NASA Fires Up Powerful Lithium-Fed Thruster for Trips to Mars

[OKIsItJustMe]

4. The NERVA engine used hydrogen, so (you know) lithium is heavier than that, but certainly lighter than mercury

NERVA (Nuclear Engine for Rocket Vehicle Applications)
https://www1.grc.nasa.gov/wp-content/uploads/NERVA-Nuclear-Rocket-Program-1965.pdf

❝With nuclear rockets man will have the capability of much longer range space exploration) because of their inherent superiority over chemical rockets. The NERVA program has demonstrated the feasibility of such nuclear rockets.❞

https://en.wikipedia.org/wiki/Nuclear_thermal_rocket

This thruster is similar to the ones used by Discovery in 2001.


https://ntrs.nasa.gov/api/citations/20070032050/downloads/20070032050.pdf

❝…Propellants of choice for MPD thrusters are hydrogen and lithium, because of their low atomic mass and relatively low ionization energies (Ageyev, 1993 and Lapointe, 2002). Lithium’s very low first ionization energy makes it particularly advantageous at lower powers (0.5 – 5 MW) and moderate exhaust velocities (20-70 km/s). Hydrogen is more amenable to multimegawatt and high specific impulse operations, is easier to supply to the thruster as a gas, and is less likely to condense on spacecraft surfaces.❞