"Mars Orbit insertion" was the point in the mission when Mars Reconnaissance Orbiter arrived just short of Mars, fired onboard rockets to slow its speed relative to the planet, and was captured into a long, looping orbit.
As the orbiter approached Mars in March, 2006, it passed under the planet's southern hemisphere at an altitude of about 300 kilometers (190 miles), traveling at about 3 kilometers per second (about 6,500 miles per hour).
In order to be captured into orbit around Mars, the spacecraft needed to perform a maneuver to slow the orbiter by about 1,000 meters per second (3,280 feet per second). The Mars orbit insertion burn used its six 170-Newton (38-pound) main engines and lasted about 25 minutes.
For most of the burn, the orbiter was visible from the Deep Space Network stations. The signal from the spacecraft was temporarily lost as the orbiter went behind Mars. The mission team held a collective breath, waiting for the orbiter to appear again approximately 30 minutes later.
The capture orbit was highly elliptical. The closest the spacecraft came to Mars in this orbit (the periapsis) was 300 kilometers (180 miles). The farthest away it traveled (its apoapsis) was 45,000 kilometers (28,000 miles). The orbiter took 35 hours to move completely around the capture orbit.