The Legacy of the Voyager Mission

The Legacy of the Voyager Mission

Subject: Science and technology

Section: Space technology

Context:

NASA detected a “heartbeat” signal from Voyager 2 more than a week after losing communication with the spacecraft.

What is the Voyager mission?

• The Voyager mission was launched in 1977, with Voyager 2 launched on August 20, followed by Voyager 1 on September 5.
• The Voyager spacecraft were designed to take advantage of a rare planetary alignment that occurs approximately every 175 years, allowing for efficient trajectories between planets.
• Voyager 1 and Voyager 2 were originally planned to explore only Jupiter and Saturn, but their success led to extended missions to Uranus, Neptune, and beyond.

Why were the Voyager spacecraft sent into space?

• The original Grand Tour mission, which aimed to explore all five outer planets, was canceled due to budget constraints and technical challenges.
• Voyager 1 and Voyager 2 were smaller, lighter, and less costly, making them a more feasible option for planetary exploration.
• The gravitational assists from Jupiter and Saturn allowed the spacecraft to continue their missions to Uranus, Neptune, and interstellar space.

What are the features of the Voyager spacecraft?

• The Voyager spacecraft are powered by radioisotope thermoelectric generators (RTGs) fueled by plutonium-238, providing electricity for their instruments and systems.
• Each spacecraft carries a golden record containing images, sounds, and greetings from Earth, serving as a time capsule representing humanity’s cultural diversity.
• The Voyager instruments provided groundbreaking data on planetary atmospheres, magnetic fields, and interactions with solar wind.

What is the radioisotope thermoelectric generator (RTG)?

• Spacecraft power source using heat from radioactive decay.
• Utilizes isotopes of plutonium, like plutonium-238.
• Converts heat into electricity through thermoelectric conversion.
• Provides long-lasting and reliable power for space missions.
• Used in missions like Voyager, Cassini, and Mars rovers.
• Ensures power in dark or distant environments.
• Designed with safety features to prevent radioactive release.
• High energy density, suitable for space missions with weight constraints.

What are the golden phonograph records on Voyager spacecraft?

• The idea for the golden records came from a committee chaired by astronomer Carl Sagan and was intended to showcase the best of humanity.
• The records include greetings in 55 languages, music from different cultures and eras, and natural sounds from Earth.
• The records also contain encoded information using a map of our solar system’s location with respect to a set of 14 pulsars, and a drawing of a hydrogen atom.
• Plated with uranium for future discoverers to date.

What are the notable achievements of the Voyager spacecraft?

• Voyager 1 and Voyager 2 reached Jupiter in 1979, where Voyager 1 found active volcanoes on Jupiter’s moon, Io, including the iconic Jupitar’s Great Red Spot.
• Both spacecraft discovered three new moons of Jupiter: Thebe, Metis, and Adrastea.
• Voyager 1 revealed that Saturn’s moon Titan was not the largest moon in the solar system and had a nitrogen-rich atmosphere with methane clouds and rain.
• Voyager 2 reached Uranus in 1986, capturing images and confirming its composition of hydrogen and helium, and discovering new moons and rings.
• Voyager 2 then flew by Neptune in 1989, discovering new moons, rings, and observing the Great Dark Spot, a massive storm in Neptune’s atmosphere with winds blowing at 1,100 kph.

What is heliopause?

• The heliopause is the outer boundary of the heliosphere,
  • which is the region of space dominated by the influence of the Sun’s solar wind.
• The point where solar wind meets interstellar medium.

What happened during the recent Voyager 2 communication issue?

• On July 21, 2023 a faulty command caused Voyager 2’s antenna to point away from Earth, resulting in communication disruption.
• Despite the communication issue, NASA detected a weak “heartbeat” signal from Voyager 2, indicating the spacecraft’s systems are still functioning.

What is the future of the Voyager spacecraft?

• Voyager 1 entered interstellar space on August 25, 2012, and Voyager 2 followed on November 5, 2018.
• Scientists estimate that the power supply of the Voyager spacecraft will eventually run out around the mid-2020s.
• After their power depletion, the Voyagers will continue their silent journey, potentially orbiting the center of the Milky Way for billions of years.
• The spacecraft will carry the golden records, serving as a time capsule of humanity, possibly for millions of years, as they traverse the depths of space.