The Crew of the Cool Starship is on the verge of a planet's gravity well or near an Unrealistic Black Hole. Perhaps they are too close for the engines to escape gravity's grasp. Perhaps an enemy ship is closing them. All seems lost...
Then the Ace Pilot makes a suggestion: Head straight for the planet / black hole! The rest of the crew look at him as if he was mad, but follow his plan, and like magic, they pick up speed and wind up shooting out of the gravity well at incredible speed using gravity to perform a slingshot maneuver (also called Gravity Assist or Gravitational Slingshot) and escape!
Of course, pulling a successful Slingshot maneuver would require some precise maneuvering and calculations, but often in fiction, it's entirely possible for the Ace Pilot to just eyeball it.note Because the pilot is just that good.
Invariably, when the move is first suggested, almost everyone is incredulous, and it always fools the enemy. Almost like no-one has ever heard of a slingshot maneuver before, or is able to spot when the other side is about to perform one. And, of course, the maneuver is always used as a last-ditch desperation maneuver, rather than a standard tactic or move.
The closest thing in real life to what the pilot does is entering an unstable orbit. But no matter what, that black hole is definitely pulling you in, and if you can't generate enough force to escape the gravitational field directly, you're probably screwed.
In Real Life, gravity assists are a well-known and often-used phenomenon and have far wider applications (and limitations) than those depicted in fiction. The Other Wiki does a good job explaining the ramifications.
See also Gravity Sucks, Unrealistic Black Hole, and Space Friction, which may factor into the maneuver. Sometimes combined with a Wronski Feint if the enemy is tricked into following and can't escape.
- In the Endless Waltz OVA to Mobile Suit Gundam Wing, Quatre uses the gravity exerted by Venus to fling his ship back to Earth, because they are low on both time and fuel.
- Irresponsible Captain Tylor: Emi and Yumi get caught in a gravity well on their maiden flight, so Kojiro talks them through this manoeuvre, only to find their course intersects with an asteroid field on the other side of the planet.
- Both the Earth and Martian forces in Aldnoah.Zero make use of slingshot maneuvers during space combat, but that's not the impressive part. The impressive part is Slaine firing off two volleys of bullets at a seemingly anonymous patch of sky before the battle, only for the bullets to slingshot around the Earth and come down to shoot his ally Saazbaum In the Back at the climax of the episode, with just enough time between the volleys for Slaine to explain his treachery to the disbelieving Saazbaum.
- In one issue of Kid Gravity, a Disney Adventures comic, Kid Gravity uses this to escape a black hole, with his nemesis wondering how such a feat is even physically possible. Upon returning to school Gravity is punished for breaking the laws of physics.
- In one of the Futurama comics, Leela does this with the Planet Express ship to avoid being late to class, unfortunately destabilizing the star she sling-shot around.
- An aquatic version in Prince Valiant, involving Val's trireme becoming caught in the whirlpool Charybdis from Greek Mythology. One of their rowers turns out to be a fisherman from the area in his day job, and he advises them to row with the current, which allows them to accelerate out. They later make use of this to wreck the entire Roman navy in a Wronski Feint.
- In the Lost in Space movie, time travel has taught Professor Robinson that they can't escape the gravity of the collapsing planet — but he figures out that they can escape it by diving through it as it's breaking up. Another character (Major West) does the driving, though. Earlier the Jupiter 2 was supposed to slingshot around the Sun on its way to Alpha Prime, but Smith's sabotage sent them falling into it instead forcing them to make a Blind Jump.
- Apollo 13: The service module is too damaged to fire for a direct abort, and the lunar module engine doesn't have enough power. Only a slingshot maneuver around the moon, assisted by the lunar module engines, can get them on a course for home.
- Inverted with the aerobraking maneuver in 2010: The Year We Make Contact, used to reduce the Leonov's speed so it can enter Jupiter's orbit. Not that it's any less dramatic with a fire-enshrouded spaceship tearing through the upper atmosphere.
- Kamen Rider × Super Sentai: Super Hero Taisen has Kamen Rider Fourze and Red Buster and Blue Buster piloting the Double Rocket Drill Go-Buster-Oh around Saturn to slingshot around and deliver a Rider Kick onto Big Machine.
- In Interstellar, the Endurance slingshots the black hole Gargantua in order to get up to the speed needed for the onward flight to Edmunds' planet.
- In The Martian, the Hermes spacecraft performs a gravity-assisted maneuver around the Earth so it can quickly return to Mars, then have to do another round Mars so they can return to Earth. Unfortunately because of this they can't stop to pick up our protagonist, who must launch into an orbit high enough to be intercepted by the Hermes (much higher than originally planned). The concept is apparently so novel to the NASA scientists that the man who suggests it has to physically act it out.
- In Passengers the Avalon makes a slingshot maneuver around the star Arcturus, mostly to provide Scenery Porn for the movie.
- Used a few times in the Star Wars Expanded Universe:
- Han Solo has the Millennium Falcon does this to escape the Genius Loci in Star Wars: Galaxy of Fear. He lampshades this by calling it the "oldest trick in the manual."
- A semi-regular appearance during the Yuuzhan Vong War where the maneuver is called a Solo Slingshot. In this instance the ship is being slingshot around a miniature singularity instead of a planet and is thus much faster and more dangerous that usual with Han being the first pilot skilled/crazy enough to pull it off. Late in the war the Yuuzhan Vong themselves make use of this tactic much to the chagrin of Han's daughter Jaina.
- Combined with a Wronski Feint in The Privateer by James Doohan and S.M. Sterling. The damaged light carrier Invincible has a Mollie flotilla in hot pursuit, so it heads for a recently discovered system that has a pulsar perilously close to the jump point. Since they're expecting it, they're able to slingshot around the pulsar and back to the jump point to escape. The Mollies aren't so lucky; they end up smeared across its surface with their very atoms crushed into degenerate matter.
- In the Humanx Commonwealth novel The Tar-Aiym Krang, the protagonists use a neutron star as an FTL slingshot to escape pursuing AAnn, who refuse to follow due to the danger of the maneuver.
- A strikingly realistic depiction of a gravity turn, a real-world technique for achieving a stable orbit, appears in The Last Hero of all books.
- In the Star Carrier series Space Fighters' main drive system is a singularity drive, which generates a high-gravity field ahead of the ship to pull it forward. If generated to the side of a fighter, the drive allows for extremely tight high-speed turns via gravity assist. However this is extremely dangerous: the slightest perturbation of the turn, like, say, getting hit by gunfire from a Turusch Planet Spaceship, can send the fighter into a spin that will disintegrate it in seconds.
- End Run features an escort carrier making a raid behind enemy lines in the Kilrathi home system of Kilrah that uses a gravity slingshot around a gas giant in the system to make an escape after sustaining significant damage during the raid. However, the configuration of the system and the nature of FTL travel in the Wing Commander universe means that the only escape path using that slingshot is a string of single-exit star systems before making it to a Confed held system.
- In the Great Ship series, humanity claimed the derelict Greatship while it was streaking towards the Milky Way at a significant fraction of the speed light, and slung it around a red dwarf to put it in the galactic plane, where they turned it into a cruise ship of sorts by granting berths in exchange for technology, colonization rights, and pledges of assistance. At the climax of Marrow, the ship is seized as it slings around another star to keep it within the Milky Way; the mutineer attempts to direct the ship into the star to destroy the ship and release whatever is contained within Marrow, the planet in the ship's core
- In Ciaphas Cain: The Last Ditch the ship carrying Cain and the 597th is damaged transiting from the Warp because the Geller fields keeping its denizens out glitched and let a daemon onto the bridge. They're forced to use their target planet to do a gravity assist and to slow down with the upper atmosphere in order to slow down enough to get everyone off the ship before it goes careening off into space.
- Joshua Calvert does this in The Night's Dawn Trilogy, however the drama is in how he does it, rather than the stunt itself.
- This is a major plot point in The Martian: The so-called Purnell Maneuver involves slingshotting the Hermes around Earth so that it can get to Mars before Watney starves, and around Mars so they can get back with the fuel on board; NASA initially rejects the plan because it risks the lives of the Hermes crew, but Mitch Henderson sends Vogel the flight path and the crew mutinies.
- In Abaddon's Gate a Belter teenager in a slapped-together ship slingshots past Jupiter and Saturn to "thread the needle" through the Ring in Uranus counter-orbit, the lack of drive signature allows him to evade detection by the ships around the Ring until it's too late to stop but also keeps him from slowing down enough before the deceleration field on the other side turns him into red paste.
- The Red Dwarf novels;
- In Infinity Welcomes Careful Drivers, the Red Dwarf does this around a planet in order to turn back towards Earth without spending 3 million years decelerating.
- In Better than Life, Lister wants to do this around an Unrealistic Black Hole in order to accelerate over the speed of light and tow Earth back to the solar system.
- In Backwards, the crew are stranded on Backwards Earth and have to wait ten years until When the Planets Align so Starbug can slingshot around them and go through the Omni Zone and back into their own universe.
- In Donald Moffitt's Second Genesis, the humans of the Yggdrasil slingshot between two black holes to help put them on a course out of the galaxy just ahead of the radiation wave the colliding black holes produce, ending all life in the galaxy.
- Gravity assists are common in Aeon 14, being a relatively realistic Space Opera franchise, but in A Path in the Darkness the turn around Estrella de la Muerte (what the cast names Gliese 1061/LHS 1565 after being sabotaged while passing it) is unusually harrowing: Intrepid is already severely damaged by the saboteurs and has to harness a sunspot cluster's magnetic field to accelerate, which causes a solar eruption and damages her still further.
- A fixture of naval tactics in Kris Longknife, with Kris in particular known for planning complex combinations of gravity assists to come at her enemies from unexpected angles. It's not the slingshot itself that is unusual, just her proficiency at it.
- In Flight of the Eisenstein, the titular starship slingshots around one of Istvaan III's moons to break away from Horus' fleet, so they can jump to warp and bring word of the Warmaster's treachery to the Emperor. The pursuing battleship Terminus Est is unable to match the carefully-plotted manoeuvre, and must break off and escape the moon's gravity well with brute engine power.
- Stargate SG-1:
- A slingshot maneuver around Jupiter is attempted by O'Neill and Teal'c in "Tangent", but the attempt fails as the rockets they use (the pair of Sidewinder missiles their Space Fighter prototype is armed with) lack thrust, and the experimental X-301 is making automated trajectory corrections anyway because of its sneaky Goa'uld programming.
- At the end of "The Pegasus Project" the Odyssey successfully pulls one around a black hole, after goading a Wraith Hive Ship to follow them. They make it, while the Hive Ship has no such luck due to the Odyssey using the fact that the black hole is disrupting their systems to beam a nuke inside the ship.
- Stargate Universe:
- One of Destiny's shuttles attempts the maneuver around a planet to catch up to Destiny itself.
- Destiny also performed an aerobraking maneuver around a Gas Giant to slingshot it into a Sun. It's later revealed that this was intentional and flying into stars is how the ship refuels.
- Star Trek:
- Warp-powered gravitational slingshots are used a method of time travel in the franchise, especially in Star Trek: The Original Series and Star Trek IV.
- Conventional slingshots without time travels feature in Star Trek: The Animated Series episode "Beyond the Farthest Star" and Star Trek: The Next Generation episode "Booby Trap".
- One episode of Star Trek: Voyager had Janeway attempting to drive an alien force that had been experimenting on her crew off by flying between a pair of pulsars. Tuvok remarks that it's a far more reckless course of action than he'd come to expect from her. The aliens leave rather than face the pulsars, but Voyager flies through, counting on their momentum to help them escape. Once they're safe on the other side, Janeway remarks she didn't know Tuvok thought she was reckless, to which he responds, "Poor choice of words, Captain. It was clearly an understatement."
- Andromeda starts this way. They attempt to slingshot around a black hole to escape an enemy fleet, but sabotage leaves them stranded in orbit so close to the event horizon that from their point of view a few seconds went by, while a whole 300 years passed in the rest of the galaxy.
- Integral to the pilot of Farscape. Proving the feasibility of this maneuver is the whole reason John went into space with Farscape One. By the conclusion of the pilot, he proves his theory using Moya, with Aeryn Sun piloting and him doing the calculations on the floor, using the maneuver to escape the Peacekeepers. He performs the maneuver several times throughout the series, trying to recreate the accident that sent him to that part of space. The only thing he knows is that it involved this maneuver and a solar flare. (The maneuver here doesn't, incidentally, make terribly much sense: rather than a traditional gravity assist, he seems to be trying to accelerate to escape velocity by skipping across the upper atmosphere, a maneuver which rightly ought to brake his Space Plane.)
- In the first season of The Expanse Miller comes across a "Slingshot club" where people follow pilots attempting such stunts and bet on whether they live, the one they're watching then doesn't. While in season 2 Alex and the Rocinante's military-grade computer plot an extremely complicated maneuver through Jupiter's moons in an attempt to get to Ganymede without firing the main drive, it works until he almost collides with an MCRN destroyer and has to abort to avoid detection.
- Blake's 7. In a couple of episodes a "fast orbit" is used to evade a Federation patrol while the Liberator is hanging around above a planet. It's implied to be this trope though due to No Budget for special effects the audience has to Take Our Word for It.
- Dans une galaxie près de chez vous: The crew attempts this in Season 2, the scientist however explain how dangerous it is to pull off a gravitational slingshot and to top it off it sends them straight into an asteroid field. The first attempt is a failure because the scientist keeps insulting and yelling at the radar operator and pilot (even trying to pull the pilot off the seat in a fit of neurosis) . A similar attempt is proposed but using twin stars for the gravity pull in Season 4 and end almost killing the crew because of the heat. In both cases it's not used to escape danger but simply to travel faster.
- Done in Sega Pinball's Apollo 13 for the "Moon's Gravity" Mission, where the player can slingshot a pinball around the Moon up and over it (actually done via a magnet).
- Stern Electronics' Orbitor 1 was a pinball game built around this trope, using a warped transparent playfield to allow pinballs to slingshot around bumpers and other obstacles.
- Starfire, Nexus magazine #2 article "Incidents from the First Terran-Khanate War". When a Terran ship first encountered a ship of the Khanate of Orion, the Terran commander was under orders to obtain information about the other side before leaving. He altered course to make a tight high-speed parabolic course around a nearby Khanate planet so he could scan it and use the planet's gravity to return to the warp point at maximum speed. He had to fight (and destroy) a Khanate ship while performing this maneuver.
- Mission: SPACE involves a trip to Mars, started off with a slingshot assist around the moon. Even then, it takes three months to get to Mars, which is passed over by putting the crew in hypersleep for most of that trip.
- The Star Control games features top-down 2D maps where two ships at a time duke it out, usually complete with a planet in the middle to act as a hazard and a gravity well. Using the planet's gravity to slingshot yourself across the map (or to trap an enemy ship) is a cornerstone of the game's combat style.
- A Difficult, but Awesome way of saving fuel in Kerbal Space Program. Experienced players can even learn to pull off this sort of maneuver manually for common transfers like Kerbin-to-Munar-Orbit using dead reckoning and some mental geometry. Extremely experienced players eventually learn to use elaborate flight plans to slingshot and break spacecraft into and out of velocities nearing fractions of light speed with absurdly small fuel costs. This is both helped and required, however, by the game's only slight indulgence in Space Compression. While players can fast forward through the days or months of travel between burns, even high speed, low-tolerance burns can last several seconds or minutes, leaving plenty of time to correct for pilot error or use vector nodes to plan out that next burn.
- Also possible in Orbiter.
- Parodied in one Futurama episode, in which Zapp Brannigan does this while piloting the Titanic space-liner for pretty much no reason.
Zapp Brannigan: Ah, yes. Comets. The icebergs of the sky. By jack-knifing from one to the next at breakneck speed, we might just get some kind of gravity boost... or something.
- Used in Green Lantern: The Animated Series where Hal Pilots a ship Into a pinhole (miniature black hole), making it "skip" over the accretion disk like a stone over water which somehow lets the ship shoot out of the pinhole's event horizon towards safety. Made further confusing when earlier in the episode the gravity was strong enough to "spaghetti" the prow of the ship, yet when later they are much closer to The pinhole, skipping on its accretion disk, the ship suffers no structural damage.
- Apollo 13 was launched by NASA in 1970 as the planned third manned mission to land on the moon. An explosion in the oxygen tank of Apollo 13's service module rendered the spacecraft's core systems and main propulsion engine inoperable. Forced to rely on the limited power of the command and lunar modules, Apollo 13 used the Moon's gravity for a circumlunar return.
- Slingshot manouevres around Jupiter and its moons were used to give the Voyager spacecraft the extra impetus and direction to go onwards to encounter Uranus and Neptune. Otherwise they would have run out of fuel and propulsive power and taken a lot longer to reach the outermost planets.
- The New Horizons probe used Jupiter's gravity to slingshot it and boost its speed towards Pluto and the Kuiper Belt.
- The Galileo spacecraft, which was disposed of in the Jovian atmosphere in 2003, used slingshots from Venus, Earth, and Earth again to gain enough velocity to reach jupiter. The Cassini spacecraft (which was controlled to crash into Saturn in Sep 15th, 2017), has taken this trope Up to Eleven making two flybys of Venus, one of the Earth, and one of Jupiter to boost her towards Saturn, as well as using Titan's (Saturn's largest moon) gravity to change her orbit, allowing exploration of the Saturnian system. The Rosetta mission which used four gravity assists (Earth, Mars, Earth and Earth again) to catch the comet 67P.
- The Parker Solar Probe inverts the typical version of this, using a grand total of 7 Venus flybys (the first of which was in early October 2018) to shed orbital velocity until its orbit is much closer around the Sun instead of reaching Earth or near-Earth orbit every perihelion.