News from space transport.
Launches, milestones and background from the world of space transport.
How Many Satellites Are in Medium Earth Orbit? GPS, Galileo and O3b mPOWER
An overview of the main satellite systems in medium Earth orbit (MEO), how many satellites GPS, Galileo and O3b mPOWER use and at which altitudes they fly.
Heliosynchronous Orbit: What It Means and Why Earth Observation Depends on It
What a heliosynchronous (sun-synchronous) orbit is, how it keeps a satellite at the same local time, typical altitudes and the example of NASA’s Terra satellite.
Mars Lagrange Points: What They Are and Why They Matter for Mars Communications
Where the Sun–Mars Lagrange points are, what Mars Trojan asteroids are and how Lagrange points could help avoid communication blackouts between Earth and Mars.
LEO, MEO and GEO Satellites Compared: Altitudes, Uses and Examples
What LEO, MEO and GEO mean, at which altitudes these orbits lie and what satellites in each orbit are used for, with examples from ISS, GPS, Galileo and O3b mPOWER.
Vega-C Launches FLEX and Sentinel-3C: Europe's First Dual Launch on Vega-C
ESA's FLEX Earth Explorer and the Copernicus Sentinel-3C satellite launched together on Vega-C flight VV30. FLEX will measure how plants photosynthesise from orbit.