Starship

Starship is SpaceX's fully reusable super-heavy-lift launch system, comprising the Super Heavy booster and the Starship upper stage, both powered by Raptor engines burning liquid methane and liquid oxygen. Standing approximately 121 metres tall when stacked, it is the largest and most powerful rocket ever to fly. By late 2025 the full stack had completed five test flights, with the system's reusability demonstrated through booster catch manoeuvres at the Starbase launch site in Boca Chica, Texas. A V3 variant, targeting over 100 tonnes to low Earth orbit, was in preparation for its first flight in late April 2026.

For NASA's Artemis programme, a specialised lunar lander variant, Starship HLS, is contracted to carry two astronauts from lunar orbit to the Moon's surface for Artemis III and IV. Starship HLS stands 52 metres tall and must land vertically near the Lunar South Pole, where terrain is rugged and slopes exceed the vehicle's stability margins, prompting NASA's OIG to flag a 171-foot tip-over risk as a mission-critical safety concern. The vehicle requires multiple in-space propellant transfer flights before each lunar mission, a complex logistics chain that has contributed to schedule delays.

Starship's significance extends well beyond NASA. SpaceX is simultaneously developing it for commercial payload delivery, Starlink satellite deployment, point-to-point Earth transport, and eventual crewed Mars missions. The vehicle's development pace and Artemis commitments are in direct tension, and NASA's OIG has noted that SpaceX's contractual milestones for Starship HLS are running at least two years behind.