The High Altitude and LOng Range (HALO) Research Aircraft (based on a Gulfstream G550) is the research aircraft for atmospheric research and earth observation of the German science community. HALO was funded by the Federal Ministry of Education and Research, the Helmholtz-Gemeinschaft and the Max-Planck-Gesellschaft. The aircraft is operated by the Flight Experiments facility of DLR.
The Israel Air and Space Force (IASF) operates two types of modified Gulfstream Special Mission aircraft based on Gulfstream V and Gulfstream G550 airframes. Click the picture for an introduction.