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To boldly go beyond the Solar System | To boldly go beyond the Solar System |
(about 7 hours later) | |
By David Shukman Environment & science correspondent, BBC News, Pasadena | By David Shukman Environment & science correspondent, BBC News, Pasadena |
Keep your voice down, the press officer warns me, as I step inside Nasa's mission control room in California, a centre with an utterly unique role in the exploration of space. | Keep your voice down, the press officer warns me, as I step inside Nasa's mission control room in California, a centre with an utterly unique role in the exploration of space. |
It's almost silent and very dark, here at the Jet Propulsion Laboratory in Pasadena and operators are hunched over banks of consoles. | It's almost silent and very dark, here at the Jet Propulsion Laboratory in Pasadena and operators are hunched over banks of consoles. |
These are people with an extraordinary job: they provide the sole connection with mankind's most distant creations. | These are people with an extraordinary job: they provide the sole connection with mankind's most distant creations. |
Above us a giant screen is gently filling with numbers, row after row of digits - it's the daily flow of data from an inconceivably remote corner of space. | Above us a giant screen is gently filling with numbers, row after row of digits - it's the daily flow of data from an inconceivably remote corner of space. |
At the start of each line of figures, there's a three-letter code - VGR - that represents the longest expedition ever mounted in human history. | At the start of each line of figures, there's a three-letter code - VGR - that represents the longest expedition ever mounted in human history. |
VGR stands for the pair of spacecraft, Voyagers 1 & 2, launched way back in 1977 and now entering a realm never visited before - the very edge of the Solar System. | VGR stands for the pair of spacecraft, Voyagers 1 & 2, launched way back in 1977 and now entering a realm never visited before - the very edge of the Solar System. |
As another row of figures nudges its way on the screen, I try to comprehend what they've crossed to reach here. | As another row of figures nudges its way on the screen, I try to comprehend what they've crossed to reach here. |
Waiting game | Waiting game |
One measure is that it takes an incredible 16 hours for their radio transmissions to arrive on Earth. | One measure is that it takes an incredible 16 hours for their radio transmissions to arrive on Earth. |
And if the controllers need to send a signal back out to them, it takes the same again - 32 hours in all to fire off a message and get a response. | And if the controllers need to send a signal back out to them, it takes the same again - 32 hours in all to fire off a message and get a response. |
Guiding me through this is the godfather of the mission, a sprightly professor in his 70s who is still bursting with the same enthusiasm he felt when he began the project in 1972. | Guiding me through this is the godfather of the mission, a sprightly professor in his 70s who is still bursting with the same enthusiasm he felt when he began the project in 1972. |
This is Ed Stone, something of a legend in space circles. Few other scientific endeavours have lasted this long and he's followed every twist and turn. | This is Ed Stone, something of a legend in space circles. Few other scientific endeavours have lasted this long and he's followed every twist and turn. |
I ask about the distances involved and he can't wait to explain. | I ask about the distances involved and he can't wait to explain. |
"When you feel the effects of the Sun," Professor Stone tells me, "that's how the Sun was eight minutes ago. But when you get a message from Voyager, that's how it was 16 hours ago." | "When you feel the effects of the Sun," Professor Stone tells me, "that's how the Sun was eight minutes ago. But when you get a message from Voyager, that's how it was 16 hours ago." |
He seems to relish the scale of the numbers - and is obviously used to having a reporter stand open-mouthed beside him. | He seems to relish the scale of the numbers - and is obviously used to having a reporter stand open-mouthed beside him. |
The Voyagers, he says, are travelling at 17 kilometres per second (38,000 mph). And their computing power? A decent smart phone has ten million times more memory than all three on-board computers combined. | |
Yet what they have shown us still inspires. Among many revelations, Jupiter's moon Io was seen to be the most volcano-wracked body in the Solar System and Neptune's deep-frozen moon Triton to be blasted by geysers. | Yet what they have shown us still inspires. Among many revelations, Jupiter's moon Io was seen to be the most volcano-wracked body in the Solar System and Neptune's deep-frozen moon Triton to be blasted by geysers. |
And then the little craft ventured beyond the orbits of the planets - further than any other manmade machines - and entered a region labelled with a bizarre vocabulary unfamiliar to most of us. | And then the little craft ventured beyond the orbits of the planets - further than any other manmade machines - and entered a region labelled with a bizarre vocabulary unfamiliar to most of us. |
They travelled through the exotically-named "termination shock" - where the Sun's flow, or wind, of particles suddenly decelerates. | They travelled through the exotically-named "termination shock" - where the Sun's flow, or wind, of particles suddenly decelerates. |
Now they're in the heliosheath - the outer zone of the Sun's influence. At some unknown point they'll cross the heliopause, defined as the final limit of the Solar System. | Now they're in the heliosheath - the outer zone of the Sun's influence. At some unknown point they'll cross the heliopause, defined as the final limit of the Solar System. |
Then they'll enter interstellar space - the void between stars - where our Sun will become just another speck, one among billions. | Then they'll enter interstellar space - the void between stars - where our Sun will become just another speck, one among billions. |
According to Professor Stone, with four instruments still working on Voyager 1 and five on Voyager 2, new findings are made almost every day. | According to Professor Stone, with four instruments still working on Voyager 1 and five on Voyager 2, new findings are made almost every day. |
Sensors measure the speed and density of the solar wind, the magnetic field, energetic particles and radio waves - all providing clues about the pioneering moment when humankind will first venture beyond the Solar System. | Sensors measure the speed and density of the solar wind, the magnetic field, energetic particles and radio waves - all providing clues about the pioneering moment when humankind will first venture beyond the Solar System. |
Borrowed time | Borrowed time |
I ask why he thinks the Voyager expedition attracts such support and so much attention. It's a mission everyone loves to hear about. | I ask why he thinks the Voyager expedition attracts such support and so much attention. It's a mission everyone loves to hear about. |
"It's the urge," he says, "to explore our solar neighbourhood and now we're about to explore outside our solar bubble. It's remarkable how it resonates with the public." | "It's the urge," he says, "to explore our solar neighbourhood and now we're about to explore outside our solar bubble. It's remarkable how it resonates with the public." |
So, what next? | So, what next? |
The plutonium power source will stop generating electricity in about 10-15 years and there's no way to extend it so the spacecraft's electronic systems will die. No more messages will be sent after 2025. | The plutonium power source will stop generating electricity in about 10-15 years and there's no way to extend it so the spacecraft's electronic systems will die. No more messages will be sent after 2025. |
"Then they'll become silent ambassadors orbiting around the centre of the Milky Way." | "Then they'll become silent ambassadors orbiting around the centre of the Milky Way." |
And where are they heading once they leave the Solar System? | And where are they heading once they leave the Solar System? |
Voyager 1 is on course to approach a star called AC +793888 - but it will only get within two light-years of it. | Voyager 1 is on course to approach a star called AC +793888 - but it will only get within two light-years of it. |
Voyager 2 is hurtling towards another star named Ross 248 - but, again, even at its closest, it will still be a whole light-year away. | Voyager 2 is hurtling towards another star named Ross 248 - but, again, even at its closest, it will still be a whole light-year away. |
And when are these encounters due? Professor Stone can't help laughing with delight. He knows his answer will amaze me. | And when are these encounters due? Professor Stone can't help laughing with delight. He knows his answer will amaze me. |
"In about 40,000 years' time." | "In about 40,000 years' time." |
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