JWST suffers new problem during spacecraft testing
In a presentation at a meeting of the National Academies' Space Studies Board here May 3, Greg Robinson, the JWST program director at NASA Headquarters, said some "screws and washers" appear to have come off the spacecraft during recent environmental testing at a Northrop Grumman facility in Southern California. Technicians found the items after the spacecraft element of JWST, which includes the bus and sunshield but not its optics and instruments, was moved last weekend from one chamber for acoustics tests to another to prepare for vibration testing.
"Right now we believe that all of this hardware — we're talking screws and washers here — come from the sunshield cover," he said. "We're looking at what this really means and what is the recovery plan." The problem, he said, was only a couple of days old, and he had few additional details about the problem. "It's not terrible news, but it's not good news, either," he said. The incident, Robinson argued, showed the importance of the wide range of tests the spacecraft is put through prior to launch. "That's why we do the testing," he said. "We do it now, we find it now, we fix it and we launch a good spacecraft."
This latest incident comes as an independent review board, chartered by NASA in late March after announcing a one-year delay in JWST's launch because of other technical issues, is in the midst of its analysis of the mission and its launch readiness. That review, led by retired aerospace executive and former NASA Goddard director Tom Young, is scheduled to be completed at the end of the month.
NASA is expected to brief Congress on the status of the James Webb Space Telescope in late June.
Also at Popular Mechanics.
Previously: James Webb Space Telescope Vibration Testing Completed
Launch of James Webb Space Telescope Delayed to Spring 2019
JWST: Too Big to Fail?
GAO: James Webb Space Telescope Launch Date Likely Will be Delayed (Again)
Launch of James Webb Space Telescope Delayed to May 2020, Could Exceed Budget Cap
NASA Announces JWST Independent Review Board Members
Related: Northrop Grumman's Faulty Payload Adapter Reportedly Responsible for "Zuma" Failure
(Score: 3, Insightful) by VLM on Friday May 04 2018, @03:19PM (2 children)
A good automobile analogy of why delays are resulting in screwed up test results, is if you rebuild your car engine in one weekend in one unitary effort, you'll remember all kinds of rando trivia and detail such that you won't have random bolts and parts laying around the garage when you're finished with the rebuild and the engine will probably work. However if you insist on spending a year very slowly rebuilding the engine you're going to have to do stuff like de-rust and hone the cylinder walls three times and you're gonna have to buy 5 spark plugs for a 4 cylinder engine because parts sit around and get lost or misplaced so you end up buying more than you need and at the end you got a pile of extra parts and you're not quite sure if every nut that needs a lockwasher had one installed or were the head bolts finger tight just to keep the parts in place for months or did you torque them down and when you fire the thing up the first time, odds are you'll have much more trouble.
(Score: 5, Funny) by Snow on Friday May 04 2018, @03:26PM (1 child)
I've taken apart things with like 5 fasteners and still had hardware left over once it was back together.
I swear to god, once you get a few nuts/screws/washers in a bowl, they breed.
(Score: 5, Funny) by Azuma Hazuki on Friday May 04 2018, @06:54PM
Well, yes...screws and nuts. What did you expect?
I am "that girl" your mother warned you about...
(Score: 0) by Anonymous Coward on Friday May 04 2018, @04:12PM (9 children)
"but it's not good news, either"
I completely disagree. Finding these problems ahead of time is very good news. I would much rather find the problems now than leave it unfound and have a failure after launch. There is no such thing as a failure during testing unless you fail to find the problems at all.
(Score: 0) by Anonymous Coward on Friday May 04 2018, @04:22PM (5 children)
So you think finding screws and washers on the floor as opposed to not finding them is good news? If I were the NASA administrator, I might hope that Congress cuts the JWST, so I don't have to explain a $10 billion lost mission.
(Score: 2) by bob_super on Friday May 04 2018, @04:41PM
I have no doubt that more than a few people wouldn't mind if Ariane blew up, because not knowing whether their piece would have failed and crippled the whole thing could be better than the alternative.
I am counting on all the others involved, to make sure those people get to say "I helped build this wonder" instead.
(Score: 2) by takyon on Friday May 04 2018, @06:34PM (3 children)
There's about zero chance of JWST getting cancelled. It's too big to fail (on the ground). If it fails on launch or in space, well, it will be a bad day + years for a lot of people.
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(Score: 0) by Anonymous Coward on Friday May 04 2018, @09:58PM (2 children)
It has already been bad years for a lot more people, not that any of them want to see it fail. It has sucked the money out of many smaller, but arguably equal value space/science projects.
(Score: 2) by takyon on Friday May 04 2018, @11:56PM
It could be a good thing if it gets the juices flowing about how to make telescopes big and cheap from the start, preventing a future telescope design from repeating the mistakes of JWST.
The Kilometer Space Telescope [nasa.gov] just got NIAC funding. The Giant Orbiting Astronomical Telescope [insideunmannedsystems.com] would use modular components flown on multiple launches, although that may not be the best approach given that BFR is around the corner.
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(Score: 2) by frojack on Saturday May 05 2018, @01:51AM
No, that's not arguable.
The value of something is what people are willing to pay for it, and since JWST is getting the bulk of the funding it is clearly valued more than those other projects.
Are there people who would "Value" their pet project more than JWST?
Probably, but it doesn't matter, because they have neither the votes nor the money.
No, you are mistaken. I've always had this sig.
(Score: 4, Interesting) by bob_super on Friday May 04 2018, @04:25PM (1 child)
One the other hand, you're not talking about a very advanced 3D-printed part having a flaw, or a camera that's near-sighted.
You're talking about someone not counting their screws right, or not specifying the torque right, or not torque-wrenching right.
When the budget is north if five billion dollars, one would hope those basics are at least done right.
Which relates to my PCB design theory: it's the darn FET that kills you.
In short: everyone reviews the high-speed high-power stuff ten times, carefully vets it and simulates every detail ... and nobody notices the LED or FET is on backwards.
(Score: 2) by frojack on Friday May 04 2018, @06:06PM
It's also possible they were just dropped parts, of the "I'll get it later" type.
Or two or three technicians doing one job resulting in the predictable Bob tightened them, no Bill did, just check the box and let's go to lunch.
The paperwork at NASA can be mountainous, all of it piled on to prevent things like this, but ultimately causing things like this.
No, you are mistaken. I've always had this sig.
(Score: 0) by Anonymous Coward on Saturday May 05 2018, @08:12PM
I disagree with your disagreement.
Your argument is based on the notion that there is a specific number of problems, and by finding this one there is one fewer problem to surface after launch.
The
I don't think this is the best way to look at it. The number of mission compromising problems is unknown. The point of design is to have no unknown problems. There can be potential problems, but they should have been considered.
This shows us problems that nobody considered exist. If that is true, it indicates insufficient design and more may exist.
(Score: 0) by Anonymous Coward on Friday May 04 2018, @04:13PM (2 children)
So somebody dropped some screws into the thing during assembly. Now we have to hope that random dropped parts don't jam the mechanism after launch. You'd think NASA would be tracking every fastener to avoid this situation. Sounds like a management problem, which does not bode well.
Alternatives such as insufficient torque or bad design are not good either.
(Score: 2) by bzipitidoo on Friday May 04 2018, @09:25PM
Screws coming off or extra ones being dropped in is sheer carelessness and incompetence. Someone, somewhere has an engineering position for which they are not fit, to make such a shoddy design. Or possibly it's someone in assembly who, uh, screwed up.
(Score: 2) by frojack on Saturday May 05 2018, @01:54AM
JWST was on its way to the vibrator chamber, probably to find problems like this.
Guess what, they found problems like this.
I suppose thats why they test.
No, you are mistaken. I've always had this sig.
(Score: 0) by Anonymous Coward on Friday May 04 2018, @04:47PM
All the parts falling off this spacecraft are of the very finest American manufacture!
(Score: 3, Funny) by Snotnose on Friday May 04 2018, @05:59PM (11 children)
When a friend is rebuilding an engine, or putting together IKEA, stop by and sprinkle some extra nuts, bolts, and washers around. Then have a beer while they try to figure out where they came from. If I actually like them I'll let them in on the secret before they start tearing the item down again so they can "rebuild it right this time".
Bad decisions, great stories
(Score: 3, Funny) by Snow on Friday May 04 2018, @07:15PM (10 children)
I bought a barbecue a couple years ago. It required some assembly. No problem; everything bigger than a toaster oven does nowadays.
I had the thing 98% built. All I needed to to was attach the doors to the propane tank area. Easy-peasy. A screw, a couple of washers and a nut. I found that there was no hole in the base-plate for the door to fit into. It turns out that I had the base-plate (the part where the propane tank sits) backwards. By this time my knuckles were bleeding because I have shitty tools and I was pretty pissed off. I thought about drilling a hole for the door but ended up just throwing the doors in the trash. We don't need no stinkin' doors...
-- Snow
(Score: 2) by takyon on Friday May 04 2018, @09:02PM (7 children)
The grill cover can perform the role of protecting the grill. The door on the last grill I had would come off the hinge during heavy wind with no cover on. Or just come off from swinging it open too hard.
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(Score: 2) by Snow on Friday May 04 2018, @09:16PM (6 children)
Look over here at this fancy pants with his grill cover.
The only thing my BBQ gets covered with is bird shit.
(Score: 2) by takyon on Friday May 04 2018, @09:23PM (5 children)
https://www.doityourself.com/stry/barbeque-propane-cylinders-weather-safety-tips [doityourself.com]
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(Score: 2) by Snow on Friday May 04 2018, @10:00PM
Pro-Tip: Pawn off old/rusted tanks on those propane tank exchanges. You'll never have to buy another propane tank again.
(Score: 2) by vux984 on Friday May 04 2018, @10:38PM (2 children)
Sure if you've bought a Broil King, or Napoleon worth 100s or even thousands you'd be a damned fool not to spring for a $50 cover.
If you bought a walmart special for $88... you may as well skip the $50 cover and just buy another walmart special when the first one disintegrates. :)
(Score: 2) by takyon on Friday May 04 2018, @10:52PM (1 child)
A quick search finds some covers at $15-17. You could also use whatever's available, such as a blue tarp (can be bought for $8 at Walmart).
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(Score: 3, Funny) by vux984 on Monday May 07 2018, @08:29PM
Meh...a walmart special will disintegrate within a few years whether you put a tarp on it or not. I think its on a timer. :)
(Score: 2) by slap on Saturday May 05 2018, @12:13AM
My grill has quick disconnect fittings on the tanks - similar to the fittings on airhoses. The grill stays in the basement (walk out), and the tanks stay outdoors.
(Score: 3, Informative) by bzipitidoo on Friday May 04 2018, @09:15PM (1 child)
Do yourself a favor and get some decent hand tools. It's not that expensive, can be only a few cents difference between a good quality screwdriver and a cheap one. It's sad that so much material, cursing, sweating, and pain and bleeding is expended over such a little difference in cost.
One way to tell whether a Phillips screwdriver is good is look carefully at the tip after it's been used for a while. Of course, rather know before you buy. However, if the four ridges at the tip are straight, it's good. If they are notched and worn and ragged, it's a bad tool, and will be a lot harder to use. Takes a lot more force to hold a bad Phillips screwdriver on a screw, and it'll likely slip off anyway and tear up the screw head.
And as for slotted screws and screwdrivers, avoid those whenever possible. The slotted screwdriver is far more prone to slipping off. Just about any other head is better. I once ragged on the local Home Depot for stocking more slotted screws than any other type.
(Score: 0) by Anonymous Coward on Saturday May 05 2018, @01:53AM
Personally, I like to find flathead drivers that fit into Philips screws and Torx drivers for Allen screws.
(Score: 3, Interesting) by krishnoid on Friday May 04 2018, @09:07PM (2 children)
Does Loctite (or similar) work in this environment? Just curious if it would work or if not, why not.
(Score: 2) by corey on Friday May 04 2018, @10:26PM
Yep. I worked on a defence product once and they used loctite on every fastener as normal routine for shock and vibration.
I'm surprised this has made it into the public. They might just be robustness testing it sans loctite which is what we did too. You really only use loctite once you are destructive testing the unit under test.
Then again loctite might not suit space applications, due to outgassing, radiation etc.
(Score: 1) by erichill on Monday May 07 2018, @01:02PM
There's quite a few different variants of Loctite. Some of the lower end Loctite will soften in extreme heat or cold. It's possible they need to move to a different version of it. For more extreme applications, they may skip the Loctite in favor of bolts with a hole drilled laterally through the head, and they run a piece of steel cable through the hole to a tie-off point. It prevents the bolt from turning in *very* extreme conditions where chemistry could break down.