Every satellite in orbit that lasts more than a week or two uses solar or nuclear energy. Starlink is solar powered and uses electric rockets to reach final orb

Every satellite in orbit that lasts more than a week or two uses solar or nuclear energy. Starlink is solar powered and uses electric rockets to reach final orbit and maintain position. Hydrogen is one of the most common rocket fuels, and Starship will need to used synthesized methane (which we actually make on board ISS using direct cabin air carbon capture and the Sabatier process using hydrogen made from water split with solar electricity) on Mars to return to be reused, and Musk said SpaceX would eventually use synthesized methane for Earth-side refueling of Starship as well.