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I wonder how they address radiation hardening and other space specific environmental drivers in this hardware.
by digikata 14y ago
I wonder how they address radiation hardening and other space specific environmental drivers in this hardware.
- est 14y agoUse a shield.
- sliverstorm 14y agoOf lead? At $10,000/lb launch cost?
- deleted 14y ago[deleted]
- ars 14y agoLead wouldn't work anyway - it would make things worse actually. Lead is good for gamma (and X) rays, but very very terrible for cosmic radiation which is protons and neutrons (nucleons). For those you want water. It works like this: For photons you want them absorbed, so heavy metals are great. But it's not possible to absorb nucleons. Instead you want to steal their energy. If you use lead they simply bounce loosing hardly any energy. Instead you want very light elements - hydrogen especially. Then when they bounce all the energy gets transfered to the hydrogen. Lead can make things worse because the nucleon can actually fission the lead atom emitting secondary radiation that is even worse than the original. If you are shielding from electrons you can get Bremsstrahlung radiation if you use lead see: http://en.wikipedia.org/wiki/Bremsstrahlung#Radiation_safety http://en.wikipedia.org/wiki/Bremsstrahlung#Radiation_safety In summary: Lead for photons, water (or other light materials like wax or plastic) for everything else.
- mootothemax 14y agoYou've written an incredibly interesting comment addressing something I had no idea about, thank you.
- ars 14y agoYou can try it out a bit. Shoot various size coins at each other and watch how they interact, then try a coin against a wall. If you have a very slippery surface try making a line of 3 coins (or more if it's super slippery) to bounce against each other.
- greenyoda 14y agoRadiation, such as cosmic rays, would tend to cause transient bit errors in memory that would cause the phone to crash or otherwise stop working. The article mentions that they have a circuit that automatically re-boots the phone when it stops transmitting a signal, so it can recover from these problems.
- sliverstorm 14y agoWow. That's surprisingly un-NASA. I wonder if they have qualified the MTBF? For this kind of solution to work, it'd have to be at least a couple hours.
- KirinDave 14y agoActually, a lot of smaller things that go up just go into reboot cycles when they detect that kind of error. Because at the end of the day, "Radiation hardening" just means, "Less likely to experience one of these errors but oh hey a solar flare is inc..." Satellites just sort of float until their orbit decays, they are de-orbited, or they are lost. You wouldn't do this for a spy satellite you need to send you images of the sky in realtime for end-of-the-world missile guidance, but for something that's doing science missions it's probably way more important to make something light and cheap that a russian mission can drop out the back of its launch.
- natep 14y agoMaybe in this case it's cheaper to just send them up and measure it directly? It won't survive much TID, either, but with such a short mission and such cheap hardware, hopefully none of that matters.
- wtracy 14y agoIs radiation hardening really that important when you're still this side of the Van Allen belt? My understanding is that it's not, but IANARS.
- emiliobumachar 14y agoEven airliners start having issues at 30000 ft.
- JosephRedfern 14y agoYes, it is. http://www.solarstorms.org/SEUavionics.pdf http://www.solarstorms.org/SEUavionics.pdf
- mturmon 14y agoNice link, thanks. Very detailed.
- StuieK 14y agoWe have short operating lifetimes and use orbits that minimise this problem.