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Exceptional Seeing At Dome C in Antarctica
Michael Ashley writes "A paper published in Nature
today reports on the exceptional
astronomical seeing conditions at Dome C (Coral link)
in Antarctica. Obtaining the data posed some significant technological
challenges, given that Dome C is uninhabited over winter. The
experiment was controlled by a PC/104
computer system that had to survive temperatures down to -85C, and
supervise the generation of its own electricity using a jet-fuel
powered stirling engine. The computer, running Linux, communicated with
the outside world using an Iridium
phone. The results are also covered in New
Scientist, and the Sydney
Morning Herald. Disclaimer: I'm a co-author."
Looks like making the ozone hole actually accomplished something.
polluters, the other scientists.
Dome C is uninhabited over winter. The experiment was controlled by a PC/104 computer system that had to survive temperatures down to -85C
Now, that's a savage dome!
Free XBox, PS2
The experiment was controlled by a PC/104 computer system that had to survive temperatures down to -85C...
;-)
Wait a sec! =-P Computing equipment *loves* cold, as long as you don't have to worry about condensation. =-P In other words, it's not hard to design a system that can survive -85C. Just do a google search for Liquid nitrogen cooling. Yay for overclocking fiends who make it so you don't even need to mention computing hardware.
btw, there's a tom's hardware link on the results page. Check it out. There's a pic of a CPU mount covered in frost. That *can't* be good! =-P
Look at this photo. It is the author's Kyocera mobile phone with a web page showing the temperatures, memory usage and free disk space. Says battery temperature is -34.5 (is that C or F?)
2bits.com, Inc: Drupal, WordPress, and LAMP performance tuning.
What is "seeing"?
"Seeing" is a term that astronomers use to quantify the turbulence in the atmosphere and how it affects observations from the ground. The stars appear to twinkle because of the effect of this turbulence. In conditions of bad seeing, the stars appear to twinkle vigorously, and the images that you take with your telescope are blurry. In conditions of good seeing, the stars appear more stable, and you can take very sharp images.
You'd think they'd have a cooler word for that...
I would have to say Linux was the ideal choice in this case. Penguins are polar creatures. you know. I wonder how the Microsoft Rainbow-bee-man would've fared under such conditions.
An Indian-American Hindu committed to non-violent thought/speech/action alarmed by the global explosion of radical Islam
Hell, all that they had to do was stick a new Geforce and an Athlon in there and she'd be warm as toast ;)
You create your own reality - Leave mine to me.
The link that the submitter provided to himself doesn't work. The correct link is: Michael Ashley
God I hate those jerks in Dome C!
I work with Diamond Systems PC/104 computers everyday. These systems are robust and the specifications for operating environments are crucial to applications such as these. Their ability to operate in extreme conditions, temperature, vibration, make them fit for such roles.
We've used PC/104 computers (running QNX 4.25) for everythign from Remote power stations, Fuel cells, even UAV's.
Harder.. Better.. Faster.. Stronger
Base camp: So how's it going there?
Dome C: Weh, Biwwy daywed me to stiwck my tung to the waw. Oh, and we'we outta beew....
"All great things are simple & expressed in a single word: freedom, justice, honor, duty, mercy, hope." --Churchill
A PC/104 is just a form factor. And provides standards for things such as environmental operating parameters.
CPU boards usually have an intel clone processor MACH86 or VIA Athena.
So they can run any OS your desktop can.
Harder.. Better.. Faster.. Stronger
But I've applied for a job down there (no reply so out for this year); anyone work down there and have any advice for getting a foot in the door?
Thanks
Vote monkeys into Congress. They are cheaper and more trustworthy.
PC/104 is a form factor and external bus specification, not a CPU type. It could have had any of many embeddable cpus on it.
What's a link?
Just stick .nyud.net:8090 on the end of your domain name (before the /) and it'll grab the content and cache it -- any future queries will return their cache instead of downloading from the original page. The coral links also work like your web browser and update the content when it is out of date.
Their assets were bought, very shortly before their satellites were supposed to have been deorbited. I don't recall who bought them.
tasks(723) drafts(105) languages(484) examples(29106)
One experiment, ICECAM, relied entirely on a 5 kg pack of lithium thionyl chloride batteries. The batteries had to provide power for a year, so minimized the power consumption of the computer. The experiment only needed to take data every two hours, so we built a CMOS oscillator to power-up the computer for 30 seconds every two hours. We used MS-DOS 6.22 for the PC/104 computer since it boots quickly and was able to average 10 frames from the CCD camera and store them to CompactFlash disk.
www.bannination.com Two things float to the top he
http://www.diamondsystems.com/
Heres our PC/104 supplier. We also use a GPIB card from National instruments connected to an Agilent Data logger. Add a Modem Card, Video Card, and two DMM32 Data Aquisition cards. Plus the DMM16 thats already on-board.
The new Athena Processors have video on-board, and faster CPU's.
I believe Intel sued over teh Mach86 processor and they had to switch.
Harder.. Better.. Faster.. Stronger
The hard part would be coming up with a thermal control system that worked at both extremes, a hot summer day and the dead of winter.
Mea navis aericumbens anguillis abundat
so, how far is the secret nazi base from Dome C?
They seem to maintain a good sense of humor despite the cold. What do the authors look like?
Analogies don't equal equalities, they are merely somewhat analogous.
However, I think Site C shows promise for imaging sites that are not in the right plane for Hubble to get a look at, or where the long winter night would allow for extended exposures...
Obligatory plug - please check out my online novel
Stay away from the Norwegian camp....they dug up something in the ice and we've lost contact with them....
Last we heard, one of their sled dogs were running this way with a helecopter following it....
"Leo Fender was in a 'state of grace' when he designed the Stratocaster." -- Paul Reed Smith
So they went bankrupt, and no one would buy the system. It was a textbook case of a colossal business failure, and no one would touch it with a 10-ft pole. The judge hated to rule that a $5 billion infrastructure system burn up in the atmosphere, and luckily, at the last minute, Dan Colussy stepped in with a $25 million bid- less than half a cent on the dollar of initial construction costs, and swept it up.
Then what? The new Iridium Satellite LLC started cleanning up, which it's still doing. Very profitable. It turns out that, while it's impossible to recoup a $5 billion investment on a satellite phone system is impossible, recouping an investment 1/200 that size isn't so bad.
Can anyone tell me how to set my sig on Slashdot?
From the article in case it get's slashdotted:
To operate our experiments over winter, when there was no one at Dome C, we had several problems to address:
1. For hardware reliability, we wanted to remove all moving parts in the computers, i.e., no disk drives, and no fans. So we used a small PC/104 form-factor computer system with solid-state disk drives.
2. We had to generate our own electricity. We took two approaches to this:
1. One experiment, ICECAM, relied entirely on a 5 kg pack of lithium thionyl chloride batteries. The batteries had to provide power for a year, so minimized the power consumption of the computer. The experiment only needed to take data every two hours, so we built a CMOS oscillator to power-up the computer for 30 seconds every two hours. We used MS-DOS 6.22 for the PC/104 computer since it boots quickly and was able to average 10 frames from the CCD camera and store them to CompactFlash disk.
2. For the experiment that obtained the seeing results, the AASTINO, we needed much more power, up to 400W, and we had to operate continuously, so we used stirling engines running on jet fuel. For software reliability we chose Linux, Redhat 9 to be precise. Software and hardware watchdog timers helped to ensure that the system would recover from most failure modes.
3. The ambient temperature at Dome C reaches a low of -85C during winter. Computers, and electronics in general, are not designed to operate at these temperatures. We took two approaches:
1. With ICECAM we had no reserves of power for heating, so we buried the computer in a crypt seven meters below the ice surface, at which point the temperature is stable at the yearly average of -57C. This is still outside the computer's specfication. Fortunately, a test in a low-temperature fridge showed that the computer and solid-state disks worked reliably at these temperatures. ICECAM's camera, a Watec 902-HS, had to remain outside, and tests shows that it was able to operate flawlessly down to at least -80C.
2. With the AASTINO, the stirling engines produced up to 6 kW of waste heat, which we utilized to maintain a comfortable operating temperature of about -10C.
4. Internet connectivity was provided by an Iridium phone, which acts like a 2400 baud modem.
5. The hardware and software had to be carefully designed so that we could recover from most problems remotely. There were no reset buttons to press, and no prompts to "click OK to continue".
The PC/104 computers we used were made by DSP Design, however it in unclear whether the company still exists, since all our attempts (using e-mail and filling out their laborious on-line enquiry form) over the past 6 months to have a simple technical question answered have received no response.
"Leo Fender was in a 'state of grace' when he designed the Stratocaster." -- Paul Reed Smith
What?
I'm apalled that we are polluting Antartica with this radioactive material. What if the phone melts down? This could have devastating consequences for all of Antartica's residents.
paintball
The CPU is called the VIA C3 and the chipset is the VIA Eden. The "Athena" in your post refers to a Diamond Systems product name for the board which uses this CPU, not the name VIA calls their own CPU.
;-)
The "Mach86" you're thinking of is the ZFMicro ZFx86 chip. They are battling National Semiconductor, who produced these CPUs under contract for ZFMicro until ZFMicro was no longer able to pay their bills. Intel is not involved at all.
The other big PC/104 CPU vendors are Transmeta, STMicro (STPC), and AMD (Geode). Recently the Pentium 4-M have been popular for boards which don't need to support extended temperature.
PC/104 rocks for applications like this. Disclaimer: I work for a PC/104 company.
Has to be the most hellish place on the surface of the earth. Dante's Inferno does in fact have the very heart of hell full of darkness and ice, in fact. A more miserable condition than any volcanic brimstone, I'd say.
The US Military.
TANSTAAFI: There Ain't No Such Thing As A Free iPod.
Okay I'm interested in seeing this jet-fuel stirling engine. How well does it work in extreme cold?
For those of you who may not know much about stirling engines, here's some information.
Thanks to the excellent astronomical seeing conditions at Dome C, the Australian scientists started work on their second paper:
"Quasi-Formulaic Investigations into the Space-Time Arrival Calculations of the Zarlanian Horde"
The paper is being rushed to press with journals such as Nature and New Scientist in the hopes of beating the inevitable alien invasion and, thus, enjoying the publicity prior to enslavement and/or annihilation.
"We're pretty excited about this second research opportunity. As soon as we turned on our Dome C equipment and saw the bristling plasma gun turrets from the Zarlanian Horde lead star cruiser, we knew that we had at least 1 more paper opporunity in us," said Rich Godfrey, a previously unmentioned post-doc working on the project.
The research team is taking full advantage of the excellent seeing conditions now, confident that they'll be able to put together a rough draft of the paper shortly before the first scout troops from the Zarlanian Horde arrive.
IronChefMorimoto
No moving parts to freeze? Can you say Hard Drive? Keyboard? Power Switch?
Last but not least. The user. You got to have some damn heavy mittens for -85C.
The article specifically says that they used solid-state hard drives. The system was operated remotely so I imagine no keyboard was used.
In addition, -85C was only the exterior surface temperature. One computer was installed under the surface with an average operating temperature of -57C. Another experiment was warmed by waste heat from the stirling engine.
You'd think they'd have a cooler word for that...
As someone with myopia, I'd suggest laymen's terms like "20/20" or "20/10" or whatever (what would it be? "20/8") to describe the improved perspicacity available in low turbulence air. [BTW, I'm looking into Lasik and wondering just how good my vision could get...]
Or, you could perhaps express it in terms of
The ultimate, of course, is the Hubble, above the atmosphere. But the transportation and maintenance costs of the Hubble are considerably greater than Dome C.
BTW, nice work, nice web page. Thanks for sharing it.
"Provided by the management for your protection."
Can you tell us about the dramatic events of 17 May 2004?
By 17 May 2004 the AASTINO had worked remotely for 100 days in 2004, and then something went wrong...
The WhisperGen engine has a control panel connected to it using an RS-485 bus running on CAT-5 cable. The control panel contains a microprocessor, and the engine expects to communicate with it regularly (at least once a second). When this communication is interrupted, the engine shuts down and reboots its own microprocessor.
Unfortunately, this is what happened on 17 May. - the engine went into a cycle of rebooting every 40 seconds. Once the engine has stopped, we had a ten hour window in which to try to restart it before the 200AH lead-acid batteries would lose too much capacity and become too cold for a restart (which requires 15A at 24V for about 15 minutes).
During this period we worked feverishly to come up with a solution. Our first priority was to shut down all unnecessary power consumption in the AASTINO - we can do this via a series of Dallas one-wire switches which control power to all the subsystems. A call to the engine manufacturer came up with the suggestion that we wiggle the CAT-5 cable connection - we suspect they forgot that we were over 4000 km away from our engine!
The PC/104 computer was also on the RS-485 bus, and we reasoned that by rewriting the Linux device driver (which we had written in the first place, so we knew what we were doing) we could make the computer impersonate the control panel, and convince the engine that it should keep running. Fortunately, we had a snapshot of the communication traffic between the engine and the control panel from earlier testing in the lab with the manufacturer's MSDOS-based software. But with no hardware available to test our code, we had to modify the driver, send patches over the 2400 baud Iridium link, and rmmod/insmod the driver to try to restart the engine.
All the while, the internal temperature of the AASTINO was plumetting towards ambient, at about -60C. We first modified the driver to allow the link traffic to be analysed, and this confirmed the communication problem with the control panel. After several attempts at generating fake packets from the control panel, punctuated by breaks in the Iridium link and agonizing waits for the system to redial (it is dialout only, controlled by a crontab entry), we were unable to prevent the engine from rebooting.
We watched helplessly as the battery temperatures sank below the minimum threshold for engine restart. Over the next 24 hours we received the occasional connection from the AASTINO computer, but that was all. We are now hoping that the solar panels will be able to recharge the batteries suffiently to re-establish communication before the Dome C station opens for the summer.
as others have said, PC/104 is a board form-factor, but it's more than just a size (roughly 4" square). It also dicates the bus. PC/104 uses .1"x2 stackable headers for the ISA 8-bit and another, smaller, .1"x2 header for the ISA 16-bit bus. The two headers are stuck right next to each other. So you can have non-x86 processors on PC/104 but they must be able to read/control the ISA bus. So chips like the StrongArm must include a little glue logic as a bridge.
Additionally, there is PC/104+ which includes the 32-bit PCI bus in a 4x2mm stackable connector on the opposite side as the ISA headers.
There are more features to PC/104 but the size and bus signals are the most important.
This actually happens quite a lot and is one of the reasons large companies farm off risky things to spinoffs. Typically they wait for the spinoff to flounder AFTER it has sucked in huge amount of external capital and then at the last moment buy everything back for pennies on the dollar.
A good portion of certain companies DSL setups was done this way.
--- I do not moderate.
You can view the health reports (temperature etc.) that that telescope sent back via Iridium here.
There may be other tasties too -- I haven't dug too much.
Freezing point of mercury is -38C (which is just about -38F) ... so it would be solid through much of the Antarctic winter.
When I froze mercury in the lab, it made a surface that wasn't optically useful -- lots of tiny bumps.
Also of interest: the century old Mt. Wilson 100-inch telescope used mercury bearings for the polar axis. In the 1970's, mercury pollution worried the operations staff; I don't know what was done about it.
This is off-topic, but in html, a link is made by Free gmail invites!. Clicking on "Free gmail invites" would then take you to http://www.goatse.cx.
The 'a' I believe stands for 'anchor', and 'href' for HTTP Reference. Note the '/' before the 'a' in the closing tag, it's important.
Why a stirling engine and not a thermoelectric
generator? Because ordinary bismuth telluride
modules running as a Seebeck generator are no
more than 3%, and in practice more likely 1.5%
efficient. That's why.
AC