It would be greatly appreciated if you would like to do some research and see what you come up with.
I've been doing some research into using COTS hardware in space.· Most of the papers, etc. are directed at satellites in orbit around Earth.
Space is full of energetic charged particles, from solar and/or galactic sources.· The particles range from electrons and protons up to iron nuclei.· When one of these particles passes through an integrated circuit it can temporarily alter the operation of a circuit and/or cause permanent damage.· There seem to be three major considerations.
First, the particle can change the state of a transitor in the IC.· For example, a particle can·turn·a transistor on or off, which in turn can flip a bit in a register, memory location, etc.· This is called an SEU or Single Event Upset.· An SEU can usually be cleared by reseting the IC.
Second,·a particle can turn on a parasitic·transistor.· This effectively·creates short circuit between Vcc and ground through the IC, which may destroy·the IC.· This is called SEL or Single Event Latch-up.· An SEL can usually be cleared by cycling power to the device.
And third, a particle can also knock atoms out of place in the crystal permanently·damaging the IC.· Over time, the damage accumulates, and eventually the IC stops working.
Susceptability to SEU/SEL transients depends on the design of the device.
From what I've read, you can expect up to several SEU events every day.· Typically, ECC codes and redundancy are used to protect against SEU.· For example, a background process continually calculates an ECC on the system code, and corrects any errors when one is detected.· Redundancy is often achieved by having multiple processes or processors·vote--2-of-3, 3-of-5, etc.· The processes can be run sequentially on a single processor, or in parallel on multiple processors.
An SEL is typically detected by an increase in device current draw.· Excessive current triggers a power shutdown and restart.
A number of papers give a lifetime dose limit of 20 krad for COTS devices such as a PIC or a 80386.··A few mm of aluminum shielding can help with lifetime dose.
Before you decide on what processor you are going to use you should figure out what computational power you will need. Are navigation instructions going to be calculated on the ground or on the space craft? How much video compression is going to be needed? etc... The navigation should not be a lot of processing power but finding you current position may be. Video compression is going to need a lot more power than a prop will give you. To help keep the sheilding weight down you could use some tubular structural members and make circuit boards that fit inside.
As for the pressure, you may well have problems with cameras and radios that are not specifically space/low preassure rated. Just a sugestion if you want to get the launch weight down some and the space craft is sealed you could replace the air with helium. This will save you about 1 kg / cubic meter.
Brian Beckius said...
Bubblehead,
They are about $150,000 a piece , we need 3 of them. I won't lie to you , I love the Prop (and I'm cheap)and have been trying as hard as I can to shield it for the van allen. Nasa has a ton of documents on making normal electronics make it in space .
Brian
The FPGA's are $150K? Ouch.
Are you thinking of using redundant Props, or·redundant cogs on one prop, or a combination of the two?
Look at the Actel RTAX250S chips. They are about $5K each.
RT1280A - Only comes in 172 pin CQFP: $2,100-4,000
RT1425A - Only comes in 132 pin CQFP: $1,390-2,700
RT14100A - Only comes in 256 pin CQFP: $2,850-5,000
Our Electronics Engineer thinks we can get away with one RTAX4000S for Trans lunar vehicle and use none rad hard on the rover . I'm vacume testing a propeller tomarrow to see if it blows up :-)
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Thank's Brian
·"Imagination is more important than knowledge..."··Albert Einstein
The Xilinx parts in the article continually run a CRC check of the configuration bits in the background.· This lets them detect a SEU and reload from the configuration ROM.
The Alctel parts use anti-fuse technology, so they are not in-circuit programmable.
Come see our Rover and Lander in person at the Embedded Systems Conference in April . We will be located in the entry way. If you think you know what the rover looks like , you might be surprised
Wow, it's been a while since I checked up on this, school's consumed my life. It looks like some progress has been made though! at least on the rover design. If I might make a suggestion, the website could probably be more "attention grabbing" if you included some pictures of the current rover, just so people know it's for real. Have you decided on an FPGA as the central brain aboard the rover?
Whelzorn, ·The rover for the ESC looks like a Parallax catalog , even Bean's overlay board found it's way in there. We are most certainly going with rad hard FPGA's for space (sorry).·The rover is "TOP SECERT" untill the ESC , opps.
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Thank's Brian
·"Imagination is more important than knowledge..."··Albert Einstein
Searider,
sorry for taking so long to answer this, the ping sensor will not be making a space trip. I just was seening what I could wreck, The ping sensor did not totally fail .It just change it's measuring ability, I think the vacuum change the cones in the sensor.
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Thank's Brian
·"Imagination is more important than knowledge..."··Albert Einstein
The Ping))) won't work in space because there is nothing to transmit the sound waves. Also, there may be air trapped in different parts of the Ping))) which may be causing problems.
Comments
Space is full of energetic charged particles, from solar and/or galactic sources.· The particles range from electrons and protons up to iron nuclei.· When one of these particles passes through an integrated circuit it can temporarily alter the operation of a circuit and/or cause permanent damage.· There seem to be three major considerations.
First, the particle can change the state of a transitor in the IC.· For example, a particle can·turn·a transistor on or off, which in turn can flip a bit in a register, memory location, etc.· This is called an SEU or Single Event Upset.· An SEU can usually be cleared by reseting the IC.
Second,·a particle can turn on a parasitic·transistor.· This effectively·creates short circuit between Vcc and ground through the IC, which may destroy·the IC.· This is called SEL or Single Event Latch-up.· An SEL can usually be cleared by cycling power to the device.
And third, a particle can also knock atoms out of place in the crystal permanently·damaging the IC.· Over time, the damage accumulates, and eventually the IC stops working.
Susceptability to SEU/SEL transients depends on the design of the device.
From what I've read, you can expect up to several SEU events every day.· Typically, ECC codes and redundancy are used to protect against SEU.· For example, a background process continually calculates an ECC on the system code, and corrects any errors when one is detected.· Redundancy is often achieved by having multiple processes or processors·vote--2-of-3, 3-of-5, etc.· The processes can be run sequentially on a single processor, or in parallel on multiple processors.
An SEL is typically detected by an increase in device current draw.· Excessive current triggers a power shutdown and restart.
A number of papers give a lifetime dose limit of 20 krad for COTS devices such as a PIC or a 80386.··A few mm of aluminum shielding can help with lifetime dose.
As for the pressure, you may well have problems with cameras and radios that are not specifically space/low preassure rated. Just a sugestion if you want to get the launch weight down some and the space craft is sealed you could replace the air with helium. This will save you about 1 kg / cubic meter.
http://nepp.nasa.gov/docuploads/3C8F70A3-2452-4336-B70CDF1C1B08F805/JPL%20Rad-Tolerant%20FPGAs%20for%20Space%20Applications.pdf
Bean
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www.iElectronicDesigns.com
Post Edited (Bean (Hitt Consulting)) : 2/13/2008 3:58:47 PM GMT
Thats a cool article, here is the pricing I received from Actel.
RTAX250S/SL - Either 208: $4,380-11,000
RTAX250S/SL - 352 CQFP: $5,010-12,570
RTAX1000S/SL - 352 CQFP: $8,780-22,660
RTAX2000S/SL - 352 CQFP: $10,980-34-860
RTAX4000S - 352 CQFP: $57,100-159,840
RTSX32SU - 256 CQFP: $3,800-7,400
RTSX72SU - 256 CQFP: $5,400-10,400
RT1280A - Only comes in 172 pin CQFP: $2,100-4,000
RT1425A - Only comes in 132 pin CQFP: $1,390-2,700
RT14100A - Only comes in 256 pin CQFP: $2,850-5,000
Our Electronics Engineer thinks we can get away with one RTAX4000S for Trans lunar vehicle and use none rad hard on the rover . I'm vacume testing a propeller tomarrow to see if it blows up :-)
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Thank's Brian
·"Imagination is more important than knowledge..." ·· Albert Einstein
http://www.diycalculator.com/subroutines.shtml· My favorite website
The Alctel parts use anti-fuse technology, so they are not in-circuit programmable.
http://www.cmp-egevents.com/web/esv/exposition/opportunities
edit: Booth #3042
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Thank's Brian
·"Imagination is more important than knowledge..." ·· Albert Einstein
http://www.diycalculator.com/subroutines.shtml· My favorite website
Post Edited (Brian Beckius) : 3/1/2008 10:57:57 PM GMT
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Thank's Brian
·"Imagination is more important than knowledge..." ·· Albert Einstein
www.PropelX.com
Post Edited (Brian Beckius) : 3/1/2008 11:05:20 PM GMT
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Thank's Brian
·"Imagination is more important than knowledge..." ·· Albert Einstein
www.PropelX.com
Cool logo - Super cool rover. The wheels alone are a masterpiece!
"To the moon Beckius!"
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Whit+
"We keep moving forward, opening new doors, and doing new things, because we're curious and curiosity keeps leading us down new paths." - Walt Disney
Post Edited (Whit) : 3/3/2008 3:07:14 AM GMT
www.propelx.com
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Thank's Brian
·"Imagination is more important than knowledge..." ·· Albert Einstein
www.PropelX.com
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Whit+
"We keep moving forward, opening new doors, and doing new things, because we're curious and curiosity keeps leading us down new paths." - Walt Disney
·The rover for the ESC looks like a Parallax catalog , even Bean's overlay board found it's way in there. We are most certainly going with rad hard FPGA's for space (sorry).·The rover is "TOP SECERT" untill the ESC , opps.
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Thank's Brian
·"Imagination is more important than knowledge..." ·· Albert Einstein
www.PropelX.com
Post Edited (Brian Beckius) : 3/17/2008 2:11:49 AM GMT
http://www.youtube.com/watch?v=K1GOGdNdQNc
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Thank's Brian
·"Imagination is more important than knowledge..." ·· Albert Einstein
www.PropelX.com
http://www.youtube.com/watch?v=n0PcwZucVs0
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Thank's Brian
·"Imagination is more important than knowledge..." ·· Albert Einstein
www.PropelX.com
Edit: snowmobile pic is for Jay Leno : -)
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Thank's Brian
·"Imagination is more important than knowledge..." ·· Albert Einstein
www.PropelX.com
Post Edited (Brian Beckius) : 3/28/2008 4:15:05 AM GMT
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Whit+
"We keep moving forward, opening new doors, and doing new things, because we're curious and curiosity keeps leading us down new paths." - Walt Disney
Costly rover test session ,rover suffered 4 gear box failures .New motors arrived today ,very,very stout but weigh less than first ones.
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Thank's Brian
·"Imagination is more important than knowledge..." ·· Albert Einstein
www.PropelX.com
Post Edited (Brian Beckius) : 3/26/2008 4:14:22 AM GMT
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Thank's Brian
·"Imagination is more important than knowledge..." ·· Albert Einstein
www.PropelX.com
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Whit+
"We keep moving forward, opening new doors, and doing new things, because we're curious and curiosity keeps leading us down new paths." - Walt Disney
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www.fd.com.my
www.mercedes.com.my
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Max Wooden
Reedley, California
·We do have a weight budget . I can not really talk about it.
·Ps , CA will never be the same :- )
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Thank's Brian
·"Imagination is more important than knowledge..." ·· Albert Einstein
www.PropelX.com
I understand. Great early video of the Rover on the ESC website!
Hope the next couple of days go well for the team.
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Whit+
"We keep moving forward, opening new doors, and doing new things, because we're curious and curiosity keeps leading us down new paths." - Walt Disney
New rover video :- )
http://www.youtube.com/watch?v=U4u00B38Ngk
SV-NBC video , click on play botton on mechanical giraff.
http://www.nbc11.com/news/15893752/detail.html#
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Thank's Brian
·"Imagination is more important than knowledge..." ·· Albert Einstein
www.PropelX.com
Post Edited (Brian Beckius) : 4/21/2008 2:54:57 AM GMT
2 Propeller’s under 26 lbs of vacuum for 6 hours, NO failures :- )
Edit: 26 in hg
edit: Ping sensor did not fair so well.
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Thank's Brian
·"Imagination is more important than knowledge..." ·· Albert Einstein
www.PropelX.com
Post Edited (Brian Beckius) : 4/25/2008 3:18:08 AM GMT
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Searider
sorry for taking so long to answer this, the ping sensor will not be making a space trip. I just was seening what I could wreck, The ping sensor did not totally fail .It just change it's measuring ability, I think the vacuum change the cones in the sensor.
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Thank's Brian
·"Imagination is more important than knowledge..." ·· Albert Einstein
www.PropelX.com
Additionally, the Ping))) doesn't have temperature compensation so I imagine it would become very unreliable in space.
Ken Gracey