02:13 08-03-2015
Rather than belching flame and smoke, producing tremendous power, and accelerating like a rabbit, Dawn's ion engine takes a more leisurely approach, with a quiet blue glow of electrically charged xenon ions that push with a force of only 91 millinewtons.
To put that into perspective, that’s about the force exerted by a piece of paper lying on your hand. At that rate of acceleration, it would take Dawn four days to go from zero to 100 km/hr. At the drag strip, you wouldn’t use a stopwatch to time it, you’d need a calendar!
[...]An ion engine is seven to 10 times more efficient that a regular rocket, partly because it’s solar powered. Run the ion engine long enough and you can reach interplanetary speeds — you just have to be patient.
[...]Pluto is so much farther away that New Horizons needed a big push to get there, and even then it took almost a decade. In theory you could get there with an ion engine in a slow and steady way, with constant low acceleration. But the problem would be power. The ion engine on the Dawn spacecraft is solar-powered, and Pluto is so far from the Sun that there just isn’t enough energy available out there to run an ion drive.
NH è Dawn: çàÿö è ÷åðåïàõà
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