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The 100-Million Mile Network
mykepredko writes "eWeek has an article on the network and radio topography of the two Mars rovers and how they communicate with satellites in Mars' orbit as well as the Earth. The article ends by giving four rules for maintaining a space network, a) Automate processes, b) Bulletproof your gear, c) Be persistent and d) Simulate potential problems, which are probably good rules for any network."
NEVER! BUT NEVER! Install Windows unless you want openly relayed spam from space!
Even if I knew that tomorrow the world would go to pieces, I would still plant my apple tree. -Martin Luther
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b) Bulletproof your gear
I'd think micrometeorite-proofing my gear would be more useful.
funny munging
I didn't RTFA, but it sounds like they're just running ethernet cables (or OC12 or whatever) to Mars. Didn't they stop to think that the planets move? Ridiculous! The ESA and NASA really need to get their acts together.
True story.
Replace 'spacecraft' with 'child'...
"The most difficult thing is to know how to talk to the spacecraft when you're getting no response from it," says Douglas J. Mudgway
Join moola.com, play games to earn money.
MWAN - Multi-World Area Network i guess....
b) Bulletproof your gear
For what? Those pesky Martians?
If only the Beagle 2 people had seen this article beforehand.
Persistantly empty clip after clip of rounds from an automatic rifle at your prototype. If it survives, begin production.
...Starfleet can communicate over extremely long distances with out an lag. Apparently, the lag is encountered occasionally when it is necessary to fill plot holes. But otherwise, not at all. The laws governing subspace communication elude me.
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e) submit your URL to /. and start up the benchmark server.
They are just perpetuating the myth that the rovers are really on mars. Everyone knows that it is all done in a Hollywood sound stage. The problem a few weeks ago with the the first rover was traced to someone using the mircowave oven and causing interference with their radios on the set. Anyone want another burrito heated up?
Here I thought they just had a reeeeeeally long cable.
Slashdot sucks
and I can't even get a cable/DSL modem yet!!! new slogan... Earth First, We'll Network the Other Planets Later
"The orbiter then uses its more-powerful antenna to send as many as one million bits of data per second back to Earth. While fairly fast for an attenuated radio connection, that's only about a tenth of the speed of a cable-modem connection for the average home-computer user." Unless they are using Commcast, such high bandwidth usage would violate the vauge acceptable use policy, putting the rover in the top 10% of Mars bandwidth users. Ah, maybe that's what happened. NASA ignored the first warning letter, and got cut off.
It appears that one of the direct results of NASA research will be better networks, both on Earth and elsewhere. Just about anything and everything applied to a deep space network can be applied right here at home. I'm also wondering about wireless network tech resulting from all of this.
The article seemed to fail to point out that these things are using OLD technologies... UFH? Jesus, that's been around for ages. Their basic data transmission seems to be just that... basic. . No bells and whistles. No wireless garbage. Not super fast. I see failures when people use cutting edge stuff. My business computers need to be ROCK SOLID. I don't use wireless. My hardware uses serial and parallel ports instead of USB/firewire/whatever. I use W2K as a platform. I use an external modem through a parallel port for important credit card stuff.
I use what has worked reliably for years and years. I'm not gonna risk my business being down because of some stupid gee-whiz technology that's only been out for a few years. Engineers that build solid, reliable, critical systems (financial, medical, avionics) do the same thing.
The orbiter then uses its more-powerful antenna to send as many as one million bits of data per second back to Earth. While fairly fast for an attenuated radio connection, that's only about a tenth of the speed of a cable-modem connection for the average home-computer user.
... did I miss something? My DSL line peaks at 1.5Mb on a good day. Where can I get a ten-megabit cable modem? And "average home-computer users" have them? I thought average home-computer users were still using 56K modems.
Uhhh
Oh, I get it now. According to this calendar, it's 2008. Damn, that was a nice nap. Need to catch up on the last four years of news. Hope something horrible happened to Microsoft.
What? SCOSoft? Oh, shit.
ZFS: because love is never having to say fsck
Considering how enthralled we are about seeing Mars up close and personal now, I'd think this would be a Really Good Idea.
This sig no verb.
I think that Spirit should be considered a big win for NASA. They patched a software bug on a platform that had corrupted flash, basically having to reinstall portions of operating code.
Something about the repairing a 747 while it is in flight analogy.
It may not be as dramatic as the rescue of Apollo 13, but they should be commended for well though out design principles, instead of just taking cheap shots at them when something fails as most people are wont to do.
Apparently, they run VxWorks
Wait a minute. I got it. You could play with your magic nose goblins.
Just wait till spam starts to relay from Mars
Them crafty spamers have spoofed every other network. Just wait till the IP trace routes through Mars.
Martian Viagra pills 25% off
Order now and save on shipping.
c) Be persistent
Do they really need that in the handbook? What did they use to do when they had a problem?
Engineer 1: "Shit Fred, I can't ping it."
Engineer 2: "Oh well, cest la vie. You wanna grab a beer?"
They're using RAD6000 processors which are modified chips used to run old Macs from the early nineties. Each rover has 384 megabytes of RAM, the extra 256 is for images.
The operating system is VxWorks.
Something tells me that the communications aren't encrypted or authenticated.
Your last paragraph should tell you otherwise.
If someone did manage to DoS or somehow log in to the rover and damage the software it could be the most damaging single-target attack (dollar wise - at over $400 million per rover) of all time. I think that's kind of scary.
More info on communications between Mars/Earth and the DSN (Deep Space Network):
- NASA's MER2004 Communications with Earth Overview
- DSN (Deep Space Network) Main Page
- Wikipedia entry on Deep Space Network
--
For news, status, updates, scientific info, images, video, and more, check out:
(AXCH) 2004 Mars Exploration Rovers - News, Status, Technical Info, History.
Bulletproofing your gear is extremely important. The old IBM XT's were up for that, I took one camping once (just the case and CPU) and we set up it and took shot's at it with .22's. Only 1 shot pierced the 1/4 inch thick steel case, and the only actual damage done was a really noisy fan afterwards.
Think martians have more firepower then .22's, though? d'oh!
Mod +5 Drunk
Not to nitpick but,
<nitpick>
The RAD6000 is a radiation hardened RS/6000 PowerPC chip from IBM. A similar chip was used in Apple Macintoshes, but Apple is not the source of the RAD6000 chip.
</nitpick>
I love my Mac as much as everybody else, but it's just not the case that the RAD6000 is a 'mac' chip. It's an IBM chip, a cousin of those used in macs.
That's not maximum warp. I clearly remember Riker giving the order to go to Warp 13 in that episode when Picard was all old and shit and Geordi had his eyes fixed. I think it was called "The Ship That Couldn't Slow Down."
Support the First Amendment. Read at -1
To hell with bulletproofing, that's only useful on Earth. If they make it ASTEROID-PROOF... now THAT would be impressive.
Deep Space Network website:
http://deepspace.jpl.nasa.gov/dsn/
Not very detailed but a nice overview of the setup.
or did they not talk much about space networking? I want to know what protocols they use, how data is buffered on the sats orbiting mars, etc. Where are the technical details?
Error: Id10t detected
Clearly, Mars Channel 25 caused the original Spirit communication breakdown by interrupting it with an episode of Days of our red, dreary lives.
That was a different warp scale, apparantly they changed it sometime after the TNG timeline, to account for faster ships. The old warp scale was some kind of logarithmic scale, with warp 10 as infinite speed. This led to faster ships reaching warp 9.9, 9.99, 9.99999, etc. The new scale was used to stretch out the range a bit.
God i feel like a geek.
Rules for maintining a space network:
a) Automate processes
b) Bulletproof your gear
c) Be persistent
d) Simulate potential problems
e) Don't crash into the damn planet
f) Don't confuse feet and meters
g) Don't "misplace" quarter-billion dollar probes
h) Don't let probes explode because you left out the fuel-check valve
i) Don't press the big red shiny button (Narf!)
j) ???
k) PROFIT!
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- - You can't take something off the Internet! That's like trying to take pee out of a swimming pool.
Just think about how many cans of pringles those guys at NASA had to eat to get 100,000,000 miles out of their link.
I was wondering if NASA has actually disclosed the details of what they believe was the malfunction of the Spirit rover?
As someone who has developed backup and recovery systems for embedded systems using vxWorks and flash memory I have my own theory of what could have gone wrong.
There is an intermitant problem that can occur when using a combination of vxWorks 5.5, dosFs2 and flash memory.
The problem goes like this : When file A is written to flash memory formatted with a FAT16 table the FAT table is updated to say which disk clusters are occupied by file A, and hence no longer available as free disk space. So when file B starts writing to the hard disk it checks what clusters are free to write to.
Now a timing problem can occur when a process writing files in a sequential order closes the file handle to A and opens a new handle for B and starts writting to B. The problem exists because the clusters used by A have not been updated to the FAT in time before file B starts writing. The consequence of this is that some of the data belonging to A is overwritten hence breaking the chain. Once this has occurred the FAT and file A cluster chain are corrupt. Once this corruption occurs more corruptions occur with rate of corruption errors growing expotentially until the flash memory can longer function for disk I/O.
Now as the problem only occurs rarely it is very hard to reproduce in a lab. Also as the rate of corruption is expotential then catching the orginal culprit is even harder. I have spent weeks just trying to catch and diagnosis the problem before eventually catching it.
Unfortunately once the flash had started to become corrupt the only way to correct it was to reformat the flash memory.
As for solving the problem, before closing the handle of a file that had been written to flash memory was done an ioctl call would be made to the dosFs2 library to write the size of the file to the disk. Once this solution was is in place the problem never raised its head again.