SpaceX Starship
Starship is a two-stage, fully reusable, super heavy-lift launch vehicle under development by American aerospace company SpaceX. Currently built and launched from Starbase in Texas, it is intended as the successor to the company's Falcon 9 and Falcon Heavy rockets, and is part of SpaceX's broader reusable launch system development program. If completed as designed, Starship would be the first fully reusable orbital rocket and have the highest payload capacity of any launch vehicle to date. As of, Starship has launched times, with successful flights and failures.
The vehicle consists of two stages: the Super Heavy booster and the Starship spacecraft, both powered by Raptor engines burning liquid methane and liquid oxygen. Both stages are intended to return to the launch site and land vertically at the launch tower for potential reuse. Once in space, the Starship upper stage is intended to function as a standalone spacecraft capable of carrying crew and cargo. Missions beyond low Earth orbit would require multiple in-orbit refueling flights. At the end of its mission, Starship reenters the atmosphere using heat shield tiles similar to those of the Space Shuttle. SpaceX states that its goal is to reduce launch costs by both reusing and mass producing both stages.
SpaceX has proposed a wide range of missions for Starship, such as deploying large satellites, space station modules, and space telescopes. A crewed variant, developed under contract with NASA, is called the Starship Human Landing System, which is scheduled to deliver astronauts to the Moon as part of the Artemis program, beginning with Artemis III currently scheduled for 2027. SpaceX has also expressed ambitions to use Starship for crewed missions to Mars.
SpaceX began developing concepts for a super heavy-lift reusable launch vehicle as early as 2005, with different names throughout the years. Starship's current design and name were introduced in 2018. Development has followed an iterative and incremental approach, involving a high number of test flights and prototype vehicles. The first launch of a full Starship vehicle occurred on April 20, 2023, and ended with the explosion of the rocket four minutes after liftoff. The program has failed to meet many of its optimistic schedule goals, with its development having had several setbacks, including the failure of the first four Block 2 upper stages in 2025.
Description
When stacked and fully fueled, Starship has a mass of approximately, a diameter of and a height of. The rocket has been designed with the goal of being fully reusable to reduce launch costs; it consists of the Super Heavy booster and the Starship upper stage which are powered by Raptor and Raptor Vacuum engines.The bodies of both rocket stages are made from stainless steel and are manufactured by stacking and welding stainless steel cylinders. These cylinders have a height of, and a thickness of.
Domes inside the spacecraft separate the methane and oxygen tanks. SpaceX has stated that Starship, in its "baseline reusable design", will have a payload capacity of to low Earth orbit and to geostationary transfer orbit.
Super Heavy booster
Starship spacecraft
Raptor engine
Raptor is a family of rocket engines developed by SpaceX for use in Starship and Super Heavy vehicles. It burns liquid oxygen and methane in an efficient and complex full-flow staged combustion power cycle. The Raptor engine uses methane as fuel rather than kerosene because methane gives higher performance and prevents the build-up of deposits in the engine from coking. Methane can also be produced from carbon dioxide and water using the Sabatier reaction. The engines are designed to be reused many times with little maintenance.Raptor operates with an oxygen-to-methane mixture ratio of about, lower than the stoichiometric mixture ratio of necessary for complete combustion, since operating at higher temperatures would melt the engine. The propellants leave the pre-burners and get injected into the main combustion chamber as hot gases instead of liquid droplets, enabling a higher power density as the propellants mix rapidly via diffusion. The methane and oxygen are at high enough temperatures and pressures that they ignite on contact, eliminating the need for igniters in the main combustion chamber. The engine structure itself is mostly aluminum, copper, and steel; oxidizer-side turbopumps and manifolds subject to corrosive oxygen-rich flames are made of an Inconel-like SX500 superalloy. Some components are 3D printed.
A Raptor 2 engine produces at a specific impulse of at sea level and in a vacuum. Raptor vacuum, used on the Starship upper stage, is modified with a regeneratively cooled nozzle extension made of brazed steel tubes, increasing its expansion ratio to about 90 and its specific impulse in vacuum to. The main combustion chamber operates at a pressure of exceeding that of any prior operational rocket engine. The Raptor's gimbaling range is 15°, higher than the RS-25's 12.5° and the Merlin's 5°. SpaceX has stated they aim to achieve a per unit production cost of US$250,000 upon starting mass production.
Versions
On April 4, 2024, Elon Musk provided an update on Starship at Starbase, where two new versions of Starship were announced, Block 2 and Block 3, intended to address the shortcomings of the pre-production prototypes.Block 1
Block 1 vehicles were used for the first six flight tests and then retired.Block 2
Block 2 for both stages was used beginning with flight test 7 at the start of 2025. Block 2 upper stage vehicles feature a thinner forward flap design, flaps that are positioned more leeward, a 25% increase in propellant capacity, integrated vented interstage, redesigned avionics, two raceways, and an increase in thrust. The integrated vehicle is taller than the previous Block 1 vehicle and was planned to have a payload capacity of at least 100 tons to orbit when reused, but was retired before an orbital flight, with the final estimate of 35 t of payload to orbit. Additionally, Block 2 vehicles were planned to use Raptor 3 engines, removing the need for secondary engine shielding. However, the first Block 2 vehicle, S33, received upgraded Raptor 2 engines, with an unknown increase in thrust. The Block 2 ship and booster first flew on the seventh flight test. A total of four block 2 vehicles were produced. After Starship Flight 11, the Block 2 ships were retired.Block 3
Block 3 ships have an improved tile design, Raptor 3 engines, as well as hardware for refueling operations LEO, such as docking ports and a redesigned quick disconnect. The switch to Raptor 3 also enables the removal of most of the aft section's shielding.Block 3 boosters have an integrated vented interstage/forward dome, three grid fins instead of the prior four, as well as the use of the grid fins as tower catch points. Like with the ship, the Block 3 boosters use Raptor 3 engines, allowing for the removal of the majority of the booster's engine shielding.
Planned launch and landing profile
Payloads will be integrated into Starship at a separate facility and then rolled out to the launch site. Super Heavy and Starship are then to be stacked onto their launch mount and loaded with fuel via the ship quick disconnect arm and booster quick disconnect. The SQD and BQD retract, all 33 engines of Super Heavy ignite, and the rocket lifts off.At approximately 159 seconds after launch at an altitude of roughly, Super Heavy cuts off all but three of its center gimbaling rocket engines. Starship then ignites its engines while still attached to the booster, and separates. During hot-staging, the booster throttles down its engines. The booster then rotates, before igniting ten additional engines for a "boostback burn" which stops all forward velocity. After the boostback burn, the booster's engines shut off with Super Heavy on a trajectory for a controlled descent to the launch site using its grid fins for minor course corrections. Roughly six minutes after launch, shortly before landing, it ignites its inner 13 engines, then shuts off all but the inner 3, to perform a landing burn which slows it sufficiently to be caught by a pair of hydraulic actuating arms attached to the launch tower. The booster landing and catch was successfully demonstrated for the first time on October 13, 2024, with the landing of Booster 12.
Meanwhile, the Starship spacecraft continues accelerating to orbital velocity with its six Raptor engines. Once in orbit, the spacecraft is planned to be able to be refueled by another Starship tanker variant. Musk has estimated that 8 launches would be needed to refuel a Starship in low Earth orbit completely. NASA has estimated that 16 launches in short succession would be needed to refuel Starship for one lunar landing partially. To land on bodies without an atmosphere, such as the Moon, Starship will fire its engines to slow down. To land on bodies with an atmosphere, such as the Earth and Mars, Starship first slows by entering the atmosphere using a heat shield. The spacecraft would then perform a "belly-flop" maneuver by diving through the atmosphere at a 60° angle to the ground, controlling its fall using four flaps at the front and aft of the spacecraft. Shortly before landing, the Raptor engines fire, using fuel from the header tanks, to perform a "landing flip" maneuver to return to a vertical orientation, with the Raptor engines' gimbaling helping to maneuver the craft. The HLS and depot cannot reenter the atmosphere, as they lack a thermal protection system, flaps, and other necessary catch hardware.
If Starship's second stage lands on a pad, a mobile hydraulic lift will move it to a transporter vehicle. If it lands on a floating platform, it will be transported by a barge to a port and then transported by road. The recovered Starship will either be positioned on the launch mount for another launch or refurbished at a SpaceX facility.