Marking a first in space, Sentinel-1A and Alphasat have linked up by laser stretching almost 36,000 km across space to deliver images of Earth just moments after they were captured.
This important step demonstrates the potential of Europe's new space data highway to relay large volumes of data very quickly so that information from Earth-observing missions can be even more readily available.
Having timely access to imagery from the Sentinel-1 mission, for example, is essential for numerous applications such as maritime safety and helping to respond to natural disasters.
Orbiting from pole to pole about 700 km up, Sentinel-1A transmits data to Earth routinely, but only when it passes over its ground stations in Europe. However, geostationary satellites, hovering 36,000 km above Earth, have their ground stations in permanent view so they can stream data to Earth all the time.
This takes a great deal of coordination between the different teams working intensively. Later on, in routine operations, this will be fully automated.
Creating a link between the two kinds of satellites means that more information can be streamed to Earth, and almost continuously. Engineers have turned to laser to accomplish this.