Space Integrated GPS/INS
Space Integrated GPS/INS (SIGI) is a strapdown Inertial Navigation Unit (INU) developed and built by Honeywell International to control and stabilize spacecraft during missions. It has integrated global positioning/inertial navigation to provide three navigation solutions: Pure inertial, GPS-only and blended GPS/INS. SIGI have been employed on the International Space Station, the Japanese H-II Transfer Vehicle (HTV) the Boeing X-37 and X-40.
- "Lessons Leamed from Two Years of On-Orbit Global Positioning System Experience on International Space Station" (PDF). PDF. NASA Johnson Space Center. Retrieved 2006-09-27.
- "H-IIA Transfer Vehicle". Web Site. Japan Aerospace Exploration Agency (JAXA). Archived from the original on September 28, 2006. Retrieved 2006-10-01.
- "Independent Assessment of X-37 Safety & Mission Assurance Processes and Design Features" (PDF). PDF. NASA Headquarters Office of Safety & Mission Assurance. Retrieved 2006-09-27.