Question
Three Billion Miles to Pluto...
http://www.bbc.com/news/science-environment-33524589
"Because the observations are all run on an automated command sequence, New Horizons had to fly a perfect path past Pluto, and with perfect timing - otherwise its cameras would have shot empty sky where the dwarf or its moons were expected to be.
This necessitated aiming New Horizons at a "keyhole" in space just 100km by 150km (60miles by 90 miles), and arriving at that location within a set margin of 100 seconds.
The last indications were that New Horizons was on the button of that aim point, being perhaps 70km closer to the surface of Pluto than anticipated, and arriving about 72 seconds early.
All this was achieved after a multi-billion-km flight across the Solar System lasting nine-and-a-half years."
"Because the observations are all run on an automated command sequence, New Horizons had to fly a perfect path past Pluto, and with perfect timing - otherwise its cameras would have shot empty sky where the dwarf or its moons were expected to be.
This necessitated aiming New Horizons at a "keyhole" in space just 100km by 150km (60miles by 90 miles), and arriving at that location within a set margin of 100 seconds.
The last indications were that New Horizons was on the button of that aim point, being perhaps 70km closer to the surface of Pluto than anticipated, and arriving about 72 seconds early.
All this was achieved after a multi-billion-km flight across the Solar System lasting nine-and-a-half years."