I heard the story of a pretty remarkable accomplishment during a keynote speech at the ARC World Industry Forum last week by Doug McCuistion, who retired in 2012 as director of the Mars Exploration Program at NASA. That's the program that included the Mars Space Lab Mission that successfully landed Curiosity on the planet.
The conclusion of what was the first guided descent of a lander, which entered Martian atmosphere at about 13,000 mph, after a 170 million mile journey, was accuracy of the highest order...The ‘landing ellipse’ the team charted on the planet surface, which marked out the sort of manageable margin of error for the landing target, was 12 miles by 4 miles. Compare that with the best they could do in 2004, which was a roughly 93 mile by 12 mile ellipse for the Spirit and Opportunity landers in 2004.
“By the way, we actually landed 250 meters away from where we thought we were going to land,” McCuistion noted. Are you kidding me???
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