© Mark Ollig
In 1977, NASA launched two identical deep-space probes named Voyager 1 and Voyager 2 from Cape Canaveral, FL.
Because Voyager 2 needed to travel on a precise trajectory to pass closely by our solar system’s outermost planets, it launched on Aug. 20, 1977, 16 days ahead of Voyager 1, which launched on Sept. 5.
Each spacecraft measures 66-feet long, 12-feet wide, and 7.5-feet tall.
The
two Voyagers have been operational for nearly 44 years. They continue to
receive commands from NASA and transmit data back to Earth.
Both
have explored our solar system, sending photos and scientific data back to
Earth.
The
two spacecraft have left our solar system by breaching the heliosphere and are
currently voyaging through interstellar space.
Voyager
1 is presently 14.1 billion miles from Earth and traveling at 38,000 mph, while
its companion, Voyager 2, is 11.8 billion miles out and moving at 34,300 mph.
To
put these distances into perspective, Earth is now 240,377 miles from the moon,
93.03 million miles from the sun, and 168.4 million miles from Mars.
Because
they are traveling away from the sun, the Voyagers cannot use solar panels to
generate electricity.
Instead,
with the Department of Energy’s cooperation, NASA placed ten pounds of
plutonium-238 aboard each Voyager.
That’s
right. Voyager is powered by “nuclear batteries.”
Each
Voyager spacecraft power system consists of three separate 83-pound
radioisotope thermoelectric generators (RTG) that produce electrical power
using heat from the plutonium’s natural radioactive decay.
After
the Voyagers launched from Earth, the RTGs generated 400 watts of power to
operate the scientific instrumentation, the crafts thruster maneuverability,
and communications with Earth.
Over
the years, NASA needed to turn off the cameras and some onboard electrical
instrumentation to conserve energy.
Voyager
1 currently has four scientific instruments active, while Voyager 2 has five.
At
this time, each spacecraft is operating using 249 watts of power.
As
power availability decreases, NASA will send commands to turn off additional
electrical instrumentation on each spacecraft to prevent power demands from
exceeding its supply.
Because
of their current distance away from our solar system, Voyager 1 and 2 have the
best chance of escaping our eventual celestial cataclysm once the sun runs out
of hydrogen and the Earth becomes no more.
Our
world may disappear, but it is possible – barring any unforeseen accidents,
such as an encounter with meteorites – that at least one of the Voyagers will
survive and continue to carry with them information about Earth.
Attached
to each Voyager spacecraft is Earth’s “message in a bottle” to whoever finds it
in the vast ocean of space.
Both
Voyagers carry duplicate messages etched onto a 12-inch gold-plated 33-RPM
audio LP copper disk (a phonograph record) known as the “golden record.”
Each
record contains the sounds and images selected to represent the diversity of
life and culture on Earth.
NASA
formed a committee headed by the late astronomer Carl Sagan to select the
contents recorded on the golden records.
Sagan
and his team included 115 images and 90 minutes of analog audio recordings,
including Earth’s naturally made sounds such as wind, thunder, birds, whales,
and other animalls.
Each
disk attached to Voyager 1 and 2 includes music and spoken greetings in 60
human languages.
Each
golden record is coated in copper and gold and is encased inside a protective
aluminum jacket to protect them on their journey.
Fastened
to the spacecraft are a stylus, cartridge, and symbolic language instructions
explaining the Voyager spacecraft’s origin and how to play the record.
I
wonder if NASA included a penny to place on the tonearm in case the needle
skips.
But
I digress.
In
40,000 years, Voyager 1 will be within 1.6 light-years (9.3 trillion miles) of
a star in the constellation of Camelopardalis. In 1977, NASA scientists
believed that this star might have planets nearby possessing an intelligent
civilization.
NASA
is still receiving Voyager 1 and 2’s telemetry data and can send commands to
both, via the three giant radio antennas located in Australia, Spain, and the
United States, which make up the Deep Space Network (DSN).
By
2025, the plutonium aboard both Voyagers will have decayed to the point where
it will no longer be sufficient for the radioisotope thermoelectric generators
to create the wattage needed to operate the electronic data-collection
instruments, which, as a result, will begin to fail.
NASA
states the DSN will still be able to track both Voyager spacecraft through
2036.
In
2167, 190 years after their launch, Voyager 1 and Voyager 2 will have
completely depleted their supply of plutonium-238.
Even
without power, forward momentum will propel both spacecraft through
interstellar space, with each carrying a golden record containing information
about our world.
A
logical, reasoning intellect may someday discover one of the Voyagers, obtain
the information from the golden record, learn of our existence, listen to our
long-stilled voices, and know we were here.
Check
out Voyager’s golden record at https://go.nasa.gov/2OlA2Kv.
Space is the final frontier, and Voyager 1 and 2 continue to boldly go where no spacecraft has gone before.
