Display a zoomable Orthographic projection with countries and some locations shown. Display a longitude slider that allows the longitude to be set dynamically. The aim is to show which earth stations are visible from a satellite in geostationary orbit at the selected longitude.
Bits have been copied from several blocks
https://d3js.org/d3.v4.min.js
https://d3js.org/queue.v1.min.js
https://d3js.org/d3-geo-projection.v1.min.js
https://d3js.org/topojson.v2.min.js