Hydrogen and oxygen are propulsive fuels. Electrolysis and a source of water then gives you a pathway from electricity to propulsion. Where you get the electric

Hydrogen and oxygen are propulsive fuels. Electrolysis and a source of water then gives you a pathway from electricity to propulsion. Where you get the electricity from is up to you; giant solar panels, nuclear reactors, etc. For moving an asteroid around, it's probably OK if it takes 10 years to get it on the right trajectory... Here's an example of Nasa using electrolysis + water for maneuvering cubesats: https://www.nasa.gov/feature/ames/ptd-1 https://www.nasa.gov/feature/ames/ptd-1