Stripped screws preventing access to Bennu samples
According to the scientists working to extract the samples from the asteroid Bennu brought back by the OSIRIS-REx sample return capsule, the work has been stymied because of two stripped screws.
Last month, researchers at the Johnson Space Center in Houston, Texas, discovered that two of the 35 screws that fasten the lid of the sample-return canister couldn’t be opened — blocking access to the remainder of the space rock. Curators used tweezers to pull out what they could, but NASA is now making new screwdrivers so it can get into the equipment it flew billions of kilometres across the Solar System to the asteroid Bennu and back.
Because the capsule is kept within a sealed glovebox to prevent the samples from being contaminated by the Earth environment, removing the screws requires NASA to manufacture special screwdrivers that will also not contaminate that environment. This work is what is causing the delay.
The support of my readers through the years has given me the freedom and ability to analyze objectively the ongoing renaissance in space, as well as the cultural changes -- for good or ill -- that are happening across America. Four years ago, just before the 2020 election I wrote that Joe Biden's mental health was suspect. Only in this year has the propaganda mainstream media decided to recognize that basic fact.
Fourteen years ago I wrote that SLS and Orion were a bad ideas, a waste of money, would be years behind schedule, and better replaced by commercial private enterprise. Even today NASA and Congress refuse to recognize this reality.
In 2020 when the world panicked over COVID I wrote that the panic was unnecessary, that the virus was apparently simply a variation of the flu, that masks were not simply pointless but if worn incorrectly were a health threat, that the lockdowns were a disaster and did nothing to stop the spread of COVID. Only in the past year have some of our so-called experts in the health field have begun to recognize these facts.
Your help allows me to do this kind of intelligent analysis. I take no advertising or sponsors, so my reporting isn't influenced by donations by established space or drug companies. Instead, I rely entirely on donations and subscriptions from my readers, which gives me the freedom to write what I think, unencumbered by outside influences.
Please consider supporting my work here at Behind the Black.
You can support me either by giving a one-time contribution or a regular subscription. There are five ways of doing so:
1. Zelle: This is the only internet method that charges no fees. All you have to do is use the Zelle link at your internet bank and give my name and email address (zimmerman at nasw dot org). What you donate is what I get.
2. Patreon: Go to my website there and pick one of five monthly subscription amounts, or by making a one-time donation.
3. A Paypal Donation:
5. Donate by check, payable to Robert Zimmerman and mailed to
Behind The Black
c/o Robert Zimmerman
P.O.Box 1262
Cortaro, AZ 85652
You can also support me by buying one of my books, as noted in the boxes interspersed throughout the webpage or shown in the menu above. And if you buy the books through the ebookit links, I get a larger cut and I get it sooner.
According to the scientists working to extract the samples from the asteroid Bennu brought back by the OSIRIS-REx sample return capsule, the work has been stymied because of two stripped screws.
Last month, researchers at the Johnson Space Center in Houston, Texas, discovered that two of the 35 screws that fasten the lid of the sample-return canister couldn’t be opened — blocking access to the remainder of the space rock. Curators used tweezers to pull out what they could, but NASA is now making new screwdrivers so it can get into the equipment it flew billions of kilometres across the Solar System to the asteroid Bennu and back.
Because the capsule is kept within a sealed glovebox to prevent the samples from being contaminated by the Earth environment, removing the screws requires NASA to manufacture special screwdrivers that will also not contaminate that environment. This work is what is causing the delay.
The support of my readers through the years has given me the freedom and ability to analyze objectively the ongoing renaissance in space, as well as the cultural changes -- for good or ill -- that are happening across America. Four years ago, just before the 2020 election I wrote that Joe Biden's mental health was suspect. Only in this year has the propaganda mainstream media decided to recognize that basic fact.
Fourteen years ago I wrote that SLS and Orion were a bad ideas, a waste of money, would be years behind schedule, and better replaced by commercial private enterprise. Even today NASA and Congress refuse to recognize this reality.
In 2020 when the world panicked over COVID I wrote that the panic was unnecessary, that the virus was apparently simply a variation of the flu, that masks were not simply pointless but if worn incorrectly were a health threat, that the lockdowns were a disaster and did nothing to stop the spread of COVID. Only in the past year have some of our so-called experts in the health field have begun to recognize these facts.
Your help allows me to do this kind of intelligent analysis. I take no advertising or sponsors, so my reporting isn't influenced by donations by established space or drug companies. Instead, I rely entirely on donations and subscriptions from my readers, which gives me the freedom to write what I think, unencumbered by outside influences.
Please consider supporting my work here at Behind the Black.
You can support me either by giving a one-time contribution or a regular subscription. There are five ways of doing so:
1. Zelle: This is the only internet method that charges no fees. All you have to do is use the Zelle link at your internet bank and give my name and email address (zimmerman at nasw dot org). What you donate is what I get.
2. Patreon: Go to my website there and pick one of five monthly subscription amounts, or by making a one-time donation.
3. A Paypal Donation:
5. Donate by check, payable to Robert Zimmerman and mailed to
Behind The Black
c/o Robert Zimmerman
P.O.Box 1262
Cortaro, AZ 85652
You can also support me by buying one of my books, as noted in the boxes interspersed throughout the webpage or shown in the menu above. And if you buy the books through the ebookit links, I get a larger cut and I get it sooner.
Any clue as to what stripped the screws? A over-enthusiastic worker? Should have been done with some sort of device to measure the torque applied. Another le4sson learned, I guess.
Too much Loctite on the screws! Just drill them out, they are not using the container again.
Perhaps Osiris REX is the first deep space probe built for which no involved staffer ever took a shop class in high school.
They do not say if the heads of the screws are stripped or the threads of the screws are stripped or if the threads of the holes are stripped.
If the screw turns then removing it is easy.
If the screw is stuck then they might just have to either heat it up with a torch or grind the head off.
I hope they did not use any type of liquid fastener lock (like LockTite) in this job. The hot and cold cycles could really make things difficult later. And it could contaminate exposed areas.
Probably galled due to the obsession of designers to use stainless steel just about everywhere.
Probably best to just rip the thing apart hydraulically. Don’t want to file or drill.
Nylocs work pretty good.
It might be vacuum wielding. Using the same metal alloy on different parts will cause a slow weld to form in the vacuum of space. Not sure, but guessing is fun.
pzatchok wrote: “I hope they did not use any type of liquid fastener lock (like LockTite) in this job. The hot and cold cycles could really make things difficult later. And it could contaminate exposed areas.”
NASA is rather careful about how fasteners are retained. Anything that might outgas is discouraged (read: forbidden). NASA does not like lock washers, either (stress points). Locking threads are possible, but in this application, they may also cause unwanted shavings or particles that could contaminate the samples. How would they know that a reading of iron was from the sample or from contamination from the steel screw? Another possibility is a plastic pellet that would smear into the threads a bit like LockTite, but there is that pesky contamination problem, again.
Their best bet is to torque the screws very tight so that they resist backing out during the vibration of launch. If they are seriously worried about the screws backing out, they can always use safety wire (lock wire) to prevent screw rotation. This solution is used in several high vibration places, such as aircraft.
pawn has a good point. No matter what they do, they must make sure that the screws are not the same hardness as the threads. I worked on a project where an engineer failed to check this, and a couple of screws galled as they were being hand threaded before the tech realized that he wasn’t bottoming out in the very expensive, one-of-a-kind, steel part. I was amazed that galling can occur without much force on the threads. Since it didn’t happen to me, I can laugh about it now. Ah, no, I just tried but still couldn’t laugh. I can still only shake my head. Maybe next year I’ll be able to laugh.
Heed Matthew H Iskra‘s caution, too.