Ion drives in orbit

Hollister “Hop” David: Ion engines really suck at climbing in and out of planetary gravity wells. The (weak) engine would not be moving its mass straight up or down, but spiraling. The values he gave for that snail-crawl were: 40 days to get up from Earth LEO (which is what, 400 km) to EM-L2; 20 days to get down from Mars/Sun L2 to Mars’ LEO (Phobos?). In support Hop links to this explanation on Stack Exchange.

Hop’s aim was to debunk Neil DG Tyson. Hop pointed out that, to get through Earth’s gravity well, a 2 mms^-2 thrust will condemn any human and most electronic passengers to a death sentence in the Van Allen Belts.

I am here for Venus, whose orbital range doesn’t have belts – but that doesn’t matter. Venus instead has direct solar radiation, and an induced trailing magnetosphere. These are just as bad for humans as Van Allen, as far as I know. I’ll assume most Venerean passengers don’t want to dink around for four weeks incrementally spinning to their planet’s desired altitude, either.

Some other schmo can do the maths for exactly how long it takes to get from X to Y over whatever planet, or for ion solutions generally. I am satisfied that the time is measured in weeks.

But I counter that slow-acceleration drives (like ion) do have a place traversing orbital altitudes: for raw-material low-priority heavy freight, which is still precious enough not to drop onto the Australian outback or to fire off into an eccentric solar orbit. It won't be foodstuffs. I'm thinking ores, phosphorous, and water. Also fragile goods we don't want to subject to sudden shifts in G.

UPDATE 8:30 PM - I don't know that ion drives will be used much o'er Venus. Venus has that impressive ionic coma of its own to give to its orbiting craft that level of thrust; as "NicoNicoNekomancer" has relayed it to me, the Electric Wind. Why buy an ion drive if you can just SAIL out there [UPDATE 2/8/2020 like with a Greason q-drive]. I might have to break down and do the maths, to make that call. But ion drives will certainly help over Earth and the Moon.

UPDATE 7/28: We have better ion drives than Hop knew about in 2016. SolVen-L2 can use 'em. THRUST 1/30/21: Ebrahami.