The Gulfstream-V (G-V) aircraft is a research jet that is used by multiple agencies, including NASA and the National Science Foundation (NSF). The G-V can operate at altitudes of up to 50,000 ft and can fly up to 10 hours per flight. Its payload capacity ranges from 5,600 to 8,000 lbs, depending on the specific aircraft. The G-V can carry a variety of instruments, making it a valuable aircraft for a broad range of research applications.