Voyager 1 is heading towards the void between solar systems, and Voyager 2 follows just a few billion miles behind.
And they've been out there THIRTY YEARS. Space probes, powered by three radioisotope thermoelectric generators, still going after so long, and STILL TALKING TO US.
So much so, they have maintain archaic equipment to do it!
http://www.smh.com.au/news/science/t...067368154.html
Incredible.
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I'm not sure what's more incredible. That these spacecraft are still transmitting (aren't they the first man-made objects to leave our solar system?) or that we have the technology to still be able to receive their faint signals.
Either way, it's a testament to the people who built them. It's a cliché, but they don't build them like that any more!
Cheers,
Stephen
Yeah, I bet they used a flippin' robust modulation scheme on the probes, and know [/i]exactly[/i] where to point the receiver.
And to be fair, the Mars rovers lasted longer than intended... but nowt like this!
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They are the farthest traveled objects ever created by man; V1 is now in the heliosheath and they continue to bring us new information the farther out they travel. They are probably within the top 10 inventions of all time.
It's the pride of the human race
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Indeed they do not - they make them better, because tech has moved on.*Originally Posted by fat jez
Amazing though - just goes to show how hard it is to appriciate the scale of the solar system - you think they'd be well out of the solar system by now, but they are still on our doorstep.
* - Apart from that English prof who wheeled a Mars probe along in a shopping trolley, then smashed it into Mars. He was a gimp.
This started me thinking about that Star Trek film where some unknown thing was looking for the Creator and it turned out some alien race had found one of the Voyager probes, souped it up into a massive ship and sent it back home...
So then that started me thinking about what if alien space faring life DID find Voyagers 1 or 2.
But then I remembered that our own electromagnetic shell is WAY past the distance that the Voyager probes have reached and, given the proximity of the nearest stars I reckon that either the stars have no life capable of communicating with us OR the invasion fleets are on the way.
I mean, our nearest neighbouring star is Proxima Centauri, which is just 4.2 light years away. Now given that we've been beaming radio and television signals about for, for the sake of argument, the last 50 years, that means anyone in the neighbourhood of Proxima Centauri has been able to pick up our signals for the last 46 years as it'd take 4 years for the first signals to get there.
So, they've had 46 Earth years to respond which, if they had sent a message back shortly after getting ours, we should've received something 42 years ago... or anytime since then.
Of course, let's expand that to stars within 50 light years, (the extent that our radio broadcasts have reasonably reached so far) and the number of Sun-like stars likely to have planetary systems similar to ours and therefore life, jumps up to 133 known stars... and around 2000 other stars and systems that may or may not have planets.
Ok, so we could wait another 50 years to hear a response back but, and here's the really profound bit... if someone did respond it's likely it will be IN OUR LIFETIME!!!
Yep, how's that for an optimistic approach to whether we're alone in this universe or not?
133 Sun-like star systems are right now being bombarded with our radio signals... and could be beaming back to us RIGHT NOW.
But I wouldn't worry too much about alien invasion fleets just yet. The fastest man-made object, which just happens to be Voyager 1 is travelling at 34K/sec... so if we assume that another race is more advanced than us with the whole space travel and we assume that they’re using the solid/liquid fuel booster system that we use (let’s not get all theoretical and let’s just stick with stuff that works) then we’d be looking at them being able to travel at most, and being generous, let’s say a top speed of 200Km/sec...
But even if the alien invasion fleet set out from the disturbingly quiet Proxima Centauri right now it’s take them ooh, around 6300 years to travel the 39,707,870,813,049Km from there to here... Just to see if we’re worth killing? So somehow, I think that if we DO ever have contact with an alien race, it’ll be over the airwaves long before we ever actually meet them...
Thinking about it, it’d be the DADDY of online, long distance relationships! And I bet it turns out that four breasted love goddess who doesn’t know what a headache is turns out to be a guy...
Haven't they may ion propulsion vehicles that can travel faster... although they take a while to accelerate?
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Yeah, the Voyager probes really are incredible... talk about return on investment!
Yup... ion propulsion is low-g... but it's the fact that you can sustain it for a very long time that's the good thing.
Fusion-based engines FTW! Or better still something really far-fetched like asymmetric Casimir engines.
And if it was a high tech warfaring race.. i'm fairly sure we wouldn't see much warning before we were wiped out(which is nice..)
Ah right... and is there an ion-propulsion based vehicle zipping around right now?
No?
Ok, so that'd make Voyager the fastest mad-made object then, yes? Yes.
Bloody pedants!
The Japs sent a probe to an asteroid the other year. It used four Xenon Ion-Drive engines to get there. Another probe is being sent to Ceres using Ion-drives this month apparently. There have been several craft which have used some form of ion-drives since the 70's
Last edited by Dorza; 02-09-2007 at 11:56 PM.
There are ion-propulsion engines working in space right now, it's just that none has had the time to accelarate for 34 years or they are used in satellites. The benefit of using ion propulsion is that you gain 10 times more thrust per weight of fuel over conventional chemical rockets.
Here is a little story that you might find interesting. I worked for a company called Matra Marconi Space (now Astrium) in '96 and '97. I was a materials technician working in one of their labs. The company had been working on a satellite called Artemis which was going to use an ion propulsion engines for maneuver and sustain it's orbit and stretch the mission past 10 years to something like 15.
2 of the 4 ion propulsion engines were being built on our site. I used to go into the building quite a bit cos they had a powerful x-ray machine there that was used for looking at aluminium inserts in carbon fibre structures. The engine was tiny, not much more than a metre long and 1/2 a metre wide with loads of stainless steel piping.
This piping (small diameter less than 10mm) was produced by welding together small sections of this pipe by means of an autogenous welder. But they were having some problems with producing good welds so we were asked to help them out. We asked for some samples and on inspecting the joints we realised that they had been welding sections using the wrong material. It was out of spec!! Now this was a huge issue because Artemis was way over budget and delayed. Any further delay and added cost and the project would be cancelled.
We called over the ion engine project manager and explained that they had been welding using type 316 instead of 316L. (The L is important because niobium or titanium is added as a "stabiliser" which preferencially forms carbides so chromium carbide does not form. Chromium carbide formation is bad because it takes chromium out of solution and these carbides form at grain boundaries. The differing levels of chromium produce a localised galvanic couple which we commonly call "weld decay")
We had to sit him down with a cup of hot sugary tea because he had turned green. They had no idea how much of this piping had been made using the unspecified and unqualified material nor what effect using it would cause. It would take 6 months to redo the work and that would kill the whole Artemis project. So we decided to requalify the materials and find out how much of the wrong material had been used.
So we had to retest 316/316, 316/316L and 316L/316L joints to make sure they all came upto the required spec. The corrosion testing was gonna be the big one. We also had someone take slivers of metal from each pipe section (50+) so we could determine how much had been done using the wrong material. If it was only a couple of sections then it wouldn't be so bad and we'd chop them out and continue with minimal time loss for the project. A friend spent 2 weeks solid 12 hours a day 7 days a week doing the analysis on the SEM (poor bugger!) while myself and another lad did the rest of the qualification. Something that would normally take 6 months we did in 3 weeks.
In the end everything passed the requirements, we wrote the report and recommended they fly the engine as is. The reason the 316 got used was because the supplier had inadvertently labelled that bar as 316L. Big meeting was had and our previously green project manager got to keep his job.
The launch of Artemis was a disaster. The satellite was put into too lower orbit and was essentially lost. But they did some amazing stuff, reprogrammed the space craft and used the ion engines to get it into the correct orbit. Artemis holds some impressive records. More info here and here.
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Nice story
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