The remarkable venture of NASA’s Voyager 2 into the expanse of space beyond the solar system is a significant milestone in the annals of space exploration. Launched in 1977, the spacecraft, along with its counterpart, Voyager 1, have now both crossed the boundary of the Heliosphere. This remarkable feat makes Voyager 2 the second human-made object in history to exit the Heliosphere, following Voyager 1 which crossed this frontier in 2012. However, they are yet to leave the solar system as they are still within the Sun’s gravitational field.
The Voyager Journey Beyond Planets
The Voyagers are the third and fourth spacecraft to travel beyond all the planets in our solar system after Pioneers 10 and 11. Voyager 2 remains unique in its accomplishment of having visited all four gas giant planets- Jupiter, Saturn, Uranus, and Neptune.
Significance and Challenges of the Voyager Missions
Voyager 1 and Voyager 2 provide invaluable data on how the Heliosphere interacts with the constant interstellar wind flowing from outer space. This information is used to supplement data from NASA’s Interstellar Boundary Explorer (IBEX), which remotely senses the solar system’s periphery. One of the major challenges faced by these spacecraft is managing the gradual loss of heat and power, especially in the increasingly cold temperatures of space.
About the Voyager Missions: A Brief History
Voyager 2 was launched first on August 20, 1977, followed by Voyager 1 on September 5, 1977. These spacecraft were designed to last five years and conduct close studies of Jupiter and Saturn. Despite their intended lifespan, the Voyager missions continue till date, with Voyager 2 being NASA’s longest-running mission.
| Voyager Spacecraft | Launch date | Main Objective |
|---|---|---|
| Voyager 1 | September 5, 1977 | Study Jupiter and Saturn |
| Voyager 2 | August 20, 1977 | Study Jupiter, Saturn, Uranus, and Neptune |
Terminologies Associated with the Voyager Missions
The terminologies associated with these missions vary widely, each pertaining to a different aspect of space science. For example, ‘Termination shock’ refers to the point where the solar wind speed drops abruptly upon coming in contact with the interstellar wind. ‘Heliosphere’ is a bubble created by the solar wind that extends far past the orbits of the planets. The ‘Heliopause’ is the boundary between the solar wind and the interstellar wind, while the ‘Heliosheath’ is the outer region of the Heliosphere.
The Role of Deep Space Network (DSN)
Deep Space Network, comprising three ground stations located approximately 120 degrees apart on Earth, provides communication support to NASA and non-NASA missions exploring the furthest points of our solar system. Its locations include Canberra in Australia, Madrid in Spain, and Goldstone in California, US.
A Glimpse Into Future Missions: Interstellar Mapping and Acceleration Probe (IMAP)
NASA plans to launch the Interstellar Mapping and Acceleration Probe (IMAP) in 2024 to build on observations made by the Voyagers. This mission complements the objectives of the Interstellar Boundary Explorer (IBEX) launched in 2008, to understand the nature of interactions between solar wind and the interstellar medium at the edge of our solar system.