Explore a gravity assist - a hyperbolic flyby that can raise heliocentric speed by about +10 km/s in the Voyager / Jupiter teaching case.
Published teaching figure: Voyager Jupiter assist ~+10 km/s heliocentric speed gain (order of magnitude). Hohmann Transfer 3D teaches two burns on ellipses - this page teaches a flyby assist.
Drag to orbit and scroll or pinch to zoom. Scrub periapsis, scrub flyby phase, or play/pause the craft.
Gravitational Slingshot 3D Explorer
A gravitational slingshot is a hyperbolic flyby past a moving planet that can raise heliocentric speed - the Voyager / Jupiter teaching case is about +10 km/s.
In Gravitational Slingshot 3D Explorer, scrub periapsis in planet radii to bend the blue flyby path, scrub flyby phase, or play/pause the craft along the hyperbola. The planet shows a prograde velocity arrow so the assist direction stays readable.
- Planet with prograde velocity arrow
- Blue hyperbolic flyby path
- Spacecraft scrub along the path with play/pause
- Periapsis distance scrubber in planet radii
- Facts panel lists the ~+10 km/s Voyager / Jupiter teaching figure
- Runs fully in the browser with the vendored three.js engine - no account, no upload
Operating Gravitational Slingshot 3D Explorer in five steps
Open the explorer, read the ~+10 km/s figure in the facts panel, then scrub periapsis and flyby phase while the craft flies the hyperbola.
- Open the page and wait for the planet, the green prograde velocity arrow, and the blue flyby path to draw.
- Read the facts panel: the ~+10 km/s teaching delta-v and the current periapsis in planet radii (R).
- Scrub Periapsis (R) - a closer flyby bends the hyperbola more.
- Scrub flyby phase, or press Pause flyby to hold the craft at one point on the path.
- Switch to Hohmann Transfer 3D when the question needs two burns instead of a single assist.
Students see why a planet can "throw" a probe; teachers contrast assists with Hohmann burns; curious readers connect Voyager's path to a one-screen schematic.
| Figure | Value | Source note |
|---|---|---|
| Teaching delta-v | ~+10 km/s | Voyager Jupiter assist order of magnitude |
| Geometry | hyperbolic flyby | Single pass, no burn; not a closed transfer ellipse |
| Contrast | vs Hohmann burns | See Hohmann Transfer 3D sibling |
Gravitational Slingshot 3D Explorer next to its sibling explorers
Gravitational Slingshot 3D Explorer teaches a single flyby assist; the two siblings below teach burns and launch speeds instead.
| Explorer | What it teaches | Access | Trade-off |
|---|---|---|---|
| Gravitational Slingshot 3D (this page) | ~+10 km/s Voyager / Jupiter flyby assist | Free, in the browser | Teaching approximation, not an ephemeris |
| Hohmann Transfer 3D | Two burns on transfer ellipses | Free, in the browser | No flyby assist geometry |
| Escape Velocity 3D | Local escape-speed comparisons | Free, in the browser | Launch speeds, not a heliocentric assist |
Everything renders on your device with WebGL. The 3D engine loads once (about 0.7 MB) and is cached; no scene data is sent to a server.
The scene is an educational gravity-assist schematic - it does not integrate n-body ephemerides, does not play real Voyager SPICE trajectories, and does not optimize mission design. For two-burn ellipses use Hohmann Transfer 3D Explorer; for local launch speeds use Escape Velocity 3D Explorer.
The five-step walkthrough above covers every control on the page. When you need session fit and limits, see when to use Gravitational Slingshot 3D Explorer. The Space 3D collection also includes those siblings side by side.
Frequently Asked Questions
What does the Gravitational Slingshot 3D Explorer show?
A teaching schematic of a hyperbolic flyby past a moving planet, with the Voyager / Jupiter ~+10 km/s literacy figure and periapsis / flyby scrubbers.
How is this different from Hohmann Transfer 3D?
Hohmann Transfer 3D teaches two burns on elliptical orbits. This page teaches a flyby gravity assist on a hyperbola.
How is this different from Escape Velocity 3D?
Escape Velocity 3D compares local launch speeds from a body. This page shows how a planetary flyby can change heliocentric speed.
What does periapsis change?
A closer flyby bends the hyperbola more. The scrubber is in planet radii on a teaching scale.
Is +10 km/s exact for every assist?
No. It is an order-of-magnitude Voyager / Jupiter teaching figure. Real assists depend on geometry and epoch.
Is this an N-body simulator?
No. It is an educational gravity-assist schematic - not an N-body ephemeris.