I’m not familiar with any concepts using the charged particles of the ionosphere itself, but there are approaches to use the Earth’s magnetic field while in Low Earth Orbit (LEO) traveling through the ionosphere. These are based on Faraday’s Law, where a conductor (wire, or tether) moving through a magnetic field results in a current.
There is a small company (founded by aerospace legend Robert Forward) in Redmond Washington called Tether’s Unlimited, which specializes in using tethers in space for many purposes, including power generation.
The latest date we were targeting was May 7th, but it’s now not looking like everything will be ready in time to make that date. There’s no official word yet on what the new date will be.
Regarding Dragon you are correct, it is a highly automated spacecraft, similar to the European ATV, Japanese HTV, and Russian Soyuz. Lots of good info here!