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Mars 2053 [Spirit rover sends back data stating that it is in the year 2053!]
Astrobiology Magazine ^
| 1.26.04
| Astrobiology Magazine
Posted on 01/29/2004 1:59:28 PM PST by ambrose
Mars 2053 Date Monday, January 26 @ 23:35:33 Topic Mars Life
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After 18 martian days of a near-perfect mission, a Spirit rover message came to Earth with corrupted data. When decoded, this tiny clue showed that the mobile laboratory's software considered that it was the year 2053. Based on a hunch from the software architect, the problem may be a byproduct of the mission's early success. The rover captured so much data and may have stored too many files to manage.
Mars 2053
Our Truths are Temporaryby Astrobiology Magazine staffwriter
Imagine getting a message from Mars, saying the spacecraft is communicating from the future. The year, 2053, to be precise.
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Spirit's Empty Nest. The base station that was home to the rover for 12 martian days is now considered spacecraft debris, since the rover's wheels got dirty. Credit:NASA/JPL |
For the Spirit rover, that science fiction became science fact on the eighteenth martian morning, in the year 2004.
But unlike Rip Van Winkle, who awakened from a deep sleep to find himself in the distant future, the Spirit rover refused to go to sleep at all. When not sleeping, the rover drains its solar arrays at night--a condition that threatened to put the mobile laboratory into a low-power shutdown.
Rob Manning, the Development Engineer for the risky Entry, Descent and Landing phase of both rover missions, put the problem in present perspective. During the jubilation of Opportunity's successful touchdown, Manning remarked that as engineers have learned from the Sol 18 glitch in Spirit's otherwise perfect profile, "our truths are temporary".
This same aphorism was repeated the next day by both Pete Theisinger, project manager, when describing Spirit's progress made overnight and Steve Squyres, principal investigator, when describing an early hypothesis about the Opportunity site.
A similar philosophical approach to such explorer's challenges was adopted by a Mars Global Surveyor image team member, Bill Hartmann, when describing what was a difficult sky-color calibration on the Viking mission: "That amusing mistake with the first Viking 1 pictures -- releasing an image with a blue sky -- really was an example of what we didn't know and why we went there and what we were learning!" Even the color of the martian sky may be a temporary truth.
A timeline of the problems on Spirit begins on Wednesday, Sol 18. "We believe in testing like you fly," said Jennifer Trosper, mission manager. "Our longest operational readiness test was nine days. But on Sol 18, a problem may have arisen with the file management system, because of the number of files on the spacecraft".
"There are not alot of scenarios that put us in [the year] 2053 on Mars," said Trosper about the corrupted file system onboard.
The picture for Spirit proved particularly cloudy on Sol 21, three martian days later, when the spacecraft refused to answer a beep. Fortunately later that day, Spirit detected its own fault status with enough wits to confirm that it had tried unsuccessfully to reset or reboot its operating system 77 times! It was at this point that the team conjectured Spirit was having a reset problem with its operating system, and modified their early diagnosis that a high-gain antenna or solar flare may have caused their loss of spacecraft command and control. Armed with this hypothesis, however, they still couldn't put the rover to sleep.
"Based on a hunch from the rover's lead software architect," Trosper said, the JPL mission support area sent Spirit a "hardware command, which removes flash from the operating system initialization." After ending the continuous reset loop, the rover became commandable. "It was behaving like the software we'd always known." With the risk retired of the rover not sleeping, actual software debugging could begin in earnest without risking further damage to power and thermal controls.
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Mars Exploration Rover with main instruments indicated by location on the unfurled instrument after stand-up. Credit:NASA/JPL |
These problem files are stored in flash memory, similar to what one might use to store digital camera images before transfers. The panoramic camera however generates files that, according the the pancam's lead scientist, Jim Bell, are "not trivial using a 20 Megapixel camera in a harsh environment...That represents three and half years of fabrication preceded by four to five years of design."
Trosper suggested that one workaround being considered is to delete "about 100" files from flash memory, a memory cleanup beginning with old files from the cruise part of the mission. If flash memory file management turns out to be the root cause, the troubleshooting team may be able to run the rest of the mission using random access memory (RAM). "Without flash memory, there is more space in RAM," said Trosper, "because alot of RAM is being used to manage the files stored in flash. When we don't mount flash, data can be written to RAM, which doesn't worry or know about whatever is happening in flash."
"A script has been loaded to get a stack trace during initialization," said Trosper, "and validate our hunch." The team is currently loading many files onto the rover testbed in Pasadena, in an effort to probe the limits and explore workarounds in as close a case as Earth simulation can allow. Overloading a test rover with too many files may eventually push the design to what Spirit discovered on Sol 18.
For Opportunity, one lesson learned from the Spirit experience may be to delete files often, particularly those accumulated during the spacecraft's cruise phase from Earth to Mars. "We don't want to reach Sol 18 on Opportunity, without some recommendations," said Trosper.
"We learned alot from the end of [the 1997] Pathfinder" mission, said Trosper. Watching that rover go well beyond its expected lifetime, a slow death of sorts under harsh thermal conditions with little reserve power, showed what problems are likely to jeopardize a mission. "Spirit stayed up two nights without a low-power anomaly. It didn't get too hot or cold. That speaks to the robustness of the design, that Spirit can recover." But when communication was a system in jeopardy, the outlook moved from critical to serious to its present status in recovery. "Pathfinder taught us how to extend a mission."
When Steve Squyres was asked if the stand-down on Spirit science would jeopardize their task to 'follow the water' history of Mars, he thought the rover may exceed its expected surface lifetime eventually. "The 90 day operation on Mars is when the warranty expires. The wheels don't fall off at 91 days. Thermal and power systems are well above their margins, so we may go significantly more than 90. We planned for one out of every three Sols being blown away with non-science" or engineering-related maintanence. "Instead we went 17 for 17 with daily science" up until Sol 18. "So if we had to stand-down for thirty days, we could still reach the warranty limit with 60 days of science on Mars".
Theisinger concluded that the temporary truth for Spirit function will evolve towards some kind of "rules of the road"--a command sequence that enables the rover to ignore software faults that are telling it contradictory truths.
Related Web PagesWater Signs Microscopic Imager Gusev Crater Pancam- Surveying the Martian Scene Mössbauer spectrometer Alpha Proton X-ray Spectrometer Mars Rover: The Owner's Manual Reverse Robotic Origami Mars Life
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This article comes from Astrobiology Magazine http://www.astrobio.net/news/
The URL for this story is: http://www.astrobio.net/news/modules.php?op=modload&name=News&file=article&sid=804 |
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TOPICS: Extended News; Foreign Affairs
KEYWORDS: mars; martians; timetravel
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To: brooklin
I wonder if they brought it back because K-9 was getting fresh with it. ;-)
Would spirit have fit through the door on the tardis?
Stuck in 'police box' mode, I don't know.
To: ambrose
fascinating
22
posted on
01/29/2004 3:50:04 PM PST
by
dware
(ingredients include mechanically separated chicken and beef parts)
To: ambrose
So what happened did it over-write its bios with a buffer overflow??
To: ambrose
Yea, my watch says 2053 too. Spirit (or Spirit & Opportunity) must have stumbled onto a tear in the space/time continuum. Feels just like 2004, though. Still trying to party like it's 1999, although I'm a bit behind schedule.
To: diamondjoe
ROFLMAO!
To: Truth666
still untouched by global warming
You are not keeping up on the news are you?
Red Planet Warming;
"It might seem like the weather's getting warmer here on Earth, but Mars appears to have an even bigger global warming problem."
Seems that when the Sun warms up everyplace does.
To: Publius
...or it encountered a time warp.
This is actually brilliant PR.
At one stroke, NASA gets the Star Trek crowd and the Rocky Horror Picture Show fans.
Now I won't be suprised if I see that Sean What's-His-Name of NASA decked out in
Frank-n-furter garb and leading all those NASA/JPL braniacs at Pasadena
in a chorus of "Let's do the time warp again!"
27
posted on
01/29/2004 5:52:38 PM PST
by
VOA
To: Howlin; Ed_NYC; MonroeDNA; widgysoft; Springman; Timesink; dubyaismypresident; Grani; coug97; ...
Exterminate! Exterminate!Just damn.
If you want on the list, FReepmail me. This IS a high-volume PING list...
28
posted on
01/29/2004 6:04:52 PM PST
by
mhking
To: ambrose
29
posted on
01/29/2004 6:06:48 PM PST
by
cyborg
To: ambrose
30
posted on
01/29/2004 6:13:48 PM PST
by
LRS
To: _Jim
I remember, many many moons ago, running into a somewhat similar problem (bus contention, priorities). My code was slamming bits to the graphics accelerator using IO instructions, effectively flooding the PCI/Vesa bus. Meanwhile, the floppy driver was busy formatting a disk. The floppy hardware on a PC is extremely primitive and has tight timing for interrupt servicing - especially during a format. Anyway, my code would hog the bus long enough so that the floppy driver didn't get around to servicing the format interrupt in time. The result: error formatting floppy disk even though there was no real hardware problem.
The floppy driver guy raked me over the coals for hogging the bus. My reply was that I wasn't about to slow down the font code, which is used millions of times a day, in order to handle the rare case of floppy formatting. Eventually, I got him to do a better retry algorithm.
Anyway, IMHO, most of the bugs in software are because of performance pressure. In order to make code fast you make design decisions that end up biting you (deferring too many operations, don't do full parameter validation, hog the bus, etc.). This is especially bad in graphics software/hardware. How many bad video drivers are out there, 100%? Every driver I've ever used has display corruption to some degree. Yet, if you go to review websites all you read about is that one piece of hardware is 2% faster than a competitor. Display corruption is occasionally noted but basically passed over.
31
posted on
01/29/2004 7:28:44 PM PST
by
mikegi
To: ambrose
bttt
32
posted on
01/29/2004 8:46:06 PM PST
by
gcruse
(http://gcruse.typepad.com/)
To: Petronski
It's 2053 on Mars? Wow, I wonder how the flag at the Apollo-11 landing site is holding up, it's almost 84 years old.According to Sheila Jackson Lee, it's holding up fine.
33
posted on
01/29/2004 8:57:37 PM PST
by
dougherty
(I saw the angel in the marble and carved until I set him free.
-Michelangelo)
To: cyborg
Is it just me, or did a great premise become yet another lousy movie. I could not watch it out of sheer boredom.
And I usually enjoy B movies.
Geez, I remember ramdisks under dos. They would fill up without crashing the system.
Maybe they should have used the archive bit for "xmited successfully - okay to delete".
To: Calvin Locke
Hehe... I can hear the pen scratching away for the movie treatment... Event Horizon was one creepy movie. God I wish Art Bell was on during the week so I can hear him speculate whether Spirit is in this dimension.
35
posted on
01/29/2004 9:18:59 PM PST
by
cyborg
To: Salamander
Great Pic!
36
posted on
01/30/2004 6:00:02 AM PST
by
SquirrelKing
(a href="http://www.michaelmoore.com" target="_blank">miserable failure)
To: ambrose
Well, he is called Rover, so it stands to reason that his timescale is calibrated in Dog years. This is Sirius.
To: Salamander
I like it! Thanks
38
posted on
01/30/2004 6:43:28 AM PST
by
Professional Engineer
(NASA bumper sticker: My other Rover is a FORD too.)
To: Professional Engineer
:)
To: SquirrelKing
Thank you...:)
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