NASA’s Mars Reconnaissance Orbiter entered orbit around Mars in 2006.
The spacecraft launched from Cape Canaveral on August 12, 2005, and reached Mars on March 10, 2006. It used aerobraking—repeatedly passing through the upper atmosphere—to reduce its orbit and conserve fuel before beginning its main science mission.
Mars Reconnaissance Orbiter carries instruments for studying the planet’s surface, atmosphere, and subsurface. Its HiRISE camera has produced extraordinarily detailed images of Martian terrain, while other instruments have mapped minerals, temperature, and atmospheric behavior.
The spacecraft is often confused with Mars Global Surveyor, an earlier NASA orbiter that arrived in 1997. MRO also serves as a communications relay for surface missions, transmitting data between rovers or landers and Earth. Its long operational history has made it one of the most valuable spacecraft in Mars exploration.