I remember hearing about ion engines 40 years ago and then lost track of the details of most NASA/European Space Agency developments. Today I sat in a innovation seminar where the topic was mentioned so I checked out the status. In case others are not up to speed (pun intended) on the topic - for your viewing pleasure...

I hope you speak French or can read subtitles.​

NOTE: hard to believe the precision possible - mentioned at 1:00 to 1:30. I already confirmed this level of precision is possible from a knowledgeable US source.

http://www.safran-group.com/video/7434

 

Cool stuff. They made a distinction between plasma and ion engines that I don't get. Do you know what that distinction is?

Also, when they compare to chemical propellant, it's not quite fair to ignore the power source. The propellant supplies its own power. The plasma engine needs big solar panels.

 

Cool stuff. They made a distinction between plasma and ion engines that I don't get. Do you know what that distinction is?

Also, when they compare to chemical propellant, it's not quite fair to ignore the power source. The propellant supplies its own power. The plasma engine needs big solar panels.

I don't see much of a distinction unless they mean how the plasma is accelerated before stripping out the propellant ions. You can have a single stage plasma generation stage where ions are directly extracted and accelerated by an electrical potential (low thrust) or you can accelerate the plasma after generation with a separate electro-magnetic stage then use an electrostatic shield to separate (neutralize) the stream of ions for higher energy/mass transfer of acceleration power to the thrust propellant.

 

I don't know the difference, if I call my NASA contact again soon, I will ask (if I remember). Apparently, the positioning experiments went extremely well right out of the box and thrust calculations are so simple because there is no ambiguity as to the thrust and remaining mass on the vessel - ignition delays and valve actuation variables cause all kinds of issues with precision positioning.

 

I don't know the difference, if I call my NASA contact again soon, I will ask (if I remember). Apparently, the positioning experiments went extremely well right out of the box and thrust calculations are so simple because there is no ambiguity as to the thrust and remaining mass on the vessel - ignition delays and valve actuation variables cause all kinds of issues with precision positioning.

I can see how it would be very precise and stable. The gas flow control would be with a MFC and the acceleration of that mass would be controlled with an RF generator.