not only on the engineering side, but also on the political and zeitgeist-management side (e.g., managing different adminstrations with often antithetical perspectives on the value of science, etc).

A lot of folks on HN only see this from their own perspective, of "how-can-I-disrupt-X", or "I would have done it so much better", without a real appreciation of the overwhelming complexities in pulling off a task with so many moving parts (literally and figuratively).

Sure, you could have done it better. Then do it. But don't diminish the value of a truly monumental accomplishment when it happens; they don't come often enough, and more often than not, projects with this level of ambition fail far before they ever get to the point they can be critiqued by arm-chair geniuses.

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by JohnJamesRambo on Tuesday January 11, 2022 @11:27AM (#29893577)
Leave it to HN engineers to hand wave away going 10x over budget and a decade late.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by username_my1 on Tuesday January 11, 2022 @11:32AM (#29893680)
it's something that was never done before and one of the few things that will create all kind of new sciences.

Your comment is really frustrating. few people in this life can do something that was never done before, much much fewer on this scale, much much much fewer with such impact on science and humanity.

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by dredmorbius on Tuesday January 11, 2022 @11:54AM (#29894049)
I find it interesting that planning overruns such as this seem to get pinned on implementation, rather than the planning and approval processes themselves.

The evidence is that the time and cost it took to produce JWST are what they are. That planners lowballed these estimates, or that administrators and legislators wouldn't have approved greenlighting based on accurate estimates, speak to failures in planning and administration, rather than engineering.

Much of the planning / large-project literature, which I've studied for some three decades, seems itself to be largely blind to this distinction.

As to many comments found on the Internet mirroring such viewpoints.

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by thehappypm on Tuesday January 11, 2022 @12:29PM (#29894567)
Maybe it’s by design. A 5 year project can be greenlit by Congress, and delays forgiven.

20 year project? Dies in committee.

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by dredmorbius on Tuesday January 11, 2022 @01:11PM (#29895274)
Nothing to show the folks back home, risk of being either primaried or challenged by the other party.

Welcome to politics.

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by redisman on Tuesday January 11, 2022 @01:26PM (#29895508)
Hilarious criticism coming from software engineers which is never late or over budget. Even when there’s nothing actually novel in the product
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by adtac on Tuesday January 11, 2022 @01:34PM (#29895635)
I don't want to tell NASA/ESA/CSA how to operate, but I haven't heard of a single software product that launched 10 years late. Such a product would be immediately DOA because of how fast technology moves. Obviously a space telescope is literally rocket science, so it's nothing like the next popular JavaScript library, but I think NASA could adopt a little bit of the move-fast-break-things mentality. Apparently they're running Python 1.5 on the JWST ffs.

All I'm saying is there's room to improve. JWST would be a monumental success for humanity even if it launched 20 years late.

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by qsmi on Tuesday January 11, 2022 @01:38PM (#29895694)
I can count so many I can't even decide where to begin. This being the classic:

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

"The video game Duke Nukem Forever spent fifteen years in development, from 1996 to 2011."

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by Okx on Tuesday January 11, 2022 @03:08PM (#29897101)
I don't think you should be risking anything when there's $5bn at stake and a single failure can cause you to lose all of it
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by baq on Tuesday January 11, 2022 @02:25PM (#29896466)
yeah most get cancelled before that time, so you don't hear about them.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by oneoff786 on Tuesday January 11, 2022 @11:39AM (#29893809)
For one of the most complicated pieces of engineering ever achieved sure
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by onion2k on Tuesday January 11, 2022 @11:43AM (#29893872)
The initial estimate turned out to be wrong. I hand wave that sort of thing away every day.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by jimkleiber on Tuesday January 11, 2022 @11:45AM (#29893901)
I'm curious as to why and whether some of the delay had to do with the public and lawmakers getting impatient and trying to cut it short, then actually forcing it longer, then blaming the engineers.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by dahfizz on Tuesday January 11, 2022 @11:33AM (#29893708)
Yeah, the limited lifespan would be much less concerning if we had any reason to believe we could iterate and crank out more / better telescopes in the future.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by jimkleiber on Tuesday January 11, 2022 @11:51AM (#29894001)
I guess I just assume they learned a lot in building this and that knowledge will transfer into new telescopes, launches, deployments, etc. Do you think they didn't learn enough by figuring this out?
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by dahfizz on Tuesday January 11, 2022 @12:54PM (#29895007)
I am not confident that whatever caused JWT to take so long will be solved for the next project. NASA by its nature does not really benefit from "scale". Every important thing they do / produce is novel.

I am sure they have learned alot from building JWT, as they certainly learned a lot from building Hubble or the space shuttle. I don't think that knowledge necessarily transfers forwards to make the next project easier.

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by jimkleiber on Tuesday January 11, 2022 @06:27PM (#29899959)
Well, as you seem to have said, NASA doesn't seem too interested in scaling but rather in doing things that stretch the bounds. If their goal isn't to scale the previous project but to push past what people thought were possible with experiments, that seems OK to me.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by emptyfile on Tuesday January 11, 2022 @12:30PM (#29894585)
IIRC the companies that made the beryllium main mirror went bankrupt because the material is much more tricky then anticipated.

So you would have to do that again basically or come up with another mirror design.

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by jimkleiber on Tuesday January 11, 2022 @06:30PM (#29899992)
Ah I hadn't know. That being said, perhaps one thing they learned from this is which materials they may not want to use again in the future. I dunno, I just struggle to imagine that they didn't learn a lot from this and that most of us have really any idea whether the learnings are worth $10B, $1B, $100B, etc.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by malfist on Tuesday January 11, 2022 @03:25PM (#29897316)
I have a few qualms with this telescope:

1. For an astronomer, you can already build such a system yourself quite trivially by getting an large mirror, mounting it in space with a really big catapult, and then using origami to unfold everything. From earth, this telescope could be accessed through everyday ham radios.

2. It doesn't actually replace the Hubble. Most people I know still want to see things in the visible spectrum, and IR fake images just don't cut it. This does not solve the visible spectrum issue.

3. It does not seem very "viral" or income-generating. I know this is premature at this point, but without charging users for the service, is it reasonable to expect to make money off of this?

This is all sarcasm, modified from this infamous comment: https://news.ycombinator.com/item?id=9224

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by treesknees on Tuesday January 11, 2022 @03:57PM (#29897754)
You had me fired up before I hit the last sentence. Well done, I should have recognized the infamous dropbox comment :)
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by malfist on Tuesday January 11, 2022 @04:36PM (#29898334)
Haha! Glad you enjoyed it. I thought I was too over the top with the large catapult as a launch system and HAM radio for telephony, but I guess people oversimplify/handwave worse details
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by wpasc on Tuesday January 11, 2022 @11:23AM (#29893501)
Well, considering the progress in space in reaching the moon and the arguably stagnant (except recent developments like reusable boosters) developments since then, I think it's very reasonable to be disappointed in the past years of space development.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by FourHand451 on Tuesday January 11, 2022 @11:30AM (#29893627)
> arguably stagnant (except recent developments like reusable boosters) developments since then

What about Voyager, ISS, Hubble, Mars rovers, Mars helicopter(!), and Cassini/Huygens missions? There's more to do in space than just going to the moon. I'd love to see us back there as well, but I think there's still a whole lot to be excited about.

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by wpasc on Tuesday January 11, 2022 @11:38AM (#29893790)
agreed, all incredible stuff, I replied to another comment with a fuller reply, but despite these incredible recent achievements I think the years since apollo have been overshadowed by failures in rocket development and innovation (except spacex) and nasa under funding. I linked a story about SLS delays and funding levels and Nasa budget in my other reply
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by lapetitejort on Tuesday January 11, 2022 @11:29AM (#29893606)
Human spaceflight has stagnated for sure. However, we have multiple rovers on Mars. We have satellites that tell us exactly where we are on Earth. We took pictures of Pluto. We exited the solar system. We landed on an asteroid. We slammed into a comet. I choose to be excited.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by wpasc on Tuesday January 11, 2022 @11:36AM (#29893757)
All undeniably incredible achievements. I look at Nasa's budget [1] and see the government achieve something incredible in the apollo project and take their foot off the gas on the most exciting (and potentially unifying) frontier. I also look at the corruption and stagnation in US rocket systems like SLS and the sinkhole of hours and dollars it has been [2].

I am very excited about space and the future, I just think that in the years since Apollo the story has been emblematic of wastefulness, contractor level benign corruption (cost plus contracting) more than it has been inspiring with the stories you mentioned. just my opinion.

1 https://en.wikipedia.org/wiki/Budget_of_NASA

2 https://techcrunch.com/2020/03/11/nasas-sls-moon-rocket-is-2...

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by ufmace on Tuesday January 11, 2022 @02:58PM (#29896960)
Seems like the real and hard truth is that, at anything resembling our current tech levels, human spaceflight just doesn't add much value compared to the massive, overwhelming difficulty.

We've sent hundreds of robots all over the place. To Mars, Jupiter, asteroids, comets, the outer planets, out of the Solar System entirely, as close to the Sun as can be managed, and everywhere else in between. For basically all of these missions, sending humans along would be 1000x more expensive, and the humans would be bored to tears for 99.9% of the time. For most of the rest of the time, they'd be relying on the same instruments as the robotic missions, as the environment is too harsh for anything else. So what's the point?

And who would we be sending? We could send super-smart scientific experts to maybe follow up on things a little faster, but it'd be a waste to have them sit around for years on the voyage back and forth. Or we could send more ordinary folks, who might not be all that much more capable than the robots we're sending now.

Sorry, it might burst some peoples bubbles of romance and sexy space adventures, but it mostly just doesn't make sense to send humans into space for the type of exploration missions we're doing. Maybe if we can send enough resources to actually have a colony on Mars or something, but we're not there yet.

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by jimkleiber on Tuesday January 11, 2022 @11:58AM (#29894104)
From your first link:

> NASA's budget peaked in 1964–66 when it consumed roughly 4% of all federal spending....In 1973, NASA submitted congressional testimony reporting the total cost of Project Apollo as $25.4 billion (about $156 billion in 2019 dollars).

I wonder if there also wasn't that level of waste at that point but not too many people cared because the country was mostly terrified by the USSR and wanted to win.

Ironically, I think the more we think there's corruption and waste, the more that may lead to corruption and waste, as we distrust and defund and discourage. Again, I imagine some of the waste comes from the fickle attitude that some of the public and lawmakers have towards funding these orgs.

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by gameswithgo on Tuesday January 11, 2022 @12:09PM (#29894244)
NASA was wasteful and full of contractor corruption during Apollo as well. They just had the political will to get funded and keep pushing forward so they did.

The stagnation in aerospace is mostly due to us running into fundamental limits of physics pretty quickly, not due to some kind of work ethic or creative failures. to keep pushing forward in space would have required another order of magnitude in funding, and funding during Apollo was already huge. That said, I wouldn't mind if all the worlds military $$$ had been dumped into mars colonization either.

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by lapetitejort on Tuesday January 11, 2022 @11:59AM (#29894116)
I only get opportunities every few years to affect in a minuscule way NASA's budget and mission, the rest of the time I have to act as a passive observer. In that time I choose to be happy with what they've accomplished and excited for what comes next.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by madengr on Tuesday January 11, 2022 @12:13PM (#29894316)
It has to be cost-plus or no one would do something that has not been done before. Fixed cost is fine for something you have a grasp on production costs.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by wiz21c on Tuesday January 11, 2022 @11:44AM (#29893892)
I'm not a space scientist but it look sto me that human space travel is insanely hard and, if there's no infrastructure at the destination humans won't be able to do much... So, maybe it's too early to wish space travels ? Maybe it'd be safer to first colonize with robots, install infrastructure, make sure the travels are safe enough by sending animals or other life forms and then once ready, send humans ?
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by willis936 on Tuesday January 11, 2022 @11:32AM (#29893686)
It's a perspective thing. We have incredible technology but at a loss of what to do with it. We had the cold war pushing us to achieve great things in competition but now we are stagnant. Our tools are too powerful and dangerous to wave around, we don't know how to balance investor and worker class wealth allocation, we can't seem to control anything about society that used to just fall in line.

As to what we can do in space: the value of reusable boosters is very understated. Why don't we have a manned mission to Mars? Because it takes a huge payload with lots of delta-V. Sending ten rockets up for orbital refueling was always a pipe dream in terms of cost. Suddenly it's attainable and the solar system is our oyster. It's still expensive, but we now have the tools.

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by hackeraccount on Wednesday January 12, 2022 @06:24AM (#29904917)
Look - super impressive but it's not hard to find downsides. This thing took 20 years and near a billion dollars; at some point you should be asking, "Why couldn't we have had it sooner or cheaper or some combination of the two?"

Say it wildly over performs reliability.. it lasts not 20 years but 1,000 years - is that more of success? I'd argue against that - it's more of a failure because we don't need it to last that long.

What if - hypothetically - we had JWST 10 years ago for half the cost but it were just winking out right now? Would that be a failure? I think that's at least an arguable point.

Re:NASA says Webb’s excess fuel likely to extend its lifetim... by _b on Tuesday January 11, 2022 @12:20PM (#29894417)
20 years of taking pictures, but we'll be able to study the data it gathered, and benefit from discoveries it enabled, for an indefinite amount of time.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by awb on Tuesday January 11, 2022 @01:46PM (#29895843)
Technology advances so fast though. Imagine a desktop from 20 years ago. We’ll be ready for an upgrade long before it runs out of fuel.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by nemacol on Tuesday January 11, 2022 @11:39AM (#29893815)
Maybe in 15 years we will have space drones to refuel it! :D We can dream.
Re:NASA says Webb’s excess fuel likely to extend its lifetim... by cfaulkingham on Tuesday January 11, 2022 @11:39AM (#29893811)
I would hope we have something better to replace it with before then.