Voyager 1: ‘The Spacecraft That Could’ Hits New Milestone
Jet Propulsion Laboratory
August 15, 2006
Voyager 1, already the most distant human-made object in the cosmos,
reaches 100 astronomical units from the sun on Tuesday, August 15 at
5:13 p.m. Eastern time (2:13 p.m. Pacific time). That means the
spacecraft, which launched nearly three decades ago, will be 100 times
more distant from the sun than Earth is.
In more common terms, Voyager 1 will be about 15 billion kilometers
(9.3
billion miles) from the sun. Dr. Ed Stone, Voyager project scientist
and
the former director of NASA’s Jet Propulsion Laboratory in Pasadena,
Calif., says the Voyager team always predicted that the spacecraft
would
have enough power to last this long.
“But what you can’t predict is that the spacecraft isnt going to wear
out or break. Voyager 1 and 2 run 24 hours a day, seven days a week,
but
they were built to last,” Stone said. The spacecraft have really been
put to the test during their nearly 30 years of space travel, flying by
the outer planets, and enduring such challenges as the harsh radiation
environment around Jupiter.
The spacecraft are traveling at a distance where the sun is but a
bright
point of light and solar energy is not an option for electrical power.
The Voyagers owe their longevity to their nuclear power sources, called
radioisotope thermoelectric generators, provided by the Department of
Energy.
Voyager 1 is now at the outer edge of our solar system, in an area
called the heliosheath, the zone where the sun’s influence wanes. This
region is the outer layer of the ‘bubble’ surrounding the sun, and no
one knows how big this bubble actually is. Voyager 1 is literally
venturing into the great unknown and is approaching interstellar space.
Traveling at a speed of about one million miles per day, Voyager 1
could
cross into interstellar space within the next 10 years.
“Interstellar space is filled with material ejected by explosions of
nearby stars,” Stone said. “Voyager 1 will be the first human-made
object to cross into it.”
Voyager Project Manager Ed Massey of JPL says the survival of the two
spacecraft is a credit to the robust design of the spacecraft, and to
the flight team, which is now down to only 10 people. “But its these 10
people who are keeping these spacecraft alive. Theyre very dedicated.
This is sort of a testament to them, that we could get all this done.”
Between them, the two Voyagers have explored Jupiter, Uranus, Saturn
and
Neptune, along with dozens of their moons. In addition, they have been
studying the solar wind, the stream of charged particles spewing from
the sun at nearly a million miles per hour.
Media contact: Jane Platt/JPL (818) 354-0880