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As a young space professional, I may sound a bit biased when I say this: The era of space exploration is one of the greatest chapters in the history of all humanity. My eyes turned to the universe for the first time when I was ten years old. My parents bought me a telescope for Christmas and, for so many nights, I stood outside in the cold with my dad looking at the moon, Jupiter, the Galilean moons, and Saturn. I continued throughout my childhood mainly concentrated on my studies of art and music, but deep down I always had a love for astronomy and the cosmos instilled within me.
After graduating high school, I was lucky to return to my love for space, this time, in a new and refreshing way. Instead of viewing it as a distant, inaccessible place, I saw it as an opportunity. The universe soon became something I could reach for. Looking to the stars from a world that was plagued with war, violence, and other evils, space exploration for me became a hopeful symbol of unity and collaboration. It was one field in which humans from all over the world, from many different backgrounds, could come together to accomplish extraordinary things and make the seemingly impossible become reality. My favorite example of this excellence is NASA's Voyager mission.
A Rare Alignment
In 1977, twin spacecraft Voyager 1 and 2 were launched from Cape Canaveral, Florida to start a history-making journey through space that would span many decades to come. Despite its name, the first spacecraft to launch was actually Voyager 2 on August 20th - Voyager 1 followed just a couple of weeks later on September 5th. This reversed order can be credited to one thing: incredibly precise, mathematical trajectories. The trajectory - or carefully calculated course - of Voyager 1 required a length of time to reach the outer planets that was considerably shorter than Voyager 2's. Ultimately, although Voyager 1 was the second of the two to leave this Earth, it was the first to reach Jupiter.
The twin spacecraft were sent on their unique missions to the outer planets thanks to a rare geometric planetary arrangement. In the summer of 1965 (less than a decade before launch), scientists revealed new calculations which showed that a spacecraft launched in the 1970s could visit the Jovian planets using gravitational slingshots to swing from one planet to the next. A gravitational slingshot, or gravity assist, is a technique in which a spacecraft flies by a large object (such as a planet) and uses the object's massive gravity field to increase in velocity, allowing the spacecraft to arrive at its destination in less time and with minimum fuel. In the case of Voyager, this alignment would only occur once every 176 years.
The Voyager mission was originally designed to last five years with the spacecraft exploring only Jupiter and Saturn, but over forty years later, they are still going. In this span of time, the two spacecraft delivered a number of scientific surprises and discoveries - a series of rewarding treats as Voyager 2 visited all four outer planets of our solar system for the first time in history and both spacecraft eventually arrived into interstellar space.
The Rewriting of Astronomy
The Voyager missions were the source of many major findings that revolutionized astronomy. Some of those breakthroughs are listed below (an asterisk, or *, denotes the first time the listed phenomenon was recorded outside of Earth):
Jupiter
Voyager 1 approach date: March 1979
Voyager 2 approach date: July 1979
Turbulent atmosphere with dozens of hurricane-like storms and lightning*
Faint ring system around planet
Three new moons: Thebe, Metis, Adrastea
Indication of liquid ocean beneath Jupiter's moon, Europa's icy surface
Volcanic activity* on Jupiter's moon, Io
Io
Over 400 active volcanoes
Volcanic activity affects the entire Jovian system
Primary source of matter in the magnetic field around Jupiter
Saturn
Voyager 1 approach date: November 1980
Voyager 2 approach date: August 1981
Detailed observations in structure of Saturn’s rings; confirmation of scientists’ “shepherd moon” theory
Three new moons: Atlas, Prometheus, Pandora
Saturn's moon, Titan’s nitrogen-rich atmosphere* and indication of liquid methane and ethane on surface
Indication of liquid water below surface of Saturn's moon, Enceladus
Titan
Thick, Earth-like atmosphere
First time an atmosphere composed of mostly nitrogen was found outside of our own
Surface pressure is 1.6 times higher than Earth’s
Uranus
Voyager 2 approach date: January 1986
Tilted magnetic field
Imaging of dark planetary rings
Detection of the coldest planetary temperatures in our solar system (-353 degrees Fahrenheit/59 Kelvin)
Insight into the surface of Uranus' moon, Miranda
Eleven new moons: Puck, Juliet, Portia, Cressida, Desdemona, Rosalind, Belinda, Perdita, Cordelia, Ophelia, Bianca
Miranda
Innermost and smallest major Uranian moon
Puzzling juxtaposition in textures: Coronae, ridges, valleys, craters, smooth surfaces, deep canyons
Indication of vigorous tectonic and thermal activity in Miranda’s past
Neptune
Voyager 2 approach date: August 1989
First images of Neptune’s rings
The Great Dark Spot: huge, counterclockwise rotating storm in planet’s southern hemisphere
Erupting geysers on Neptune's largest moon, Triton’s polar cap
Six new moons: Despina, Galatea, Larissa, Proteus, Naiad, Thalassa
Interstellar space
Voyager 1 was recorded on August 25, 2012 as the first human-made object to ever enter interstellar space. This tremendous feat was achieved when the spacecraft broke through a boundary known as heliopause. Heliopause is defined as the outermost limit of our sun's magnetic field. Within this bubble, the sun's influence diminishes as solar winds slow from about a million miles per hour to just 250,000 miles per hour, and it begins to mark the border between outer flowing solar wind and incoming interstellar wind. Here, pressure is balanced. In December 2018, Voyager 2 became the second human-made object to cross the boundary into interstellar space. As of today, the Voyager 1 and 2 probes are the only two objects built by humans to ever enter interstellar space - making them, perhaps, the loneliest objects ever.
"To the makers of music – all worlds, all times"
The teams who developed the Voyager missions had big plans for the twin spacecraft, and they determined they couldn't send them into space without including a message from humanity. Thus, the two Voyager Golden Records were born. The Voyager Golden Records were 12-inch, gold-plated copper phonograph records with intricately detailed instructions and information etched onto the cover, just in case any intelligent extraterrestrial life may encounter it. Each golden record, titled "The Sounds of Earth", was placed on a Voyager spacecraft and contained a compilation of music, sounds, and images that were thought to represent the rich diversity of life here on Earth. They also each had an engraved message: "To the makers of music - all worlds, all times." Currently, the Voyager 1 and 2 spacecraft are anticipated to stop sending data back to Earth sometime around 2025; however, the golden records were designed to keep their data intact for a billion years. So even once our civilization as we know it is long gone, we can at least count on this story of remarkable human ingenuity to continue traveling throughout the cosmos.
Read about the meanings behind each marking here: https://voyager.jpl.nasa.gov/golden-record/golden-record-cover/
Kayla Dio Robinson is a Computer Science student at Norfolk State University. Last Summer, Kayla completed a 10-week internship for NASA's Katherine Johnson Independent Verification & Validation Facility (IV&V) and she is currently an intern at NASA Langley Research Center.