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. 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.
Often used as an Establishing Character Moment
if it occurs early in the work, to show the Ace Pilot
's skills. If calculations are made, it might act as such a moment for The Smart Guy
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 ramification.
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.
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- 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 did 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, tho.
- Real Life: Apollo 13's service module was too damaged to fire for a direct abort, and the lunar module engine didn't have enough power. Only a slingshot maneuver around the moon, assisted by the lunar module engines, could get them on a course for home. Granted, they were already on a semi-slingshot course, but since they'd left the 'free return trajectory' from earlier missions and would have missed Earth without it, it still likely counts. Depicted in the Apollo 13 movie.
- Used a few times in the Star Wars Expanded Universe:
- 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.
Live Action Television
- 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 used (the pair of Sidewinder missiles their Space Fighter prototype is armed with) lacked thrust.
- 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.
- In Stargate Universe, one of Destiny's shuttles attempts the maneuver around a planet to catch up to Destiny itself.
- Destiny also performed an aerobreaking 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 but sabotage leaves them stranded in orbit so close to the black hole 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.
Table Top Games
- 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.
- 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.
- 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.