Flyby (spaceflight) in the context of "Space exploration"

The Voyager program is an American scientific program that employs two interstellar probes, Voyager 1 and Voyager 2. They were launched in 1977 to take advantage of a favorable planetary alignment to explore the two gas giants Jupiter and Saturn and potentially also the ice giants, Uranus and Neptune—to fly near them while collecting data for transmission back to Earth. After Voyager 1 successfully completed its flyby of Saturn and its moon Titan, it was decided to send Voyager 2 on flybys of Uranus and Neptune.

After the planetary flybys were complete, decisions were made to keep the probes in operation to explore interstellar space and the outer regions of the Solar System. On 25 August 2012, data from Voyager 1 indicated that it had entered interstellar space. On 5 November 2019, data from Voyager 2 indicated that it also had entered interstellar space. On 4 November 2019, scientists reported that on 5 November 2018, the Voyager 2 probe had officially reached the interstellar medium (ISM), a region of outer space beyond the influence of the solar wind, as did Voyager 1 in 2012. 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 that was first detected in 1992 by the two Voyager spacecraft.

Voyager 1 is a space probe launched by NASA on September 5, 1977, as part of the Voyager program, to study the outer Solar System and the interstellar space beyond the Sun's heliosphere. It was launched 16 days after its twin, Voyager 2. It communicates through the NASA Deep Space Network (DSN) to receive routine commands and to transmit data to Earth. Real-time distance and velocity data are provided by NASA and JPL. At a distance of 170.02 AU (25.4 billion km; 15.8 billion mi) as of November 2025, it is the most distant human-made object from Earth. Voyager 1 is also projected to reach a distance of one light day from Earth in November of 2026.

The probe made flybys of Jupiter, Saturn, and Saturn's largest moon, Titan. NASA had a choice of either conducting a Pluto or Titan flyby. Exploration of Titan took priority because it was known to have a substantial atmosphere. Voyager 1 studied the weather, magnetic fields, and rings of the two gas giants and was the first probe to provide detailed images of their moons.

Interplanetary spaceflight or interplanetary travel is spaceflight (crewed or uncrewed) between bodies within a single planetary system. Spaceflights become interplanetary by accelerating spacecrafts beyond orbital speed, reaching escape velocity relative to Earth at 11.2 km/s, entering heliocentric orbit, possibly accelerating further, often by performing gravity assist flybys at Earth and other planets. Most of today's spaceflight remains Earth bound, with much less being interplanetary, all of which performed by uncrewed spacecrafts, and only just a few spaceflights having accelerated beyond, to system escape velocity, eventually performing interstellar spaceflight.

Uncrewed space probes have flown to all the observed planets in the Solar System as well as to dwarf planets Pluto and Ceres, and several asteroids. Orbiters and landers return more information than fly-by missions. Crewed flights have landed on the Moon and have been planned, from time to time, for Mars, Venus and Mercury. While many scientists appreciate the knowledge value that uncrewed flights provide, the value of crewed missions is more controversial. Science fiction writers propose a number of benefits, including the mining of asteroids, access to solar power, and room for colonization in the event of an Earth catastrophe.

A planetary flyby is the act of sending a space probe past a planet or a dwarf planet close enough to record scientific data. This is a subset of the overall concept of a flyby in spaceflight.

The first flyby of another planet with a functioning spacecraft took place on December 14, 1962, when Mariner 2 zoomed by the planet Venus.

A gravity assist, gravity assist maneuver, swing-by, or generally a gravitational slingshot in orbital mechanics, is a type of spaceflight flyby which makes use of the relative movement (e.g. orbit around the Sun) and gravity of a planet or other astronomical object to alter the path and speed of a spacecraft, typically to save propellant and reduce expense.

Gravity assistance can be used to accelerate a spacecraft, that is, to increase or decrease its speed or redirect its path. The "assist" is provided by the motion of the gravitating body as it pulls on the spacecraft. Any gain or loss of kinetic energy and linear momentum by a passing spacecraft is correspondingly lost or gained by the gravitational body, in accordance with Newton's Third Law. The gravity assist maneuver was first used in 1959 when the Soviet probe Luna 3 photographed the far side of Earth's Moon, and it was used by interplanetary probes from Mariner 10 onward, including the two Voyager probes' notable flybys of Jupiter and Saturn.

The exploration of Jupiter has been conducted via close observations by automated spacecraft. It began with the arrival of Pioneer 10 into the Jovian system in 1973, and, as of 2024, has continued with eight further spacecraft missions in the vicinity of Jupiter and two more en route. All but one of these missions were undertaken by the National Aeronautics and Space Administration (NASA), and all but four were flybys taking detailed observations without landing or entering orbit. These probes make Jupiter the most visited of the Solar System's outer planets as all missions to the outer Solar System have used Jupiter flybys. On July 5, 2016, spacecraft Juno arrived and entered the planet's orbit—the second craft ever to do so. Sending a craft to Jupiter is difficult due to large fuel requirements and the effects of the planet's harsh radiation environment.

The first spacecraft to visit Jupiter was Pioneer 10 in 1973, followed a year later by Pioneer 11. Aside from taking the first close-up pictures of the planet, the probes discovered its magnetosphere and its largely fluid interior. The Voyager 1 and Voyager 2 probes visited the planet in 1979, and studied its moons and the ring system, discovering the volcanic activity of Io and the presence of water ice on the surface of Europa. Ulysses, intended to observe the Sun's poles, further studied Jupiter's magnetosphere in 1992 and then again in 2004. The Saturn-bound Cassini probe approached the planet in 2000 and took very detailed images of its atmosphere. The Pluto-bound New Horizons spacecraft passed by Jupiter in 2007 and made improved measurements of its and its satellites' parameters.

617 Patroclus (/pəˈtroʊkləs/ pə-TROH-kləs) is a large binary Jupiter trojan asteroid. It is a dark D-type asteroid and a slow rotator, due to the 103-hour orbital period of its two components. It is one of five Jupiter trojan asteroids targeted by the Lucy space probe, and is scheduled for a flyby in 2033.

Patroclus was discovered on 17 October 1906, by astronomer August Kopff at the Heidelberg Observatory in Germany, and was named after Patroclus in Greek mythology. It was the second trojan to be discovered and the only member of the Trojan camp named after a Greek figure, as the convention of naming one 'camp' after Greek figures of the Trojan War and the other after Trojan figures had not yet been established.

Deep Impact was a NASA space probe launched from Cape Canaveral Air Force Station on January 12, 2005. It was designed to study the interior composition of the comet Tempel 1 (9P/Tempel), by releasing an impactor into the comet. At 05:52 UTC on July 4, 2005, the Impactor successfully collided with the comet's nucleus. The impact excavated debris from the interior of the nucleus, forming an impact crater. Photographs taken by the spacecraft showed the comet to be more dusty and less icy than had been expected. The impact generated an unexpectedly large and bright dust cloud, obscuring the view of the impact crater.

Previous space missions to comets, such as Giotto, Deep Space 1, and Stardust, were fly-by missions. These missions were able to photograph and examine only the surfaces of cometary nuclei, and even then from considerable distances. The Deep Impact mission was the first to eject material from a comet's surface, and the mission garnered considerable publicity from the media, international scientists, and amateur astronomers alike.