3 ms·

Is it an EMI issue? Slower speeds somehow stand the trip better? If there was enough money in it, I'd bet our top minds could find solutions to these problems.

by Pigo 10y ago

takingflac 10y ago
Less speed = less heat which is surprisingly a large concern in space. The other factor is that the transistors on the chips are larger than the ones used on Earth. I don't remember the specifics but the reasoning was that less transistors would be damaged if a spot on the chip was hit by radiation and built in redundancies would be able to compensate. (Source: had a few EE classes where this kind of thing was brought up been awhile though)
Balgair 10y ago
Its answered downthread, but I'll tell you too and add some. The main issue is that the project started 10 years ago, and that is when the general specs were set for pretty much the whole bird. Minor upgrades are made, but you have many many teams working on many little things that have to be integrated, and that spec is 10 years old. I mean, our tech from 10 years ago is billions of times better than a Viking lander, but I get the sentiment. For silicon devices, the VERY hard rad environment of inter-planetary space is pretty much instadeath. So you are forced to be 'dumb'. You can shield it, but that adds weight and heat issues. Redundancy is out, it just doubles/triples the weight, heat, and interfacing issues. You can use rad-hardened devices (best idea) but then you have to fab that silicon anew, and this is really expensive. Then you have to test all these things before you put them up there. So you need to put your device in a vacuum-rad chamber. Governments are not so hot on just having these rad sources laying about and letting a piece of silicon 'cook' next to a power station that is in use. So you do accelerated testing, aka, super radiation. I've been in those chambers before, it's scary. After the magic glow machines are turned off, you have to evac all the air as the O2 in the room has been turned into O3 and you can't breathe in there. The roaches in the corners are literally cooked and brittle. It's nuts. Unfortunately for your testing, this environment is more like the sun's corona than the Earth-Mars transit, so you have to take the testing with a grain of salt. Also your vac chamber is not nearly as good as real space. So everything is oxidized and hat messes up your analysis. You do the best you can, but we don't get many sample returns from outside the Earth's magnetic field to test against. NASA et al do a GREAT job, but they are dealing with very extreme jobs and we just don't have a lot of data about what we are dealing with. We can't do a lot of in situ tests.

Is it an EMI issue? Slower speeds somehow stand the trip better? If there was enough money in it, I'd bet our top minds could find solutions to these problems.

by Pigo 10y ago

Is it an EMI issue? Slower speeds somehow stand the trip better? If there was enough money in it, I'd bet our top minds could find solutions to these problems.

takingflac 10y ago

Less speed = less heat which is surprisingly a large concern in space. The other factor is that the transistors on the chips are larger than the ones used on Earth. I don't remember the specifics but the reasoning was that less transistors would be damaged if a spot on the chip was hit by radiation and built in redundancies would be able to compensate. (Source: had a few EE classes where this kind of thing was brought up been awhile though)

Balgair 10y ago

Its answered downthread, but I'll tell you too and add some. The main issue is that the project started 10 years ago, and that is when the general specs were set for pretty much the whole bird. Minor upgrades are made, but you have many many teams working on many little things that have to be integrated, and that spec is 10 years old. I mean, our tech from 10 years ago is billions of times better than a Viking lander, but I get the sentiment. For silicon devices, the VERY hard rad environment of inter-planetary space is pretty much instadeath. So you are forced to be 'dumb'. You can shield it, but that adds weight and heat issues. Redundancy is out, it just doubles/triples the weight, heat, and interfacing issues. You can use rad-hardened devices (best idea) but then you have to fab that silicon anew, and this is really expensive. Then you have to test all these things before you put them up there. So you need to put your device in a vacuum-rad chamber. Governments are not so hot on just having these rad sources laying about and letting a piece of silicon 'cook' next to a power station that is in use. So you do accelerated testing, aka, super radiation. I've been in those chambers before, it's scary. After the magic glow machines are turned off, you have to evac all the air as the O2 in the room has been turned into O3 and you can't breathe in there. The roaches in the corners are literally cooked and brittle. It's nuts. Unfortunately for your testing, this environment is more like the sun's corona than the Earth-Mars transit, so you have to take the testing with a grain of salt. Also your vac chamber is not nearly as good as real space. So everything is oxidized and hat messes up your analysis. You do the best you can, but we don't get many sample returns from outside the Earth's magnetic field to test against. NASA et al do a GREAT job, but they are dealing with very extreme jobs and we just don't have a lot of data about what we are dealing with. We can't do a lot of in situ tests.