Snake River Jump

How to play

The goal

Launch a car off the south rim of Idaho’s Snake River Canyon and land it on the far side. You touch down on the landing zone, the strip between the two flags. A landing only counts if it’s inside the zone and not too hard, so getting across is only half the job. Beat a level to unlock the next one. You can replay any level you’ve unlocked.

Controls

• Speed and Ramp sliders: set how fast you leave the ramp and how steep it is. Each level has its own range.
• Launch (or Enter): go.
• Jets: hold Space, or press and hold the JETS button on a phone or tablet, to fire the jets straight up. The Jet time box shows how much is left. It runs out fast.
• ↻ Try again: reset the level and fly again.
• Sound: turn the sound effects on or off.

How stars work

Every landing can earn up to three stars:

• ★ Landed: you touched down inside the zone without crashing.
• ★ Soft: your landing was at or under half the level’s g limit. How hard a landing is depends only on how fast you’re dropping straight down at touchdown. Your forward speed and the car’s angle don’t matter. Watch the Landing meter as you come down: gold means soft, green means safe, red means crash. It also tells you the sink speed you need to stay under.
• ★ Centered: you landed in the middle third of the zone, the gold stripe marked with a star.

Tip: a short burst of jets just before touchdown slows your drop and turns a hard landing into a soft one. Save some jet time for the end.

Pillar levels

Levels 5–8 add basalt pillars in the canyon. Land on top of each pillar in order. Its kicker throws you on toward the next one, and finally the far rim. One tank of gas has to last the whole run, and for the soft star your hardest landing of the run is the one that counts.

A secret

Some say there’s more to this canyon than the far rim. Very good pilots who explore a little might find a way in somewhere…

Rides and unlocks

You start in a Roadster. Mastering the hardest level earns a new ride, and each ride keeps its own stars. A full set of three stars on every level in a special ride counts as a run. Gold runs and Red runs are counted toward a legendary reward. Your progress is saved only in this browser.

The physics behind it

Gravity

Once the car leaves the ramp, gravity pulls it down at 9.81 m/s² (about 32 ft/s²) the whole time. That’s why the path is a curve: the forward speed carries you across while your upward speed shrinks, hits zero at the top, and then turns into a downward speed that grows until you land.

Air drag

Air pushes back on the car. Drag grows with the square of speed, so going twice as fast means four times the drag. That’s why the real path falls a little short of a perfect parabola, and why just adding speed has diminishing returns.

Jet thrust and fuel

The jets blast compressed gas straight down, pushing the car up. Thrust is a force, so it changes your vertical speed for as long as it fires. The tank is small, and the car gets a little lighter as the gas is used up. Firing early lifts your whole path; firing late slows your drop for the landing.

g-force from sink speed

When the car lands, its suspension and tires squash about 10 ft to stop the downward motion (we call this the cushion). Stopping a downward speed v over a distance d takes an average deceleration of v² ÷ 2d. Divide by gravity to get g’s:

g = sink² ÷ (2 × 10 ft) ÷ 9.81 m/s²

Because the sink speed is squared, cutting your drop speed in half makes the landing four times softer. That’s why the Landing meter shows your sink speed.

Wind

A headwind pushes against you and shortens the jump. A tailwind carries you farther. Wind can change during a flight, so watch the arrow at the top of the screen.

The levels change the gas, wind and landing limits to make it a game, but the gravity, drag, thrust and gas use come from the same physics model throughout.