The Longest Space Mission

[ErnstBlofeld]

Space Daily via SPX:

NASA has now sent five spacecraft heading outwards from the solar system. We have Pioneers 10 and 11, Voyagers 1 and 2, and the New Horizons mission, headed for a 2015 rendezvous with Pluto and probably another small world beyond.
The Voyagers have already given us an interesting taste of the boundary of the solar system, detecting the first evidence of the "heliopause", or the region where the sun's influence fades away and interstellar space begins. Neither Voyager has crossed the heliopause, but controllers hope that it will happen in a few years, with at least one of the spacecraft still functioning.

The Voyagers are expected to run out of operational life around 2017, when the power levels from their radioisotope generators will fall too low to transmit properly to Earth. After this, they will join the Pioneers as silent emissaries from Earth to the universe beyond.

Eventually, some time after 2020, New Horizons will also fall silent.

These spacecraft have performed marvelously on their missions, and it's incredible to think that we've been working with the Voyagers for more than 30 years!

This begs the question of how far we can go with our current technology. None of these spacecraft were really designed to do much beyond the edge of the solar system. What if we designed a mission specifically to go beyond the edge?

There's an easy objection to raise for such a proposal. What exactly is out there? After Neptune, we have the Kuiper belt of minor planets, populated by Pluto and many other small worlds.

There are other minor planets beyond the Kuiper belt, some in strange orbits. After that, as far as we currently know, there's a lot of empty space. The next feature we encounter on any map of our region of space is the Oort cloud, a huge spherical shell of space that's believed to contain dormant comets. A mission to the Oort cloud would take a while.

It's thought to be roughly one light year from the Sun! Nothing we can build right now can reach it for centuries, assuming that the probe itself could work for that long.

So our solar system looks like an archipelago of islands, surrounded by a vast sea of apparently empty space.

Is the region beyond the planets and minor planets really so empty? We can't really say for sure. Just decades ago, we knew little of what lurked in the Kuiper belt. We still had no firm knowledge of the heliopause, and we still have much to learn about it.

Until something travels well beyond the heliopause and samples the real environment of interstellar space, we won't have any direct measurements of its properties.

We also don't know for sure that there aren't more dark and mysterious objects lurking in very deep space. Some astronomers still hunt for the elusive Planet X, or an "evil twin" of the Sun that sends comets from the Oort cloud streaming inwards on lethal attacks to life on Earth.

We need to map particles, fields, and small objects such as dust in the interstellar medium. We can also gain much by studying the trajectory of objects in this region, to understand the gravitational properties of the outer solar system, and possibly learn more about the force of gravity itself!

Placing an instrument package into very deep space would also give us an interesting perspective on very distant objects in space. Telescopes are regularly flown above Earth's atmosphere to allow them to see more clearly. Imagine how some instruments would perform if they were removed from the influence of the Sun. This is not regularly discussed by astronomers, but it's worth considering as a long-term project.

How could we go beyond the solar system? It would require a spacecraft far more complex and expensive than any unmanned space mission ever launched. But it could be done with our current technology.

The spacecraft would need a good power supply. Solar power won't work when the Sun is just a bright star. Current radioisotope sources would not provide enough power and would fade too quickly.

The only option is to use a small nuclear fission reactor. These have been flown in space before. There are safety and regulatory issues aplenty. The infamous crash of the Cosmos 954 satellite into Canada showed how careful any handling of reactors in space must


http://www.spacedaily.com/reports/The_Longest_Space_Mission_999.html

[ErnstBlofeld]

You can keep in touch with Voyager 1 and 2 with NASA's weeky Voyager operational reports

 

http://voyager.jpl.nasa.gov/mission/weekly-reports/index.htm

[ErnstBlofeld]

http://pluto.jhuapl.edu/mission/whereis_nh.php

 

The current position of the New Horizons deep space probe.It is updated every hour.

[Pepper]

You can keep in touch with Voyager 1 and 2 with NASA's weeky Voyager operational reports

 

http://voyager.jpl.nasa.gov/mission/weekly-reports/index.htm

 

 

Thanks sonofstrangelove.

 

Voyager 1 was 10,572,000,000 miles from earth at that last report or 10.5 billion, and still has lots of propellant left.

[ErnstBlofeld]

You can keep in touch with Voyager 1 and 2 with NASA's weeky Voyager operational reports

 

http://voyager.jpl.nasa.gov/mission/weekly-reports/index.htm

 

 

Thanks sonofstrangelove.

 

Voyager 1 was 10,572,000,000 miles from earth at that last report or 10.5 billion, and still has lots of propellant left.

 

The propellant is hydrazine.The hydrazine keeps the spacecraft oriented.The Voyager space probes left Earth with with about 115 kg of hydrazine.It has enough hydrazine until 2040. But its suffering from a creeping paralysis because of power.As the electrical power becomes less and less, power loads on the spacecraft must be turned off in order to avoid having demand exceed supply. As loads are turned off spacecraft capabilities are eliminated.