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rynner2

Gone But Not Forgotten
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Voyager probes celebrate 30 years

The US space agency's (Nasa) venerable Voyager mission is celebrating its 30th anniversary.
Its two probes were launched within weeks of each other in 1977 to make a detailed study of the outer planets.

The probes were then sent on trajectories that will eventually take them out of the Solar System and into interstellar space.

Three decades on, they continue to return data from distances more than three times farther away than Pluto.

Currently, Voyager 1 is farthest away. Launched on 5 September 1977, it is about 15.5 billion km (9.7 billion miles) from the Sun.

Voyager 2, which was lofted on 20 August 1977, is about 12.5 billion km (7.8 billion miles) away from the Sun.

They are travelling in the general direction of the centre of our galaxy. Mission managers believe the probes' power packs should maintain their working systems until at least 2020.

Although there are no planets in their vicinity to investigate, they are helping scientists understand the extent of the heliosphere, the huge "bubble" within which the Sun dominates its region of space.

It contains electrically charged particles that have been blown off the Sun at high speed and which are now pressing up against matter from other stars.

'Much to learn'

At some point in the next few years, the Voyagers will cross the "official" edge of the Solar System - the heliopause. Past here, the probes would be in interstellar space and, by that stage, probably some 40 years on from their launches.

"The Voyager mission has opened up our Solar System in a way not possible before the Space Age," said Edward Stone, the Voyager project scientist at the California Institute of Technology, Pasadena, California.

"It revealed our neighbours in the outer Solar System and showed us how much there is to learn and how diverse the bodies are that share the Solar System with our own planet Earth."

Both Voyagers carry gold-plated copper discs containing sounds and images selected to portray the diversity of life and culture on Earth. Music on the discs includes Bach and Chuck Berry.

http://news.bbc.co.uk/1/hi/sci/tech/6979696.stm
 
It's fascinating to think a man made object is heading out to interstellar space, how long I wonder will it take to travel one light year?
 
Ronson8 said:
It's fascinating to think a man made object is heading out to interstellar space, how long I wonder will it take to travel one light year?
As it's now about 800 light minutes away (or something over 18 light hours), and is still slowing down, I'm pretty sure I won't be around when it does hit the light year mark!

Space is really B-I-I-I-G...!
 
rynner said:
As it's now about 800 light minutes away (or something over 18 light hours), and is still slowing down, I'm pretty sure I won't be around when it does hit the light year mark!

Why would it be slowing down?
 
Frobush said:
rynner said:
As it's now about 800 light minutes away (or something over 18 light hours), and is still slowing down, I'm pretty sure I won't be around when it does hit the light year mark!

Why would it be slowing down?
Cos it's getting older, happens to us all. :)
 
Ronson8 said:
Frobush said:
rynner said:
As it's now about 800 light minutes away (or something over 18 light hours), and is still slowing down, I'm pretty sure I won't be around when it does hit the light year mark!

Why would it be slowing down?
Cos it's getting older, happens to us all. :)
Ha ha! :D

But it's slowing down because it's still fighting the sun's gravity.

It's effectively rolling uphill, but because it has escape velocity, it will never stop completely and roll back. You could say it's on a hill that gets less and less steep with time, so it'll keep going forever (or until it falls into the gravity well of another star...)
 
I realised that might be it moments after I posted, but had to dash out before I could delete (this site is way too slow)!
 
Nice article, sunsplash.
"The Voyager technology is so outmoded," said Tidbinbilla's spokesman, Glen Nagle, "we have had to maintain heritage equipment to talk to them."

That is because the ageing probes can only chat at a sluggish 32 bits a second, far too slow for modern computers.

"The computers look like the stuff out of the old sci-fi movies, with blinky lights and big colourful buttons," Mr Nagle said.

To keep them humming, Tidbinbilla relies on its most experienced engineers, including John Murray, who will have been working there for 40 years on Monday. His colleague Ian Warren has knotched up 42 years in the space business.

With the nuclear-powered Voyagers tipped to keep transmitting until at least 2020, Mr Murray has to show younger staff how to maintain the vital hardware. "I find it funny that I send people I am teaching to go and get parts for these machines that are older than them," he said.

But I rather doubt that modern computers couldn't be programmed to do the job. Way back when, Turing showed how a universal computer could perform all possible computations, and even mimic simpler machines.

If the signal rate is slow, well, it's easy to include delays in computer programs so their responses match - in other words, you could program a 'mimic' of Tidbinbilla's old computers.

I'd guess that the computer you're reading this on could do the job in between all the other jobs you use the computer for, without you noticing a thing!

I suspect the reason that the old computers are still used is that it's easier to go with what you know, plus a bit of "If it ain't broke, don't fix it!" philosophy! 8)

Any comments from computer or programming experts?

EDIT: There'sa lot on the web about Turing and universal computers, eg this snippet:
The boldest idea to emerge from Turing’s analysis was that of a universal Turing machine: one that, when furnished with the number describing the mechanism of any particular Turing machine, would perfectly mimic its behavior. In effect, the “hardware” of a special-purpose computer could be translated into “software” and then entered like data into the universal machine, where it would be run as a program—the way, for example, the operating system on your laptop treats a word-processing program as data. What Turing had invented, as a by-product of his advance in logic, was the stored-program computer.
http://infoproc.blogspot.com/2006/02/ne ... ofile.html
 
I suspect the reason that the old computers are still used is that it's easier to go with what you know, plus a bit of "If it ain't broke, don't fix it!" philosophy!

Any comments from computer or programming experts?

Slower than the teleprinters used upto the 70's (certainly prewar too) which could do 50 bits per seconds. It could the cost of the hardware to decode the signal, we still do some work at 50 bits per second but you need to write your own routines (and modern PCs aren't really suited to it) to handle that kind of rate (as well as dedicate recevier circuitry). If you're using a standard UART then the lower limit is normally 110 bit per second.
 
People, I still have an acoustic coupler in a cupboard somewhere, just in case the interweb goes pear shaped, or attains sentience...

:p

Then it's back to bulletin boards!
 
OMG, Bulletin Boards! Please no! I remember those, and I didn't think much of them. God thank the Internet! LOL
 
This may be a very stupid question.

What if Voyager was sent in the wrong direction?

I assume it is flying out into space, say to the right of Earth. But what if life beyond our solar system is to the left!? :shock:
 
McAvennie_ said:
This may be a very stupid question.

What if Voyager was sent in the wrong direction?
The purpose of the mission was to explore the gas giant planets.
At the time the Voyagers were launched there was a rare but convenient alignment of the planets, which made it possible to use 'gravitational slingshots' to achieve this mission without having to carry impossible amounts of fuel.

A side-effect of this was that the probes achieved solar system escape velocity, so they just kept on travelling outwards afterwards, and, remarkably, the probes kept on working. This was a flukey bonus, because the designed mission had already been accomplished.

The two Voyagers are in fact now well separated from each other, but the chance of either of them discovering anything really stunning now must be pretty remote.

http://en.wikipedia.org/wiki/Voyager_program
 
Perhaps "V-GER" will encounter the Enterprise :D


rynner2 said:
McAvennie_ said:
This may be a very stupid question.

What if Voyager was sent in the wrong direction?
The purpose of the mission was to explore the gas giant planets.
At the time the Voyagers were launched there was a rare but convenient alignment of the planets, which made it possible to use 'gravitational slingshots' to achieve this mission without having to carry impossible amounts of fuel.

A side-effect of this was that the probes achieved solar system escape velocity, so they just kept on travelling outwards afterwards, and, remarkably, the probes kept on working. This was a flukey bonus, because the designed mission had already been accomplished.

The two Voyagers are in fact now well separated from each other, but the chance of either of them discovering anything really stunning now must be pretty remote.

http://en.wikipedia.org/wiki/Voyager_program
 
rynner2 said:
McAvennie_ said:
This may be a very stupid question.

What if Voyager was sent in the wrong direction?
The purpose of the mission was to explore the gas giant planets.
At the time the Voyagers were launched there was a rare but convenient alignment of the planets, which made it possible to use 'gravitational slingshots' to achieve this mission without having to carry impossible amounts of fuel.

A side-effect of this was that the probes achieved solar system escape velocity, so they just kept on travelling outwards afterwards

That is true, but there must have been an element of considering the chance of contacting 'life' beyond our solar system or they would not have stowed the time capsule aboard.

Would just be amusingly ironic if the message of greetings was being sent deeper and deeper into space in the opposite direction to where any intelligence is.
 
rynner said:
Nice article, sunsplash.
"The Voyager technology is so outmoded," said Tidbinbilla's spokesman, Glen Nagle, "we have had to maintain heritage equipment to talk to them."

That is because the ageing probes can only chat at a sluggish 32 bits a second, far too slow for modern computers.

"The computers look like the stuff out of the old sci-fi movies, with blinky lights and big colourful buttons," Mr Nagle said.

To keep them humming, Tidbinbilla relies on its most experienced engineers, including John Murray, who will have been working there for 40 years on Monday. His colleague Ian Warren has knotched up 42 years in the space business.

With the nuclear-powered Voyagers tipped to keep transmitting until at least 2020, Mr Murray has to show younger staff how to maintain the vital hardware. "I find it funny that I send people I am teaching to go and get parts for these machines that are older than them," he said.

But I rather doubt that modern computers couldn't be programmed to do the job. Way back when, Turing showed how a universal computer could perform all possible computations, and even mimic simpler machines.

If the signal rate is slow, well, it's easy to include delays in computer programs so their responses match - in other words, you could program a 'mimic' of Tidbinbilla's old computers.

I'd guess that the computer you're reading this on could do the job in between all the other jobs you use the computer for, without you noticing a thing!

I suspect the reason that the old computers are still used is that it's easier to go with what you know, plus a bit of "If it ain't broke, don't fix it!" philosophy! 8)

Any comments from computer or programming experts?
http://infoproc.blogspot.com/2006/02/ne ... ofile.html[/quote]

It is a bit disengenious to say its sending data slowly because its old technology, even a modern probe would have to send the data slowly at that distance in order to avoid errors in the reciever, you can use squiggly maths to show why that should be but its the same reason that people speak slowly when they are in a noisy enviroment and they want to be heard.
 
Voyager near Solar System's edge
By Jonathan Amos
Science correspondent, BBC News, San Francisco

Voyager 1, the most distant spacecraft from Earth, has reached a new milestone in its quest to leave the Solar System.

Now 17.4bn km (10.8bn miles) from home, the veteran probe has detected a distinct change in the flow of particles that surround it.
These particles, which emanate from the Sun, are no longer travelling outwards but are moving sideways.
It means Voyager must be very close to making the jump to interstellar space - the space between the stars.

Edward Stone, the Voyager project scientist, lauded the explorer and the fascinating science it continues to return 33 years after launch.
"When Voyager was launched, the space age itself was only 20 years old, so there was no basis to know that spacecraft could last so long," he told BBC News.
"We had no idea how far we would have to travel to get outside the Solar System. We now know that in roughly five years, we should be outside for the first time."

Dr Stone was speaking here at the American Geophysical Union (AGU) Fall Meeting, the largest gathering of Earth scientists in the world.

Voyager 1 was launched on 5 September 1977, and its sister spacecraft, Voyager 2, on 20 August 1977.
The Nasa probes' initial goal was to survey the outer planets Jupiter, Saturn, Uranus and Neptune, a task completed in 1989.

They were then despatched towards deep space, in the general direction of the centre of our Milky Way Galaxy.

Sustained by their radioactive power packs, the probes' instruments continue to function well and return data to Earth, although the vast distance between them and Earth means a radio message now has a travel time of about 16 hours. 8)

The newly reported observation comes from Voyager 1's Low-Energy Charged Particle Instrument, which has been monitoring the velocity of the solar wind.

This stream of charged particles forms a bubble around our Solar System known as the heliosphere. The wind travels at "supersonic" speed until it crosses a shockwave called the termination shock.

At this point, the wind then slows dramatically and heats up in a region termed the heliosheath. Voyager has determined the velocity of the wind at its location has now slowed to zero.

"We have gotten to the point where the wind from the Sun, which until now has always had an outward motion, is no longer moving outward; it is only moving sideways so that it can end up going down the tail of the heliosphere, which is a comet-shaped-like object," said Dr Stone, who is based at the California Institute of Technology in Pasadena, California.

This phenomenon is a consequence of the wind pushing up against the matter coming from other stars. The boundary between the two is the "official" edge of the Solar System - the heliopause. Once Voyager crosses over, it will be in interstellar space.

First hints that Voyager had encountered something new came in June. Several months of further data were required to confirm the observation.

"When I realized that we were getting solid zeroes, I was amazed," said Rob Decker, a Voyager Low-Energy Charged Particle Instrument co-investigator from the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland.
"Here was Voyager, a spacecraft that has been a workhorse for 33 years, showing us something completely new again."

Voyager is racing on towards the heliopause at 17km/s. Dr Stone expects the cross-over to occur within the next few years.

http://www.bbc.co.uk/news/science-environment-11988466
 
That is utterly remarkable, rynner. That's us out there. We are 17.4 billion klicks from home and it is fucking wonderful that this tub still transmits the experience home so we can be part of the event. I am in true awe.

Can you tell us if there's a destination? A direction? I could find out linkwise, but I reckon you'd know. so..
 
skinny said:
That is utterly remarkable, rynner. That's us out there. We are 17.4 billion klicks from home and it is fucking wonderful that this tub still transmits the experience home so we can be part of the event. I am in true awe.

Can you tell us if there's a destination? A direction? I could find out linkwise, but I reckon you'd know. so..
Its planned destination - a grand tour of the gas giant planets - was succesfully achieved years ago. Since then it's been coasting in free-fall, drifting ever outward under the declining influence of the Sun's gavity.

I don't know which direction it's headed, but I'm pretty sure that it'll have been long out of contact with Earth by the time it next passes anything interesting!
http://en.wikipedia.org/wiki/Voyager_pr ... ar_Mission
 
It's beautiful. Was this drop in Solar influence anticipated? If not, who knows what it might report back in the operating time it has left. And if so, all the same. The imagination boggles.
 
The OP of this thread mentions that both Voyagers are heading roughly towards the centre of the galaxy. Which would be interesting to see, if the probes were still working in a few billion years time!

And long before then we'll probably have sent out far faster probes into deep space, leaving the Voyagers behind like Model T Fords being overtaken by a Formula 1 racer!

But it's a business forever cramped by the limitations of the speed of light. The centre of the galaxy is 24,824 ly (light years) away, so if we sent a probe there at the speed of light, it would be nearly 50,000 years before we got the data back!
 
So does the oblique shape of the heliosphere with the system at one end indicate that the system has velocity in the direction of that end?
 
Wasn't there a star trek film where they found voyager in deep space around the 23rd century ?
 
Ronson8 said:
Wasn't there a star trek film where they found voyager in deep space around the 23rd century ?

Yes. It becomes intelligent and calls itself V'ger.
Let's wait and see if that happens.
 
rynner2 said:
skinny said:
So does the oblique shape of the heliosphere with the system at one end indicate that the system has velocity in the direction of that end?
Briefly, yes.

In much more depth (including Voyager interactions) see
http://en.wikipedia.org/wiki/Heliosphere

According to your link, Dr Stone at the California Institute of Technology is a little out of date saying the heliosphere has a comet-like shape.
 
The destination is Further! Laughing

Beyond the rim of the starlight :p

iirc one of the other Trek movies had a bit with (i think) the other Voyager probe flaoting in deep space and being used for target practice by bored Klingons.
 
BlackRiverFalls said:
iirc one of the other Trek movies had a bit with (i think) the other Voyager probe flaoting in deep space and being used for target practice by bored Klingons.

It was Pioneer (10 or 11, I'm not sure), with the plaque on the side.
 
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