HALO (High Altitude and Long Range Research Aircraft), the new research aircraft of the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR), is complete. In a 20-month project, RUAG Aerospace Services have converted the brand-new Gulfstream G550 from a standard business jet into the state-of-the-art and highly specialised high-altitude research aircraft for DLR's atmospheric research activities. The graphic shows the modifications on the upper and lower fuselage.