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 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.
New Horizons is an interplanetary space probe launched as a part of NASA's New Frontiers program. Engineered by the Johns Hopkins University Applied Physics Laboratory (APL) and the Southwest Research Institute (SwRI), with a team led by Alan Stern, the spacecraft was launched in 2006 with the primary mission to perform a flyby study of the Pluto system in 2015, and a secondary mission to fly by and study one or more other Kuiper belt objects (KBOs) in the decade to follow, which became a mission to 486958 Arrokoth. It is the fifth space probe to achieve the escape velocity needed to leave the Solar System.
Mariner Mark II was NASA's planned family of uncrewed spacecraft for the exploration of the outer Solar System that were to be developed and operated by JPL between 1980 through the year 2010.
The Grand Tour is a NASA program that would have sent two groups of robotic probes to all the planets of the outer Solar System. It called for four spacecraft, two of which would visit Jupiter, Saturn, and Pluto, while the other two would visit Jupiter, Uranus, and Neptune. The enormous cost of the project, around $1 billion, led to its cancellation and replacement with Mariner Jupiter-Saturn, which became the Voyager program.
An interstellar probe is a space probe that has left—or is expected to leave—the Solar System and enter interstellar space, which is typically defined as the region beyond the heliopause. It also refers to probes capable of reaching other star systems.
The exploration of Saturn has been solely performed by crewless probes. Three missions were flybys, which formed an extended foundation of knowledge about the system. The Cassini–Huygens spacecraft, launched in 1997, was in orbit from 2004 to 2017.
Neptune has been directly explored by one space probe, Voyager 2, in 1989. As of September 2023, there are no confirmed future missions to visit the Neptunian system, although a tentative Chinese mission has been planned for launch in 2024. NASA, ESA, and independent academic groups have proposed future scientific missions to visit Neptune. Some mission plans are still active, while others have been abandoned or put on hold.
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 exploration of Pluto began with the arrival of the New Horizons probe in July 2015, though proposals for such a mission had been studied for many decades. There are no plans as yet for a follow-up mission, though follow-up concepts have been studied.
Argo was a 2009 spacecraft mission concept by NASA to the outer planets and beyond. The concept included flybys of Jupiter, Saturn, Neptune, and a Kuiper belt object. A focus on Neptune and its largest moon Triton would have helped answer some of the questions generated by Voyager 2's flyby in 1989, and would have provided clues to ice giant formation and evolution.
Europa Clipper is an interplanetary mission in development by NASA comprising an orbiter. Planned for launch in October 2024, the spacecraft is being developed to study the Galilean moon Europa through a series of flybys while in orbit around Jupiter.
2014 PN70 (internally designated g12000JZ, g1 and PT3) is a trans-Neptunian object from the cold classical Kuiper belt located in the outermost region of the Solar System. It measures approximately 40 kilometers (25 miles) in diameter. The object was first observed by the New Horizons Search Team using the Hubble Space Telescope on 6 August 2014, and was a proposed flyby target for the New Horizons probe until 2015, when the alternative target 486958 Arrokoth was selected.
2014 OS393, unofficially designated e31007AI, e3 and PT2, is a binary trans-Neptunian object in the classical Kuiper belt, the outermost region of the Solar System. It was first observed by the New Horizons KBO Search using the Hubble Space Telescope on 30 July 2014. Until 2015, when the object 486958 Arrokoth was selected, it was a potential flyby target for the New Horizons probe. Estimated to be approximately 42 kilometres (26 mi) in diameter, the object has a poorly determined orbit as it had been observed for only a few months.
The Planetary Missions Program Office is a division of NASA headquartered at the Marshall Space Flight Center, formed by the agency's Science Mission Directorate (SMD). Succeeding the Discovery and New Frontiers Program Office, it was established in 2014 to manage the Discovery and New Frontiers programs of low and medium-cost missions by third-party institutions, and the Solar System Exploration program of NASA-led missions that focus on prioritized planetary science objectives. The Discovery and New Frontiers programs were established in 1992 and 2001 respectively, and have launched fourteen primary missions together, along with two missions launched under the administration of the Planetary Missions Program Office. The Solar System Exploration Program was established alongside the office, with three missions planned for launch under the new program.
REX or Radio Science Experiment is an experiment on the New Horizons space probe to determine various aspects of the atmosphere of Pluto during the 2015 flyby.
Shensuo, formerly Interstellar Express is a proposed Chinese National Space Administration program designed to explore the heliosphere and interstellar space. The program will feature two space probes that will purportedly be launched in 2024 and follow differing trajectories to encounter Jupiter to assist them out of the Solar System. The first probe, IHP-1, will travel toward the nose of the heliosphere, while the second probe, IHP-2, will fly near to the tail, skimming by Neptune and Triton in January 2038. There may be another probe—tentatively IHP-3—which would launch in 2030 to explore to the northern half of the heliosphere. IHP-1 and IHP-2 would be the sixth and seventh spacecraft to leave the Solar System, as well as first non-NASA probes to achieve this status.
Timeline for the New Horizons interplanetary space probe lists the significant events of the launch, transition phases as well as subsequent significant operational mission events; by date and brief description.
