2007-08-21 10:10:00
SPACE.com Staff
SPACE.comMon Aug 20, 1:30 PM ET
NASA's two Voyager spacecraft are celebrating three decades of flight as they
careen toward interstellar space billions of miles from the solar system's
edge.
Voyager 2 launched on Aug. 20, 1977, and Voyager 1 launched on Sept. 5, 1977.
Both spacecraft continue to return information from distances more than three
times farther away than Pluto, where the sun's outer heliosphere meets the
boundary of interstellar space.
"The Voyager mission is a legend in the annals of space exploration. It opened
our eyes to the scientific richness of the outer solar system, and it has
pioneered the deepest exploration of the sun's domain ever conducted," said
Alan Stern, associate administrator for NASA's Science Mission Directorate,
Washington, D.C. "It's a testament to Voyager's designers, builders and
operators that both spacecraft continue to deliver important findings more than
25 years after their primary mission to Jupiter and Saturn concluded."
Voyager's designers, builders and operators that both spacecraft continue to
deliver important findings more than 25 years after their primary mission to
Jupiter and Saturn concluded."
Voyager 1 currently is the farthest human-made object at a distance from the
sun of about 9.7 billion miles (15.6 billion kilometers). Voyager 2 is about
7.8 billion miles (12.6 billion kilometers).
Originally designed as a four-year mission to Jupiter and Saturn, the Voyager
tours were extended because of their successful achievements and a rare
planetary alignment. The two-planet mission eventually became a four-planet
grand tour. After completing that extended mission, the two spacecraft began
the task of exploring the outer heliosphere.
During their first dozen years of flight, the spacecraft explored Jupiter,
Saturn, Uranus, Neptune and their moons. These planets were previously unknown
worlds. The Voyagers returned never-before-seen images and scientific data and
helped make fundamental discoveries about the outer planets and their moons.
The spacecraft revealed Jupiter's turbulent atmosphere, which includes dozens
of interacting hurricane-like storm systems, and erupting volcanoes on
Jupiter's moon Io. They also showed waves and fine structure in Saturn's icy
rings from the tugs of nearby moons.
"The Voyager mission has opened up our solar system in a way not possible
before the Space Age," said Edward Stone, Voyager project scientist at the
California Institute of Technology, Pasadena, Calif. "It revealed our neighbors
in the outer solar system and showed us how much there is to learn and how
diverse the bodies are that share the solar system with our own planet Earth."
In December 2004, Voyager 1 began crossing the solar system's final frontier.
Called the heliosheath, this turbulent area, approximately 8.7 billion miles
from the sun, is where the solar wind slows as it crashes into the thin gas
that fills the space between stars. Voyager 2 could reach this boundary later
this year, putting both Voyagers on their final leg toward interstellar space.
Each spacecraft carries five fully functioning science instruments that study
the solar wind, energetic particles, magnetic fields and radio waves as they
cruise through this unexplored region of deep space. The spacecraft are too far
from the sun to use solar power, and instead run on radioactive generators that
produce less than 300 watts of power, the amount of power needed to light up a
bright light bulb..
"The continued operation of these spacecraft and the flow of data to the
scientists is a testament to the skills and dedication of the small operations
team," said Ed Massey, Voyager project manager at NASA's Jet Propulsion
Laboratory in Pasadena, Calif.
The Voyagers call home via NASA's Deep Space Network, a system of antennas
around the world. The spacecraft are so distant that commands from Earth,
traveling at light speed, take 14 hours one-way to reach Voyager 1 and 12 hours
to reach Voyager 2. Each Voyager logs approximately 1 million miles per day.
Each of the Voyagers carries a golden record that is a time capsule with
greetings, images and sounds from Earth. The records also have directions on
how to find Earth if the spacecraft is recovered by something or someone.
NASA's next outer planet exploration mission is New Horizons, which is now well
past Jupiter and headed for a historic exploration of the Pluto system in July
2015.
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