Posted on 05/04/2018 1:46:23 PM PDT by Red Badger
The James Webb Space Telescope hits another snag.
On anything that moves, from vehicles to rolling office chairs, you need to be wary of bolts rattling loose over time. Thread-locking fluids and tapes are a great way to make sure your suspect bolts stay where they should, and nyloc nuts can also keep components snug and secure.
Northrop Grumman might need to look into something along these lines, because apparently "screws and washers" are falling off the spacecraft and sunshield it is building to carry NASA's James Webb Space Telescope. Space News reports that NASA's JWST program director, Greg Robinson, said that hardware was found underneath the spacecraft element of JWST (everything but the mirror and instruments) after it was moved from an acoustic testing chamber to a vibration testing chamber.
“Right now we believe that all of this hardware—we’re talking screws and washers here—come from the sunshield cover,” Robinson said today at the National Academies’ Space Studies Board in Washington D.C., according to Space News. “We’re looking at what this really means and what is the recovery plan.”
It's probably a good thing the falling screws and washers were discovered before the spacecraft went into the vibration testing chamber. “It’s not terrible news, but it’s not good news, either,” Robinson continued. The JWST program director reiterated that issues like this are why NASA and its partners do extensive testing on new spacecraft before launch.
The issue was only just discovered, and NASA and Northrop Grumman are determining the best way to move forward. NASA recently announced that tears in the sunshield and leaks in the thruster valves of JWST's spacecraft element were likely to delay the $8-plus-billion space telescope's launch to May 2020 from spring 2019 (already delayed from 2018).
In response to the troubling findings, NASA has initiated an independent review of JWST launch readiness led by former NASA Goddard director Tom Young, which is expected to be completed by the end of the month. Additionally, the national space agency has sent more personnel to Northrop Grumman's facility in Redondo Beach, California—where the JWST optical telescope element is being mated to the spacecraft element—to oversee the work.
"I still believe we’ll go in 2020," Robinson said at the Space Studies Board, though he admitted the loose screws and washers could reveal a problem that "takes longer than we expect.”
Space scientists from astrobiologists to atmospheric scientists to cosmologists are chomping at the bit to switch on James Webb and turn the biggest space telescope ever built out to the firmament. Maybe someone can send Northrop a little Loctite.
Source: Space News
Think “temperature extremes with different expansion coefficients”.
The same agency that sent men to the moon a half century ago now seems to be incapable of tightening a bolt.
Fatigue? Embrittlement?
Sometimes you feel like a nut....sometimes you don’t.....
Unfortunately that type doesn’t survive the extreme cold of deep space
Teflon tape works better so do good technicians who know how
If they are now saying fly in 2020 that’s another slip
Mission creep and snake bit from the start. It is a giant money sucking hole that prevents other projects from being funded
It's named after James Webb, the second head of NASA who ran the organization from 1962 to 1968.
Webb died in 1992.
-PJ
James Webb......first director of NASA
You do not know what you are talking about. James Webb was well respected by one and all
Local tote doesn’t really withstand the cold of deep space. Teflon tape works better
Precisely
clinton named it after his daughter’s father
Excellent!
I’ll use some harbor freight tools and materials but the nuts and bolts, no thanks.
I’m a novice when it comes to car repairs. Search the net a lot. Removed a heat shield next to the transmission. They said put blue loctite on it. And there was the old blue there too. Seems the thin plate of the shield (like this “thin” solar shield) will vibrate. And probably the heating and cooling of the heat shield as well will work the bolts loose.
On my chevy truck, I swear the guy that designed it has a mean streak. Just to drop the transmission pan the exhaust was 1/4-inch too close, and a bracket was 1/2-inch too close on the other side to easily drop the pan.
After several attempts trying different things, I finally used a cable and turnbuckle to “winch” the bracket away - but still needed a pry bar for the last 16th of an inch.
Excellent!
As many as 20,000 pairs of nuts and bolts are required to assemble the 16 cars on a Shinkansen bullet train. With the trains whizzing along at 250 kilometers per hour, a single loose bolt could cause a major disaster. Painstaking safety checks and regular retightening of nuts is one way to prevent accidents, but one that involves serious investments of time and money. One of the unsung heroes whose work has enabled the Shinkansen to operate safely and affordably year after year is Wakabayashi Katsuhiko, the 78-year-old president of Hard Lock Industry Co., Ltd, who revolutionized rail safety by inventing a unique nut that never comes loose.
More at the linky.
I have great admiration for what NASA engineers have been able to accomplish - when unfettered by political types. I nearly puked when Obama’s guy made “Moslem outreach” a goal. WTF? I mean, if we were going to “outreach” Moslem terrorists into space (and leave them there), that’d be fine...but its a whole lot cheaper to just toss them out the back of a cargo jet or helicopter over the ocean, and cheaper yet to just shoot the SOBs and let the pigs clean up the mess...but I’m thinking that Obama intended something else.
Thanks for the Loctite link - after getting through all of the bureaucratic language, the lessons learned were short and simple: Loctite works to keep fastened things fastened, so long as you follow the application instructions...otherwise, its of questionable use.
So...I go back to my original point that the engineers should’ve just used Loctite. :>)
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