PARIS–The expanding use of space is creating new cases in geostationary orbit where conventional satellites weighing several metric tons would be too expensive. Established and would-be manufacturers ...

The orbits of the planets around the sun have been the source for many a scientific debate. Their current orbital properties are well understood but the planetary orbits have evolved and changed since ...

Mathematicians think abstract tools from a field called symplectic geometry might help with planning missions to far-off moons and planets. In October, a Falcon Heavy rocket is scheduled to launch ...