A researcher at the University of Stuttgart developed an atmosphere-breathing electric propulsion system that could allow satellites in Very Low Earth Orbit to remain aloft indefinitely by using atmospheric gases as fuel instead of conventional propellants. The concept uses a contactless plasma thruster paired with an optimized intake system to address challenges like atomic oxygen corrosion and atmospheric variability, showing promising laboratory results though real-world mission performance remains unproven.
This article explains how SpaceX's Raptor engine works by progressively introducing engineering solutions to propulsion challenges, from simple compressed gas thrusters to fuel-burning engines with turbopumps that spin via gas generators. The piece traces the evolution across Raptor 1, 2, and 3 versions, illustrating how each design iteration solves specific problems in rocket propulsion efficiency and performance.