[meteorite-list] Mars Reconnaissance Orbiter Adjusts Angle of Orbit

[Ron Baalke]

http://mars.jpl.nasa.gov/mro/mission/orbiter_update.html

Mars Reconnaissance Orbiter Adjusts Angle of Orbit     
September 6, 2006

NASA's Mars Reconnaissance Orbiter fired its six 
intermediate-size thrusters for 210 seconds Tuesday 
in a maneuver to make the shape of its orbit closer 
to the planned geometry for the mission's main 
science phase, beginning in November.

The maneuver raised the portion of the elliptical 
orbit at which the spacecraft comes nearest to Mars -- 
the periapsis -- from 216 kilometers (134 miles) above 
the surface to 320 kilometers (199 miles). A thruster 
firing on Aug. 30 had lifted the periapsis high enough 
to end a five-month process of dipping into the 
atmosphere every orbit to gradually shrink the orbit. 
The spacecraft now completes each loop around Mars in 
just under two hours.

The Sept. 5 maneuver also fine-tuned the orbit's angle 
relative to Mars' equator, tweaking it less than one 
degree to 92.5 degrees.

A longer firing of the engines next week is planned 
for lowering the high point of the orbit to make the 
shape more circular and for locking into a pattern of 
keeping the periapsis over Mars' South Pole and the far 
point -- the apoapsis -- over the North Pole.