And the end of Voyager 2's Planet Tour on August 25, 1989 ended with a dazzling display of Neptune and its moon, Triton. The images and scientific data returned by Voyager 2 would change our understanding of the solar system.
Voyager 2 is still the only spaceship to visit the outer planets of Neptune and Uranus.
The Voyager probes were launched in 1977. Together, they visited Saturn and Jupiter and their moons. But then Voyager 2 had a unique opportunity.
"We had the opportunity to make a close flyby with Voyager 2," said Suzanne Dodd, Voyager Project Manager. "Because of the planetary alignment, when the probes were launched in 1977, the four huge outer planets were all aligned on the same side of the Sun, so we could move from one to the next, which was a great opportunity."
This allowed the spaceship to use a gravitational assistant from one planet to visit the next, and the Voyager program to visit four planets in four years. This alignment takes place only once every 1
Trina Ray worked at NASA's Jet Propulsion Laboratory for the Neptune flyby at Voyager 2 Mission. She joined the General Science Data team as the first non-college member.
There was a Voyager operations lab in JPL Monitore's Building 264 throughout, with teams spanning several floors. Since Voyager 2 always pointed the antenna to the ground, data was constantly being sent back.
Chris Jones helped develop the flight software for the Voyager mission and helped the agency identify the best ways to handle the ever-increasing distance to communicate with the spacecraft. He also helped the mission overcome the problem of diminishing lighting conditions to obtain clear images of Neptune.
The images would fall line by line on the monitors. Slowly approaching Neptune, the planet began with several pixels, a blurry blue dot that grew slightly each day.
As the approach approached, everything changed.
Ray would sit at her desk and someone would say, "Wow," which would make everyone look up at the monitors.
"This is the best picture of Neptune we have ever seen," one of the scientists would say. They would return to work until someone else exclaimed and brought another image to life.
"The incredible flow of the encounter was hugely exciting," Ray said. "In the month that led to the next approach, you were really involved in what was happening, it had that feeling of acceleration, I've never seen another mission profile of a spacecraft have that building intensity for months, which An Incredible Record from the Days Around the Next Approach. "
During the flyby week, Ray did not want to go to sleep or move away from the monitors. Everyone else was the same. While the spaceship was temporarily out of communication Ray used one of the on-site showers and took a nap. Nobody she knew was going home.
Media from all over the world were parked in the JPL car park and came to the daily press conference to discuss the new images and scientific findings.
"It was five days of incredible science," Ray said. "And there was this intense emotion to know that this was the last flyby, it was the end of an era."
A New Look at Neptune
For 20 to 30 years, the Voyager team has been working together smoothly, full of people who knew each other well and to whom they were capable.
Ray was a newcomer. Voyager would put all its team-work expectations to the fore for the remainder of Ray's 30-year career at NASA. It ignited a spark in her and she spent the next 20 years working on the Cassini orbiter at Saturn, which was inspired by Voyager.
The scientific evidence gathered during the Neptune flyby showed that the existing models for the gas giant were too simple to show what really happened.
They discovered that the magnetic field of Neptune had tilted to the side. They found a huge patch, the Great Dark Spot on the planet, similar to the Great Red Spot of Jupiter. The event, however, passed away as it was no longer there when the Hubble Space Telescope had looked four years later. It has been discovered that Neptune has some of the fastest and coldest winds in the solar system.
Four rings were found around the planet.
And when Voyager 2 flew past Triton, Neptune's Moon, the scientists found that it was circling backwards. Unlike Neptune's other moons, which had been formed from the remnants after Neptune had become a planet, Triton was a trapped object being drawn into a declining orbit.
Six more moons were discovered during the flyby.
Triton was the coldest object Voyager 2 had ever seen has reached a negative 391 degrees Fahrenheit. The wild-looking surface proved to be geologically active. On Triton, geysers erupted from the frozen nitrogen ice.
The understanding of the diversity of our solar system came from the Voyager flyby.
"Time and again we found objects that did things we did not expect," said Ed Stone, Voyager Project Scientist since 1975 and a physics professor at the California Institute of Technology. "It changed our view of the solar system."
"It was a wonderful experience because there was so much to learn," Stone said, thinking about his time with the Voyager mission. "We shared this journey with the public for many decades, and we were able to take people on the trip as we spotted things with each flyby."
Stone believes that three aspects of Voyager have contributed to the continuation of NASA's legacy: Innovative Technology, Transformative Science and the extraordinary inspiration to learn what is "out there".
Voyager 1 and 2 are the longest-flying spacecraft in history. Forty-two years after their launch, both are still strong, sending data back while exploring interstellar space. It's the furthest thing we've ever pushed into space. And the spacecraft was originally designed to last only five years.
Dodd started working on Voyager in 1984 and stayed with the project to see the encounters with Uranus and Neptune. After that, Dodd worked on missions inspired by the information that came from Voyager's data. And now Dodd has returned to the top of Voyager.
Dodd's 12-member team takes care of both spacecraft to make sure the probes are healthy and safe, work well, and do not get too cold.