Voyager Probes Give Us ET's View

← Back to Stories (view on slashdot.org)

Voyager Probes Give Us ET's View

Posted by samzenpus on Thursday December 1, 2011 @06:52PM from the a-different-look dept.

astroengine writes "For the first time, scientists have been able to measure a type of radiation streaming out from the Milky Way that in other galaxies has been linked to the birthplaces of young, hot stars. There was no way to make our own galaxy's measurement of the radiation, known as Lyman-alpha, until the Voyager probes were about 40 times as far away from the sun as Earth — any closer and the solar system's own emissions drowned out the fainter glow from the galaxy."

72 of 166 comments (clear)

Min score:

Reason:

Sort:

For Science, of course... by Anonymous Coward · 2011-12-01 19:03 · Score: 5, Funny

Pictures of young, hot, stars?! Count me in!
1. Re:For Science, of course... by Framboise · 2011-12-01 20:21 · Score: 2
  
  These stars are known to be strong in X.
2. Re:For Science, of course... by Anonymous Coward · 2011-12-02 01:09 · Score: 5, Funny
  
  As with most hot young stars, they do tend to cool quickly and their waistline expands as they run out of good, hot material. Eventually they can either have a big blowup or become small, not so hot, older stars when they begin using different materials.
  
  Damn. That sounded better in my head but the metaphor got a bit muddled. But, think stars, hydrogen, red giants, helium, novas, etc...
3. Re:For Science, of course... by phatsonic · 2011-12-02 02:47 · Score: 2
  
  All stars pictured here are at least 18 years or older.
4. Re:For Science, of course... by Jason+Levine · 2011-12-02 02:51 · Score: 2
  
  You just have to be careful. Looking at photos of young, hot stars under 180 million years old can get you in trouble.
  
  --
  My sci-fi novel, Ghost Thief, is now available from Amazon.com.
5. Re:For Science, of course... by rubycodez · 2011-12-02 03:42 · Score: 2
  
  yeah, watch out for those damn pervert protophiles
So Cool... by steevven1 · 2011-12-01 19:06 · Score: 5, Insightful

Voyager has to be the coolest space probe ever. It's been operating for 34 years straight and is LEAVING OUR GALAXY, still receiving commands from Earth and still transmitting data back. If that's not marvelous, I don't know what is. Anyone interested should read: http://en.wikipedia.org/wiki/Voyager_1
1. Re:So Cool... by steevven1 · 2011-12-01 19:09 · Score: 3, Insightful
  
  Correction: solar system, not galaxy. D'oh!
2. Re:So Cool... by deroby · 2011-12-01 20:24 · Score: 2
  
  Patience my friend, one day it might actually leave our Galaxy =)
  
  --
  If there is one thing to be learned on slashdot, it has to be sarcasm.
3. Re:So Cool... by QuoteMstr · 2011-12-01 20:27 · Score: 5, Interesting
  
  The Voyager computers are awesome too. How many other 18-bit word systems are actively maintained today?
  I'd love to see the source code, though I'm sure it's terribly boring.
4. Re:So Cool... by agentgonzo · 2011-12-01 22:13 · Score: 5, Informative
  
  Unfortunately not. Milky way's escape velocity is approx 525km/s (wikipedia) and voyager and our solar system are moving at approx 18km/s (Monty Python Song). Unless it happens to get flung out of the galaxy by the impending collision with Andromeda in 3-5 billion years it's not going to be leaving the Milky way anytime soon. It'll just float around in the vicinity of the solar system and go around the Milky way.
5. Re:So Cool... by Anonymous Coward · 2011-12-01 22:31 · Score: 5, Funny
  
  Meanwhile my smartphone will be lucky to survive 34 months, and is only able to receive commands from Earth if I hold it out of an upstairs window...
  Out of interest, are there many computers down here on the planet that have been operating constantly for 34 years?
6. Re:So Cool... by deroby · 2011-12-01 22:53 · Score: 3
  
  Ah, I was not aware of that. My bad.
  I simply assumed it would take a (ridiculous) amount of time but hadn't considered the required escape velocity of the Milky Way, nor the fact that the probe is just coasting...
  Damn, you DO learn something on /. now and then, I'll have to adapt my signature some day =)
  
  --
  If there is one thing to be learned on slashdot, it has to be sarcasm.
7. Re:So Cool... by dtmos · 2011-12-01 23:37 · Score: 5, Funny
  
  I have personally seen 50's Univac and 60's IBM systems running
  Yes, but when? I, too, have personally seen 50's Univac and 60's IBM systems running.
  However, it was in the 50's and 60's.
8. Re:So Cool... by flyingfsck · 2011-12-02 00:07 · Score: 5, Funny
  
  Cool, so you must also be in your 60s or 70s and still running...
  
  --
  Excuse me, but please get off my Pennisetum Clandestinum, eh!
9. Re:So Cool... by dtmos · 2011-12-02 02:01 · Score: 4, Funny
  
  Yes, and before you ask, I, too, have been receiving inquiries from museums.
10. Re:So Cool... by Mojo66 · 2011-12-02 02:30 · Score: 2
  
  Not true. While its current velocity is too low to escape our galaxy, this can change quickly (in terms of the cosmic time scale) should the probe have a close encounter with a planet or star. This is known as swing-by and was actually used to accelarate the Voyager probes out of the solar system.
11. Re:So Cool... by Mojo66 · 2011-12-02 02:51 · Score: 2
  
  I agree that the odds for an encounter that would propel the probe to galactic exit velocity or more, are very low. However, the time and space scales we're talking about are so big that agentgonzo's seemingly conclusive statement shouldn't be left uncommented.
12. Re:So Cool... by Jason+Levine · 2011-12-02 03:03 · Score: 2
  
  True, but that would be more or less a chance encounter. Right now, it is going at 17.26 km/s. I don't know offhand if it is headed anywhere in the general vicinity of Alpha Centauri, the nearest star to us and the closest gravity boost Voyager could get. For the sake of argument, let's say it is. Alpha Centauri is about 4.24 light years away from us or about 4 × 10^13 km. At its current speed, it would take about 73,437 years for the Voyager probe to reach Alpha Centauri. In 73,000+ years, we went from the Middle Stone Age to the present day. I wonder what mankind's civilization will be like (if it is even around) in 73,000+ years. I doubt anyone will even remember about Voyager.
  
  --
  My sci-fi novel, Ghost Thief, is now available from Amazon.com.
13. Re:So Cool... by tgd · 2011-12-02 03:54 · Score: 2
  
  I guess my point is, in theory its possible to calculate if it is actually possible. He may be correct (although accidentally).
  If the type of encounter that Voyager could actually survived added little enough speed, and the time between those encounters are long enough, and the odds of surviving non-ideal encounters is low enough, presumably you could calculate the time it would take to build up that kind of speed *even in that one in quintillion chance*, and compare that time to the time the galaxy will actually be around with the appropriate types of masses useful for accelerating Voyager like that.
  The point is, there's definitely swaths of solutions to that math that result in conditions where Voyager could *never* leave the galaxy, and its entirely possible that the parameters ensure that you're always in that range, and Voyage could *never* leave the galaxy.
  I suck at that sort of math, but I'm sure someone could work through all the variables. Might even make an interesting paper.
14. Re:So Cool... by Archangel+Michael · 2011-12-02 04:11 · Score: 2
  
  I have a similar story, the difference was, they were replacing the server and couldn't remember the password and asked me if I knew what it was. .. of course I did.
  Then the guy replacing the server started asking me all these questions about the setup and what not because he couldn't figure it out (ARCNET was alien space technology). I told him that I would be happy to help at my normal rates.
  It was that job that made me realize that it wasn't what you know, it is who you know. Being better at the job doesn't mean you get the job, as people have favors they have to cash in. I now collect favors as part of my jobs.
  
  --
  Agent K: A *person* is smart. People are dumb, stupid, panicky animals, and you know it.
15. Re:So Cool... by Sigmon · 2011-12-02 04:48 · Score: 2
  
  Kinda makes you wonder if there might be more of our space probes coasting through the cosmos... put up there by a long forgotten civilizations that collapsed.
16. Re:So Cool... by mcgrew · 2011-12-02 05:01 · Score: 2
  
  Voyager has to be the coolest space probe ever.
  Yes, literally as well as figuratively. Pretty damned cold out there past the Kupier belt!
  
  --
  Free Martian Whores!
17. Re:So Cool... by HiThere · 2011-12-02 09:19 · Score: 2
  
  It could still leave out galaxy, eventually, via a gravity slingshot. I'll admit it's quite unlikely (and I'm not even sure how unlikely) but it's possible.
  P.S.: I haven't calculated things out, but this might require that it be near a supernova explosion, in which case while the mass might leave out galaxy, it might not be fair to call it Voyager. But I suspect a pair of close binary neutron stars could give it enough velocity without even noticing.
  
  --
  
  I think we've pushed this "anyone can grow up to be president" thing too far.
30 years later... by guruevi · 2011-12-01 19:22 · Score: 2

You never know when such research will pay off. The US and EU is scrapping programs now while China, India and a few others try to get into space, you can bet that a lot of cool research will be coming from that side of the globe in the next 30 years.
Imagine if we could launch a probe now with what we have available. We could cheaply launch 10's of much faster probes with incrementally better sensors for the price of the voyager program (~$3B in today's dollars).

--
Custom electronics and digital signage for your business: www.evcircuits.com
1. Re:30 years later... by Brett+Buck · 2011-12-01 19:27 · Score: 4, Insightful
  
  We could cheaply launch 10's of much faster probes with incrementally better sensors for the price of the voyager program (~$3B in today's dollars).
  
  I am not sure why you say that. The costs of space technology haven't changed much at all relative to the rate of inflation, and there haven't been any important breakthroughs in launchers. The only thing consequentially different is computer capability, but a faster/more complex computer would just as likely be a liability as a bonus. Software design techniques, if anything, have gone rapidly backwards for this sort of application since the late 70s/early 80s.
2. Re:30 years later... by steevven1 · 2011-12-01 19:33 · Score: 2
  
  I'd say that the hardware for collecting data has substantially improved with time too (imaging sensors, etc.). Not to mention storage capacity, and I'm sure there is plenty of other stuff I can't think of right now, even if launching technology hasn't changed much. There could definitely be huge benefits.
3. Re:30 years later... by Brett+Buck · 2011-12-01 19:44 · Score: 2
  
  Those same advantages have tended to reduce reliability and robustness, particularly robustness to radiation damage.
4. Re:30 years later... by Kjella · 2011-12-01 19:51 · Score: 5, Insightful
  
  Software design techniques, if anything, have gone rapidly backwards for this sort of application since the late 70s/early 80s.
  I'd say the Mars rovers are a good counterexample of that, they're "new" and have been operating for many, many years now. Particularly when it comes to data compression the current probes have a huge leg up on the old ones. That said, yeah computers can't rewrite physics and launching anything into space is still quite expensive and they don't really go faster from it either.
  
  --
  Live today, because you never know what tomorrow brings
5. Re:30 years later... by Anonymous Coward · 2011-12-01 20:53 · Score: 5, Funny
  
  If we build the probe from neutrinos we could possibly launch it faster than light. And get the results a few years ago.
  If we had known to listen to them, that is.
6. Re:30 years later... by JasterBobaMereel · 2011-12-01 21:15 · Score: 5, Informative
  
  Launched today they would not do much .... they relied on a chance alignment of the planets that allowed them to use gravitational slingshots to get there in a reasonable time, tour most of the planets, and leave the solar system ... next time this will happen is around 2150 ...
  
  --
  Puteulanus fenestra mortis
7. Re:30 years later... by Tastecicles · 2011-12-01 21:26 · Score: 5, Interesting
  
  Oh, I don't know... electrostatic ion propulsion is already proven to be more efficient than ordinary chemical propulsion (once you get out of the gravity well).
  As long as you have fuel, you'll keep accelerating, albeit at a very small rate. It might take ten or twenty years, but I reckon that if an ESI probe was launched tomorrow it'd overtake Voyager and still have propellant to go faster.
  The bonus is with computer technology; that while it's gotten thousands of times faster in practically every respect, it's also gotten a lot smaller - a non-hardened computer package these days weighs no more than 3lb, with terrestrial ruggedised coming in at little more. The advantage of this is obvious: with the single biggest non-fuel component of the spacecraft now the size of a paperback, you have far less mass to push.
  Of course, you don't need a screen or a keyboard in deep space, so cut the weight in half and you've got something a smidge lighter than the several hundred pounds of GE custom machine that went up with Voyager, that has its own battery, that pulls about ten Watts rather than over a hundred, that uses solid state storage, and in most cases can automagically govern its own power load (this would be why the later Shuttle missions used self-contained laptops rather than a room full of mathematicians and radio that meant data moved at the speed of speech) - I've metered my netbook off the line and found it runs on between 3-35W, averaging 11, including the screen on minimum brightness.
  That said, you do need to protect the computer against hard radiation. That will obviously push the weight up, but not so much as to make it unmanageable. A couple or three pounds of lead and a steel cage to protect against EMI/RFI I think is all that is needed. The major part of the probe is then going to be propulsion systems and fuel, and the science package.
  
  --
  Operation Guillotine is in effect.
8. Re:30 years later... by khallow · 2011-12-01 21:40 · Score: 4, Interesting
  
  The costs of space technology haven't changed much at all relative to the rate of inflation
  When you get away from government projects and missions you find an interesting thing. They've gone down in absolute dollars. It's not rare to find private analogues which cost an order of magnitude or more less than the government counterpart.
  
  For example, prior to the early 80s, there was no commercial space flight of any sort. When it first opened up with offerings from Arianespace, Boeing, and Lockheed, prices were on the order of $20k per kg (to low Earth orbit or "LEO"), a bit better than the Space Shuttle. Now there's perhaps a dozen private space launch providers, some offering flight costs well under $10k per kg. So we've gone from $20k per kg in 80s dollars to under $10k per kg in today's dollars. And if SpaceX delivers, we'll be hitting $5k per kg (in today's dollars), perhaps less. The Russians have a good chance of meeting that price point as well.
  
  It'll never be a Moore's Law thing, but we are seeing a remarkable long term decline in launch costs over a few decades. So no breakthrough in launch technology (with the exception of the creation of commercial space flight in the 80s and the possible exception of SpaceX now) yet we still manage to drop prices considerably even before adjusting for inflation.
  
  Second, there are great economies of scale in launching tens of probes. For example, R&D is divided up over a large number of probes. There are learning curve effects from building tens of probes and part costs will go down. Now maybe building a Voyager-level vehicle wouldn't be as cheap as the original poster claimed, but I bet $3 billion can buy a lot of interstellar probes, just the same. Especially, if one cuts out the slick tools that Voyager used for its planet flybys, but which weren't used for the interstellar portion of the mission (such as the imaging cameras).
9. Re:30 years later... by amRadioHed · 2011-12-01 21:45 · Score: 5, Interesting
  
  They wouldn't be using state of the art chips, but even the old radiation hardened chips needed for space travel would be an big improvement over 30 year old technology.
  Probably the biggest improvement would be in propulsion. Isn't this the exact sort of mission the new ion propulsion systems would be perfect for?
  
  --
  We hope your rules and wisdom choke you / Now we are one in everlasting peace
10. Re:30 years later... by Kagura · 2011-12-01 21:53 · Score: 2
  
  You never know when such research will pay off. The US and EU is scrapping programs now while China, India and a few others try to get into space, you can bet that a lot of cool research will be coming from that side of the globe in the next 30 years.
  Imagine if we could launch a probe now with what we have available. We could cheaply launch 10's of much faster probes with incrementally better sensors for the price of the voyager program (~$3B in today's dollars).
  As a side related note, I have heard nothing about New Horizons' after-rendezvous plans other than a possible second Kuiper belt flyby, but I'll bet you a million bucks that they've over-engineered this probe to later provide the kind of science that 1970s' Voyager is doing for us still today.
11. Re:30 years later... by stephanruby · 2011-12-01 22:16 · Score: 5, Informative
  
  The only thing consequentially different is computer capability, but a faster/more complex computer would just as likely be a liability as a bonus. Software design techniques, if anything, have gone rapidly backwards for this sort of application since the late 70s/early 80s.
  Thankfully, some of our/your assumptions about space technology are currently being proven wrong. For instance, take the Nexus One. NASA has been testing it to see if it could make cheaper smaller satellites with it, and its performance in that regard has been completely outstanding.
  Granted, it hasn't survived 30 years in space yet, only time will tell on that one.
  But it can survive in all kinds of extreme temperatures, all kinds of G forces, and it works perfectly well in a vacuum. And it's so small to begin with, the extra hardware it needs to power it, recharge it, move it, etc, doesn't have to be that big to begin with.
  During one of its space test, the Nexus One was even strapped to the tip of a rocket and the rocket accidentally crashed back into the desert leaving a large crater, but the phone only got a cracked screen and was still fully functional otherwise.
  And this is probably something that's not unique to that phone, or to Android, in particular. Consumer-grade devices, because they've been designed to survive actual consumers and sometimes even little kids, have come a long way in terms of reliability.
  And granted, a Nexus One will still have bugs that would normally be intolerable in the older type of computers designed for space, but it has enough computing power to be reprogrammed remotely and compensate for most bugs that are found after the fact. And since they take much less space and weight, and are much cheaper to launch. You can launch half a dozen for a fraction of the cost it used to launch an older type of satellite, thus building a type of redundancy that we just couldn't afford to have with the older kind.
  So if anything needs to improve, it's probably not our technology, but our mindset. We have good technology. That technology may not be perfect, but it should be more than good enough for unmanned space exploration at least. And it's grand time we start using it for that purpose.
12. Re:30 years later... by peragrin · 2011-12-01 23:33 · Score: 2
  
  nope you want the communication system using neutrino's. that way only the results get sent back.
  Of course even if the neutrino experiment is true, it only means a an hour or two shaved off the 16 hours it takes to get the data at the ranges in question.
  
  --
  i thought once I was found, but it was only a dream.
13. Re:30 years later... by Talderas · 2011-12-02 00:51 · Score: 2
  
  So we've gone from $20k per kg in 80s dollars to under $10k per kg in today's dollars. And if SpaceX delivers, we'll be hitting $5k per kg (in today's dollars), perhaps less.
  Convert for inflation..
  $20k 1980 dollars = $52k current
  $20k 1982 dollars = $45k current
  $20k 1985 dollars = $40k current
  $20k 1987 dollars = $38k current
  $20k 1989 dollars = $35k current
  So at best, you're talking about around a 70-80% decrease in cost. SpaceX's cost would be about 85-90% lower than the 1980s.
  
  --
  "Lack of speed can be overcome. In the worst case by patience." --Znork
14. Re:30 years later... by necro81 · 2011-12-02 01:00 · Score: 2
  
  We could cheaply launch 10's of much faster probes with incrementally better sensors for the price of the voyager program (~$3B in today's dollars)
  you are off in your reckoning. We could perhaps launch a handful of small craft, but certainly not 10's. And although technology has progressed, the speed with which we can travel in the solar system hasn't changed much.
  
  For comparison, the New Horizons mission to Pluto has an expected lifetime cost of about $650 million - and that is a very modest probe. If it were an Earth-sensing mission (leaving aside the RTGs vs. solar panels), the mission cost would probably be half that - chump change as satellites go. The additional cost comes in part from the need for a more powerful rocket, but also because there is so much added rigor in testing the spacecraft beforehand (all their eggs in one basket, so to speak), and because you need to employ an entire support staff for a decade before you even get there.
  
  Another example is the recently launched Juno mission to Jupiter. That's a ~$1 billion mission (again, lifetime costs from inception through eventual death-plunge into Jupiter). The spacecraft itself is probably more expensive than would otherwise be expected because of all the radiation-hardening it needs (and testing that accompanies that). The spacecraft uses a huge (60 m^2) array of high-efficiency (triple junction GaAs, I would guess) solar panels for power, which may actually be more expensive than the conventional alternative of RTGs.
  
  On the plus side, both of these spacecraft are amazing science platforms and will provide impressive results over their missions. New Horizons has already provided new data regarding Jupiter (flyby in 2007).
15. Re:30 years later... by Muad'Dave · 2011-12-02 01:20 · Score: 4, Informative
  
  A couple or three pounds of lead and a steel cage to protect against EMI/RFI I think is all that is needed.
  At the high gamma energies found in space, lead is no better than aluminum as a gamma shield, and both are pretty anemic. 1 cm of either will attenuate high energy gamma rays by only about 50-70%.
  
  --
  Tiller's Rule: Never use a word in written form that you've only heard and never read. You will end up looking foolish.
16. Re:30 years later... by Tastecicles · 2011-12-02 02:03 · Score: 3, Informative
  
  ESI is the way (as I said, sans gravity well effects), generation of electrical power is somebody else's problem. As you've pointed out, solar is useless as a source for deep space probes; self contained generation of power is the only option, and right now all we have is RTG. This is what ion engines have used in every practical application so far (examples that spring to mind are SERT I and II, and DS1) and until something better comes along, it'll continue to be a sink for RTGs in deep space exploration. As to your claim that there are no RTGs available: I could build a crude but functional one in about five minutes (if I had a pellet of [insert name of suitable isotope here]), and it's not as if we're short of radioisotopes suited for the task. The problem lies in a particular nation state unilaterally and unjustifiably denying any other from possessing any quantity of refined radioisotopes for any reason other than the manufacture of smoke alarms. That nation state continues to throw RTGs all over the Arctic in the name of science and monitoring the military movements of others without the need to lay thousands of miles of power lines, and there is far more than the Apollo 13 RTG sitting at the bottom of the ocean - the Atlantic passive SOSUS net buoys are all RTG powered (there is very little sunlight three miles underwater).
  
  --
  Operation Guillotine is in effect.
17. Re:30 years later... by Anonymous Coward · 2011-12-02 02:13 · Score: 2, Interesting
  
  My understanding is that the noise from radiation only became a significant problem with newer chips running at lower voltages. The radiation shielding is a better solution for better systems, but ironically the old technology wasn't good enough to have this problem. Older logic systems (eg TTL but possibly not in this case) were designed for noisier, less stable circuits in general and radiation in space just happened to be just the sort of interferance it could tolerate.
18. Re:30 years later... by tibit · 2011-12-02 02:47 · Score: 2
  
  But it can survive in all kinds of extreme temperatures, all kinds of G forces, and it works perfectly well in a vacuum. And it's so small to begin with, the extra hardware it needs to power it, recharge it, move it, etc, doesn't have to be that big to begin.
  Sorry, that's engineering fantasy. No, a phone not designed for it will not survive "all kinds of extreme temperatures", "all kinds of G forces", etc. You'd have to test it -- you know, environmental chambers, shakers, etc. Without such tests any assumptions are pure fantasy. We don't know how it works in vacuum, because it hasn't really been in vacuum, only in atmosphere that's survivable to humans with supplemental oxygen. There's plenty of components that I'd expect will experience problems in vacuum simply because there's no reason at all to put ones rated for vacuum operation in a consumer device. Silly things such as plastic encapsulant outgassing can have dire consequences for quite short-term reliability (weeks). Thermal management becomes a big issue because you have to radiate all the heat out of the enclosure with no convection to help you.
  I have once seen tests of a fairly unassuming low-key data acquisition device in vacuum at -100C to 100C temperature ranges, and there was a lot of redesign involved to get it to work acceptably with no air present around it. It still could be done by qualifying everyday COTS components that you can get from any distributor like DigiKey (no milspec stuff), but this requires quite good recordkeeping and procedures/software to make sure human mistakes don't slip through.
  
  --
  A successful API design takes a mixture of software design and pedagogy.
19. Re:30 years later... by dmatos · 2011-12-02 05:37 · Score: 3, Insightful
  
  This is indeed correct. Radiation hard electronics are created at the microchip layout and design level, rather than with external shielding. It requires an understanding of the damage that occurs from ionizing radiation and high-energy particles, and implementing device layouts that are tolerant of that damage.
  Let me give you a little hint: current generation designs with tiny FETs and low voltage drivers cannot operate for very long when the gate Vts start to shift.
  
  --
  
  It may look like I'm doing nothing, but I'm actively waiting for my problems to go away.
  --Scott Adams
Impressive by PortaDiFerro · 2011-12-01 19:22 · Score: 5, Insightful

That must be one of the most successful space exploration projects so far, too bad it's running out of juice!
1. Re:Impressive by niktemadur · 2011-12-01 21:26 · Score: 5, Interesting
  
  The distance at which the Voyagers are still collecting and transmitting useful data back to Earth, is mind boggling.
  Over a light day away!
  Back in 1989, when Voyager 2 flew past Neptune, the JPL command center was probably dismantled and refitted for the next glamor project, while the long final phase of the Voyager mission was relocated to a much tinier space, probably the basement, with a couple of old-school, hardcore Voyager geeks down there, living on Doritos, pizza and Usenet, a rickety AC rattling and slowly dripping water over a puddle, unfixed for months because the Maintenance Department is constantly needed up at Voyager's old stomping ground, kept immaculate for the Galileo probe people, or Cassini, or the Mars Rovers, whatever the Flavor Of The Lustrum was / is.
  Nice and quiet down there among the rusted ceiling pipes and aged Crays, though. They didn't bother nobody, nobody bothered them. Beer could be smuggled to work and no one would notice, everybody upstairs would be swooning over Neil DeGrasse Tyson filming a segment on Pluto and the Horizons mission. Only time anybody saw the strange Voyager geeks, was when they went up to the ground floor vending machines, as the supply guy always forgot to restock the one in the JPL basement, forgot there was one in the basement.
  Little did anybody know (except for these guys) that the Voyagers were like an aging boxer with one good fight left in them, very low bitrate coupled with an ultra-weak signal perhaps, but with still one final, grand potential payoff - a peek at the outside, which may end up being the longest lasting legacy of all.
  Look at it now bitches, it's on the other side of the heliopause!
  
  --
  Lil' Thindime, lilting a lacrimose lament, krashes the kwaint konfines of Kokonino Kounty
2. Re:Impressive by Kjella · 2011-12-01 23:53 · Score: 3, Informative
  
  The distance at which the Voyagers are still collecting and transmitting useful data back to Earth, is mind boggling. Over a light day away!
  Uh? 120 AU is only 0.7 light days. And if that's far depends on perspective, it's 0.05% of the way to the closest star. Somehow the Mars rovers have been a lot more visual in saying that yes, we can do interplanetary with their cameras. The Voyager probes are more of a reminder that interstellar is a completely different ballgame. Thirty three years and 18 billion kilometers out yet it's still gotten nowhere in interstellar terms. Though it's fun to see them still operational and still doing science...
  
  --
  Live today, because you never know what tomorrow brings
3. Re:Impressive by garyebickford · 2011-12-02 07:49 · Score: 2
  
  Funny (giving up mod points to reply...) When I saw that 0.05%, I thought of it just the other way - to me it meant that we could launch a probe now that would arrive at the nearest star in ONLY 200 * 33 = 6600 years, using old-for-us technology. And that made me think that with a bit of thought and effort, maybe we could reduce that by an order of magnitude. And that was on the outer edge of something that the nations of earth might actually think was worth trying.
  200 years would be better, of course. It's only two long human lifetimes. That's less than the time it took to build many of the old cathedrals, and much less than the time it took to build some ancient monuments.
  Just checking the back of my envelope, an an RTG-powered ion propelled probe with a reasonable fuel load for a 500 year journey under constant acceleration, could be feasible. Constant acceleration, even 0.001% G adds up over time. Adding 0.009 m/s every second, times 86400 * 365.25 = 284018.4 m/s or 284 km/s - about 1/1000 the speed of light after just one year. After 100 years that's 28 km/s, or about 1/10 light speed. I'm too lazy to do the integrals, but this is looking like a plausible 200 year trip. The strength of the RTG would be dropping the whole time, but so would the mass. In fact, at those speeds I would think that rad hardening and other issues with high-speed particles would be the primary survival concern.
  Of course, in order for the probe to 'stop' at the other end to do anything useful, it would have to turn around and decelerate for the same amount of time. And it would have to be smart enough to figure out a reasonable exploration orbit.
  So for me, 0.05% was an optimistic number, not a pessimistic number. I can imagine the nations getting together to finance such a probe. In fact, I think it's within the financial capabilities of several individuals and many large businesses to finance the launch and the first 50 years of monitoring of such a probe. I'd give them naming rights to whatever they find at the other end. :) In fact, I'd strongly consider giving them a franchise (within some limits) to whatever they found.
  
  --
  It's easier to be a result of the past, but more fun to be a cause of the future! http://www.spacefinancegroup.com/
Question About Voyager(s)... by steevven1 · 2011-12-01 19:29 · Score: 4, Interesting

It receives commands from Earth, and it's 34 years old. What's to keep enemies of the United States from sending it bad instructions, or from collecting all data it sends back to us? I realize that Voyager isn't of any military importance, but I guess this is more of a hypothetical question. Does it use some type of encryption? Is that encryption still unbreakable today? The keys haven't been compromised after all this time? Just curious.
1. Re:Question About Voyager(s)... by Anonymous Coward · 2011-12-01 19:52 · Score: 3, Insightful
  
  > What's to keep enemies of the United States from sending it bad instructions, or from collecting all data it sends back to us?
  The fact that they are so far away that talking or listening to the Voyagers _REQUIRES_ a POINTABLE satellite dish 70 fucking meters in diameter. Only three that big exist in the world, and guess who owns them?
  http://voyager.jpl.nasa.gov/news/profiles_dsn.html
2. Re:Question About Voyager(s)... by ETEQ · 2011-12-01 20:02 · Score: 4, Interesting
  
  I don't think it's encrypted, but I think the methods of encoding the transmissions are incredibly arcane and the formats for the data are nothing even approaching standard (standards for such things didn't exist back then). Probably more important is that the only radio receivers in the entire world that are capable of detecting its signal are run by NASA...
3. Re:Question About Voyager(s)... by Framboise · 2011-12-01 20:41 · Score: 4, Interesting
  
  In the linked article I didn't find that "only three" such antennae exist. The deep space network made of three big antennae is able to follow and control Voyager without interruption, but other isolated and big antennae exist and might be used to perturb the spacecrafts, probably with slight modifications.
  Germany has a 100 m radiotelescope (Effelsberg), UK a 76m one (Jodrell Bank), Australia a 64 m one (Parkes), and China builds a 300m equivalent one, FAST, to be ready in 2013 (http://en.wikipedia.org/wiki/Five_hundred_meter_Aperture_Spherical_Telescope).
4. Re:Question About Voyager(s)... by vikingpower · 2011-12-01 20:58 · Score: 2
  
  Your is the strangest of mindsets. "Enemies of the United States" ? "Collecting all data it sends back to us" ? This is about science, dude. Cool down. The moment is not close for the US to militarily occupy outer space. ( It will have gone bankrupt before that time ).
  
  --
  Religous speak to God. Insane are spoken to by God. When all shut up, one can finally hear Shostakovich in peace
5. Re:Question About Voyager(s)... by Kagura · 2011-12-01 22:00 · Score: 3, Interesting
  
  Obvious troll is obvious
  No... you're just dumb. I've always wondered this, too. Not just about Voyagers, but all space exploration probes. No states have an interest in sending these false commands, but I wonder if it is possible or practical.
  
  Edit: I just reread the grandparent's reply, and the way he posed the question makes him out to be an idiot. I won't suggest modding him up, but his question is at least valid. Anyone know about how secure communications with space probes is accomplished? :)
6. Re:Question About Voyager(s)... by Tastecicles · 2011-12-01 22:04 · Score: 4, Interesting
  
  It's not just single large antennae that can be used to detect signals from Voyager.
  The VLA uses technology developed in Britain (actually, a quirk of physics) to use several small antennae to simulate one large antenna. You can do the same, using similar frequencies to those used for the Voyager downlink (2.3GHz), a few lengths of coaxial cable, some one and a half inch nails, and four feet of marine ply.
  1. Set two nails in the ply a set distance apart, call this distance D. You'll need this.
  2. Connect each nail to its own demodulator (AKA receiver), then connect the receivers to a phase correlator.
  3. Set the phase correlator to cycle the sinD differential between the two signals.
  4. Take the output to a computer for decoding.
  It is possible to do the phase correlation on the computer, or simply use the computer to record the signals from each receiver (forgetting about the phase correlator altogether) and combine them later. If you're dealing with streaming data (like you would be if using WiFi) you'll need a phase correlator* or set sinD as close to zero as you can get it (by setting the nails in the case of WiFi at multiples of 1.21"/30.734mm apart - as far apart as you can get them).
  *There is a way around this, but it also requires precise angle measurement. If you know which direction your signal is coming from, you can point your interferometer toward it (the elements set exactly perpendicular to the signal source so they receive the signal in precise phase alignment). It helps if the interferometer is mounted on a common axis as this does away with the need for a phase correlator.
  An improvement on this extremely simple design is the use of "cantennas" or other narrow-field antenna, which develops a narrow but high gain cone for the receiving antenna, making life a bit easier for finding the transmitter. If you want to get ambitious, the VLA uses 27 antennas, a 21+21+21km 3-way rail baseline, and several supercomputers.
  
  --
  Operation Guillotine is in effect.
7. Re:Question About Voyager(s)... by agentgonzo · 2011-12-01 22:22 · Score: 5, Interesting
  
  It's an interesting question, but regardless of whether anyone can theoretically crack the authorisation to upload commands to the Voyagers, I believe that it's only NASA's deep space network that can actually send the signals that far to be received by the probes.
8. Re:Question About Voyager(s)... by Zoxed · 2011-12-01 23:22 · Score: 2
  
  I work in ground based space systems, and can confirm it is tough enough to write the code for a modern satellite *with the documentation* :-0
9. Re:Question About Voyager(s)... by Tastecicles · 2011-12-02 01:35 · Score: 2
  
  easiest way to play with (recorded) signals is to use stereo audio waveforms in something like Audacity: take each channel (representing the signal recorded from each receiver) and subtract one from other (destructive interferometry), add them together (constructive interferometry), phase shift (same as signal correlation) then subtract or add... there are all sorts of ways to get all sorts of effects from three filters which come with the software: add, subtract, phase, and you can hear the results practically instantly. Great for demonstrations once you get your head around why it's doing what it's doing (which is very basic in terms of mathematics).
  Once you do get your head around it, the rest is gravy - it's all just waves in space, the only practical difference is the nature of the receiver.
  
  --
  Operation Guillotine is in effect.
10. Re:Question About Voyager(s)... by Muad'Dave · 2011-12-02 01:35 · Score: 2
  
  http://en.wikipedia.org/wiki/Beamforming
  http://en.wikipedia.org/wiki/Phased_array
  On a slightly different scale: http://www.km5kg.com/array.htm
  If you're interested in modern radio techniques, I suggest getting a decent book on Digital Signal Processing and software-defined radio. The things that can be accomplished with software are amazing!
  
  --
  Tiller's Rule: Never use a word in written form that you've only heard and never read. You will end up looking foolish.
11. Re:Question About Voyager(s)... by rimcrazy · 2011-12-02 01:48 · Score: 5, Interesting
  
  Not that anyone is probably interested but I worked in the group that made the radios that are in Voyager. I just missed working on those specific models but I worked on the next generation following those use on Voyager. Working there (Motorola GED) I worked close with NASA and was in the loop on all the programs, past and current that we were working on with NASA. What is really remarkable here is both Voyager probes have "failed" receivers on them. There was a problem with the capacitors that were used for the input loop bandwidth filters. These failed in such a manner as to cause the acquisition loop bandwidth to be a very narrow band instead of the intended wide band. NASA was able to recover using these radios by basically making an empirical model of each of the spacecraft. They did this when the spacecraft were relatively close to the earth and they could blast them with wideband signals to ensure acquisition. What they did with the model was to identify exactly how the on board xtals in the radio aged or varied with power and temp and then threw in compensation for age and doppler. With all of this data then then had a model that told them on such and such a date, the correct xmit frequency to use to put the carrier in the middle of the narrow band filter is X. They would dial it in, send it out and everything still worked. Actually a very clever fix for what would have been a disaster.
  
  --
  "TV, a medium as it is neither rare nor well done." Ernie Kovacs
12. Re:Question About Voyager(s)... by tibit · 2011-12-02 03:07 · Score: 3, Informative
  
  There's nothing to crack. An interplanetary mission is pretty much the ultimate in security through obscurity. You won't have a clue what to send until you get a backseat worth of documentation. That's all that's to it.
  
  --
  A successful API design takes a mixture of software design and pedagogy.
13. Re:Question About Voyager(s)... by rubycodez · 2011-12-02 04:07 · Score: 2
  
  it's not just funding that is an obstacle of our total occupation of all space, no matter how many people we send, they quickly get spread out too thin to do any effective occupying. Even if every U.S. person occupies 1,000 cubic light-years, we would then need 39 billion people to occupy the Milky Way. Clear we need a much higher level of unprotected sex among the fertile portion of our populace if we are to ever achieve the goal.
14. Re:Question About Voyager(s)... by rimcrazy · 2011-12-02 04:46 · Score: 2
  
  There are probably only a very small number of people that know about this. Certainly the group of people I worked with at Motorola and the NASA engineers and techs associated with the program. Since NASA was able to come up with a fix to make everything work, I would guess it's probably not something they would want to publicize in general but I've always thought this was a very ingenious solution. The truth be known, there are probably stories like this on just about every mission they ever did. Stuff happens as they say. In the end, people can be very, very clever, especially when they have their backs against the wall. Problems like this are especially difficult as you can't just go hang a scope on something a million miles away. You have to first discover the problem and then, more difficult, given the only tools you have at hand and a spacecraft millions of miles away, come up with a solution that will solve your problem.
  They (NASA) had done a few bone headed things too on programs I worked on but in general, they were right and bright more often than not. All of us screw the pooch some time or another but I look back on those days with a fond remembrance. I had radios I worked specifically on, on GRO, COBE, SME and the Hubble to mention a few. Interesting work and privileged to be a part of it.
  
  --
  "TV, a medium as it is neither rare nor well done." Ernie Kovacs
15. Re:Question About Voyager(s)... by jcgam69 · 2011-12-02 05:14 · Score: 4, Informative
  
  On March 31, 2006, the amateur radio operators from AMSAT in Germany tracked and received radio waves from Voyager 1 using the 20-meter (66 ft) dish at Bochum with a long integration technique. Retrieved data was checked and verified against data from the Deep Space Network station at Madrid, Spain.[22] This is believed to be the first such tracking of Voyager 1. http://en.wikipedia.org/wiki/Voyager_1
40 times as far away? by agentgonzo · 2011-12-01 22:24 · Score: 3, Interesting

Last I heard, the voyagers are about 100-110 AUs from the sun. Is the summary incorrect or do you only need to be 40 AUs from the sun to make these measurments? In which case, why is it news now and not in the 80s/90s when they reached this distance?
1. Re:40 times as far away? by Shadowmist · 2011-12-01 23:51 · Score: 3, Insightful
  
  Last I heard, the voyagers are about 100-110 AUs from the sun. Is the summary incorrect or do you only need to be 40 AUs from the sun to make these measurments? In which case, why is it news now and not in the 80s/90s when they reached this distance?
  Presumably because it's only recently that they discovered techniques to make these observations with the remaining equipment on board. Voyager is now making measurements it was never designed to. Keep in mind that the engineers who built these ships did not expect them to last as long as they did, nor that we would still be able to get useful signal strength from them at this point. Also remember that with the twin factors of half life decay and thermocouple degradation, they're only getting about half the power from the RTG's that they used to, so some equipment has had to have been permanently turned off.
2. Re:40 times as far away? by Kjella · 2011-12-02 00:06 · Score: 2
  
  Not just the summary, but the article is probably horribly wrong. The new measurements are almost certainly related to the probes approaching the edge of the heliosphere, but the journalist didn't have a clue and confused it with the distance to Pluto - which is about 40 AU.
  
  --
  Live today, because you never know what tomorrow brings
I feel better for knowing they are out there by donkeyb · 2011-12-01 23:07 · Score: 2

A surprisingly large part of me feels good that those amazing spacecraft are so far away, nearing the depths of interstellar space and will continue on for as near as makes no difference to forever. An even larger part of me regrets that I won't be around to see the day when they make contact with another civilisation.
1. Re:I feel better for knowing they are out there by Tastecicles · 2011-12-01 23:20 · Score: 2
  
  In other news, a partial image was just received from Voyager 2 which has DHS worried. Contact with the probe has not been reestablished.
  
  --
  Operation Guillotine is in effect.
Um, no. by dtmos · 2011-12-02 00:27 · Score: 3, Interesting

You're confusing antenna angular resolution with antenna effective area. The problem with reception of the Voyager probes isn't being able to discern them among other relevant signals. The problem is that the signals are so weak that they need an antenna with large area just to collect enough energy per bit to reliably overcome noise generated in the receiving system. Until you do this, you can't get a signal strong enough for your correlator to work on -- all you'll get out of the correlator is noise, because that's all that's going in to the correlator from your receivers.
Ergo, the 70m dishes.
1. Re:Um, no. by dtmos · 2011-12-02 01:58 · Score: 2
  
  By moving from one to nine antennas, you'll get an effective area improvement of at most 9, or 8 dB, but most of the improvement you're seeing is, in fact, the phenomenon you describe -- you're creating a phased array that rejects signals from undesired transmitters in the ISM band, in order to receive the desired signal.
  The problem in receiving the Voyager probes, however, is not this problem. The Voyager problem is that one doesn't have enough incoming signal to manipulate at all -- when received by even a 10m dish it's so far buried in the noise that it is undetectable at practical integration times. The solution, as you state, is to "increase the incident signal voltage" into the receiver, and the only way to do this is to increase the effective area of the antenna.
Re:ET's View by dtmos · 2011-12-02 01:27 · Score: 3, Insightful

This seems to be a pretty good description of the Voyager telecom system. Based on this, the X-band transmitter provides 18 watts to the high-gain antenna, which has a gain of 48 dB, for an effective radiated power of just over 18 * 10^(48/10) = 1.1 megawatts. (At least at launch; I assume the output power will have fallen somewhat over the intervening decades, as the RTG output falls and RF components age.)
This sounds like a healthy amount of power, and it is, but keep in mind that antenna gain comes easy at X-band (8 GHz), and such ERP levels are common in terrestrial point-to-point microwave links. Also keep in mind that the half-power beamwidth of the high-gain antenna is only 0.5 degrees, so any alien not in that narrow beam would hear substantially nothing.
Also, to answer your direct question, the frequencies and beam shapes are different, and one has to consider the shielding effects of the ionosphere vs. frequency, but just to compare (US regulations, YMMV): AM broadcast stations (~1 MHz) are usually limited to 10 kW with more-or-less 0 dB gain antennas, for an ERP of 10 kW; but UHF TV stations (~500 MHz) may have an ERP of up to 5 MW.
Of course, there are a zillion broadcast stations, all transmitting non-coherently (some would say incoherently), but only two Voyagers, so that would have to be taken into account, too.