188
3 A Brief History of Space Flight
resources for other equipment, the onboard cameras were shut down and
their software also removed from the spacecraft.
(6) On February 17, 1998, the Voyager-1 caught up with the Pioneer-10 at a
velocity of 17 km/s, and reached the position about 69.419 AU (1.04 × 10
10
km) away from the Sun.
(7) On December 17, 2004, the Voyager-1 passed through the termination shock,
reaching the position of 94 AU away from the Earth, and entered into the
heliosheath.
(8) On February 2, 2007, the onboard plasma wave system stopped operating.
On April 11, the heater of the plasma wave system no longer also worked.
(9) On January 16, 2008, the radio astronomy experiments ever conducted by the
Voyager-1 were stopped.
(10) On August 25, 2012, the Voyager-1 passed through the heliopause, reaching
121 AU away from the Sun, and sailed into interstellar space.
(11) On August 2, 2013, the Voyager-1arrived in the interstellar space of 125 AU
away from the Sun.
(12) On December 6, 2014, the Voyager-1 reached 130.62 AU away from the
Earth.
(13) On May 18, 2016, the Voyager-1 reached 135 AU away from the Sun.
(14) On April 9, 2019, the Voyager-1 was predicted to be 144.82 AU away from
the Earth.
(15) On April 9, 2020, the Voyager-1 was predicted to be 148.39 AU (2.22 × 10
10
km) away from the Earth, which is the most distant man-made vehicle away
from the Sun and Earth.
At present, the Voyager-1 is flying towards the Oort cloud at a velocity of 3.6 AU
per year, and will arrive in there about 300 years later. And then, it will take about
30,000 years to pass through the Oort cloud. Although it is not heading towards any
particular star, about 40,000 years later, it will pass within 1.6 light years of star Gliese
445, 17.6 light years away from the Earth. The Gliese 445 is currently located in the
constellation of Camelopardalis, and is generally moving towards the solar system at a
velocity of 119 km/s. Perhaps eternally, the Voyager-1 is destined to wander the Milky
Way. The Voyager-1 is powered by radioisotope thermoelectric generators, which
create power by converting heat released by the decay of radioactive material. The
Voyager-1 will run out of power around 2025, at which point the onboard scientific
instruments will stop working, no longer transmitting data back to the Earth [12].
Compared to the Voyager-1, the Voyager-2 expanded the exploration missions for
the planets of the outer solar system, and not only flew sequentially by the Jupiter,
Saturn, Uranus and Neptune, but also deeply investigated the Kuiper Belt in the edge
of the solar system, the heliosphere and the interstellar space. Its specific flight paths
and key events were as follows:
(1) At 14:29:00 UTC on August 20, 1977, by using Titan IIIE rocket, the Voyager2 was launched from Launch Complex 41 at Cape Canaveral, Florida. On
December 20, it entered into the asteroid belt between the Mars and Jupiter.
(2) On October 21, 1978, the Voyager-2 flew out of the asteroid belt.
3 A Brief History of Space Flight
resources for other equipment, the onboard cameras were shut down and
their software also removed from the spacecraft.
(6) On February 17, 1998, the Voyager-1 caught up with the Pioneer-10 at a
velocity of 17 km/s, and reached the position about 69.419 AU (1.04 × 10
10
km) away from the Sun.
(7) On December 17, 2004, the Voyager-1 passed through the termination shock,
reaching the position of 94 AU away from the Earth, and entered into the
heliosheath.
(8) On February 2, 2007, the onboard plasma wave system stopped operating.
On April 11, the heater of the plasma wave system no longer also worked.
(9) On January 16, 2008, the radio astronomy experiments ever conducted by the
Voyager-1 were stopped.
(10) On August 25, 2012, the Voyager-1 passed through the heliopause, reaching
121 AU away from the Sun, and sailed into interstellar space.
(11) On August 2, 2013, the Voyager-1arrived in the interstellar space of 125 AU
away from the Sun.
(12) On December 6, 2014, the Voyager-1 reached 130.62 AU away from the
Earth.
(13) On May 18, 2016, the Voyager-1 reached 135 AU away from the Sun.
(14) On April 9, 2019, the Voyager-1 was predicted to be 144.82 AU away from
the Earth.
(15) On April 9, 2020, the Voyager-1 was predicted to be 148.39 AU (2.22 × 10
10
km) away from the Earth, which is the most distant man-made vehicle away
from the Sun and Earth.
At present, the Voyager-1 is flying towards the Oort cloud at a velocity of 3.6 AU
per year, and will arrive in there about 300 years later. And then, it will take about
30,000 years to pass through the Oort cloud. Although it is not heading towards any
particular star, about 40,000 years later, it will pass within 1.6 light years of star Gliese
445, 17.6 light years away from the Earth. The Gliese 445 is currently located in the
constellation of Camelopardalis, and is generally moving towards the solar system at a
velocity of 119 km/s. Perhaps eternally, the Voyager-1 is destined to wander the Milky
Way. The Voyager-1 is powered by radioisotope thermoelectric generators, which
create power by converting heat released by the decay of radioactive material. The
Voyager-1 will run out of power around 2025, at which point the onboard scientific
instruments will stop working, no longer transmitting data back to the Earth [12].
Compared to the Voyager-1, the Voyager-2 expanded the exploration missions for
the planets of the outer solar system, and not only flew sequentially by the Jupiter,
Saturn, Uranus and Neptune, but also deeply investigated the Kuiper Belt in the edge
of the solar system, the heliosphere and the interstellar space. Its specific flight paths
and key events were as follows:
(1) At 14:29:00 UTC on August 20, 1977, by using Titan IIIE rocket, the Voyager2 was launched from Launch Complex 41 at Cape Canaveral, Florida. On
December 20, it entered into the asteroid belt between the Mars and Jupiter.
(2) On October 21, 1978, the Voyager-2 flew out of the asteroid belt.