Who doesn't recall the first Star Trek Movie, where an unknown craft threatens Earth and the crew of the Enterprise must stop it? "Vger" is discovered and finally it's true name and original purpose reveal.
Just what is in store for Voyager 1 and 2 as they leave our solar system and begin the trek across interstellar space? Time will tell if we lose them forever to the deep of space, or if one day, like in the movie, one or both of them return home. -SW
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FoxNews- Endeavour may be grounded, but Voyager just keeps on going.
NASA experts noted that more than 30 years after the twin Voyager probes set sail for space, they are now poised on the edge of the solar system -- and set to continue their voyage into interstellar space.
And they're both working fine.
“It’s uncanny,” says Ed Stone of the California Institute of Technology in Pasadena, Voyager Project Scientist since 1972. “Voyager 1 and 2 have a knack for making discoveries,” he added.
Voyager 1 has visited Jupiter and Saturn, while Voyager 2 has flown past Jupiter, Saturn, Uranus and Neptune. Stone’s partial list of discoveries from those missions include the discovery of volcanoes on Jupiter’s moon Io; evidence for an ocean beneath the icy surface of Europa; hints of methane rain on Saturn’s moon Titan; icy geysers on Neptune’s moon Triton; and more.
Each of these discoveries changed the way we thought of other worlds,” says Stone. In 1980, Voyager 1 used the gravity of Saturn to fling itself slingshot-style out of the plane of the solar system. In 1989, Voyager 2 got a similar assist from Neptune.
With that assist, both probes set sail into the void.
They presently navigate the "heliosheath," a strange place filled with a magnetic froth no spacecraft has ever encountered before, echoing with low-frequency radio bursts heard only in the outer reaches of the solar system, so far from home that the Sun is a mere pinprick of light.
“In many ways, the heliosheath is not like our models predicted,” says Stone.
No one knows exactly how many more miles the Voyagers must travel before they “pop free” into interstellar space, however. But most researchers believe the end is near.
“The heliosheath is 3 to 4 billion miles in thickness,” estimates Stone. “That means we’ll be out within five years or so.”
There is plenty of power for the rest of the journey. Both Voyagers are energized by the radioactive decay of a Plutonium 238 heat source.This should keep critical subsystems running through at least 2020.
After that, he says, “Voyager will become our silent ambassador to the stars.”
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Voyager probes to leave solar system by 2016
Twin spacecraft about to 'get outside of our bubble,' says scientist
|Image: Artist's concept of the Voyager probes near interstellar space|
MSNBC- It may be decades before humanity sets foot on Mars, but we're only five years away from sampling the vast stretches of interstellar space beyond our solar system for the first time, researchers say.
NASA's twin unmanned Voyager spacecraft, which were launched in 1977, are streaking toward the edge of the solar system at around 37,000 mph. At that rate, they'll probably pop out of our sun's sphere of influence and into interstellar space by 2016 or so, according to mission scientists.
"They are about to break free of the solar system," Ed Stone, Voyager project scientist at Caltech in Pasadena, Calif., said during a media teleconference April 28. "We are trying to get outside of our bubble, into interstellar space, to directly measure what is there."
A long history of exploration
Voyager 2 was launched on Aug. 20, 1977, and its twin Voyager 1 blasted off a few weeks later, on Sept 5. Both spacecraft were tasked mainly with studying Jupiter, Saturn and their moons. [ 5 Facts About NASA's Voyager Spacecraft ]
The spacecraft are also carrying so-called "golden records" containing the distilled essences of humanity, such as various musical offerings and greetings to the universe in 55 different languages. The goal is to teach alien civilizations a little about us, should they ever pluck the Voyagers out of the void.
In their early years, the Voyagers made a series of important discoveries about the giant planets. For example, the mission detected active volcanoes on Jupiter's moon Io — the first time such features were found beyond Earth. The spacecraft also found evidence of a liquid-water ocean beneath the icy surface of Jupiter's moon Europa.
"Each of these discoveries changed the way we thought of other worlds," Stone said in a statement.
The Voyagers made it past Saturn, with the spacecraft examining Neptune and Uranus as well. And then they just kept on going, zooming toward the edge of the solar system in different directions and different planes.
Voyager 1 is now about 11 billion miles from Earth, while Voyager 2 is about 9 billion miles away, Stone said. Voyager 1 is the most far-flung human-made object in the universe. [ NASA's 10 Greatest Science Missions ]
Probing the heliosheath
While the Voyagers have left the planets well behind, they're not beyond the solar system yet. They're still within a huge bubble called the heliosphere, which is made of solar plasma and solar magnetic fields. This gigantic structure is about three times wider than the orbit of Pluto, researchers said.
Specifically, the Voyagers are plying the heliosphere's outer shell, a turbulent region called the heliosheath.
"We're smelling, we're touching the ionized matter in the heliosheath," said Merav Opher of Boston University, a Voyager guest investigator.
The Voyagers are helping scientists better understand the mysterious heliosphere. For example, measurements from the spacecraft revealed that the structure is distorted and asymmetric, yanked out of shape by the interstellar magnetic field, researchers said.
And in June 2010, Voyager 1 measured the outward velocity of the solar wind — the million-mile-per-hour stream of charged particles coming from the sun — to be zero in its location in the heliosheath. That surprising reading hasn't changed since.
Researchers don’t think the solar wind has stopped out there; they believe it may have just turned a corner. So they've recently started ordering Voyager 1 to do a series of acrobatic maneuvers, to point its instruments in different directions so the craft can pick up and track the puzzling solar breeze.
The heliosheath looks to be about 3 to 4 billion miles thick, and the spacecraft are already well into it. Based on their speed, they should be out in about five years, Stone said.
That time frame is manageable. The Voyagers' radioisotope thermoelectric generators — which convert the heat emitted by plutonium's radioactive decay into electricity — can power their instruments until at least 2020. And the spacecraft have enough hydrazine fuel left to perform maneuvers for another 60 years, researchers said.
Of course, there are no signposts marking the start of interstellar space, where the Voyagers will escape the sun's wind and magnetic field only to be buffeted by those of other, far-flung stars. So astronomers will probably have a hard time knowing when the historic moment occurs.
"We are starting to talk about what we expect to see," Stone said. "I suspect, like in the past, we will be surprised, and we may in fact have a debate for a year or two before we finally decide, 'We have crossed the boundary.'"
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