Back in November, NASA's next-generation Mars rover, Curiosity, set a course for the Red Planet. But it didn't actually chart a direct course; in order to keep Mars clean of microbes originating from here on Earth, NASA actually had to aim the spacecraft so that it would miss Mars.
This was done to ensure the upper stage of the rover's launch vehicle (which was not cleansed of Earth-borne organisms the way Curiosity was) never made it to the Martian surface. (How awful would it be if signs of life on Mars wound up being hitchhikers from Earth?) In other words, NASA has been planning all along to correct Curiosity's flight path at a later date.
Well, that date has come. Tomorrow, Curiosity will face the most important stage in its journey since launching from Kennedy Space Center 46 days ago, when the spacecraft carrying Curiosity performs a three-hour series of precisely calculated engine burns that will set the rover on the correct course.
Fingers crossed, everyone. If all goes according to plan, we're just 208 days away from Curiosity touching down on the surface of Mars.
Top image by NASA/JPL via SPACE.com