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> The surveyors would be safe enough barring a forced landing or breakdown very near the source Weird assumption. Forced landings anywhere are unsafe. They are

> The surveyors would be safe enough barring a forced landing or breakdown very near the source Weird assumption. Forced landings anywhere are unsafe. They are also very rare, because aircraft are quite reliable. The chances of the surveyors having a forced landing near the capsule must be minuscule (tiny danger zone compared to the extent of full search area, small probability of an aircraft having a forced landing at all). If you are counting such minuscule dangers then you are ignoring much bigger (but still relatively small) dangers to the surveyors: they might trip during the survey, they might get into a traffic accident as they search or their aircraft might crash injuring them (irrespective of distance from the source). They might have a wildlife encounter as they are verifying a signal (false or true positive). They might suffer from heat stroke, or get sunburnt. My intuition says that if you send out teams of people scurrying around the countryside these listed dangers are all more likely than having a forced landing right on top of the source. I also assume that you ignored them because they are all “everyday risks”, and you had tunnel vision concentrating on the radiation hazard.

throwanem 4y ago
Great catch, and you're right: lots of things can go wrong in a desert whether there's radiation involved or not, so we'd have needed those helicopters either way. This is why we work in teams - don't be shy about anything else you see me missing.
- krisoft 4y ago
  > don't be shy about anything else you see me missing I would think we need to clarify the theoretical and practical limits of the detectors. Depending on how the sensors work the search might look very different. If you can get some expensive lab gear and distinguish the radiation of this source from the background from hundreds of kilometers then you only need to measure at a few strategic locations to triangulate it. If you need to get a sensor within ten meters from the source before it can be detected then you need to lug the sensor around on the ground. That would be too low for a manned aircraft to fly at. How fast does the sensor detect? If the sensor can detect up to 100 meters but need 5 second to measure that will make the search much different than if it can measure with 500hz for the same distance. Do we think we can sense only the source or also the places the source has been at? Does it leave a detectable trace? What of these is hard limit by physics (nobody, for no amount of money can build a better detector) vs limit of resources (it would be very expensive to do x)? If it is a limit of resources how does detector quality scales with resources spent? Without having solid answers to these it would be foolish to jump at designing a search method.
  - throwanem 4y ago
    Certainly there would be significant engineering problems involved if we had to develop the survey technology and methodology from scratch, and more problems still if we first needed to confirm that such engineering is even achievable. Fortunately for us in this case, aerial radiological surveying has long since been reduced to practice. [1] [2] The detection equipment described in those references is on the order of tens of thousand times more sensitive than consumer-grade G-M counters, and is commercially available. [3] [1] https://www.osti.gov/servlets/purl/6084 https://www.osti.gov/servlets/purl/6084 [2] https://journals.lww.com/health-physics/Abstract/2016/05000/Aerial_Mobile_Radiation_Survey_Following.8.aspx https://journals.lww.com/health-physics/Abstract/2016/05000/... [3] https://www.berkeleynucleonics.com/nai-sodium-iodide https://www.berkeleynucleonics.com/nai-sodium-iodide

throwanem 4y ago

Great catch, and you're right: lots of things can go wrong in a desert whether there's radiation involved or not, so we'd have needed those helicopters either way. This is why we work in teams - don't be shy about anything else you see me missing.

krisoft 4y ago
> don't be shy about anything else you see me missing I would think we need to clarify the theoretical and practical limits of the detectors. Depending on how the sensors work the search might look very different. If you can get some expensive lab gear and distinguish the radiation of this source from the background from hundreds of kilometers then you only need to measure at a few strategic locations to triangulate it. If you need to get a sensor within ten meters from the source before it can be detected then you need to lug the sensor around on the ground. That would be too low for a manned aircraft to fly at. How fast does the sensor detect? If the sensor can detect up to 100 meters but need 5 second to measure that will make the search much different than if it can measure with 500hz for the same distance. Do we think we can sense only the source or also the places the source has been at? Does it leave a detectable trace? What of these is hard limit by physics (nobody, for no amount of money can build a better detector) vs limit of resources (it would be very expensive to do x)? If it is a limit of resources how does detector quality scales with resources spent? Without having solid answers to these it would be foolish to jump at designing a search method.
- throwanem 4y ago
  Certainly there would be significant engineering problems involved if we had to develop the survey technology and methodology from scratch, and more problems still if we first needed to confirm that such engineering is even achievable. Fortunately for us in this case, aerial radiological surveying has long since been reduced to practice. [1] [2] The detection equipment described in those references is on the order of tens of thousand times more sensitive than consumer-grade G-M counters, and is commercially available. [3] [1] https://www.osti.gov/servlets/purl/6084 https://www.osti.gov/servlets/purl/6084 [2] https://journals.lww.com/health-physics/Abstract/2016/05000/Aerial_Mobile_Radiation_Survey_Following.8.aspx https://journals.lww.com/health-physics/Abstract/2016/05000/... [3] https://www.berkeleynucleonics.com/nai-sodium-iodide https://www.berkeleynucleonics.com/nai-sodium-iodide