Voyager program

The Voyager program is an American scientific program that uses two special space machines called interstellar probes, named Voyager 1 and Voyager 2. These amazing spacecraft were launched in 1977 to take advantage of a rare alignment of planets. Their main job was to fly close to the gas giants Jupiter and Saturn, and also to visit the ice giants Uranus and Neptune, collecting important data to send back to scientists on Earth.

After Voyager 1 finished its flight by Saturn and its large moon Titan, it was decided that Voyager 2 would continue to Uranus and Neptune, just as planned. Once they finished visiting the planets, the scientists decided to keep the Voyagers working even longer, to explore the area beyond our Solar System known as interstellar space.

On 25 August 2012, Voyager 1 became the first human-made object to enter interstellar space, followed by Voyager 2 on 5 November 2019. These spacecraft have traveled farther from Earth than any other objects made by humans, showing us what the space between the stars looks like. As of 2026, both Voyagers are still working, moving through the vastness of space beyond what we call the heliosphere into the interstellar medium.

History

Further information: Grand Tour program

The Voyager space probes were part of a big plan called the Planetary Grand Tour, which started in the late 1960s. Scientists wanted to explore faraway planets like Jupiter, Saturn, Uranus, Neptune, and even Pluto. This plan used a special planetary alignment that happens only once every 175 years. It let the probes "hitchhike" on the gravity of planets to travel farther with less fuel.

The original plan was too expensive, so it was changed. Instead of many probes, two identical spacecraft were built. They were named Voyager 1 and Voyager 2. Their main job was to fly by Jupiter and Saturn and study things like their atmospheres, magnetic fields, and moons. They were launched in 1977, taking advantage of the rare planetary alignment. Voyager 2 was sent on a path that let it visit Uranus and Neptune after Saturn, while Voyager 1 flew closer to Saturn's moon Titan. Both sent back amazing pictures and information about our solar system.

Spacecraft design

The Voyager spacecraft each weighed 815 kilograms at launch and now weigh about 733 kilograms after using fuel. Each carries 105 kilograms of scientific instruments. They use special systems to keep their antennas pointed toward Earth and their instruments aimed at space targets.

The spacecraft have a large high-gain antenna and a spherical tank containing fuel. They also carry a special record and three power generators that use plutonium to create electricity, which will slowly decrease over time. The spacecraft include several instruments for measuring different aspects of space, such as cameras, spectrometers, and detectors for particles and radiation.

Voyager Interstellar Mission

The Voyager Interstellar Mission (VIM) began after the primary mission ended in 1989. Its goal was to explore beyond the outer planets to the heliopause, the edge where the Sun’s influence ends. Voyager 1 crossed this boundary in 2012 and Voyager 2 in 2018, allowing scientists to study the space between stars.

Both spacecraft continue to send data back to Earth, though some instruments have been turned off to save power. They are expected to keep operating until at least 2026 and may continue until 2036. The Voyagers are traveling toward distant stars and will take thousands of years to reach them.

Voyager Golden Record

Main article: Voyager Golden Record

Each Voyager spacecraft carries a special 12-inch golden record filled with pictures and sounds from Earth. This record also includes directions on how to play it and information about where Earth is located. It is meant to be a message from our planet to any other life forms, whether they are aliens or humans living far in the future, who might find the spacecraft. A group of experts, including Timothy Ferris and chaired by Carl Sagan, chose what to put on the record.

Pale Blue Dot

Main article: Pale Blue Dot

Pale Blue Dot is a famous photograph of Earth taken by the Voyager 1 space probe on February 14, 1990. The picture shows our planet from a distance of about 6 billion kilometers, looking like a tiny pale blue dot in the vastness of space. The image was part of a series called the Family Portrait, which featured views of the Solar System. The photo reminds us of how small our world is compared to the huge universe and encourages us to treat each other kindly and protect our home.