A re-configurable NASA receiver called the Space Communications and Navigation Testbed, SCaN [LINK to https://spaceflightsystems.grc.nasa.gov/sopo/scsmo/advanced-communications-systems/cognitive-comm/payload/scan-testbed-design/ ] is attached to the exterior of the ISS. In April 2018 the chest-sized SCaN, seen left of centre with an antenna on top, was used to make the first combined Galileo-GPS positioning fix in orbit.