A NASA mission to Mars led by the Â鶹ӰԺ is set to slide into orbit around the red planet Sept. 21 to investigate how its climate has changed over the eons, completing a 10-month interplanetary journey of 442 million miles. The orbit-insertion maneuver will begin with six thruster engines firing to shed some of the velocity from the spacecraft, known as the Mars Atmosphere and Volatile EvolutioN, or MAVEN mission. The thruster engines will ignite and burn for 33 minutes to slow the spacecraft, allowing it to be captured into an elliptical orbit around Mars.