Voyager at the edge of the Solar System 


Just as it has begun to achieve its final goal to be the first human artifact to leave the solar system and enter interstellar space, Voyager, along with several other operating NASA missions, has been budgeted for termination of operations next year. 

After over 27 years in space, the Voyager 1 spacecraft recently flew through the so-called heliospheric termination shock. Three times as far from the Sun as Pluto, it reached the place where the solar wind slows abruptly, piles up, and turns downstream, guided by the interstellar wind expanding past our solar system from the center of the galaxy. One of more than 100 science news articles worldwide can be found at: http://www.nytimes.com/2005/05/31/science/space/31voyager.html
Instructions are given there for creating an analogous termination shock in your kitchen sink (called a hydraulic jump), with some explanatory graphics.

Voyager looked back toward Earth from beyond Mars so that we could view ourselves from deep space on what Carl Sagan famously described as a "Pale Blue Dot". It then flew past Jupiter, Saturn, Uranus, and Neptune, with their numerous moons, on a grand tour of the fortuitously-aligned planets of the outer solar system. It has inspired an entire generation of explorers with detailed photographs and data that have been unobtainable by any other means but "being there".

Just as it has begun to achieve its final goal to be the first human artifact to leave the solar system and enter interstellar space, Voyager, along with several other operating NASA missions, has been budgeted for termination of operations next year. Voyager costs about $4M per year to operate, less than 0.25% of the cost of launching such a mission and guilding it to Voyager's current position. It can send back data for about 15 more years, at which point its radioisotope thermal generator will expire. By that time it should make the first measurements of conditions outside the solar system.

In the words of an editorial in Nature: "Only a confused space agency would consider shutting down the Voyager spacecraft as they approach the uncharted edge of the Solar System." Indications are that the new NASA administrator, Michael Griffin, means to remedy this. 

Posted: Sat - June 4, 2005 at 10:06 a.m.         | |

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