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I actually just wrote the policy on this topic for a space project I work on. It really depends. It’s often not cheaper to use such commodity stuff unless you
by johnwalkr 5y ago
I actually just wrote the policy on this topic for a space project I work on.
It really depends. It’s often not cheaper to use such commodity stuff unless you can tolerate a lot of risk. A lot of normal and automotive components are used in space, but it’s mostly simple stuff that’s relatively easy to qualify. A snapdragon cpu will basically never be fully qualified as a single component because you cannot control each state, let alone test it in each state (I am oversimplifying but bear with me). What you can do is apply overcurrent detection, external watchdog timers, redundancy and other techniques to mitigate the effects of radiation.
Then, you can almost fully test that mitigation in theory but not really because it will cost you millions of dollars with huge technical risk and the part will probably be obsoleted or made by a different fab next time you need it. So, you choose older proven easily-hard stuff where you can, or for anything mission critical or related to safety. Better to just buy the $200k rad hard cpu and save your millions.
Then, you are left with only bonus items such as this helicopter that simultaneously do not have many reliability requirements (because it’s not mission critical) and are not possible with traditional space grade technology due to performance requirements.
“Easier to work with” is only true when you take risks too. Yeah, you can start developing right away using a devkit and Linux, but if you find your project needs reliability or safety requirements, you may find you are spending person-years of software engineering time if it’s even possible at all. You might be required for the system to be deterministic and avoid dynamic memory allocation, for example.
Interestingly, students making cubesats don’t “know better” yet. And while the overall failure rate is probably bad on a per mission basis, it’s probably good on a per kg or per dollar basis. There’s a ton of cubesats and cubesat payloads that have raspberry pi’s inside for Leo missions.
- kanwisher 5y agoYeah but part of why they used a high speed arm, is so they could do realtime AI fo determining where to land and what not. If you use a RAD hardened chip you are limited to what 400-500mhz chips from over a decade ago. Fine if your doing a rover that doesn't need to do realtime detection and avoidance of stuff.