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General Discussion => General Discussion => Topic started by: tnphysics on 05/21/2010 02:15 pm

Title: Using commercial off the shelf electronics in space
Post by: tnphysics on 05/21/2010 02:15 pm
Can one use commercial off the shelf electronics in space? I imagine shielding would be required, but how much? I am referring to parts used in PCs, etc.
Title: Re: Using commercial off the shelf electronics in space
Post by: TyMoore on 05/21/2010 02:50 pm
The short answer is no--w/regards to computers and solid state memories. The amount of shielding needed to prevent single-event upsets is pretty substantial: meters of regolith, for instance.

Rad hard electronics is pretty expensive and also 'dumbs down' CPU's so the typical Space rated CPU is only a fraction of the speed and computing power of a typical ground rated CPU. I believe that this has to do with the necessity of having extra electronics on the chips to do real-time parity checking and correcting, and to detect and bleed off anomalous charge depositions caused by cosmic-ray strikes...


There is also the need to make the components more robust because of the inherent need for radiation damage resistance.

I really don't know how it is done, but rad hard electronics is a real art aparently.
Title: Re: Using commercial off the shelf electronics in space
Post by: cozmicray on 05/21/2010 05:13 pm
There are many laptop PCs on ISS with little change to them?

How much COTs have really been tested in space?

Without a way up and down to ISS we can't do that now?

OK  how about 16 commercial CPUs/memory in all different orientations to mitigate radiation hits?

The Solid state recorder on Terra is a 600 pound box packed with 4MB DRAM  --  could be replaced with an 10 lb array of SATA Solid state drives with Error Detection and Correction software?

Reliability--  does COTS have the reliability?
Why do ISS batteries have to be replaced after 6 years
and other spacecraft are using batteries for 10, 20, 25 years

NASA now doesn't know how to write requirements to allow COTs
and risk aversion paramount.

At times I believe some of the Wall street firms have better fault tollerant and reliable data systems than spacecraft.  Lose a computer for 10 min on a trading day lose billions?
Title: Re: Using commercial off the shelf electronics in space
Post by: Robotbeat on 05/21/2010 06:05 pm
The short answer is no--w/regards to computers and solid state memories. The amount of shielding needed to prevent single-event upsets is pretty substantial: meters of regolith, for instance.

Rad hard electronics is pretty expensive and also 'dumbs down' CPU's so the typical Space rated CPU is only a fraction of the speed and computing power of a typical ground rated CPU. I believe that this has to do with the necessity of having extra electronics on the chips to do real-time parity checking and correcting, and to detect and bleed off anomalous charge depositions caused by cosmic-ray strikes...


There is also the need to make the components more robust because of the inherent need for radiation damage resistance.

I really don't know how it is done, but rad hard electronics is a real art aparently.

This isn't necessarily true at all. Off-the-shelf electronics are used all the time on University cubesats.

There are ways to use commercial electronics in ways which are resilient to radiation but without requiring rad-hard chips. ST-8 was one such mission to test such ideas... of course, it was canceled to pay for the PoR boondoggle:
http://nmp.nasa.gov/st8/tech/eaftc_tech1.html
Title: Re: Using commercial off the shelf electronics in space
Post by: A_M_Swallow on 05/21/2010 06:25 pm
Electronic components only works within a temperature range.  Use of COTS components requires temperature controls.  Military components have a wider range than civilian components and normally are better at resisting radiation.
Title: Re: Using commercial off the shelf electronics in space
Post by: Robotbeat on 05/21/2010 06:37 pm
Electronic components only works within a temperature range.  Use of COTS components requires temperature controls.  Military components have a wider range than civilian components and normally are better at resisting radiation.
Right, but even Mil-spec components are relatively "off-the-shelf" compared to rad-hardened chips.

And besides, space electronics still are designed only for certain temperature ranges...

Which brings me to another point: there should be a way to design components for an even greater temp range so that failure of those temp controls doesn't necessarily mean end-of-the-line.
Title: Re: Using commercial off the shelf electronics in space
Post by: Patchouli on 05/21/2010 07:01 pm
The biggest thing I'd worry about with most off the shelf IC's is latchup.
http://en.wikipedia.org/wiki/Latchup

But silicon on insulator makes them more resistant.
http://en.wikipedia.org/wiki/Silicon_on_insulator

Certain off the shelf PPCs and AMD chips may do just fine in a space environment with the addition of a watch dog and error checking memory.

One big irony a Wii or PS3 might be able to deal with space radiation better then an expensive laptop simply because their CPUs are SOI based.

It probably would be a good idea to steer clear of any process smaller then 90nm.
Title: Re: Using commercial off the shelf electronics in space
Post by: Robotbeat on 05/21/2010 07:08 pm
Right, end-to-end ECC (and multi-bit ECC in some places) could certainly be done to help allow commercial off-the-shelf components to be used. No sane person runs a production server nowadays without ECC. ECC helps a lot with avoiding problems like what happened to Voyager lately (flipped bit).

Another thing is the extreme temperature range. One of the most difficult problems with spacecraft design is thermal control. If the components themselves are designed for a very high temperature range, this difficulty can be substantially relaxed.

See here for more info on using COTS components at extreme temperatures:
http://www.extremetemperatureelectronics.com/tutorial2.html
Title: Re: Using commercial off the shelf electronics in space
Post by: Patchouli on 05/21/2010 09:22 pm
You might want ECC in the cpu cache as well fortunately many off the shelf CPUs have this.

The  ARM Cortex R4 has this feature so it can be safely used in automotive applications.
http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0363e/Chdgfjac.html

http://www.arm.com/products/processors/cortex-r/cortex-r4.php

So do sever processors such as the Opteron and Xeon.

Though the cortex has much more advanced error trapping since it's aimed at embedded applications.

A server can reboot but an airbag controller or engine management computer does not have this option.

Another nice thing automotive applications are already close to mil-spec requirements in that the device must operate at extremes of temperature and vibration that would cause a typical PC processor to fail.

The chip die also is much smaller then an X86 cpu and will present a smaller target to high energy cosmic rays.
Title: Re: Using commercial off the shelf electronics in space
Post by: GreenGlow on 05/21/2010 10:14 pm
The short answer is no--w/regards to computers and solid state memories. The amount of shielding needed to prevent single-event upsets is pretty substantial: meters of regolith, for instance.

I really don't know how it is done, but rad hard electronics is a real art aparently.


Polar and GEO orbits do experience more radiation and likely require rad-hard components.  A bio-science payload I worked on (electronics and software design) was on the MIR space station for a few years.  I made inquiries as to whether rad-hard components were needed.  We were considering using lead shielding or something like that.   I was told radiation was not a problem we needed to worry about with a low inclination LEO orbit.  Our payload didn't have any electronic failures during its time on MIR.  It burned up with MIR when the space station was de-orbited.   Any radiation effects that do occur can be mitigated by the use of a "watchdog" circuit or software function.  Electronic hardware that is left on continuously with no power down cycling may be more susceptible to radiation effects if it causes latchup.  Radiation hits, even by alpha particles, does not usually cause permanent damage; if the flux is low.
Title: Re: Using commercial off the shelf electronics in space
Post by: Robotbeat on 05/21/2010 10:24 pm
The short answer is no--w/regards to computers and solid state memories. The amount of shielding needed to prevent single-event upsets is pretty substantial: meters of regolith, for instance.

I really don't know how it is done, but rad hard electronics is a real art aparently.


Polar and GEO orbits do experience more radiation and likely require rad-hard components.  A bio-science payload I worked on (electronics and software design) was on the MIR space station for a few years.  I made inquiries as to whether rad-hard components were needed.  We were considering using lead shielding or something like that.   I was told radiation was not a problem we needed to worry about with a low inclination LEO orbit.  Our payload didn't have any electronic failures during its time on MIR.  It burned up with MIR when the space station was de-orbited.   Any radiation effects that do occur can be mitigated by the use of a "watchdog" circuit or software function.  Electronic hardware that is left on continuously with no power down cycling may be more susceptible to radiation effects if it causes latchup.  Radiation hits, even by alpha particles, does not usually cause permanent damage; if the flux is low.
Very interesting. I know that the probability of a memory error here on Earth for non-ECC-protected computers with lots of memory is roughly once every few months, and a good portion of those are caused by cosmic rays (most?), evident by the fact that memory error rate increases greatly with altitude (Denver has more errors than LA, for instance). That's why servers all have ECC and why that's what you use if you want stability. Also, basically all of the errors produced by cosmic rays on the Earth's surface are produced by the shower of secondary particles produced when a cosmic ray interacts with the atmosphere, not by the cosmic ray itself (which may be why you could actually have a lower error rate in LEO than on the surface since the shower of secondary particles only occurs when a cosmic ray hits something first).

Welcome to NASASpaceflight, BTW!
Title: Re: Using commercial off the shelf electronics in space
Post by: MKremer on 05/21/2010 11:13 pm
Sure, you can use commercial electronics and digital hardware for spaceflight. The main question is - what are you going to do when they glitch or have a hard failure? Because they will, absolutely 100% encounter one of those two possibilities within their mission lifetime. (high-energy cosmic rays, high-energy Van Allen belt particles, sudden solar flare/CME eruptions)

Even expensive, purpose-manufactured and shielded spaceflight electronics encounter glitches and total failures. And they're designed to resist and survive the environment they're in as much as possible.
Consumer-grade equivalents are much, much more vulnerable to that sort of environment, even with heavy external shielding.

Title: Re: Using commercial off the shelf electronics in space
Post by: Downix on 05/22/2010 12:51 am
there is also a rAD-hardened SPARC processor on the market, which i've used before to good effect. 
Title: Re: Using commercial off the shelf electronics in space
Post by: kraisee on 05/22/2010 01:08 am
I've always wondered, just how different are the requirements between human habitation and electronics protection, in terms of space radiation?

Which is the more demanding requirement, and by how much?   Can somebody help quantify it for me?

Ross.
Title: Re: Using commercial off the shelf electronics in space
Post by: Downix on 05/22/2010 01:10 am
I've always wondered, just how different are the requirements between human habitation and electronics protection, in terms of space radiation?

Which is the more demanding requirement, and by how much?   Can somebody help quantify it for me?

Ross.
Electronics, if a single rad slips through with people, it won't kill them.  But I have delt with some electronic designs which, if they got hit by a single alpha particle, would have a cascade effect killing the whole house of cards.
Title: Re: Using commercial off the shelf electronics in space
Post by: SpacexULA on 05/22/2010 01:25 am
Also wouldn't it matter what "shelf" the parts are coming off of?

Airline equipment is minimally rad shielded.

Military equipment could be called "off the shelf" and it's minimally rad shielded.
Title: Re: Using commercial off the shelf electronics in space
Post by: Ronsmytheiii on 05/22/2010 02:55 am
Another issue would be for BEO craft, would imagine they get much more radiation after they get through the Van Allen Radiation Belts
Title: Re: Using commercial off the shelf electronics in space
Post by: TyMoore on 05/22/2010 03:07 pm
This is an interesting issue which I didn't really have an answer for. I know that some of the most extremely rad-dosed electronics ever built were on the Galileo orbiter which passed through Jupiter's Van Allen belts on several occasions.

It sounds as if off the shelf processors are O.K. as long as thorough error checking and correcting is implemented in the design. Perhaps a block of processors operating in a 5 way voting scheme--similar to the Space Shuttle GPC's--could be used for Criticality 1 applications. Data processing and non-critical applications could use more conventional networks...

Temperature extremes play hell on microelectronics: if the temperature slips below the glass transition temperature of structural components (like pc boards) then they can literally break from thermal stress. This is probably what ultimately did in the Pheonix lander on Mars.
Title: Re: Using commercial off the shelf electronics in space
Post by: Robotbeat on 05/22/2010 06:02 pm
...
Temperature extremes play hell on microelectronics: if the temperature slips below the glass transition temperature of structural components (like pc boards) then they can literally break from thermal stress. This is probably what ultimately did in the Pheonix lander on Mars.

That can be avoided if manufactured using the right materials, can't it? Make sure they have matched coefficients of thermal expansion to limit the thermal stress and select materials which aren't brittle at those temperatures. Test it beforehand. Or, don't even use PC boards for making the critical electronics, use something more flexible with chip-level integration and serial interconnects between chips so that a PC board isn't even required because of the low number of interconnects. I don't know, these are just ideas (many of which will be unworkable in practice). But there are ways to make circuits which can function at these temperatures. And thermal control is difficult and expensive and another source of failure.
Title: Re: Using commercial off the shelf electronics in space
Post by: Downix on 05/22/2010 06:26 pm
It sounds as if off the shelf processors are O.K. as long as thorough error checking and correcting is implemented in the design. Perhaps a block of processors operating in a 5 way voting scheme--similar to the Space Shuttle GPC's--could be used for Criticality 1 applications. Data processing and non-critical applications could use more conventional networks...

Error correcting and checking is not a kind of bolt-on, it needs to be inherent in the full design, top to bottom. 

Here's the list of rad-hardened CPU's on the market taken from wikipedia:
BRE440, Proton200k, Proton 100k, RCA1802, System/4 Pi, RAD6000, RAD750, RH Pentium, RH32, RHPPC, SCS750, ERC32 SPARC, LEON SPARC, RH1750, Coldfire M5208, Mongoose-V

Of these, the Protons and SCS750 do just this kind of "vote-tally" approach, but it needs to be done at the chip level.  Implimenting it on the board level, using commodity PC CPU's would be far more inefficient, and expensive, than to use the rad-hardened designs already in use.
Title: Re: Using commercial off the shelf electronics in space
Post by: Robotbeat on 05/22/2010 06:32 pm
It sounds as if off the shelf processors are O.K. as long as thorough error checking and correcting is implemented in the design. Perhaps a block of processors operating in a 5 way voting scheme--similar to the Space Shuttle GPC's--could be used for Criticality 1 applications. Data processing and non-critical applications could use more conventional networks...

Error correcting and checking is not a kind of bolt-on, it needs to be inherent in the full design, top to bottom. 

Here's the list of rad-hardened CPU's on the market taken from wikipedia:
BRE440, Proton200k, Proton 100k, RCA1802, System/4 Pi, RAD6000, RAD750, RH Pentium, RH32, RHPPC, SCS750, ERC32 SPARC, LEON SPARC, RH1750, Coldfire M5208, Mongoose-V

Of these, the Protons and SCS750 do just this kind of "vote-tally" approach, but it needs to be done at the chip level.  Implimenting it on the board level, using commodity PC CPU's would be far more inefficient, and expensive, than to use the rad-hardened designs already in use.
True, but a board or chip utilizing ECC and vote-tallying could be manufactured using the exact same processes as are used for COTS components whereas rad-hard components use different manufacturing techniques, right?
Title: Re: Using commercial off the shelf electronics in space
Post by: Downix on 05/22/2010 06:44 pm
It sounds as if off the shelf processors are O.K. as long as thorough error checking and correcting is implemented in the design. Perhaps a block of processors operating in a 5 way voting scheme--similar to the Space Shuttle GPC's--could be used for Criticality 1 applications. Data processing and non-critical applications could use more conventional networks...

Error correcting and checking is not a kind of bolt-on, it needs to be inherent in the full design, top to bottom. 

Here's the list of rad-hardened CPU's on the market taken from wikipedia:
BRE440, Proton200k, Proton 100k, RCA1802, System/4 Pi, RAD6000, RAD750, RH Pentium, RH32, RHPPC, SCS750, ERC32 SPARC, LEON SPARC, RH1750, Coldfire M5208, Mongoose-V

Of these, the Protons and SCS750 do just this kind of "vote-tally" approach, but it needs to be done at the chip level.  Implimenting it on the board level, using commodity PC CPU's would be far more inefficient, and expensive, than to use the rad-hardened designs already in use.
True, but a board or chip utilizing ECC and vote-tallying could be manufactured using the exact same processes as are used for COTS components whereas rad-hard components use different manufacturing techniques, right?
You are ignoring the volume issue.  At the volume of manufacturing you're talking, under 100 units per year, the extra complexity will cost you more even with the cheaper components.  The beauty of RAD-hardened systems is that you can use commodity manufacturing techniques, just using harder materials. 

I've worked with systems with volume of under 20 units a year, when discussing such low volume of work, the higher-quality of components always win out over cheaper.
Title: Re: Using commercial off the shelf electronics in space
Post by: A_M_Swallow on 05/22/2010 09:56 pm

Here's the list of rad-hardened CPU's on the market taken from wikipedia:
BRE440, Proton200k, Proton 100k, RCA1802, System/4 Pi, RAD6000, RAD750, RH Pentium, RH32, RHPPC, SCS750, ERC32 SPARC, LEON SPARC, RH1750, Coldfire M5208, Mongoose-V


Plus the SIDECAR microprocessor with its built in analogue-to-digital converter and ability to work at cryogenic temperatures.
Title: Re: Using commercial off the shelf electronics in space
Post by: Robotbeat on 05/23/2010 12:20 am
It sounds as if off the shelf processors are O.K. as long as thorough error checking and correcting is implemented in the design. Perhaps a block of processors operating in a 5 way voting scheme--similar to the Space Shuttle GPC's--could be used for Criticality 1 applications. Data processing and non-critical applications could use more conventional networks...

Error correcting and checking is not a kind of bolt-on, it needs to be inherent in the full design, top to bottom. 

Here's the list of rad-hardened CPU's on the market taken from wikipedia:
BRE440, Proton200k, Proton 100k, RCA1802, System/4 Pi, RAD6000, RAD750, RH Pentium, RH32, RHPPC, SCS750, ERC32 SPARC, LEON SPARC, RH1750, Coldfire M5208, Mongoose-V

Of these, the Protons and SCS750 do just this kind of "vote-tally" approach, but it needs to be done at the chip level.  Implimenting it on the board level, using commodity PC CPU's would be far more inefficient, and expensive, than to use the rad-hardened designs already in use.
True, but a board or chip utilizing ECC and vote-tallying could be manufactured using the exact same processes as are used for COTS components whereas rad-hard components use different manufacturing techniques, right?
You are ignoring the volume issue.  At the volume of manufacturing you're talking, under 100 units per year, the extra complexity will cost you more even with the cheaper components.  The beauty of RAD-hardened systems is that you can use commodity manufacturing techniques, just using harder materials. 

I've worked with systems with volume of under 20 units a year, when discussing such low volume of work, the higher-quality of components always win out over cheaper.
Well, I certainly yield to your greater experience.

I agree that you should use rad-hardened components if they are available and meet your requirements! In that case, rad-hard components would be off-the-shelf. If they don't meet your requirements, then perhaps it would be a good idea to do these more complicated end-to-end ecc (and voting) methods versus spending a bunch of money to enhance the state-of-the-art in rad-hard fabrication methods.
Title: Re: Using commercial off the shelf electronics in space
Post by: Downix on 05/23/2010 01:02 am
It sounds as if off the shelf processors are O.K. as long as thorough error checking and correcting is implemented in the design. Perhaps a block of processors operating in a 5 way voting scheme--similar to the Space Shuttle GPC's--could be used for Criticality 1 applications. Data processing and non-critical applications could use more conventional networks...

Error correcting and checking is not a kind of bolt-on, it needs to be inherent in the full design, top to bottom. 

Here's the list of rad-hardened CPU's on the market taken from wikipedia:
BRE440, Proton200k, Proton 100k, RCA1802, System/4 Pi, RAD6000, RAD750, RH Pentium, RH32, RHPPC, SCS750, ERC32 SPARC, LEON SPARC, RH1750, Coldfire M5208, Mongoose-V

Of these, the Protons and SCS750 do just this kind of "vote-tally" approach, but it needs to be done at the chip level.  Implimenting it on the board level, using commodity PC CPU's would be far more inefficient, and expensive, than to use the rad-hardened designs already in use.
True, but a board or chip utilizing ECC and vote-tallying could be manufactured using the exact same processes as are used for COTS components whereas rad-hard components use different manufacturing techniques, right?
You are ignoring the volume issue.  At the volume of manufacturing you're talking, under 100 units per year, the extra complexity will cost you more even with the cheaper components.  The beauty of RAD-hardened systems is that you can use commodity manufacturing techniques, just using harder materials. 

I've worked with systems with volume of under 20 units a year, when discussing such low volume of work, the higher-quality of components always win out over cheaper.
Well, I certainly yield to your greater experience.

I agree that you should use rad-hardened components if they are available and meet your requirements! In that case, rad-hard components would be off-the-shelf. If they don't meet your requirements, then perhaps it would be a good idea to do these more complicated end-to-end ecc (and voting) methods versus spending a bunch of money to enhance the state-of-the-art in rad-hard fabrication methods.
in those cases it is cheaper to actually roll your own with rad-hardened fpga technology or ASIC.  With modern low-volume chip production, you can custom make a chip to do the job for less than retrofitting the technology onto non-hardened tech in most scenarios i've delt with.

Of course as I say this I am working on a custom rad-hardened chip for a one-off project.
Title: Re: Using commercial off the shelf electronics in space
Post by: simonbp on 05/23/2010 05:08 am
in those cases it is cheaper to actually roll your own with rad-hardened fpga technology or ASIC.

Rad-hard FPGAs seem to have a lot of potential for one-off science missions, but last I heard, they're still pretty low in transistor count. Has this been getting better?
Title: Re: Using commercial off the shelf electronics in space
Post by: A_M_Swallow on 05/23/2010 10:33 am
in those cases it is cheaper to actually roll your own with rad-hardened fpga technology or ASIC.

Rad-hard FPGAs seem to have a lot of potential for one-off science missions, but last I heard, they're still pretty low in transistor count. Has this been getting better?

FPGAs follow Moore's Law.  Due to the high routing and programming overhead (several transistors for each of the user's gates) they are at least a decade behind dedicated chips.

At four launches a year LV are not exactly a mass production item, using FPGA in them helps make them financially viable.

edit: clarify meaning
Title: Re: Using commercial off the shelf electronics in space
Post by: Downix on 05/23/2010 02:21 pm
in those cases it is cheaper to actually roll your own with rad-hardened fpga technology or ASIC.

Rad-hard FPGAs seem to have a lot of potential for one-off science missions, but last I heard, they're still pretty low in transistor count. Has this been getting better?

FPGAs follow Moore's Law.  Due to the high routing and programming overhead (several transistors for each of the user's gates) they are at least a decade behind dedicated chips.

At four launches a year LV are not exactly a mass production item, making using FPGA in them viable.
I wouldn't put them a decade behind, but yes, their gate count is lower due to the redundancies required.  The one I am working with right now is 1.6M gates, the Actel MH1RT.  I prefer Xilinx normally, but this chip had a few features necessary for this app.
Title: Re: Using commercial off the shelf electronics in space
Post by: TyMoore on 05/23/2010 04:17 pm
O.K., I've got a question:

Without getting into too many specific, proprietary, or classified details; how much (in a rough ball park) does it cost to develop a new Rad Hard FPGA processor?
 
Title: Re: Using commercial off the shelf electronics in space
Post by: tnphysics on 05/23/2010 04:24 pm
One situation where it is certain that COTS electronics could be used is when cosmic rays force massive shielding for crew protection.
Title: Re: Using commercial off the shelf electronics in space
Post by: A_M_Swallow on 05/23/2010 09:47 pm
O.K., I've got a question:

Without getting into too many specific, proprietary, or classified details; how much (in a rough ball park) does it cost to develop a new Rad Hard FPGA processor?
 

I suspect an ambiguity in your question that you did not realise.

Do you mean
a. programming an existing FPGA?  (Army or Air Force paid for the hardware design.)  The software is called Intellectual Property (IP).
b. design a circuit board containing an FPGA?  (Same as any other NASA made-to-measure circuit board.)
c. design one from scratch?  (Several hundred million dollars.)
Title: Re: Using commercial off the shelf electronics in space
Post by: Downix on 05/24/2010 01:30 am
O.K., I've got a question:

Without getting into too many specific, proprietary, or classified details; how much (in a rough ball park) does it cost to develop a new Rad Hard FPGA processor?
 
That is akin to asking how much it would cost to make a vehicle.

A vehicle can be a unicycle or a rocket powered monorail, so you need to be more specific.
Title: Re: Using commercial off the shelf electronics in space
Post by: sdsds on 05/24/2010 01:39 am
How many ARM7 cores can dance on the head of a rad-hard FPGA pin?

Edit:  Oops, apparently I meant CortexM1 not ARM7.
http://www.actel.com/products/mpu/CortexM1/
Title: Re: Using commercial off the shelf electronics in space
Post by: Downix on 05/24/2010 01:58 am
How many ARM7 cores can dance on the head of a rad-hard FPGA pin?

Edit:  Oops, apparently I meant CortexM1 not ARM7.
http://www.actel.com/products/mpu/CortexM1/
Approx 12 of them could fit if using a simple round-robin bus system.  (took 15 minutes to try this using the FPGA I'm using atm)
Title: Re: Using commercial off the shelf electronics in space
Post by: josh_simonson on 05/25/2010 11:04 pm
Usually the grades of ICs (commercial, industrial, military) just denote the level of testing that they have undergone, IE, room, temp, extended temp.  Tri-temp testing can cost as much as the die and package, and yield loss usually goes up a couple percent, justifying the higher prices.

There are plenty of COTS rad-hard parts available.  I think COTS usually means 'already available at a reasonable price' as opposed to building a custom widget for your application or paying rapacious prices for it.  Pre-existing products have also usually had time to build a track record of success, whereas something new is more likely to have bugs left in it.

Title: Re: Using commercial off the shelf electronics in space
Post by: Robotbeat on 05/25/2010 11:18 pm
Usually the grades of ICs (commercial, industrial, military) just denote the level of testing that they have undergone, IE, room, temp, extended temp.  Tri-temp testing can cost as much as the die and package, and yield loss usually goes up a couple percent, justifying the higher prices.

There are plenty of COTS rad-hard parts available.  I think COTS usually means 'already available at a reasonable price' as opposed to building a custom widget for your application or paying rapacious prices for it.  Pre-existing products have also usually had time to build a track record of success, whereas something new is more likely to have bugs left in it.


If there are lots of COTS rad-hard parts, they should be used!!! In that case, using non-rad-hard parts is not going to make a lot of sense.

What I'm really interested in is high-temp and low-temp parts so that thermal management requirements become extremely relaxed.
Title: Re: Using commercial off the shelf electronics in space
Post by: Downix on 05/26/2010 02:04 am
Usually the grades of ICs (commercial, industrial, military) just denote the level of testing that they have undergone, IE, room, temp, extended temp.  Tri-temp testing can cost as much as the die and package, and yield loss usually goes up a couple percent, justifying the higher prices.

There are plenty of COTS rad-hard parts available.  I think COTS usually means 'already available at a reasonable price' as opposed to building a custom widget for your application or paying rapacious prices for it.  Pre-existing products have also usually had time to build a track record of success, whereas something new is more likely to have bugs left in it.


If there are lots of COTS rad-hard parts, they should be used!!! In that case, using non-rad-hard parts is not going to make a lot of sense.

What I'm really interested in is high-temp and low-temp parts so that thermal management requirements become extremely relaxed.
They do have them.  I used to love this one m68000 with its distinctive pink case.  It was thermally incredible, I used it for a controller, had to go from -120C to over 500C.  What did it in tho, me spilling a bottle of grape crush.
Title: Re: Using commercial off the shelf electronics in space
Post by: e of pi on 07/17/2010 06:18 am
This thread seems sort of related to a topic I want to ask about, so I'm bumping it rather than creating my own.

I can see why commercially available electronics are unsuited for control, avionics, ect, but are they usable in non-critical areas? Would one be able to fly an iPod or Kindle, or would one need to develop a space-rated alternative? I use mine so often to entertain myself on the ground, it seem like it might be worth it to let astronauts read without taking up pounds of books.

Also, I can get why processors and chipsets have to be shielded, but what about things like LCDs? Do those also require special versions?
Title: Re: Using commercial off the shelf electronics in space
Post by: Jorge on 07/17/2010 06:27 am
This thread seems sort of related to a topic I want to ask about, so I'm bumping it rather than creating my own.

I can see why commercially available electronics are unsuited for control, avionics, ect, but are they usable in non-critical areas? Would one be able to fly an iPod or Kindle, or would one need to develop a space-rated alternative?

http://abcnews.go.com/Technology/Space/story?id=3484420&page=1
http://www.lifeslittlemysteries.com/do-astronauts-take-ipods-to-space-0378/

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Also, I can get why processors and chipsets have to be shielded, but what about things like LCDs? Do those also require special versions?

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Title: Re: Using commercial off the shelf electronics in space
Post by: HIPAR on 07/17/2010 01:00 pm
It's not uncommon to see 20 years of service from a satellite.  We marvel about Voyager still operating 30 years while leaving the solar system.  So they must have done something special selecting electronic components and assembling the black boxes.

I'm happy to get 5 years of service from an earthbound iGadget.

---  CHAS