One of my sister's does this all the time and finds it funny when I complain; she is 51. She also asks a question but does not wait for the answer, e.g. I begin to open my mouth but never get any words out. I'm not like many people who enjoy talking at the top of their voice and having a shouting match. I enjoy listening as much as talking; you cannot have one without the other.
The comments on Rad-hard components are pretty nice regarding the test reports et cetera. Withing the space industry there is also a move towards COTS for some projects. Budgets are not infinite. That being said, CubeSats are growing up and customers are demanding longer lifetimes as well. Luckily, LEO is pretty forgiving. Going to the moon is a different story. On one of the projects I did (FUNcube-1), we found out that one of our devices that we used had come from a batch that was radiation tested for another space mission. We had paid the COTS price from a popular supplier that starts with f and ends on ll ;) The feature size thing is counter-intuitive at first, but think about it this way: an energetic particle impacting into a chip will create an energy gradient in the chip of a certain size. If your feature size is smaller, it is true that it is less robust from a size point of view, but because the transistors are closer together, the gradient per transistor is much smaller! Its a lot more complicated than that, but it maybe gives a hint to why feature size does not matter. size / gradient = constant mess ;) I am designing CubeSats for about 10 years now, and in general the advice for LEO is, don't bother with radiation shielding, but carefully select your (COTS) components. We are also working on a payload that will go to the moon, and there it is not as simple, and a lot more thought has to go into it. one thing that is also interesting to mention is Secondary Emission. This happens when a high energy particle impacts, for instance, an aluminium payload box. The high energy impact on the outside may release multiple lower energy particles, that then spray around inside your enclosure. Thanks Karsten and Dave for the nice talk! All up my alley as RF systems engineer in a space company, and AMSAT satellite builder.
shomolya Literally didnt read a single comment before commenting, but even if every comment is that way, there is purpose in telling him. All it is is constructive criticism, maybe he wont be so talkative next time! This is a topic thats been on my mind lately, been really wanting to do some good research into it, havent had the energy, but I saw this pop up in my feed! "Awesome, a topic I really want to hear about, and someone smart has done all the research for me!" I say to myself. 10 minutes later, frustrated, I close the video prematurely, unable to finish it... Pardon me for being disappointed.
+Kakunapod I agree with ya. I would have liked to hear more from the German guy. Sometimes I couldn't exactly understand what he was saying and Dave repeated it in a little cleaner English so I like that. but other than that I would really have liked to hear more from the German.
I think Dave's just aware he's recording for an audience with a variety of viewers technical levels and is simply proving little contextual comments for those that may get a little lost. Maybe I'm just used to Dave's presentation style... I thought it was fine!
Every time I hear Dave do an interview with someone, I feel that Dave is just trying to show off by interjecting with stuff he knows. It'll probably feel all right to the person he's talking to, as it shows signs of interest, but it's not so nice to look at.
I started working as a radiation effects engineer which is what this gentleman does. I started by watching this video and now ~3 months into my job, I feel like I understand everything he said where before I understood maybe 30%. Yay! Thanks for helping
Great video! I think the feature size doesn't matter too much here because although the required dosage to failure per area increases, the total dosage decreases due to smaller area. So if dosage to failure of components is roughly inversely proportional to size you get cancellation.
Contrary to seemingly everybody else here in the comments, I didn't find the interrupting annoying. Idk, maybe it just makes the conversation more natural.
I love these interviews, because its two engineers discussing it. If he had been on nearly any other interview he would have gotten a bunch of softball pre-made questions. Karsten knew he was talking to a literate audience and was able to discusses much more technical details.
I think Dave interruptions are justified. when I am explaining something I love those sign of understandnes if I did not receive that I think that wast clear enough and start to over explain the same and being redundant.
Then you have very low standards. Doing proper interviews are a skill as well as a discipline. This wasn't that great from interview point of view. A good interviewer asks questions that generate the minimum amount of confusion and ambiguity. And the interviewer also lets the person talk UNTIL it goes on some random tangent.
My "interviews" are really just chats between two technical people. I have no prepared questions, have not studied anything before hand, (in this case) have not met the person before so don't know anything about them or their ability to answer questions clearly etc. I'm also excited about the topic I'm talking about it. I hate formal interviews with prepared questions etc, and then waiting for someone to finish and go "err,um, next question", it makes the person feel like they are being "interviewed" and grilled etc. Remember, these are often people who have never been on camera before. I much prefer informal chats that put the person at ease, and ones that just flow so they forget the camera is one and they are being "interviewed". If you have two technical people then they will throw technical stuff into the ring when they think of it, it's a natural part of tech people chatting about a topic. In real time I have to try and comprehend and process what they are saying, think of new questions to ask, be receptive and show understanding for what they are saying, think of what might be valuable for my audience (and/or what I'd like to know myself), deal with unexpected answers, anticipate if their answers or going somewhere worthwhile and decide if an interjection is worthwhile etc etc. I like to think my enthusiasm for the topics and my conversational style extracts more content from people than my "poor" technique looses. But some people just like the bitch about it. Meh.
+EEVblog I enjoyed it and can relate. Two like minded people knowing the same topics can really leave some in the dust. Picking up on this,I just sit back and enjoy two tech-savvy dudes getting into it. I myself forgot the obvious,radiation in space...DOH!
However please allow the other persons thoughts and explanations conclude. You know a lot but this guy knows more than you in this field so let him speak.
@@EEVblog Yeah but we know that you know the topic. Let the guy talk. He has a lot of information to give out to listeners but you keep interjecting and interrupting, cutting the flow. Not too good. The chat is for your audience to gain out of, not you. If you want to keep cutting in then you shouldn't even bother uploading the video. My 2 pence!
It really is a small Internet sometimes. I started getting in to FPGA development some time ago. When I was researching the topic of FPGA and the various tools needed to work with them I ran across the PSHDL website. Here you are talking to its creator. When mentioning use of radiation hardened parts I wondered if someone would mention the 1802 and someone in the comments has done so. I built myself an 1802 based computer board almost three decades ago. I thought the 1802 would be an obsolete part by now but it is still being produced AFAICT.
That's quite interesting stuff! Having dealt with electronics for decades I made the mistake to take it for granted that for example thermal issues are just a matter of how big your cooler fins are and such stuff, but if there's no air then there will be no heat dissipation on that way. You have to just radiate all the thermal energy. And ionic particles and radiation is no real deal here on ground. Lots of interesting questions! And - opposing to many commenters - I do really like the discussion style of the interview. It's much more cool and easy listening than a tv-style discussion of the form "This is Mr. ...., he's an export on ..... Dear Mr. ...., what do you think of ....." THAT would be boring! Thanks Dave and "Thumbs up!" :-D
I like Dave's interview style..he might not be the next Ray Martin but he gets the job done. The way I see it when he keeps butting in (lol)..it's him trying to make sense of what the person is saying by putting it into a context that he (and hopefully also the viewers) understand. There's things the German guy might think are obvious and not even think are interesting, because he's been living and breathing the projects for years. Dave drew out a lot of stuff that was exactly what I wanted to know. Awsome vid..
+EEVblog Thoroughly enjoyed this series , and all vids that feature a guest..especially one's in the past that featured Doug or others. You seem to have plenty of negative comments, which i think is un-warranted. Your input to these "coversations" ( different to an interview) is as valuable to me as the people your talking with..Your putting stuff into context on the fly, and making sense of stuff..between you and the guest i come away understanding more..love your work.
Why can't ABC hire Dave for Catalyst TV show? get him on as a presenter, its engaging discussion..may actually get people interested in science instead of the hyped tabloid WiFi = cancer nonsense
I think it not as an interview but as a conversation. So there is more variant then in a normal interview but also more inforamation and clearification. You could of course edit the whole conservation to get a more strict red line. But I like this style.
great topic- I have my PCBs for CubeSat MOVEII and IIb in space (LEO oribit). LRT Project from university. LEO orbit is not as critical as other oribits or deep space on radiation, but we used a constant timeout with stdandrd counters to reset the CPUs &FPGAs and reboot in around several hours to recover from radiation effects. Also using special FLASHs (For example FRAM - we used MRAMs) helps to prevent data storage for the boot images.
I notice anytime 2 educated people talk on a topic like this they go back and forth showing understanding and learning. it happens all the time and signals the other person you don't need to dumb it down or explain differently. I've been accused of doing it many times but I never see an issue of it.
There are many articles about the sorts of issues one may encounter with chips and radiation, but one particularly good one comes to mind. Had to search for a while to find it again, but here you go - it's easy enough to read for most hobbyists to understand. Visuals to go with it as well. :) Just google: "Xilinx new rad-hard Virtex-5QV FPGAs - what a good idea!" First result.
I think it's along the lines of the first mm being able to block 90% of one sort of radiation, and then you need a different material to block some % of a more penetrating radiation. I'm speculating here. I think it's about what is required to block electrons vs photons vs xrays, gamma rays, etc.
No, stacking layers makes no difference*, it's all about the total thickness. The point was you get diminishing returns. Let's say 1mm blocks 50%, then a second 1mm layer would block 50% of that, bringing it down to 25%, a third layer would block 50% of that bringing it down to 12.5% ... . So the first layer was the most effective and you have to decide at what point adding another layer doesn't bring you much more shielding and just adds weight. *stacking layers of the same material. Depending on the radiation there is value in stacking layers of different materials. For example, if you have high energy electrons, stopping them with 1mm lead is a bad idea, because the electrons get decelerated so quickly in the lead that they produce x-rays in the process and x-rays are more difficult to shield. You would be better off using 0.9mm aluminium and a 0.1mm layer of lead behind it.
Stacking layers can make a difference, but it's a second order effect. A high Z material, such as Tantalum is more effective at stopping electrons. Then a low Z material can be used behind the Tantalum to absorb the secondaries (Bremsstrahlung). For normal spacecraft this is not necessary - however for missions to Jupiter, the shielding mass savings can be significant.
I dont know about the comments below but Dave, i think was so interested and thats y he kept answering hes questions. Dave always goes deep so there u go... I think it was brilliant. Tho few suggestions, face the camera and instead of sitiing stand up guys and do a full body interview, movement of arms and legs help portray an image of the conversation
To start with an old-school question, I wonder how TLL compares to CMOS? The other question is how much of this is a destruction of the circuitry--rather than an increased error rate due to external energies?
Wow. This is just soooo amazingly interesting to watch! Thank you a gazillion. This man is better than a Jarvis! And your "interrupting" doesn't bother at all. It's not even an interview ffs... Well done Dave!
Many space hardened chips are made on Ruby substrate. With multi-air-spaced titanium and aluminium shielding ,and sometimes, with super- critical components, lead is sometimes used.
Interesting, Bath Uni were making progress in self repairing chips for use in hot areas of nuclear power plants, surprised they're not being used for space missions?
I've been doing some space design recently. It's true that big-budget communications satellites will be using radiation-hardened chips, but it's also true that these are phenomenally expensive and well beyond the budgetary means of many designs. I was surprised to learn that, in fact, lots of smaller craft are operating with off-the-shelf PICs and the like. Of course there's a lot of design to do here, with the implication of lots of redundancy and a limited lifespan. All the same, a great many of these devices greatly outlast their design expectations, not to mention the consensus expectation, using off-the-shelf components. If you're building craft which cost less than about $10,000 a piece, you're probably better off designing with big margins, redundancy, and careful memory management than talking about radiation hardened/tested chips. Shield up to your mass limits, of course.
Ultimately it's about acceptable risk. If you're flying a one off billion $/€ mission, you want to minimise risk and use the more expensive components. If you're flying an experimental cubesat, then COTS will work (they can be derated to ensure they will still be in their operational envelope after degradation)...but won't last as long. Either way, the design should account for the radiation effects to ensure the risk is known and acceptable.
Great interview Dave and my question is what annealing effects was Karsten referring to as the total dose accumulates with an applied EMF. Will the semiconductor doping become permanently altered or some other effect?
Great info from Karsten, but Dave didn't let the information flow; too many interruptions from Dave... I'm a EE 2 test radiation effects engineer @ HI.
lol on the subject of constantly interrupting Karsten yeah it actually sucks to do that because since Karsten is a non-native English speaker it takes him a bit of time to figure out how to put a concept into English, and the interviewer must allow for that time. If not, the person being interviewed would feel pressured/frustrated by having those trains of thought derailed every time. Having said that, I have the same habit when talking to people haha, so I can't blame Dave unless I want to be a hypocrite. ;) I do my best to contain my own thoughts/excitement and just let the person speak. It takes conscious effort with excitable types like myself (and Dave maybe)... :P
Frustrating that "Dave" keeps incessantly interjecting in hyperactive manner, as well as trying to spoon feed the gentleman an approximation of what the non native english speaker is trying to say. Other than that, it was an informative interview, and part of the reason why i subscribe to this youtube channel.
I think he means tantalum not titanium but gave up trying to talk over dave. That is one thing I noticed dave's voice is like my brain, it says "I get it now move on to the next point", but the people watching are not that fast, especially when you start using lots of abbreviation.
I guess you're talking about ESA's SPENVIS - Project?Using the right search terms helps. Just typing 'esa radiation calculator' in any search engine brings it up. Of course, that requires noticing that this organization is named 'european space agency'...
i really prefer to hear a proper conversation between those guys instead of some presentation or commercial that is how interview works, you ask questions, ask for explanations etc.
Dave -- less coffee next time! Let the man speak. As impressed as I am with your ability to guess the answer 80% of the time, I'd rather just be told the answer by the industry expert.
Sorry, this one here is better, the other figure was about cover glass degradation: esmat.esa.int/materials_news/isme09/pdf/2-Radiation/Poster%20Radiation%20and%20Charging%20Effects%20-%20Yang.pdf
Solar panels do indeed also degrade in performance over time. I assume the sheer size of the doped surface is the main difference here, as slow damage over time isn't as critical of a problem.
The primary source of solar cell degradation (and for typical opto-electronics) is via non-ionising dose (NID), aka "displacement damage", not doping. NID is where a sufficiently energetic incident ion displaces/dislocates one of the atoms in the junction lattice structure, causing a defect and a recombination centre for electron-hole pairs. Protons are more damaging than electrons. When designing the spacecraft, the degradation of the solar arrays due to a myriad of effects (radiation, coverglass darkening, thermal issues, etc) is included in the sizing of the arrays to ensure sufficient power is available at the end of life. For a large solar particle event, e.g. Oct '03, the total power output from the array can drop by ~2-3%.
Has anyone tried to impliment active shielding, such as EMF from an active electric coil or rare earth magnets? I theorise that you may also be able to drain excess energy generated by passing through the VABs or other phenomenon, using super capacitors (with diodes) as an earth, as they have largish capacities, with very low resistance and therefore hopefully absorb the excess electrons?
So... having watched this fascinating video... does this mean that "The Martian" movie completely ignored much of these issues of long-term survivability of the componentry and electronics?
The book/movie did pretty much ignore radiation but in an interview Andy Weir mentioned that one thing he had to do for artistic license was ignore radiation shielding. He said you should just assume that there was something special about the hab canvas that gives it effectively 100% radiation shielding. I think the source of this was an interview with Adam Savage from Mythbusters/Tested. In addition, the pathfinder was buried. I don't know anything about radiation shielding, but I would guess that this would provide some level of protection.
i think alot of you are misunderstanding, dave is trying to make the content presentable in a educational format for the viewer, so his interjection are partial excitement(him understanding on the spot) and then trying to quantify these new ideas for both him and the viewer as the guest is talking about a bunch of concepts quite quickly that many people would not understand, and also having a accent barrier, this stuff isnt always easy to do for such complex topics.
Glad someone finally made a video about this, should close the door on all those who think we didn't go to the moon because of the radiation. He said it depends where you want to go and the shielding. The first layer is the important one not so much the thickness. The apollo crafts were more than "pop cans". There was shielding around the electronics. Naysayers never mention that.
The payload (astronauts) are considerably more susceptible to radiation damage than components. The electronics flown at the time (magnetic core memories, etc) were quite radiation tolerant. Between the Apollo 16 and 17 missions, the August '72 solar particle event occurred. While it might not have killed the astronauts, they would have received a sufficient dose to incur radiation poisoning (vomiting, etc.). Shielding against such events (they occur about once every 12 years and last for a days to a week) in interplanetary space requires about 20 mm of Aluminium - a very heavy mass penalty. In low Earth orbit (like the ISS) the Earth's magnetic field provides considerable shielding from these events.
Can you design a Lunar Rover to use a RTG to operate in the Lunar Polar Region to map and how to access the Lunar Polar Ice (H2O) ? Also these hardened chip may also survive an EMP. Thank you for the video ! tjl
I am not sure if it is in this video or another, but getting a RTG or even just a RHU is a very involved and complex process that no commercial entity has ever done. Plus it would be in the millions of dollars PER LAUNCH! (Just the paperwork)
They were talking in the other electronic video about that. The paper work alone to get the permission as a private to start a RTG will cost you around 20 million $ (they really asked for it when looking what would be possible). And then you still have the costs of the RTG (the RTG and higher mass, more shielding as you have an additional radiation dose). And some other problems, the RTG would be fine to go through lunar night - but for lunar day you just have more heat energy you have to get rid off. So it's an interesting thing if you don't have to look at the budget to hard.
Is this rover supposed to map the moon? It may take a VERY long time as we've seen it move. I'd be worried about some terrain problems may be too intense for this probe unless it can automatically avoid them. It would be a miracle to work properly. I am guessing you are working against vacuum conditions, extreme heat/cold, and some ionizing radiation like cosmic rays. Not to mention space matter collision that any tech must survive. Like I don't know how those plastic leg caps would hold up.
It is actually harder to land on the moon, because the atmosphere can't be used to slow you down, so you'd have to retro burn properly or just smash into the moon really fast.
16:24 Actually, turning 127 into 128 takes much more than just a single bit :-) On the other hand, 127 can easily become 255 with a single flip, and everybody will notice a burnt pixel :-0 LOL
Yeah!! I thought I was the only one feeling that Dave just wanted to proof he is smart!! This is the second irritating interview I am watching where Dave is interrupting the guy all the time just like the one with the guy at the PCB fabrication factory.
Karsten said if they 'have a solar flare they know they are F'd'. In the weapons world there's a device that detects the flash of X-ray of a bomb going off and shunts system power. In a sattelite maybe there's enough high-energy particals a tuned sensor could be detect the event. If not maybe a (should already be on board) radiation detector would flag what looked like a solar-flare, send a note home 'solar flare, checking back in 8 hours' and shut everything down. I'm not coming up with anything new--the communications satellites in LEO have got to have stuff like this designed in.
English boat in front of german coast: " We are sinking!". German coast patrol: " what are you S(th)inking about"?" They fail to get ticket for the launch. They are seeking for bankruptcy protection. Sinking. en.m.wikipedia.org/wiki/PTScientists, Dave would say, wa-wa-wa-wa.....
Agreed. Dave needs to ask leading questions and let the guy finish his explanation. He can then follow up with another probing question. This is the problem with presenters trying to do interviews. They are not used to being out of the limelight !!
so how can humans go to the moon? there are satellites up there for decades and are ok? what level of radiation are we talking about?just some questions
hello, I am not bilingual but why not your subtitled video, because I subscribe to your channel but to fustré not understand your language shakespear, cordially Jean marc
Dave, Dave, DAVE! : the substance u had trouble understanding was TANTALUM, as in Tantalum caps. I thought you should know that! (perhaps you are not as used to listening to foreign accents as Europeans!)
Yes Electronics is such a small field that one should know everything about it and what every component is capable off and how they interact with each other under every condition its just that simple...........FFS
I'm glad that he is German, so I could understand his English much better cause I'm German as well.. But one question, is "fancy" a proper term to use? Because it sounds pretty gay to me.
Dave, just let him talk, mate.
Agreed.
Agree!
Totally agreed. Got better towards the end of the video, but the first 10 minutes were painful to watch...
One of my sister's does this all the time and finds it funny when I complain; she is 51. She also asks a question but does not wait for the answer, e.g. I begin to open my mouth but never get any words out. I'm not like many people who enjoy talking at the top of their voice and having a shouting match. I enjoy listening as much as talking; you cannot have one without the other.
Use duct tape.
The comments on Rad-hard components are pretty nice regarding the test reports et cetera. Withing the space industry there is also a move towards COTS for some projects. Budgets are not infinite. That being said, CubeSats are growing up and customers are demanding longer lifetimes as well. Luckily, LEO is pretty forgiving. Going to the moon is a different story.
On one of the projects I did (FUNcube-1), we found out that one of our devices that we used had come from a batch that was radiation tested for another space mission. We had paid the COTS price from a popular supplier that starts with f and ends on ll ;)
The feature size thing is counter-intuitive at first, but think about it this way: an energetic particle impacting into a chip will create an energy gradient in the chip of a certain size. If your feature size is smaller, it is true that it is less robust from a size point of view, but because the transistors are closer together, the gradient per transistor is much smaller!
Its a lot more complicated than that, but it maybe gives a hint to why feature size does not matter. size / gradient = constant mess ;)
I am designing CubeSats for about 10 years now, and in general the advice for LEO is, don't bother with radiation shielding, but carefully select your (COTS) components.
We are also working on a payload that will go to the moon, and there it is not as simple, and a lot more thought has to go into it.
one thing that is also interesting to mention is Secondary Emission. This happens when a high energy particle impacts, for instance, an aluminium payload box. The high energy impact on the outside may release multiple lower energy particles, that then spray around inside your enclosure.
Thanks Karsten and Dave for the nice talk! All up my alley as RF systems engineer in a space company, and AMSAT satellite builder.
Dave we know youre smart, let him talk!
shomolya Literally didnt read a single comment before commenting, but even if every comment is that way, there is purpose in telling him. All it is is constructive criticism, maybe he wont be so talkative next time!
This is a topic thats been on my mind lately, been really wanting to do some good research into it, havent had the energy, but I saw this pop up in my feed! "Awesome, a topic I really want to hear about, and someone smart has done all the research for me!" I say to myself.
10 minutes later, frustrated, I close the video prematurely, unable to finish it... Pardon me for being disappointed.
+Kakunapod I agree with ya. I would have liked to hear more from the German guy. Sometimes I couldn't exactly understand what he was saying and Dave repeated it in a little cleaner English so I like that. but other than that I would really have liked to hear more from the German.
Your loss.
I think Dave's just aware he's recording for an audience with a variety of viewers technical levels and is simply proving little contextual comments for those that may get a little lost. Maybe I'm just used to Dave's presentation style... I thought it was fine!
EEVblog Yes, the way the interview/discussion was conducted certainly resulted in a loss for me
This little series with Karsten has been really great, thanks you two!
Karsten (German guy) was right, it's called tantalum *Ta*, atomic number 73.
used in capacitors
Every time I hear Dave do an interview with someone, I feel that Dave is just trying to show off by interjecting with stuff he knows. It'll probably feel all right to the person he's talking to, as it shows signs of interest, but it's not so nice to look at.
You are so right.
I started working as a radiation effects engineer which is what this gentleman does. I started by watching this video and now ~3 months into my job, I feel like I understand everything he said where before I understood maybe 30%. Yay! Thanks for helping
Awesome :)
All these rover videos are great stuff Dave !
Great video! I think the feature size doesn't matter too much here because although the required dosage to failure per area increases, the total dosage decreases due to smaller area. So if dosage to failure of components is roughly inversely proportional to size you get cancellation.
Contrary to seemingly everybody else here in the comments, I didn't find the interrupting annoying. Idk, maybe it just makes the conversation more natural.
This is one of my favorite episodes by far!
Glad you liked it.
I love these interviews, because its two engineers discussing it. If he had been on nearly any other interview he would have gotten a bunch of softball pre-made questions. Karsten knew he was talking to a literate audience and was able to discusses much more technical details.
I think Dave interruptions are justified. when I am explaining something I love those sign of understandnes if I did not receive that I think that wast clear enough and start to over explain the same and being redundant.
Then you have very low standards. Doing proper interviews are a skill as well as a discipline. This wasn't that great from interview point of view. A good interviewer asks questions that generate the minimum amount of confusion and ambiguity. And the interviewer also lets the person talk UNTIL it goes on some random tangent.
My "interviews" are really just chats between two technical people. I have no prepared questions, have not studied anything before hand, (in this case) have not met the person before so don't know anything about them or their ability to answer questions clearly etc. I'm also excited about the topic I'm talking about it. I hate formal interviews with prepared questions etc, and then waiting for someone to finish and go "err,um, next question", it makes the person feel like they are being "interviewed" and grilled etc. Remember, these are often people who have never been on camera before.
I much prefer informal chats that put the person at ease, and ones that just flow so they forget the camera is one and they are being "interviewed". If you have two technical people then they will throw technical stuff into the ring when they think of it, it's a natural part of tech people chatting about a topic.
In real time I have to try and comprehend and process what they are saying, think of new questions to ask, be receptive and show understanding for what they are saying, think of what might be valuable for my audience (and/or what I'd like to know myself), deal with unexpected answers, anticipate if their answers or going somewhere worthwhile and decide if an interjection is worthwhile etc etc.
I like to think my enthusiasm for the topics and my conversational style extracts more content from people than my "poor" technique looses.
But some people just like the bitch about it. Meh.
+EEVblog I enjoyed it and can relate. Two like minded people knowing the same topics can really leave some in the dust. Picking up on this,I just sit back and enjoy two tech-savvy dudes getting into it. I myself forgot the obvious,radiation in space...DOH!
However please allow the other persons thoughts and explanations conclude. You know a lot but this guy knows more than you in this field so let him speak.
@@EEVblog Yeah but we know that you know the topic. Let the guy talk. He has a lot of information to give out to listeners but you keep interjecting and interrupting, cutting the flow. Not too good. The chat is for your audience to gain out of, not you. If you want to keep cutting in then you shouldn't even bother uploading the video. My 2 pence!
very nice explanation!
It really is a small Internet sometimes. I started getting in to FPGA development some time ago. When I was researching the topic of FPGA and the various tools needed to work with them I ran across the PSHDL website. Here you are talking to its creator.
When mentioning use of radiation hardened parts I wondered if someone would mention the 1802 and someone in the comments has done so. I built myself an 1802 based computer board almost three decades ago. I thought the 1802 would be an obsolete part by now but it is still being produced AFAICT.
Thank you Dave for such an amazing content!
Thanks.
TANTALUM! :-)
Good video, more knowledge gained. (Tantalum Dave, It's Tantalum.)
I could listen to that all day long. Really cool.
if you look at raw images from a camera in space you can see the radiation damage as it happens. Public release images are usually corrected though.
That's quite interesting stuff! Having dealt with electronics for decades I made the mistake to take it for granted that for example thermal issues are just a matter of how big your cooler fins are and such stuff, but if there's no air then there will be no heat dissipation on that way. You have to just radiate all the thermal energy. And ionic particles and radiation is no real deal here on ground. Lots of interesting questions!
And - opposing to many commenters - I do really like the discussion style of the interview. It's much more cool and easy listening than a tv-style discussion of the form "This is Mr. ...., he's an export on ..... Dear Mr. ...., what do you think of ....." THAT would be boring! Thanks Dave and "Thumbs up!" :-D
I like Dave's interview style..he might not be the next Ray Martin but he gets the job done. The way I see it when he keeps butting in (lol)..it's him trying to make sense of what the person is saying by putting it into a context that he (and hopefully also the viewers) understand. There's things the German guy might think are obvious and not even think are interesting, because he's been living and breathing the projects for years. Dave drew out a lot of stuff that was exactly what I wanted to know. Awsome vid..
Thanks, glad you can appreciate the value of my (unusual?) style.
+EEVblog Thoroughly enjoyed this series , and all vids that feature a guest..especially one's in the past that featured Doug or others. You seem to have plenty of negative comments, which i think is un-warranted. Your input to these "coversations" ( different to an interview) is as valuable to me as the people your talking with..Your putting stuff into context on the fly, and making sense of stuff..between you and the guest i come away understanding more..love your work.
Why can't ABC hire Dave for Catalyst TV show? get him on as a presenter, its engaging discussion..may actually get people interested in science instead of the hyped tabloid WiFi = cancer nonsense
I think it not as an interview but as a conversation. So there is more variant then in a normal interview but also more inforamation and clearification. You could of course edit the whole conservation to get a more strict red line. But I like this style.
could Fukushima be a test bed for radiation hardening of robotic electronics?
I really want to congratulate you Dave for being such an outstanding interviewer on these matter
I was super curious about the issue and I finally found all the answers I was looking for in this video! Tnx a lot!
great topic- I have my PCBs for CubeSat MOVEII and IIb in space (LEO oribit). LRT Project from university. LEO orbit is not as critical as other oribits or deep space on radiation, but we used a constant timeout with stdandrd counters to reset the CPUs &FPGAs and reboot in around several hours to recover from radiation effects. Also using special FLASHs (For example FRAM - we used MRAMs) helps to prevent data storage for the boot images.
I notice anytime 2 educated people talk on a topic like this they go back and forth showing understanding and learning. it happens all the time and signals the other person you don't need to dumb it down or explain differently. I've been accused of doing it many times but I never see an issue of it.
There are many articles about the sorts of issues one may encounter with chips and radiation, but one particularly good one comes to mind. Had to search for a while to find it again, but here you go - it's easy enough to read for most hobbyists to understand. Visuals to go with it as well. :) Just google: "Xilinx new rad-hard Virtex-5QV FPGAs - what a good idea!" First result.
When it's said that the first mm of shielding does the most good, what happens if you add "layers". each one mm thick? Does that make a difference?
I think it's along the lines of the first mm being able to block 90% of one sort of radiation, and then you need a different material to block some % of a more penetrating radiation. I'm speculating here. I think it's about what is required to block electrons vs photons vs xrays, gamma rays, etc.
No, stacking layers makes no difference*, it's all about the total thickness. The point was you get diminishing returns. Let's say 1mm blocks 50%, then a second 1mm layer would block 50% of that, bringing it down to 25%, a third layer would block 50% of that bringing it down to 12.5% ... . So the first layer was the most effective and you have to decide at what point adding another layer doesn't bring you much more shielding and just adds weight.
*stacking layers of the same material. Depending on the radiation there is value in stacking layers of different materials. For example, if you have high energy electrons, stopping them with 1mm lead is a bad idea, because the electrons get decelerated so quickly in the lead that they produce x-rays in the process and x-rays are more difficult to shield. You would be better off using 0.9mm aluminium and a 0.1mm layer of lead behind it.
Stacking layers can make a difference, but it's a second order effect. A high Z material, such as Tantalum is more effective at stopping electrons. Then a low Z material can be used behind the Tantalum to absorb the secondaries (Bremsstrahlung). For normal spacecraft this is not necessary - however for missions to Jupiter, the shielding mass savings can be significant.
I dont know about the comments below but Dave, i think was so interested and thats y he kept answering hes questions. Dave always goes deep so there u go... I think it was brilliant. Tho few suggestions, face the camera and instead of sitiing stand up guys and do a full body interview, movement of arms and legs help portray an image of the conversation
To start with an old-school question, I wonder how TLL compares to CMOS? The other question is how much of this is a destruction of the circuitry--rather than an increased error rate due to external energies?
Wow. This is just soooo amazingly interesting to watch!
Thank you a gazillion. This man is better than a Jarvis!
And your "interrupting" doesn't bother at all. It's not even an interview ffs...
Well done Dave!
Many space hardened chips are made on Ruby substrate. With multi-air-spaced titanium and aluminium shielding ,and sometimes, with super- critical components, lead is sometimes used.
Interesting, Bath Uni were making progress in self repairing chips for use in hot areas of nuclear power plants, surprised they're not being used for space missions?
Awesome talk. Danke dir, Karsten!
Too much interruptions
I've been doing some space design recently. It's true that big-budget communications satellites will be using radiation-hardened chips, but it's also true that these are phenomenally expensive and well beyond the budgetary means of many designs.
I was surprised to learn that, in fact, lots of smaller craft are operating with off-the-shelf PICs and the like. Of course there's a lot of design to do here, with the implication of lots of redundancy and a limited lifespan. All the same, a great many of these devices greatly outlast their design expectations, not to mention the consensus expectation, using off-the-shelf components.
If you're building craft which cost less than about $10,000 a piece, you're probably better off designing with big margins, redundancy, and careful memory management than talking about radiation hardened/tested chips. Shield up to your mass limits, of course.
Ultimately it's about acceptable risk. If you're flying a one off billion $/€ mission, you want to minimise risk and use the more expensive components. If you're flying an experimental cubesat, then COTS will work (they can be derated to ensure they will still be in their operational envelope after degradation)...but won't last as long. Either way, the design should account for the radiation effects to ensure the risk is known and acceptable.
Great interview Dave and my question is what annealing effects was Karsten referring to as the total dose accumulates with an applied EMF.
Will the semiconductor doping become permanently altered or some other effect?
Great Chat!
Let the guest TALK!
LOVE this Channel "Teardown the rover PLS"
Great info from Karsten, but Dave didn't let the information flow; too many interruptions from Dave... I'm a EE 2 test radiation effects engineer @ HI.
I agree with Redtails, it would be more enjoyable to watch if Dave would let them answer the questions. Is he listening or just waiting to talk.
"so you got your arduino board just flapping around in space"
Please don't use the garbage imperial system. Stick to metric. Thanks.
The imperial system that put men on the moon isn't good enough for you?
They both measure the same thing. Did that blow your mind?
No
+Mini DK#9 the imperial system that caused the loss of the Mars Climate Orbiter is still stupid
*****
Why ?
Why use imperial at all, US and UK imperial systems are so different. Ever seem anyone on a forum specify which one ?
lol on the subject of constantly interrupting Karsten yeah it actually sucks to do that because since Karsten is a non-native English speaker it takes him a bit of time to figure out how to put a concept into English, and the interviewer must allow for that time. If not, the person being interviewed would feel pressured/frustrated by having those trains of thought derailed every time. Having said that, I have the same habit when talking to people haha, so I can't blame Dave unless I want to be a hypocrite. ;) I do my best to contain my own thoughts/excitement and just let the person speak. It takes conscious effort with excitable types like myself (and Dave maybe)... :P
Frustrating that "Dave" keeps incessantly interjecting in hyperactive manner, as well as trying to spoon feed the gentleman an approximation of what the non native english speaker is trying to say. Other than that, it was an informative interview, and part of the reason why i subscribe to this youtube channel.
I think he means tantalum not titanium but gave up trying to talk over dave. That is one thing I noticed dave's voice is like my brain, it says "I get it now move on to the next point", but the people watching are not that fast, especially when you start using lots of abbreviation.
Dave should do a video about marine electronics!
Great episode! Did anyone catch that website for the eso radiation calculator? My google fu is weak.
I guess you're talking about ESA's SPENVIS - Project?Using the right search terms helps. Just typing 'esa radiation calculator' in any search engine brings it up. Of course, that requires noticing that this organization is named 'european space agency'...
thanks :-) typo fail. www.sr-niel.org/
Very interesting, thanks Dave.
i really prefer to hear a proper conversation between those guys instead of some presentation or commercial
that is how interview works, you ask questions, ask for explanations etc.
19:40 "We are designing as good as we can but if we have a solar flare, we are fucked and we know that" lol
Great stuff. But Dave could you please not interrupt your interview partner so often?
Dave -- less coffee next time! Let the man speak. As impressed as I am with your ability to guess the answer 80% of the time, I'd rather just be told the answer by the industry expert.
if ions screw with the doping of the silicon, how do solar panels work in space?
Good point Kevron, so what annealing was Karsten referring to?
Sorry, this one here is better, the other figure was about cover glass degradation: esmat.esa.int/materials_news/isme09/pdf/2-Radiation/Poster%20Radiation%20and%20Charging%20Effects%20-%20Yang.pdf
Solar panels do indeed also degrade in performance over time. I assume the sheer size of the doped surface is the main difference here, as slow damage over time isn't as critical of a problem.
The primary source of solar cell degradation (and for typical opto-electronics) is via non-ionising dose (NID), aka "displacement damage", not doping. NID is where a sufficiently energetic incident ion displaces/dislocates one of the atoms in the junction lattice structure, causing a defect and a recombination centre for electron-hole pairs. Protons are more damaging than electrons.
When designing the spacecraft, the degradation of the solar arrays due to a myriad of effects (radiation, coverglass darkening, thermal issues, etc) is included in the sizing of the arrays to ensure sufficient power is available at the end of life.
For a large solar particle event, e.g. Oct '03, the total power output from the array can drop by ~2-3%.
Wow Such interesting topic
Very interesting
Has anyone tried to impliment active shielding, such as EMF from an active electric coil or rare earth magnets? I theorise that you may also be able to drain excess energy generated by passing through the VABs or other phenomenon, using super capacitors (with diodes) as an earth, as they have largish capacities, with very low resistance and therefore hopefully absorb the excess electrons?
What about capacitors, electrolitics especially
So... having watched this fascinating video... does this mean that "The Martian" movie completely ignored much of these issues of long-term survivability of the componentry and electronics?
Not really. Mars has an atmosphere to shield radiation not unlike earth does, just to lesser degree (30 µSv per hour during solar minimum)
idk about the film but in the book i recall him making allowances for electronics getting too cold and things like that.
The book/movie did pretty much ignore radiation but in an interview Andy Weir mentioned that one thing he had to do for artistic license was ignore radiation shielding. He said you should just assume that there was something special about the hab canvas that gives it effectively 100% radiation shielding. I think the source of this was an interview with Adam Savage from Mythbusters/Tested. In addition, the pathfinder was buried. I don't know anything about radiation shielding, but I would guess that this would provide some level of protection.
i think alot of you are misunderstanding, dave is trying to make the content presentable in a educational format for the viewer, so his interjection are partial excitement(him understanding on the spot) and then trying to quantify these new ideas for both him and the viewer as the guest is talking about a bunch of concepts quite quickly that many people would not understand, and also having a accent barrier, this stuff isnt always easy to do for such complex topics.
I will be a nuclear engineer soon, watched this all the way through.
Cool, got a job lined up?
Yes. I'm a nuclear officer for the US Navy, I will run a submarine reactor. I commission as soon as I graduate college.
Perfect video dave very interesting.
@EEVblog please do some more repair videos.
just done a 100K rad using local food treatment co-60 source, on some LDOs, for a cube sat
And, did they survive? I have done similar tests for CubeSats, and some LDOs died very quickly!
some survived, its about part number. no need for space grade, still trying to try out more
Isn't the material his talking about for shielding titanium?
Tantalum, I think.
Timothy Hobbs Yea you are right. I think there is also some titanium alloys for this, but tantalum makes more sense.
Yes it is tantalum. Also anyone interested in more information on radiation shielding: sci.esa.int/science-e/www/object/doc.cfm?fobjectid=46414
There are some interesting diagrams which cite need for further research. This doc is from 2010, any updated versions around?
Glad someone finally made a video about this, should close the door on all those who think we didn't go to the moon because of the radiation. He said it depends where you want to go and the shielding. The first layer is the important one not so much the thickness. The apollo crafts were more than "pop cans". There was shielding around the electronics. Naysayers never mention that.
The payload (astronauts) are considerably more susceptible to radiation damage than components. The electronics flown at the time (magnetic core memories, etc) were quite radiation tolerant. Between the Apollo 16 and 17 missions, the August '72 solar particle event occurred. While it might not have killed the astronauts, they would have received a sufficient dose to incur radiation poisoning (vomiting, etc.). Shielding against such events (they occur about once every 12 years and last for a days to a week) in interplanetary space requires about 20 mm of Aluminium - a very heavy mass penalty. In low Earth orbit (like the ISS) the Earth's magnetic field provides considerable shielding from these events.
Can you design a Lunar Rover to use a RTG to operate in the Lunar Polar Region to map and how to access the Lunar Polar Ice (H2O) ? Also these hardened chip may also survive an EMP. Thank you for the video ! tjl
I am not sure if it is in this video or another, but getting a RTG or even just a RHU is a very involved and complex process that no commercial entity has ever done. Plus it would be in the millions of dollars PER LAUNCH! (Just the paperwork)
They were talking in the other electronic video about that. The paper work alone to get the permission as a private to start a RTG will cost you around 20 million $ (they really asked for it when looking what would be possible). And then you still have the costs of the RTG (the RTG and higher mass, more shielding as you have an additional radiation dose). And some other problems, the RTG would be fine to go through lunar night - but for lunar day you just have more heat energy you have to get rid off. So it's an interesting thing if you don't have to look at the budget to hard.
sha hash your ram, place redundant ram on alternate alignment, ECC susceptible to > 1 bit flipping
what was the URL?
very interesting i found this after searching why robots wont work for long inside the fukushima reactors
Is this rover supposed to map the moon? It may take a VERY long time as we've seen it move. I'd be worried about some terrain problems may be too intense for this probe unless it can automatically avoid them. It would be a miracle to work properly. I am guessing you are working against vacuum conditions, extreme heat/cold, and some ionizing radiation like cosmic rays. Not to mention space matter collision that any tech must survive. Like I don't know how those plastic leg caps would hold up.
It is actually harder to land on the moon, because the atmosphere can't be used to slow you down, so you'd have to retro burn properly or just smash into the moon really fast.
Are you in a hurry? Can't wait to get up there?
No, it just has to last 11 days or so
No heat problems though!
EEVblog
Plenty of dense gas to conduct away the heart ?
16:24 Actually, turning 127 into 128 takes much more than just a single bit :-) On the other hand, 127 can easily become 255 with a single flip, and everybody will notice a burnt pixel :-0 LOL
Wow, lots of whinging comments about interview technique, like to see any of them do better.
Love this 'outside the normal box' stuff Dave, thanks!
Yeah!! I thought I was the only one feeling that Dave just wanted to proof he is smart!! This is the second irritating interview I am watching where Dave is interrupting the guy all the time just like the one with the guy at the PCB fabrication factory.
Karsten said if they 'have a solar flare they know they are F'd'. In the weapons world there's a device that detects
the flash of X-ray of a bomb going off and shunts system power. In a sattelite maybe there's enough high-energy particals
a tuned sensor could be detect the event. If not maybe a (should already be on board) radiation detector would flag
what looked like a solar-flare, send a note home 'solar flare, checking back in 8 hours' and shut everything down.
I'm not coming up with anything new--the communications satellites in LEO have got to have stuff like this designed in.
radiation monitors are normally flown. See www.swpc.noaa.gov/ for some examples.
Tantalum?
Is Fran there?
Dr evil vs Scotty dont! hehe.. interesting stuff though thanks!
English boat in front of german coast: " We are sinking!".
German coast patrol: " what are you S(th)inking about"?"
They fail to get ticket for the launch. They are seeking for bankruptcy protection. Sinking.
en.m.wikipedia.org/wiki/PTScientists, Dave would say, wa-wa-wa-wa.....
TANTALUM!!
It's so annoying to listen to you because you constantly interrupt each other
Agreed. Dave needs to ask leading questions and let the guy finish his explanation. He can then follow up with another probing question. This is the problem with presenters trying to do interviews. They are not used to being out of the limelight !!
Yep... that's a fellow German :D
Should retitle the video to “How to constantly interrupt a person being interviewed”
Ah...Audi logo...oh you Know about emissions (cough TDi cough) ...
so how can humans go to the moon? there are satellites up there for decades and are ok? what level of radiation are we talking about?just some questions
lol Dave has hit that age. he looks like an old sgt that already knows everything and young wippersnapper is being tested.
Dude, you need to let the guy answer and not keep jumping over him otherwise very good discussion
Tantalum it is
11:25 Hey Dave, judging by your reaction, was it painful to endure all the confabulated space babble?
Audi rover vs. Australia post
hello, I am not bilingual but why not your subtitled video, because I subscribe to your channel but to fustré not understand your language shakespear, cordially Jean marc
Dave, Dave, DAVE! : the substance u had trouble understanding was TANTALUM, as in Tantalum caps. I thought you should know that!
(perhaps you are not as used to listening to foreign accents as Europeans!)
I never knew Tantalum could be used for shielding, that's why it didn't register.
Yes Electronics is such a small field that one should know everything about it and what every component is capable off and how they interact with each other under every condition its just that simple...........FFS
Why do you keep on interruping him all the freaking time?
TANTALUM!
I'm glad that he is German, so I could understand his English much better cause I'm German as well..
But one question, is "fancy" a proper term to use?
Because it sounds pretty gay to me.
Flat Earthers will cry at this video
shut up a bit Dave.. let the guy speak!
super early!
Dave suffering from some rifa madness not recognizing tantalum?