Welcome to DU! The truly grassroots left-of-center political community where regular people, not algorithms, drive the discussions and set the standards. Join the community: Create a free account Support DU (and get rid of ads!): Become a Star Member Latest Breaking News Editorials & Other Articles General Discussion The DU Lounge All Forums Issue Forums Culture Forums Alliance Forums Region Forums Support Forums Help & Search

OKIsItJustMe

(22,089 posts)
6. Check out the NASA paper I added to the bottom of the reply
Sat May 16, 2026, 12:30 PM
Yesterday

Last edited Sat May 16, 2026, 02:23 PM - Edit history (2)

As well as this one linked to in the OP. https://alfven.princeton.edu/publications/pdf/polk-iepc-2024.pdf

I gave you the wrong impression by citing the NERVA engine, which, as you say, used a nuclear reactor to heat hydrogen which was then used as a propellant. My (unclear) point was that nuclear-powered engines have been being researched by NASA (and its predecessors) since the mid-50’s.

In the case of the “MPD thruster,” the hydrogen is being used as a plasma.
https://en.wikipedia.org/wiki/Magnetoplasmadynamic_thruster

Psyche uses xenon gas in its ion thrusters.


I read once that Gene Roddenberry rejected the use of ion thrusters for the Enterprise because they were too slow. (In the original series, they occasionally encountered more primitive spaceships which used them — as I recall Khan’s Botany Bay used ion thrusters.)

Recommendations

0 members have recommended this reply (displayed in chronological order):

Another fucking waste of money. 3Hotdogs Yesterday #1
Previous ion engines have favored very heavy atoms as propellant -- mercury or xenon. More atomic mass -- eppur_se_muova Yesterday #2
The NERVA engine used hydrogen, so (you know) lithium is heavier than that, but certainly lighter than mercury OKIsItJustMe Yesterday #4
Hydrogen is being used there as ejectable mass, nothing more. It's handled by mechanical pumps and pressure. eppur_se_muova Yesterday #5
Check out the NASA paper I added to the bottom of the reply OKIsItJustMe Yesterday #6
Thanks for the paper. I knew about the older nuclear interest. eppur_se_muova Yesterday #7
NERVA was not the same as Orion OKIsItJustMe 23 hrs ago #8
Yes, I know that, thank you. In fact you're just repeating things I've already said in my replies. nt eppur_se_muova 20 hrs ago #10
We both realize that (I was even repeating myself) OKIsItJustMe 20 hrs ago #12
Ah, OK ... writing for a larger audience ... eppur_se_muova 19 hrs ago #14
I've been watching "For All Mankind" on Apple TV OKIsItJustMe 18 hrs ago #15
Isn't lithium in somewhat short supply? erronis Yesterday #3
Meanwhile, at a grossly overspent under intellectual trump supported SpaceX 3825-87867 21 hrs ago #9
NASA is facing serious cuts OKIsItJustMe 20 hrs ago #11
More from the paper cited by OKIsItJustMe .... eppur_se_muova 19 hrs ago #13
"It must have been a real pleasure to work out the mathematics of MPD for the first time..." OKIsItJustMe 18 hrs ago #16
Latest Discussions»Culture Forums»Science»NASA Fires Up Powerful Li...»Reply #6