Tag: Voyager 2

According To NASA, Voyager 2 May Be Leaving the Solar System Soon

This NASA diagram illustrates the hypothesized positions of Voyagers 1 and 2 in the solar system as of October 2018. Voyager 1 reached interstellar space in 2012. Voyager 2 may soon hit that milestone.

Want to get away? Want to get far, far away? Voyager 2 has you beat: The spacecraft, launched in 1977, is approaching the edge of the solar system, according to a NASA statement released today (Oct. 5).

That announcement is based on two different instruments on board, which in late August began noticing a small uptick in how many cosmic rays — superfast particles pummeling the solar system from outer space — were hitting the spacecraft.

That matches pretty well with what Voyager 1 began experiencing about three months before its own grand departure in 2012, but scientists can’t be sure of the milestone until after it has been passed.

We’re seeing a change in the environment around Voyager 2, there’s no doubt about that,” Voyager Project Scientist Ed Stone, a physicist at Caltech, said in the statement.




We’re going to learn a lot in the coming months, but we still don’t know when we’ll reach the heliopause. We’re not there yet — that’s one thing I can say with confidence.

The team behind Voyager 2 knows that the spacecraft is currently almost 11 billion miles (17.7 billion kilometers) away from Earth.

But it’s hard to predict when the spacecraft will actually leave the solar system by passing through what scientists call the heliopause.

The heliopause is the bubble around our solar system formed by the solar wind, the rush of charged particles that constantly streams off our sun.

The rate of energetic interstellar particles detected by Voyager 2 started to rise at the end of August 2018. Each point represents a 6-hour average.

But that solar wind ebbs and flows over the course of the sun’s 11-year cycle, which means that the bubble of our solar system itself expands and contracts.

And because Voyager 2 isn’t following precisely in its predecessor’s steps, scientists aren’t positive that its cosmic exit will result in identical changes to the data that the spacecraft reports.

So until Voyager 2 passes through the heliopause, there’s no way to be sure precisely where it is with regard to the heliopause.

Whenever it does successfully flee the solar system, Voyager 2 will become just the second human-made object to do so.

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Voyager Spacecraft Sail On, 41 Years After Launch

Science is primary object of Voyager mission. A science boom deploys in one direction, a magnetometer boom in another; 12-foot parabolic antenna rests on 10-sided basic bus. Nuclear generator will provide power.

Nearly 41 years after lifting off, NASA’s historic Voyager mission is still exploring the cosmos.

The twin spacecraft launched several weeks apart in 1977 — Voyager 2 last Aug. 20 and Voyager 1 last Sept. 5 — with an initial goal to explore the outer solar system.

Voyager 1 flew by Jupiter and Saturn, while its twin took advantage of an unusual planetary alignment to visit Jupiter, Saturn, Uranus and Neptune.

And then the spacecraft kept on flying, for billions and billions of miles. Both remain active today, beaming data home from previously unexplored realms.

Indeed, in August 2012, Voyager 1 became the first human-made object ever to reach interstellar space.

The mission’s legacy reached into film, art and music with the inclusion of a “Golden Record” of Earth messages, sounds and pictures designed to give any prospective alien who encountered it an idea of what humanity and our home planet are like.

This time capsule is expected to last billions of years.

The spacecraft are now flying through space far away from any planet or star; their next close encounter with a cosmic object isn’t expected to occur for 40,000 years.




Their observations, however, are giving scientists more insight into where the sun’s influence diminishes in our solar system, and where interstellar space begins.

Voyager 1 is nearly 13 billion miles (21 billion kilometers) from Earth and has spent five years in interstellar space.

This zone is not completely empty; it contains material left over from stars that exploded as supernovas millions of years ago.

The “interstellar medium” (as the space in this region is called) is not a threat to Voyager 1. Rather, it’s an interesting environment that the spacecraft is studying.

Voyager 2 is nearly 11 billion miles (18 billion km) from Earth and will likely enter interstellar space in a few years, NASA officials have said.

Uranus’ icy moon Miranda is seen in this image captured by Voyager 2 on Jan. 24, 1986.

Its observations from the edge of the solar system help scientists make comparisons between interstellar space and the heliosphere.

When Voyager 2 crosses the boundary, the two spacecraft can sample the interstellar medium from two different locations at the same time.

Mission designers made the spacecraft robust to make sure they could survive the harsh radiation environment at Jupiter.

This included so-called redundant systems — meaning the spacecraft can switch to backup systems if needed — and power supplies that have lasted well beyond the spacecraft’s primary mission.

Each of the spacecraft is powered by three radioisotope thermoelectric generators, which convert the heat produced by the radioactive decay of plutonium-238 into electricity.

An artist’s rendering of a Voyager spacecraft flying past Jupiter, Saturn, and their respective moons

The power available to each Voyager, however, decreases by about 4 watts per year.

This requires engineers to dig into 1970s documentation (or to speak with former Voyager personnel) to operate the spacecraft as its power diminishes.

Even with an eye to efficiency, the last science instrument will have to be shut off around 2030, mission team members have said.

But even after that, the Voyagers will continue their journey (albeit without gathering data), flying at more than 30,000 mph (48,280 km/h) and orbiting the Milky Way every 225 million years.

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The Voyager Space Probe Left Earth 40 Years Ago Today

This month marks 40 years since NASA launched the two Voyager space probes on their mission to explore the outer planets of our Solar System, and Australia has been helping the US space agency keep track of the probes at every step of their epic journey.

CSIRO operates NASA’s tracking station in Canberra, a set of four radio telescopes, or dishes, known as the Canberra Deep Space Communication Complex (CDSCC).

It’s one of three tracking stations spaced around the globe, which form the Deep Space Network. The other two are at Goldstone, in California, and Madrid, in Spain.




Between them they provide NASA, and other space exploration agencies, with continuous, two-way radio communication coverage to every part of the Solar System.

Four decades on and the Australian tracking station is now the only one with the right equipment and position to be able to communicate with both of the probes as they continue to push back the boundaries of deep space exploration.

The Voyagers’ primary purpose was to fly by Jupiter and Saturn. If all the scientific objectives were met at Saturn, then Voyager 2 would be targeted to continue on to Uranus and Neptune.

At each planetary encounter – running on power equivalent to the light bulb in your refrigerator – the Voyagers would transmit photographs and scientific data back to Earth before being accelerated towards their next target by the planet’s gravity, like a slingshot.

Timed to take advantage of a favourable alignment of the outer planets not expected to recur for another 175 years, Voyager 2 launched first on August 20, 1977, followed by Voyager 1 on September 5.

Although launched second, Voyager 1 was sent on a faster trajectory and was timed to arrive at Jupiter ahead of Voyager 2.

When Voyager 1 arrived at Jupiter in 1979 the mission’s scientific discoveries began.

Jupiter

The world watched as the Voyagers’ cameras sent back – via the tracking stations – close up images of Jupiter and its moons, letting us see these worlds in detail for the very first time.

From the turbulence surrounding huge storms on Jupiter, to a volcano erupting on Jupiter’s moon Io, to hints that the icy surface of Europa probably conceals an ocean underneath, the Voyager mission started to reveal the outer Solar System to us in inspiring detail.

Indeed, during the course of their 12-year mission, the Voyagers discovered 24 new moons orbiting the outer planets and refined NASA’s use of the Deep Space Network to listen to signals from distant spacecraft.

Saturn

After Jupiter, both Voyagers went on to encounter Saturn. Voyager 1 achieved the major goal of closely approaching Saturn’s giant moon, Titan.

Following this encounter, with its primary mission ended, Voyager 1 was flung on a northward trajectory above the plain of the orbits of the planets.

Voyager 2 was subsequently targeted to travel outward on an extended mission to visit the next two gas giant worlds.

When Voyager 2 flew past Uranus in January 1986, the signals being received were much weaker than when it flew by Saturn, five years earlier.

Consequently, CSIRO’s radio telescope at Parkes was linked, or arrayed, with NASA’s dishes in Canberra to boost Voyager 2’s weak radio signal.

This was the first time an array of telescopes had been used to track a spacecraft. Yet this array would be insufficient to receive the even fainter signals expected when Voyager 2 reached Neptune in 1989.

So in the time between the encounters, NASA expanded Canberra’s largest dish from 64 metres to 70 metres in diameter to increase its sensitivity, and then linked it again with the Parkes 64 metre dish, to maximise the data capture at Neptune.

The Pale Blue Dot

In 1990 Voyager 1 turned its cameras towards home. The resulting photograph, known as the Pale Blue Dot, is our most distant view of Earth, a fraction of a pixel floating in a deep black sea.

The legendary astrophysicist Carl Sagan, involved with Voyager since its inception, reflected that this distant view of the tiny stage on which we play out our lives should inspire us “to preserve and cherish that pale blue dot, the only home we’ve ever known”.

The Pale Blue Dot.

Both Voyagers have long since left the outer planets behind, two explorers heading into the galaxy in different directions, still sending data back to Earth and answering questions we didn’t even know to ask when they were launched 40 years ago.

Voyagers only talk to Australia

The Canberra tracking station continues to receive signals from both Voyager spacecraft every day, and is currently the only tracking station capable of exchanging signals with Voyager 2, owing to the spacecraft’s position as it heads on its southward path out of the Solar System.

Due to their respective distances, tens of billions of kilometres from home, the signal strength from both spacecraft is very weak, only one-tenth of a billion-trillionth of a watt.

In 2012, Voyager 1 became the first spacecraft to have entered interstellar space, the region between the stars.

Lying beyond the influence of the magnetic bubble generated by our Sun, Voyager 1 is able to directly study the composition of the interstellar medium, for the first time.

Voyager 1 is still receiving commands that can only be sent from Canberra’s dishes. It is the only station with the high-power transmitter that can transmit a signal strong enough to be received by the spacecraft.

It has been an epic voyage for two spacecraft no bigger than small buses, two brilliant robots with an eight track tape deck to record data and 256kB of memory.

A golden message

The scientists and engineers at NASA’s Jet Propulsion Laboratory in California, who built the Voyagers and continue to operate them, planned ahead for Voyager’s legacy and its journey beyond our Solar System.

On board both spacecraft they placed a golden record, similar in concept to a vinyl record, featuring one and a half hours of world music and greetings to the universe in 55 different languages.

The cover art features a pictorial representation of how to play the record and a map reference to Earth’s location in our galaxy based on the positions of surrounding pulsars.

The first of the 31 recordings. Click on the video to hear the rest.

By 2030, both Voyagers will be out of power, their scientific instruments deactivated, no longer able to exchange signals with Earth.

They will continue on at their current speeds of more than 17 kilometres per second, carrying their golden records like messages in bottles across the vast ocean of interstellar space.

Heading in opposite directions, southward and northward out of the Solar System, it will be 40,000 years before Voyager 2 passes within a handful of light years of the closest star system along its flight path, and 296,000 years before Voyager 1 passes by the bright star Sirius.

Beyond that, we may imagine them surviving for billions of years as the only traces of a civilisation of human explorers in the far reaches of our galaxy.

John Sarkissian is an Operations Scientist at the CSIRO and Ed Kruzins is a Facilities Program Director Nasa Operations Canberra Deep Space Communication Complex at the CSIRO.

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