Voyager 1's exit from our solar system
Discussion
Of course, some of the original scientists and engineers who worked on Voyager are no longer with us.
But those two probes revolutionised our knowledge of the Solar System and showed us what a dynamic and violent place the outer planets and their moons are. Before 1977, it was often assumed that the outer planets (Jupiter excepted) and their moons were quiet and frozen worlds.
How wrong we were.
But those two probes revolutionised our knowledge of the Solar System and showed us what a dynamic and violent place the outer planets and their moons are. Before 1977, it was often assumed that the outer planets (Jupiter excepted) and their moons were quiet and frozen worlds.
How wrong we were.
Points like that always make me consider how much we are wrong about right now. It's not a new thought to say that if we have been wrong about nearly everything in the sciences before(outside of most of biology etc.), then we are in all probability wrong about it all right now. Prime example from the Voyager mission:
Life's Little Mysteries said:
This "stagnation region" came as a surprise. Scientists had expected to see the solar wind veer sideways when it met the heliopause, like water hitting a wall, rather than screech to a halt. As Voyager scientists explained in a paper published last month in Nature, the perplexing collapse of the solar wind at the edge of the heliosphere left them without a working model for the outer solar system.
Once saw an interview with Carl Sagan and Arthur C Clarke, they were both asked where the ultimate destiny lies for the Voyager probes.
Sagan commented about how it'll reach an extra-Solar system in about 40000 years, Clarke said they'll end up in the Smithsonian as eventually we'll have the technology to go and retrieve them.
Probably neither will happen, but either way it's an incredible story.
Sagan commented about how it'll reach an extra-Solar system in about 40000 years, Clarke said they'll end up in the Smithsonian as eventually we'll have the technology to go and retrieve them.
Probably neither will happen, but either way it's an incredible story.
Eric Mc said:
The Voyagers have working instruments on board that can record the space environment around them - like magnetometers and particle detectors. It is these intruments that are picking up the sun's magnetic field and solar wind - and also cosmic particles coming in from deep space. The cameras were switched off permanently years ago - to save power.
Regarding ion drive, in theory the craft will keep accelerating as long as the ion motor keeps pushing. How long it can keep pushing is limited by the amount of fuel it can cary on board to feed the engine. So far, the ion powered spacecraft have been big enough to carry enough fuel to push for a few months - which more or less brought the craft up to the types of speeds we would see with a traditional rocket motor. However, bigger probes with bigger fuel tanks would be able to go quite a bit faster - if and when they get around to building such a spacecraft.
Hmm, shame it would have been nice if it could have sent a few snaps back Regarding ion drive, in theory the craft will keep accelerating as long as the ion motor keeps pushing. How long it can keep pushing is limited by the amount of fuel it can cary on board to feed the engine. So far, the ion powered spacecraft have been big enough to carry enough fuel to push for a few months - which more or less brought the craft up to the types of speeds we would see with a traditional rocket motor. However, bigger probes with bigger fuel tanks would be able to go quite a bit faster - if and when they get around to building such a spacecraft.
I think I may have got my engine tech confused, I thought there were some types of ion engine which in theory could fuel themselves and go on virtually forever.
Eric Mc said:
As for an unlimited engine - that equates to perpetual energy - which is impossible. All engines need a useable fuel supply. An ion drive engine is no different.
But space is not a complete vacuum, it does have odd atoms floating about in it. So I think the idea is to get the ship moving fast enough that it can scoop up enough atoms per unit time to destructify them and poot them out the back. Like one of those ramjet jobbies.Simpo Two said:
Eric Mc said:
As for an unlimited engine - that equates to perpetual energy - which is impossible. All engines need a useable fuel supply. An ion drive engine is no different.
But space is not a complete vacuum, it does have odd atoms floating about in it. So I think the idea is to get the ship moving fast enough that it can scoop up enough atoms per unit time to destructify them and poot them out the back. Like one of those ramjet jobbies.Simpo Two said:
Eric Mc said:
As for an unlimited engine - that equates to perpetual energy - which is impossible. All engines need a useable fuel supply. An ion drive engine is no different.
But space is not a complete vacuum, it does have odd atoms floating about in it. So I think the idea is to get the ship moving fast enough that it can scoop up enough atoms per unit time to destructify them and poot them out the back. Like one of those ramjet jobbies.Smiler. said:
With the advances in technology since the build of V1 & V2, would another mission not be worth considering?
OT but there have been some really excellent programmes from the beeb recently (on 2 or 4, obviously).
I understood from the recent programme that the reason the Voyager 1 & 2 were launched was that it was suddenly discovered the planets were coming into an alignment which would allow a satellite to 'sling shot' from one to the next. This wouldn't happen again for 140 years or so and the scientists had to get a bit of a move on! A Voyager 3 launched today wouldn't get this assistance so would need vastly more fuel for a more limited list of 'visits'. OT but there have been some really excellent programmes from the beeb recently (on 2 or 4, obviously).
Maybe the fact that the Voyagers didn't have today's advanced computer systems has contributed to their long active lives?
It wasn't actually a sudden discovery.
Since at least the 1950s it was realised that the outer planets would line up favourably from the mid 1970s so that a spacecraft heading out to the far reaches of the Solar System could make use of gravitational assist to pick up some "free" additional speed and direction changes.
Planning for such a mission began in the mid 1960s. Initially, the project was reffered to as The Grand Tour and was expected to involve a highly complex and capable spacecraft - the most expensive and biggest space probe ever envisaged at that time.
However, Congress sat on the budget and effectively caused the project to be cancelled. NASA went back to the drawing board and came up with a cut-down version of the mission using two ptrobes rather than one and basing the probes on existing Mariner spacecraft hardware - the main difference being that solar power was not really feasible for a spacecraft heading out into deep space. Instead, a nuclear isotope generator would be used to power the spacecraft.
The Mariner-Jupiter project was eventually renamed Voyager.
Since at least the 1950s it was realised that the outer planets would line up favourably from the mid 1970s so that a spacecraft heading out to the far reaches of the Solar System could make use of gravitational assist to pick up some "free" additional speed and direction changes.
Planning for such a mission began in the mid 1960s. Initially, the project was reffered to as The Grand Tour and was expected to involve a highly complex and capable spacecraft - the most expensive and biggest space probe ever envisaged at that time.
However, Congress sat on the budget and effectively caused the project to be cancelled. NASA went back to the drawing board and came up with a cut-down version of the mission using two ptrobes rather than one and basing the probes on existing Mariner spacecraft hardware - the main difference being that solar power was not really feasible for a spacecraft heading out into deep space. Instead, a nuclear isotope generator would be used to power the spacecraft.
The Mariner-Jupiter project was eventually renamed Voyager.
Eric Mc said:
At the distance they are at now - there is nothing to photograph. They really are in dark, deep space.
Shirely there would be masses and masses of starts and it's still relatively close to the sun compared to proximity to other stars? I can't imagine it being anything like dark. Or are you talking about no planets to photo?The cameras were not designed to look at stars - so wouldn't be able to detect their low light levels. Also, even at that distance, stars wouldn't look much different to what they do from earth. The Hubble Space Telescope is much better equipped for that sort of work.
The clever thing to do is preserve the power supply so that the other working instruments have enough power to detect what they were designed to do - changes in the radiation and magnetic field environment through which the spacecraft is passing.
The clever thing to do is preserve the power supply so that the other working instruments have enough power to detect what they were designed to do - changes in the radiation and magnetic field environment through which the spacecraft is passing.
Dogwatch said:
Maybe the fact that the Voyagers didn't have today's advanced computer systems has contributed to their long active lives?
I think quite possibly, yes. There is a fantastic desire these days to make everything as complicated as possible, and with complexity comes fickleness.What surprise me is how they still have power, as they must be far too far away from light for solar panels to work and I can't imagine a 40 year old battery would be much good.
Guvernator said:
This is what I was referring to, I thought they are looking at the possibility of engines which could use the "free fuel" floating in space. I am sure I have read quite a bit about how this would be feasible.
Bussard ramjet - some studies suggest that the ramscoop would be a rather effective 'airbrake'.Simpo Two said:
What surprise me is how they still have power, as they must be far too far away from light for solar panels to work and I can't imagine a 40 year old battery would be much good.
radioisotope thermoelectric generatorSimpo Two said:
Dogwatch said:
Maybe the fact that the Voyagers didn't have today's advanced computer systems has contributed to their long active lives?
I think quite possibly, yes. There is a fantastic desire these days to make everything as complicated as possible, and with complexity comes fickleness.What surprise me is how they still have power, as they must be far too far away from light for solar panels to work and I can't imagine a 40 year old battery would be much good.
Simpo Two said:
Eric Mc said:
Regarding ion drive, in theory the craft will keep accelerating as long as the ion motor keeps pushing. How long it can keep pushing is limited by the amount of fuel it can cary on board to feed the engine.
And its speed. IIRC mass increases as you reach c; IIRC to infinity. To accelerate infinte mass requires infinite power - one reason why you can't go faster than light. Or so my undergraduate brain recalls.Apart from the fuel supply, the main limit is power - ion engines are electrically powered, and the probes using them to date have had large solar arrays to power the ion engine - not much use for a mission to the outer planets where solar power rapidly drops off due to the distance from the Sun. Nuclear power is the only option ( unless you have jettisonable solar panels that are dumped after you have finished accelerating while still fairly near the Sun ), and even nuclear RTG generators degrade over time as their nuclear fuel ( thorium ? ) becomes depleted - Voyager's RTGs are currently producing a fraction of the power they did when launched, which is why all non-essential systems such as the cameras have been turned off.
qube_TA said:
Once saw an interview with Carl Sagan and Arthur C Clarke, they were both asked where the ultimate destiny lies for the Voyager probes.
Sagan commented about how it'll reach an extra-Solar system in about 40000 years, Clarke said they'll end up in the Smithsonian as eventually we'll have the technology to go and retrieve them.
Probably neither will happen, but either way it's an incredible story.
And this is why ACC will always be my fav author. Such incredible imagination. I hope that becomes reality one day in the same way that life often imitates art (Star Trek communicators and the Motorola StarTac for example).Sagan commented about how it'll reach an extra-Solar system in about 40000 years, Clarke said they'll end up in the Smithsonian as eventually we'll have the technology to go and retrieve them.
Probably neither will happen, but either way it's an incredible story.
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