All systems remain on track for the long-awaited launch of Arianespace’s ECA upper stage. Flight 164, carrying a test payload as well as the commercial spacecraft XTAR-EUR is in its final preparation stages at the European launcher’s spaceport in Kourou, French Guiana. The launch window runs between 2:49 p.m. and 4:10 p.m. EST (7:49 p.m. and 9:10 p.m. GMT) on February 11.