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Voyager Probes Give Us ET's View
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."
Pictures of young, hot, stars?! Count me in!
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
That must be one of the most successful space exploration projects so far, too bad it's running out of juice!
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.
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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.
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 ...
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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.
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?
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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.
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.
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.
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