Voyager 2

A space probe flies far away.

It was sent to see big planets. It flew past Jupiter and Saturn. It also saw Uranus and Neptune.

It is the only craft to visit those last two planets. Now it flies in deep space. It has left the area around our Sun. It is even studying the space between stars. It still talks to Earth using a big dish.

This probe is on a long trip.

Voyager 2 is a space probe sent by NASA. It launched on August 20, 1977.

Its first job was to study the outer planets. It flew past Jupiter in 1979. Then it visited Saturn in 1981. Voyager 2 is special. It is the only craft to visit Uranus and Neptune. It saw Uranus in 1986 and Neptune in 1989.

Now, the probe is on an extended mission. It is studying interstellar space. This is the space between the stars. On November 5, 2018, it entered the interstellar medium. The interstellar medium is the stuff that fills space.

How does it stay powered? It uses RTGs. These are tools that make power from heat.

Voyager 2 uses a large antenna to talk to Earth. It sends data through the Deep Space Network. This network helps us hear the probe from far away. The probe is very far from our Sun now. It is still traveling through our Solar System.

Voyager 2 is a very special space probe sent by NASA. It was launched on August 20, 1977.

This probe was built to explore the outer parts of our Solar System. Its main job was to study the giant gas planets. It also wanted to see the ice giant planets. Voyager 2 is the only spacecraft to ever visit Uranus and Neptune. It is now traveling through interstellar space, which is the area between stars.

This spacecraft works using many clever tools and systems. It uses 16 hydrazine thrusters to keep its direction steady. These thrusters help it stay pointed at Earth. The probe uses a large, high-gain antenna to send data back home. It uses radio waves to talk to the Deep Space Network on Earth.

To stay powered, it uses three radioisotope thermoelectric generators, or RTGs. These tools turn heat from plutonium oxide into electricity. This power helps run the 11 scientific instruments on board. These instruments can take pictures and measure magnetic fields.

Scientists planned this mission a long time ago. In the early space age, they saw a rare alignment of planets. This alignment would let one probe visit many planets using gravity assists. A gravity assist uses a planet's pull to help a craft move. NASA first called this a Grand Tour. Later, they changed the name to the Voyager program. The Jet Propulsion Laboratory in California helped build the craft. They designed it with extra parts to make sure it would survive.

Voyager 2 has a very long list of amazing travels. It visited the Jupiter system in 1979. Then it flew by the Saturnian system in 1981. It reached Uranus in 1986 and Neptune in 1989.

On November 5, 2018, it entered the interstellar medium. This means it left the Sun's heliosphere. It is now making the first direct measurements of interstellar plasma. Plasma is a type of matter that fills space. It is measuring the density and temperature of this space.

Think of Voyager 2 as a lonely explorer in a dark ocean. The planets are like bright islands it passes on its way. Even though it is very far away, it still talks to us. It uses the Deep Space Network to send its findings. This network includes a large antenna near Canberra, Australia. The probe is still moving through our Solar System today. It continues to teach us about the world beyond our home.

Voyager 2 is a highly advanced space probe launched by NASA on August 20, 1977.

It was designed to explore the outer reaches of our Solar System. This mission was part of the larger Voyager program. The spacecraft was built to study gas giants and ice giants. Voyager 2 is unique because it is the only spacecraft to visit Uranus and Neptune. It is now traveling through the interstellar medium, which is the space between stars.

To navigate the vastness of space, Voyager 2 uses a complex Attitude and Articulation Control Subsystem (AACS). This system includes gyroscopes and celestial referencing instruments. It uses a Sun sensor and a Canopus star tracker to maintain its position. These tools help the probe keep its high-gain antenna pointed toward Earth. The spacecraft also uses 16 hydrazine thrusters for attitude control. These thrusters help with stabilization and trajectory correction maneuvers. A single titanium tank holds the hydrazine fuel needed for these tasks.

Powering a machine so far from the Sun requires a special method. Voyager 2 uses three radioisotope thermoelectric generators, known as MHW RTGs.

Each RTG contains 24 pressed spheres of plutonium oxide. These spheres produce heat, which the generators convert into electricity. At launch, the three RTGs provided a total of 470 watts of power. This power level halves every 87.7 years. Scientists use this energy to run various scientific instruments. In 2023, NASA began using a backup power reservoir to keep instruments running.

The mission began with a plan called the "Grand Tour." Scientists noticed a rare alignment of the outer planets in the late 1970s. This alignment allowed a probe to visit multiple planets using gravity assists. A gravity assist uses the gravitational pull of a planet to change a spacecraft's path. NASA originally planned two groups of probes for this massive project. One group would visit Jupiter, Saturn, and Pluto. The other group would visit Jupiter, Uranus, and Neptune. Eventually, the project was scaled back and renamed the Voyager program.

Voyager 2 completed its primary mission by visiting four different planetary systems. It encountered the Jovian system, which includes Jupiter, in July 1979. It then reached the Saturnian system in August 1981. Following this, it visited the Uranian system in January 1986. Its final planetary encounter was with the Neptunian system in August 1989. During these flybys, the probe passed many moons. For example, it flew by Ganymede at 62,130 km during its Jupiter encounter. It also passed Neptune very closely, at only 4,950 km from the planet's center.

The spacecraft carries 11 different scientific instruments to study space. These include cameras with narrow-angle and wide-angle lenses.

The cameras use various filters to see different wavelengths of light. These filters include ultraviolet, violet, blue, green, orange, and clear spectrums. Other instruments, like the Magnetometer (MAG), investigate magnetic fields. The Plasma Science (PLS) instrument measures the properties of plasma ions. The Cosmic Ray Subsystem (CRS) helps determine the origin of cosmic rays. These tools allow the probe to send back detailed data about the universe.

Communication with Voyager 2 is a massive technical feat. The probe uses a large parabolic high-gain antenna to send data. This data travels via the S-band and X-band radio frequencies. Earth receives these signals using the NASA Deep Space Network. One important communication site is the DSS 43 antenna near Canberra, Australia. As the probe moves further away, the data rate decreases due to the inverse-square law. At the distance of Jupiter, the rate can be as high as 115.2 kilobits per second. If communication is impossible, a Digital Tape Recorder can store 64 megabytes of data.

Today, Voyager 2 is in its extended mission phase. It officially entered the interstellar medium on November 5, 2018.

This means it has left the Sun's heliosphere. It is now providing the first direct measurements of interstellar plasma density and temperature. The probe continues to travel through the interstellar medium while remaining inside the Solar System. It follows in the footsteps of Voyager 1, which entered interstellar space in 2012. Voyager 2 remains a vital link to the world beyond our Sun.