"As of 2023, they were launched in 1977..."
Two NASA spacecraft launched in 1977 to study the outer Solar System, including Jupiter, Saturn, Uranus, and Neptune.
Early space exploration: The early history of humanity's journey to space.
Space race: The competition between the United States and the Soviet Union to explore space.
NASA: The National Aeronautics and Space Administration.
Voyager spacecraft: The spacecraft specifically designed for interplanetary exploration.
Mission objectives: The reasons why the Voyager missions were launched.
Scientific instruments: The tools used to collect data from space.
Planetary exploration: The study of planets beyond Earth.
Jupiter: The first planet visited by the Voyager spacecraft.
Saturn: The second planet visited by the Voyager spacecraft.
Rings of Saturn: The complex system of rings surrounding Saturn.
Uranus and Neptune: The outer planets explored by Voyager 2.
Voyager program legacy: The impact of the Voyager program on science and society.
Voyager 1 and Voyager 2: These are the two spacecrafts that were launched in 1977 by NASA to explore the outer Solar System. They have sent back valuable data and images of Jupiter, Saturn, Uranus, and Neptune, as well as their moons and rings, and are currently exploring the outermost reaches of the Solar System.
Grand Tour: This was a proposed mission that would have used gravity assists from Jupiter, Saturn, Uranus, and Neptune to explore the outer Solar System. However, due to budget constraints, the mission was never fully realized.
New Horizons: This is a spacecraft that was launched in 2006 by NASA to explore Pluto and its moons, and later, the Kuiper Belt. It made its closest approach to Pluto in 2015 and sent back valuable data and images of the dwarf planet.
Pioneer missions: These were a series of spacecrafts that were launched by NASA in the 1970s to explore the inner and outer Solar System. They were the first spacecrafts to flyby Jupiter and Saturn, and they also explored the asteroid belt.
Galileo: This was a spacecraft that was launched by NASA in 1989 to explore Jupiter and its moons. It sent back valuable data and images of the gas giant and its moons, and also discovered evidence of subsurface ocean on the moon Europa.
Cassini-Huygens: This was a spacecraft that was launched by NASA and the European Space Agency (ESA) in 1997 to explore Saturn and its moons. It sent back valuable data and images of the gas giant and its moons, and also discovered evidence of subsurface ocean on the moon Enceladus.
MESSENGER: This was a spacecraft that was launched by NASA in 2004 to explore Mercury, the smallest planet in the Solar System. It made its closest approach to the planet in 2011 and sent back valuable data and images of the planet's surface and environment.
Mars missions: These are a series of missions that have been sent to explore Mars and its environment, searching for evidence of life and potential habitability. Some of the Mars missions include the Viking, Pathfinder, and Mars Exploration Rover missions.
Hayabusa missions: These are a series of Japanese spacecrafts that were launched to explore asteroids and bring back samples to Earth. The first Hayabusa mission successfully returned a sample from the asteroid Itokawa. The second Hayabusa2 mission successfully returned samples from asteroid Ryugu.
Dawn: This was a spacecraft that was launched by NASA in 2007 to explore two of the largest objects in the asteroid belt, Vesta and Ceres. It sent back valuable data and images of both objects and discovered evidence of water and organic molecules on Ceres.
"They were launched... to fly near the two gas giants Jupiter and Saturn, and the ice giants Uranus and Neptune..."
"After launch, the decision was made to send Voyager 2 near Uranus and Neptune to collect data for transmission back to Earth."
"As of 2023, the Voyagers are still in operation beyond the outer boundary of the heliosphere in interstellar space."
"As of 2023, Voyager 1 is moving with a velocity of 61,185 kilometers per hour (38,019 mph), or 17 km/s, relative to the Sun..."
"Voyager 1 is 23,820,000,000 kilometers (1.480×1010 mi) from the Sun..."
"On 25 August 2012, data from Voyager 1 indicated that it had entered interstellar space."
"As of 2023, Voyager 2 is moving with a velocity of 55,335 kilometers per hour (34,384 mph), or 15 km/s, relative to the Sun..."
"Voyager 2 is 19,864,116,000 kilometers (1.2342989×1010 mi) from the Sun..."
"On 5 November 2019, data from Voyager 2 indicated that it also had entered interstellar space."
"At Uranus, Voyager 2 discovered a substantial magnetic field around the planet and ten more moons. Its flyby of Neptune uncovered three rings and six hitherto unknown moons, a planetary magnetic field, and complex, widely distributed auroras."
"Close-up images from the spacecraft charted Jupiter's complex cloud forms, winds and storm systems, and discovered volcanic activity on its moon Io."
"Saturn's rings were found to have enigmatic braids, kinks, and spokes and to be accompanied by myriad 'ringlets'."
"As of 2023, Voyager 2 remains the only spacecraft to have ever visited the ice giants Uranus and Neptune."
"In August 2018, NASA confirmed, based on results by the New Horizons spacecraft, the existence of a 'hydrogen wall' at the outer edges of the Solar System..."
"The Voyager spacecraft were built at the Jet Propulsion Laboratory in Southern California..."
"...funded by the National Aeronautics and Space Administration (NASA), which also financed their launches..."
"The cost of the original program was $865 million..."
"The Voyager Interstellar Mission costing an extra $30 million."
"NASA indicates '[I]f we define our solar system as the Sun and everything that primarily orbits the Sun, Voyager 1 will remain within the confines of the solar system until it emerges from the Oort cloud in another 14,000 to 28,000 years.'" Note: Due to the limited availability of direct quotes in the provided text, some of the study questions may not have corresponding quotes. In such cases, the quotes provided are the most relevant available.