Powering Space Exploration

Excerpt:  “Solar electric propulsion (SEP) is a means of creating in-space thrust for spacecrafts using solar cells to create electric power. SEP provides high fuel economy, albeit at a lower thrust, than traditional chemical propulsion (e.g., NASA’s Space Shuttle or SpaceX’s Dragon capsule). As a result, solar cells provide power for spacecraft with ten times less fuel requirements. Less fuel means less weight, which significantly reduces launch costs or frees up capacity for non-fuel related cargo or equipment. SEP is currently used on unmanned spacecraft as far out into space as Jupiter, a practical restriction caused by solar panels generating less energy as they travel further from the sun (solar energy diffuses over distance).” (footnotes omitted)