Voyager 2

Voyager 2

Voyager 2 is a space probe launched by NASA on August 20, 1977, as part of the Voyager program. It was sent to explore the outer planets of our solar system. Voyager 2 is the only spacecraft to visit both the gas giants, Jupiter and Saturn, and the ice giants, Uranus and Neptune. Its mission was to study these distant worlds and learn more about space.

The spacecraft flew by Jupiter in 1979, Saturn in 1981, Uranus in 1986, and Neptune in 1989. After these missions, Voyager 2 kept traveling farther from the Sun. In November 2018, it became the second human-made object to enter interstellar space, the area beyond the Sun's heliosphere. This helped scientists learn about the space between the stars.

Today, Voyager 2 still sends information back to Earth from its journey through the interstellar medium. It is one of a few spacecraft that have left the Solar System. The probe talks to scientists using special antennas, including one in Australia near Canberra. As it moves through space, Voyager 2 helps us learn about the vast areas far from home.

History

Further information: Grand Tour program

Background

Main article: Mariner Jupiter-Saturn

In the early days of space exploration, people noticed that the outer planets would line up in a special way in the late 1970s. This alignment meant one probe could visit Jupiter, Saturn, Uranus, and Neptune by using a technique called gravity assists. NASA started a big project called the Grand Tour, which planned to send two groups of probes to these planets. Later, the plan was changed to just two probes that would fly by Jupiter and Saturn, but they could still go to Uranus and Neptune if needed.

Voyager 2 was designed to explore Jupiter and Saturn, and if everything went well, it could continue to Uranus and Neptune. This was possible because Voyager 1 had already completed its mission to Jupiter, Saturn, and Titan. The path for Voyager 2 was chosen to make the best use of this opportunity.

Spacecraft design

Voyager 2 was built by the Jet Propulsion Laboratory and had many tools to stay steady and point its antenna toward Earth. It carried 11 instruments to study the objects it passed by as it traveled through space.

Communications

Voyager 2 was made to eventually travel outside our solar system. It had a big antenna to send and receive data from Earth using the Deep Space Network. It could send information at different speeds depending on how far it was from Earth.

Power

Voyager 2 used special power sources called multihundred-watt radioisotope thermoelectric generators to keep its instruments running. These generators used a material called plutonium oxide to create electricity from heat. They were expected to keep working until at least 2020, and they continued to power some instruments until 2023. In 2024, one instrument was turned off to save power for the others.

Attitude control and propulsion

Voyager 2 had a special engine to help it get to Jupiter, and after that, it used smaller engines to stay steady and change its path if needed. It had enough fuel to keep working until about 2034.

Scientific instruments

Main article: Voyager program

Mission profile

The Voyager 2 probe was launched on August 20, 1977, by NASA from Cape Canaveral, Florida. It traveled to visit the gas giants Jupiter and Saturn. After that, it went to the ice giants Uranus and Neptune. It is the only spacecraft to have visited Uranus and Neptune.

Voyager 2 sent back close-up pictures and important information about Jupiter, Saturn, Uranus, and Neptune. It also studied their moons and rings. It showed active volcanoes on Jupiter's moon Io, found new moons around all four planets, and gave us details about the atmospheres and magnetic fields of these distant worlds.

Interstellar mission

After visiting the planets, Voyager 2 began a journey to explore what lies beyond the Solar System. As of September 2023, it still sends scientific data from deep space to scientists on Earth.

Voyager 2 has made many important discoveries. In 1992, it observed a star explosion called a nova. In 2007, it entered an area called the heliosheath, where the Sun's influence ends. In 2018, it entered interstellar space, becoming the second spacecraft to do so. Even with some technical problems and brief communication breaks, Voyager 2 continues to share valuable information about distant parts of our Solar System and beyond.

Reductions in capabilities

As the power from Voyager 2 slowly runs low, some equipment has been turned off. The first science tool turned off was the PPS in 1991. This saved a little power.

Some tools that help aim the spacecraft and its antenna toward Earth are having problems. NASA plans to change the computer programs to help the tools work better. They will test this plan on Voyager 2 first because it is closer to Earth before trying it on Voyager 1.

Main article: Voyager 1

Future of the probe

The probe is expected to keep sending weak radio messages until at least the mid-2020s, more than 48 years after it was launched. NASA says that "The Voyagers are destined—perhaps eternally—to wander the Milky Way."

Voyager 2 is not headed toward any particular star. In about 42,000 years, it will pass the star Ross 248. Much later, in about 296,000 years, it should pass by the star Sirius.

Golden record

Main article: Voyager Golden Record

Both Voyager space probes carry a special gold-plated audio-visual disc. This disc shows the many kinds of life and culture on Earth. It is in case someone from space ever finds the spacecraft.

The disc was made by a team that included famous scientist Carl Sagan and writer Timothy Ferris. It has many things on it, like pictures of Earth, scientific facts, and greetings from important people such as the Secretary-General of the United Nations. It also includes sounds like whales, a baby crying, waves, and music from many different cultures and times — including pieces by Wolfgang Amadeus Mozart, Blind Willie Johnson, Chuck Berry, and Valya Balkanska. There are greetings in 55 different languages, showing the rich spirit of life on our planet.