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6.7 Meter Telescope To Capture 30 Terabytes Per Night
Lumenary7204 writes "The Register has a story about the Large Synoptic Survey Telescope, a project to build a 6.7 meter effective-diameter ground-based telescope that will be used to map some of the faintest objects in the night sky. Jeff Kantor, the LSST Project Data Manager, indicates that the telescope should be in operation by 2016, will generate around 30 terabytes of data per night, and will 'open a movie-like window on objects that change or move on rapid timescales: exploding supernovae, potentially hazardous near-Earth asteroids, and distant Kuiper Belt Objects.' The end result will be a 150 petabyte database containing one of the most detailed surveys of the universe ever undertaken by a ground-based telescope. The telescope's 8.4 meter mirror blank was recently unveiled at the University of Arizona's Mirror Lab in Tucson."
... launch it into space? We need to replace the Hubble.
It not being in space might have something to do with the amount of data it would have to transmit and the speed limitations... Besides, you can't replace Hubble, its impossible to exactly replicate that many technical difficulties...
When I worked at the CFHT a few decades ago, they had a bunch of "data reduction" algorithms they ran on each night's run that reduced the amount of data they needed to store by at least a factor of 10.
When information is power, privacy is freedom.
What does this story add that the following LSST stories didn't?
http://science.slashdot.org/article.pl?sid=07/01/10/0111227
http://science.slashdot.org/article.pl?sid=08/04/22/0116259
http://science.slashdot.org/article.pl?sid=08/09/02/2346240
30 Terabytes, consisting mainly of #000000.
This project was presented at the MySQL Users Conference 2008 in a dedicated talk and a keynote.
The storage will be organized in clusters based on MySQL databases.
Astronomy, Petabytes, and MySQL
The Science and Fiction of Petascale Analytics
30 TB per night sounds like a lot, but 1.5 TB drives are about AUD 350 each, retail. By 2016, I'd expect vendors to have released at least a 10 TB hard drive at that price point, and I wouldn't be surprised if we're using 30 to 50 TB drives.
So it all boils down to about $1000 per night of operation, or about $350K per year. Not exactly expensive for a science project. A single mars mission costs about $300M, but this telescope would generate more discoveries. That's not even considering that storage costs would continue to drop over the lifetime of the telescope, so the eventual total cost may be less than $100K per year. That's the salary of just one person!
we might be reaching the physical (or practical) limit of data density for hard disk platters, but we'll probably just move to new technologies. it's very unlikely that magnetic disk drives are the pinnacle of data storage technology. there are probably more efficient storage mediums in the works already.
i don't know what can currently match magnetic disks drives in terms of IO speed, but holographic storage shows a lot of promise. in theory, holographic storage can read/write millions of bits of data in parallel rather than one bit at a time as with conventional optical or magnetic media. the theoretical limit of holographic storage density is tens of Tb (terabits) per cm^3. and already commercial industries have achieved 500 Gb per square-inch (about 5x the density achievable on magnetic hard disks).
holograms also have some very interesting properties that may or may not transfer to digital data storage. for instance, if you record a hologram of a 3D object onto a photographic plate, you can in essence reproduce a 3D image of the whole object with any piece of that photographic plate. Wikipedia explains this phenomenon thusly:
since holographic data storage also uses optical interference patterns to store information, i guess it's possible that this phenomenon would also transfer over, though it might not since we're talking about digital data in this case rather than analog data. with analog data, losing a part of the interference pattern simply reduces the resolution of the holographic image, though it remains whole. with digital data, that loss of resolution could simply corrupt the data. but i don't know, i'm not a holography expert.
But sometimes it contains nice #ffffff pixels! But I agree, it's very compressible anyway. RLE compression? ;)
So consider it a beta... I imagine that the reason its still on the ground is a lack of funding to get it up there... its far cheaper to set it up on the ground, and extremely cheap to fix and maintain in comparison, plus when its on the ground you (they) have essential complete control over it, when its in space you have to let other people play with your toy, or be sacrificed to debris...
I highly doubt this is the be-all, end-all of this telescope (or at least the work the people involved are/will do) or any other telescope... if it proves effective, it'l be up-scaled (or down-scaled and perfected more) and thrown up in space unless something better comes along in the meantime.
Presuming that the phenomenen reported by Lysergic Acid holds true and does, in fact, apply to holographic data storage:
> if you record a hologram of a 3D object onto a photographic
> plate, you can in essence reproduce a 3D image of the whole
> object with any piece of that photographic plate.
Would this mean the end of "bad sectors" as we know it?
It would seem to me that if a part of the holographic storage device degrades in some way, one could simply read the data from any number of different "windows" (as described in the Wikipedia article) and get the proper result.
In fact, this could be used as a form of default error detection and correction: If, for example, the hologram is stored in a sphere, one could read the hologram from coordinates (x, y, z, lat1, lon1) and (x, y, z, lat2, lon2) -- where latitude and longitude combine with x, y, and z to create a vector from the surface of the sphere to coordinates x, y, and z within the sphere -- and see if one gets the same result. If one does not, the sphere is simply rotated so the target coordinate address is read from a different relative point on the surface. Since the surface of the sphere is large compared to the block of data stored at x, y, and z, there is bound to be a set of vectors which will result in identical blocks of data (unless the complete and total degredation of the sphere has taken place).
... How many furlongs per meter? How many fortnights per night? I can't understand these eeeevil foreign units.
SSC
What hard drives do they use? Gosh, how do their computers look? I mean if 1TB or 1.5TB hard drives really are the largest drives out there, then they would have to get like 150,000 hard drives!
Quantum do 112 drives in a 4U rack, which with controllers and raid, and assuming they've moved to 1.5TB drives since I last saw it (when it was 1TB) give you about a petabyte in a rack -- maid to reduce power consumption.
Pretty cheap too, under a million per rack.
From TFA title: (emphasis added)
<nit>
That's 6.7 Meter effective diameter Telescope. The primary mirror has a diameter of 8.4m but the tertiary mirror (5.2m diameter) sits right in the middle of the primary, so its area needs to be subtracted from the primary. The area of the primary is pi*(8.4/2)^2 which is 55.4m^2 and the area of the tertiary is pi*(5.2/2)^2 which is 21.2m^2; a single mirror of that area would have a diameter of about 6.7m.
</nit>
<grin>
Hey!! I thought information wanted to be free! And here they plan to go off and capture 30 TERAbytes? Each night? OMG!!!!11Eleventy!! Say it ain't so!!
</grin>
Not to mention there is an even easier way,which is simply adding more slots and/or shrinking the sizes of drives. Hell my going on 5 year old machine has slots for 4 drives(2 EIDE and 2 SATA) and we are now seeing plenty of boards with 6 SATA slots or more. And as we have seen drives like chips can still be shrunk a ways. So I kinda doubt we'll be hitting the wall for awhile yet.
That said,where we ARE hitting a wall,and pretty hard at that,is easy to use consumer backup storage. The days of easily backing up your data to DVD is long gone. I was hoping that BD would turn out to be a decent choice,but like nearly everything Sony has made in the past decade they were more concerned with DRM than selling their product. So I really do hope that someone comes out with affordable holodiscs or some other easy to use format that will hopefully then spread into the consumer sector quickly like DVD. Because right now DVD is really the only choice a consumer has when it comes to backups.
ACs don't waste your time replying, your posts are never seen by me.
Jennifer Gates was right, 640TB ought to be enough for anybody.
Knowledge is how to play a game, intelligence is how to win, wisdom is knowing what game to play.
Funny, but the idea of buying and installing twenty top-of-the-line new disks each day sounds like really big numbers to me...
Not to mention that they need backups. How many tapes do they have to buy? And data transfer, too. All those bytes are worthless if no one gets to see them, so they need at least 30 TB / day data link capacity.
This telescope is amazing. The three-mirror configuration gives sharp focus, over a very wide field...the only problem is that the focus is on a spherical surface.
The LSST fixes this by having three relatively small (small compared to the mirrors) lenses to flatten the field, and they use a very large image sensor.
I am curious if they considered using a non-flat image sensor. It would be hard, but with e-beam or UV-laser lithography, I would think that you would be able to build a big sensor on a curved surface, and eliminate the inevitable light loss, distortion, chromatic abberations, and other problems with lenses.
This is something that could be added in the future, too, much as Hubble was modified after-the-fact. It just seems to this layman that it's too good an idea to pass up.
I love Mondays. On a Monday, anything is possible.
... the p0rn industry for doing the groundbreaking research needed to manage this quantity of data.
Have gnu, will travel.
I'm no astronomer or physicist but isn't the fact that there is so much dark sky, even with powerful telescopes, suggestive of the presence of dark matter?
How bright would the night sky be if there were no dark space visible to the naked eye?
It would be far less cost effective to upgrade Hubble than to build the LSST. Shuttle launches cost a TON of money not to mention you are risking astronauts lives to try and upgrade something we CAN build better on Earth. Hubble has had optical problems in the past and the 2 flights to repair it cost about one billion dollars. Imagine what a complete rebuild would require. "Making the most advanced telescope, ON THE GROUND, seems like an oxymoron to me." And the reason it is considered such an advanced telescope: http://en.wikipedia.org/wiki/Adaptive_optics
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Slashdot took out the space in "Personal life."
Knowledge is how to play a game, intelligence is how to win, wisdom is knowing what game to play.
Large Hadron Collider, Syntoptic Telescope Survey, Seismic Data Acquisition, Genome Decoding all use as much data capacity that exits. That now measures in the terabytes-per-day rate. Video tapes now have that capacity.
I'm no astronomer or physicist but isn't the fact that there is so much dark sky, even with powerful telescopes, suggestive of the presence of dark matter?
No, but the existence of dark sky *is* interesting.
Look up Olbers' paradox. Any matter that respects the laws of thermodinamics (be it dust, interstellar gas or the newly defined "dark matter") should heat up to the temperature of its ambient medium and start radiating, so absorbtion can't be an explanation for the dark sky. There are however other theories that could explain it (see the Wikipedia article for some of them).
No. Dark matter is not really related to the darkness of the night sky. Dark matter is so named because it doesn't interact with light one way or the other. It doesn't absorb light, it doesn't emit light, so it ends up being separate from the question. But the question of why is the night sky dark is sometimes known as Olbers' Paradox and has been used as one suggestion that the Universe is finite.
The detector surface is indeed effectively curved. It's made up of a large number of CCDs which will each be tangent to the focal surface at their location.
How much porn can one person save onto 150 petabyte drive? thats so much pornabytes. jeezes