'UPDATE (CORRECTION): the time of the rocket burn is 1:24 p.m. Pacific time, not Eastern as I originally said in this entry. I have corrected that in the text below.
The next big step to the Red Planet, the Mars Reconnaissance Orbiter, will perform a critical rocket firing Friday at 1:24 p.m.
Eastern Pacific time. This will slow it enough and aim it such that it will be captured by the planet, causing it to enter a closed, highly elliptical orbit. Over the next few months it will dip into the martian atmosphere in a process called "aerobraking", which will further reduce the probe's velocity, which in turn will lower and circularize the orbit. Plans are for science observations to begin in earnest in November of this year.
But that all-important 27 minute backwards thrust is the first step. I'll have more information here as it comes in.'