◠ orb3e

Continuous-thrust (electric-propulsion) orbit transfers — the slow spirals that ion engines actually fly. Numerically propagated, with animated playback and elliptical starts and targets.

Hohmann vs bi-elliptic transfers — the impulsive counterpart to Spiral, with a side-by-side Δv and time comparison over a to-scale visualization.

Transfer between two points in a set time — the workhorse behind interplanetary targeting. First-cut: coplanar, single revolution (porkchop grids to come).

The path a satellite traces over a rotating Earth, on a world map. First-cut: circular orbits — the classic sinusoid with its westward drift.

Clohessy–Wiltshire relative motion — the proximity-operations problem in the target's co-orbiting frame, V-bar and R-bar.

A launch ascent where gravity pitches the vehicle over — layered US Standard atmosphere, Mach-dependent drag, multi-stage vehicles with reentry traces, and the launch-latitude rotation assist.

Interplanetary launch windows — a Lambert transfer for every departure/arrival date pair against the real planet ephemerides, coloured by Δv, with the cheapest trip found.