29.8 KM/S
YOUR CURRENT VELOCITY, COURTESY OF EARTH'S ORBIT
2
BODIES WHOSE MOTION MUST CANCEL BEFORE YOU STEP THROUGH
1
CALCULATOR THAT DOES THIS MATH FOR YOU
// PORTAL_SAFETY_BULLETIN
A portal is a door. It is not a brake.
Science fiction cuts this scene. The hero steps through, the far side politely holds still, everyone walks away. In practice the far side is a planet — falling around the Sun at its own speed, rotating at its own rate. Step through with the wrong velocity and the difference does not disappear. It becomes yours, immediately, in one of two directions.
OUTCOME_01 · EJECTION
Leftover velocity, pointed at the sky
You exit moving away from the ground at several kilometers per second. The destination recedes. You are now on an unscheduled solar orbit. The view is excellent, briefly.
OUTCOME_02 · LITHOBRAKING
Leftover velocity, pointed at the ground
You exit moving toward the surface, and the planet absorbs the difference on your behalf. This procedure works exactly once, and you will not be filing the incident report.
OUTCOME_03 · NOMINAL
Entry velocity matched. Exit uneventful.
You enter at the velocity this calculator specifies. You exit standing still — boots down, camera steady, itinerary intact. The physics never notices you were there.
// TRANSIT_PLANNING
Plan the entry. Survive the exit.
01 · SET YOUR DEPARTURE PAD
Any body, any coordinates. Pick a landmark or enter latitude and longitude by hand — your backyard counts as a launch facility.
02 · SET YOUR DESTINATION
Anywhere from Mercury to the moons of Neptune. The calculator tracks both surfaces live in a shared heliocentric frame.
03 · READ YOUR ENTRY VELOCITY
Orbital and rotational motion combined into the number that keeps you attached to your destination — with a 3D vector view and a time-dilation readout for the paperwork.