NASA Probe Blasts 461 Gigabytes of Moon Data Daily 203
coondoggie writes "On its current space scouting mission, NASA's Lunar Reconnaissance Orbiter (LRO) is using a pumped up communications device to deliver 461 gigabytes of data and images per day, at a rate of up to 100 Mbps.
As the first high data rate K-band transmitter to fly on a NASA spacecraft, the 13-inch-long tube, called a Traveling Wave Tube Amplifier, is making it possible for NASA scientists to receive massive amounts of images and data about the moon's surface and environment.
The amplifier was built by L-3 Communications Electron Technologies in conjunction with NASA's Glenn Research Center. The device uses electrodes in a vacuum tube to amplify microwave signals to high power. It's ideal for sending large amounts of data over a long distance because it provides more power and more efficiency than its alternative, the transistor amplifier, NASA stated." It kills me that the moon has better bandwidth than my house.
Insane (Score:5, Funny)
Their Cingular bill is going to suck.
Re:Insane (Score:4, Funny)
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Re:Insane (Score:5, Insightful)
My question is why you need a vacuum tube in a vacuum? Just put the parts out in open space, save a bit of weight, no problem with the tube getting deposits on it over time, or thermal expansion and contraction stressing the tube, etc.
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My question is why you need a vacuum tube in a vacuum?
You're laboring under the idea that space is empty. But it's not, and throwing highly charged particles around (required for RF transmission) is going to attract the wrong kind of folk to the party. -_-
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Don't you mean their Verizon [blogspot.com] bill is going to suck?
I thought about making a Verizon joke, but since that also offer fiber service, which doesn't charge you per transferred byte, I was afraid the joke would be too confusing.
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no, they couldnt risk having a Verizon tech punching the oribter in the face if they needed onsite service
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NASA has a contract with Cingularity, not Cingular. Perhaps you've heard their marketing slogan? "All Bars in All Places..."
Re:Insane (Score:5, Funny)
That was my slogan for a while, too. Pity my liver couldn't take the strain.
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Nah. It's only 5.46 MB/s. So it's slightly more than half of 10Base Ethernet.
Re:Insane (Score:5, Informative)
5.46MB/s is close to half of a 100BaseT.
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--In reality with 10Mbit link, you'd be lucky to get ~850-900KB/sec for an FTP transfer over a small LAN, in real-world speeds. ( From what I recall ) Feel free to correct if you have a real-world story...
Sure, it can blast huge amounts of data (Score:5, Funny)
Re:Sure, it can blast huge amounts of data (Score:5, Funny)
Sure it can, after all it's got a 13 inch "tube".
Don't feel bad, CmdrTaco (Score:5, Funny)
Re:Don't feel bad, CmdrTaco (Score:5, Insightful)
Re:Don't feel bad, CmdrTaco (Score:4, Funny)
At the very least, he could buy a new house near somewhere that has 100mbps connections.
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Real estate is cheap, it's the cost of the building permit and materials thats the real SOB.
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Because the total NASA budget is, what, $1 per year per taxpayer?
Don't try this in Space (Score:2, Funny)
Re:Don't try this in Space (Score:5, Funny)
Tomorrow's headline: "RIAA Lobbies Congress to Shut Down NASA"
Re:Don't try this in Space (Score:5, Funny)
Bandwidth, sure, but the Ping? (Score:3, Funny)
It may have better BW than your house, but the ping is going to suck.
Or would you like your internet connection to be served by a SUV carrying hard drives?
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And can I keep the hard disks???
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Hard drives? Dude, we're talking USENETs. About 0.3 USENETs, but hey, it's coming from the moon.
USENETs? Sorry, I'm American and don't know how to convert that from metric to Libraries of Congress.
Re:Bandwidth, sure, but the Ping? (Score:5, Insightful)
Or would you like your internet connection to be served by a SUV carrying hard drives?
Never underestimate the bandwidth of a fedex truck packed with 250 lbs of hard disks!
Depending on the file size of what you would be downloading and with what technology, overnight shipping might STILL be better latency too!
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Or would you like your internet connection to be served by a SUV carrying hard drives?
Never underestimate the bandwidth of a fedex truck packed with 250 lbs of hard disks!
Depending on the file size of what you would be downloading and with what technology, overnight shipping might STILL be better latency too!
Right, but remember that full hard drives weigh more than empty ones, so you only want to buy about 200 lb of empty drives if you have a 250 lb limit.
better bandwidth? (Score:3, Informative)
1 - http://www.vendian.org/envelope/dir0/light_delay.html [vendian.org]
Re:better bandwidth? (Score:4, Informative)
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I hope Time Warner Cable falls off a cliff.
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He's right, you know, if you understand "way faster" as "almost immeasurably faster".
Spam (Score:3, Funny)
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"In space, no one can eat ice cream"? (One of the not best b grade movies)
And what the hell? Vacuum tubes over transistors? Seriously? Are they super vacuum-ized because they are used in the vacuum of space? Makes me think of one of those medical shows where a surgeon is like "we need more suction". Vacuums FTW!
Re:Spam (Score:4, Informative)
Vacuum tubes have always had higher frequency limits than transistors, since WWII in fact. Take a look at THz radiation sources, all tubes. No tranny is going to touch that for a while. And then tubes will have gotten better too.
http://en.wikipedia.org/wiki/Backward_wave_oscillator
Tubes just have more geometric freedoms to create bizarre fields and strange structures to do whatever you need.
Re:Spam (Score:5, Funny)
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And what the hell? Vacuum tubes over transistors? Seriously?
Seriously. Pretty much all television transmitters use klystron valves - transistors are only used for very low power transmitters, typically below 25kW output.
So wait... (Score:3, Funny)
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This is not exactly a new device... (Score:5, Informative)
Traveling Wave Tubes have been a mainstay of microwave communications and radar systems for the better part of a century. They're a very efficient way of amplifying microwave signals to the very high power levels needed to cross long distances.
Re:This is not exactly a new device... (Score:5, Interesting)
Re:This is not exactly a new device... (Score:5, Funny)
Re:This is not exactly a new device... (Score:5, Insightful)
the point is that before you read it, did you know there was a TWT orbiting the moon withh 100Mbps bandwidth transferring over 400GB of data a day? if not, then you learned something new.
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Can you build your own?
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Yes. But it's not easy. A TWT is, in many ways, very similar to a linear acclerator, except that instead of using RF to put energy into an electron beam to make it faster, it takes energy out of a fast electron beam to amplify an RF signal. So whip out those books on linear accelerator design and construction, and have at it. You need an electron gun and some electron optics to make the beam, and then the section where the RF interacts with the beam, either a helix or a series of coupled resonant cavitie
Re:This is not exactly a new device... (Score:5, Informative)
You need an electron gun and some electron optics to make the beam,
Check, old 19" TV tube... all the parts are there.
and then the section where the RF interacts with the beam, either a helix or a series of coupled resonant cavities.
Again, can be found in other surplus tech.
but screw it, just buy one....
http://cgi.ebay.com/NEC-LD7306A-B61-Travelling-Wave-Tube-TWT_W0QQitemZ200255211587QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item2ea0240843&_trksid=p3286.c0.m14 [ebay.com]
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Actually, try getting a ham license and you will find plenty of equipment and help experimenting with microwaves. I regularly see TWTs, brick oscillators [nr6ca.org], http://home.swbell.net/k5oe/K-Band/K-Band.htm [slashdot.org]">K-band (24 GHz) and X-band (10 GHz) equipment in the under $100 price range. Even the old Gunn Diode Oscillators can provide some fun [youtube.com]. Hams even launch their own satellites [amsat.org] and send their own microwave [home.wxs.nl] and VHF/UHF signals [youtube.com] to the moon and back.
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Yes it is old tech but frankly that makes it all the more interesting in a way.
It is a tube and not solid state.
And now here is the joke that I know must come.
If we used these for wireless internet then it really would be a bunch of tubes.
Sorry but it had to be done..
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And these have been used in space applications since the early 60's. In fact every satellite program that I have worked on used TWTA amplifiers. People are always looking for alternatives because they are very squirrely devices, but it's pretty difficult to generate much power at microwave frequencies with solid-state alternatives.
Brett
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Exactly...
http://en.wikipedia.org/wiki/Traveling-wave_tube [wikipedia.org]
They have been in use on Comms satellites in GeoSync for a very long time.
nothing really new here.
Re:This is not exactly a new device... (Score:4, Informative)
Cause Joe Sixpack never heard of them? And with the possibility of NASA losing some more budget [newscientist.com], it's best to keep talking up all that cool tech that's been around since the Stone Age, makes people think you just found something cool.
Yeah, but the latency's a bitch (Score:3, Funny)
Radar (Score:4, Interesting)
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Well, as it happens, yes, the LRO does have a Synthetic Aperture Radar payload (called MiniRF).
But it's separate.
Vacuum Tube? (Score:5, Funny)
Anybody else think it's funny that in this case, a vacuum tube is a step up from a transistor?
Re:Vacuum Tube? (Score:4, Informative)
Re:Vacuum Tube? (Score:5, Informative)
When you need to make serious power, tubes are still the way to go. Transistors have a significant reliability benefit.
Also, for 99% of applications, transistors are better. For the other 1%, you have very application-specific tube designs such as TWTs and magnetrons, which rearrange the tubes in such a manner as to negate its usual disadvantage (large size USUALLY translates to nasty frequency limits - TWTs and magnetrons are exceptions that use various Neat Tricks to allow microwave operation from a large device.)
BTW, one of the other common microwave tubes (magnetrons), while it is a "niche" device, it is a VERY widely deployed niche - basically all microwave ovens use magnetron tubes.
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no because they always have kicked the arse of a transistor.
Show me a 10,000 watt transistor.. Oh wait, you haveto use a Tube for that kind of power....
Tubes have kicked the Transistors butt forever when you need high power comms.
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With the glass on you can test your transmitter on the ground.
Re:Vacuum Tube? (Score:4, Informative)
Because the tube would get contaminated by the pollutants & particles in the atmosphere, and some of that won't outgas as the probe gets into a decent vacuum. Also, the solar wind [wikipedia.org] kicks particles out as well, and some of those could also contaminate the tube, threatening its lifespan and/or performance.
Good idea, but it just won't work in practice.
Vacuum (Score:5, Interesting)
Did they even bother to seal the tube, or are they using the vacuum of space?
if not, the tube would be ruined before launch (Score:5, Informative)
curious thing about tubes, they don't become useful until they're sealed in vacuum, and boiled out in a high RF magnetic field to take impurities off the elements. and then you have to flash the last of the gases off by igniting a getter inside the envelope.
that provides a higher vacuum on earth, inside the tube, than you can ever develop in space. and the electrons can do their work, instead of hitting stuff and just making a useless glow.
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Traveling Wave Tube Amplifier? (Score:5, Funny)
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Dammit, you stole my joke. :(
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At an old company, our lead tech kept talking about how to configure one of our digital scanners, using the acronym for "Scanner Look-Up Table"... even writing it in big, bold letters on the board. Being a 50+year-old Vietnamese guy, it didn't mean anything to him, and he just kept on going.
We peed ourselves laughing... our boss didn't when he walked into the room to see a huge "SLUT" written on the board. :)
MadCow.
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Probably because someone told him "But Bill, we named it after you!"
Which didn't help either.
I hope Nasa has the right ISP (Score:5, Funny)
That much data and Comcast would throttle it no matter what the scientists said. If AT&T had it going through their "unlimited" 3G connection, NASA would be hosed and we would be increasing the national debt by trillions.
One last thing, I m wondering if the **AA doesn't want access to the data stream to make sure it isn't a bittorrent containing their precious copyrighted work. After all, we all know there is no legitimate use for that much bandwidth.
Silly name (Score:2, Funny)
Slow news day from what it sounds like... (Score:4, Informative)
TWT amps have been used in microwave systems since the 2nd world war. The use of TWT in satellites are recent, as in 25-30 years ago. The NSA's LACROSSE and the new ONYX satellites use TWT amps in the finals on their radar systems. The Soviet ROARSAT's probably use them as well, or something similar, they love to overbuild their stuff.
Hell, the YF-12a used 2 TWT's in tandem in its Hughes AN/ASG-18 radar, putting out over 10MW of raw power.
But they are power gobblers, The YF-12A's ate over 40KVA of juice to operate.
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Huh?! Traveling-wave tube [wikipedia.org]:
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30 years ago is recent in satellite tech? As opposed to those 200 year-old satellites up in orbit, propelled by horse and buggy...?
The moon vs. your house (Score:2)
Re:The moon vs. your house (Score:4, Interesting)
The best available at my house is 512Kbs DSL. I offered to lay the fiber myself for the final 2 1/2 miles or so, or pay them to do it, but they insist that there are legal reasons they can't serve me.
So, in typical geek fashion, I set up a P2P wifi link for that distance. It works, and I get about 50 Mbs on a good day. I get terrible packet loss when it rains hard, though.
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Of course the moon will have better bandwidth (Score:4, Insightful)
CmdTaco comments in the original posting:
It kills me that the moon has better bandwidth than my house.
I know that Taco's trying to be funny here, but, seriously, the moon should most certainly have better bandwidth. That is to say, a research project that is able to afford a custom solution to a highly specialized problem with plenty of money to throw at had damned well better have better performance than what is available to commodity markets. I expect this to be true just as nearly every other bit of the hardware they send up will be better, faster, stronger, lighter, and more able to withstand ionizing radiation than the equivalent, when available, from K-Mart. There's a good reason these projects cost hundreds of millions of dollars for a probe to be sent somewhere. The Mars rovers, as another example, are using a 256 kbps channel -- deployed five years ago when DSL was still considered fast -- over a distance that ranges 55 to 400 million miles. Now *that's* performance.
It actually rather amazes me that Taco's or anyone else's house has close to the bandwidth available from the moon.
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Rocket Science (Score:2)
It kills me that the moon has better bandwidth than my house.
That why its called "Rocket Science".
Tone (Score:3, Funny)
Traveling Wave Tube Amplifier
..and there's always the advantage of having data with a warmer, richer feel to it than using a solid-state amp. Just think how much better the data will be once they start storing it on vinyl!
Library of Congress? (Score:2)
Now we only need to know how many Library of Congress can be transfer each day?
or should we switch our Library of Congress unit to Data transmitted per day from the Moon?
terabytes for Hadron Collider and large telescopes (Score:3, Interesting)
Some of the large ground telescopes are partnering with Google and MicroSoft to put large portions of their data online. The computer programs and main scientists only have enough time to give a cursory glance at it. Maybe it will be a kid in a junior high school science lab that looks at something more closely and makes a discovery. Some of this is occuring with google earth imagery now.
the TWT is a 50-year-old technology (Score:3, Insightful)
but for high power, squirrelly conditions, and reliability under real world conditions, tubes are still the go-to player in a lot of situations. a solar storm will roach semiconductor outputs, but it takes a monster pulse straight down the gullet to take a tube out.
Latency (Score:2)
You wouldn't like the latency though.
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no wonder the images NASA shows us are sweet, warm, smooth, full, and very detailed. Must be a NOS tube they are using
No, it's because the probe uses Monster Cable interconnects!
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Nasty Old Stuff
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"and real video footage as opposed to footage put together from still images"
We tried to get real video footage but all we got was a message that said "buffering"
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do you not know what video is?
video is a series of still images.Unless you want that crap from the early days where is fields of interlaced lines.
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Um....
Not sure if you're trolling or serious.
Video (especially progressive scan stuff) is nothing but a sequence of pictures.
Color photos are wasteful of imaging sensor resolution.
To make a color photo you have to filter the light that hits the image sensor, either the way home digicams do it (RGBG filtering over individual pixels, thus 1/4 of your raw sensor resolution is available for final image resolution), or the way instrumentation cameras do it: Spin a color wheel (RGB) in front of your sensor eleme
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that level of bandwidth availability may not equal its use. And as someone who has a 100Mbps connection i realistically only see about 50-70Mbps. I dont have any sort of service level agreement with my ISP, and i can pretty much guarantee neither does NASA, afterall its space. so if they're net result is a daily avearge of 46Mbps of data thats pretty awesome considering all the variables that would determine the total bandwidth.
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Probably not. Distorted electric guitar is an instrument, sure, but one that's only been around a few decades with few examples of musical genius. The vast majority of truely great guitar music ever written by mankind would sound like crap on an overcranked tube amp.