SpaceX Starship

Starship is a two-stage fully reusable super heavy-lift launch vehicle under development by American aerospace company SpaceX. On 20 April 2023, with the first Integrated Flight Test, Starship became the most massive and most powerful vehicle ever to fly. SpaceX has developed Starship with the intention of lowering launch costs using economies of scale, aiming to achieve this by reusing both rocket stages by "catching" them with the launch tower's systems, increasing payload mass to orbit, increasing launch frequency, mass-manufacturing the rockets and adapting it to a wide range of space missions. Starship is the latest project in SpaceX's reusable launch system development program and plan to colonize Mars.
Starship's two stages are the Super Heavy booster and the Starship spacecraft. Both stages are equipped with Raptor engines, the first flown and mass-produced full-flow staged combustion cycle engines, which burn liquid methane (natural gas) and liquid oxygen.
As of 2024, Starship is in development with an iterative and incremental approach, involving test flights of prototype vehicles. As a successor to SpaceX's Falcon 9 and Falcon Heavy rockets, Starship is intended to perform a wide range of space missions. For missions to further destinations, such as geosynchronous orbit, the Moon, and Mars, Starship will rely on orbital refueling; a ship-to-ship propellant transfer demonstration is expected to occur in 2025. SpaceX also plans other versions of the Starship spacecraft, such as cargo (deploying SpaceX's second-generation Starlink satellite constellation) and human spaceflight (the Human Landing System variant will land astronauts on the Moon as part of the Artemis program, starting in 2027).
When stacked and fully fueled, Starship has a mass of approximately 5,000 t (11,000,000 lb), a diameter of 9 m (30 ft) and a height of 121.3 m (398 ft). 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 1.8 m (5 ft 11 in), a thickness of 4 mm (0.16 in) and a mass of 1,600 kg (3,500 lb) each.
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 100–150 t (220,000–331,000 lb) to low earth orbit and 27 t (60,000 lb) to geostationary transfer orbit.
Super Heavy is 71 m (233 ft) tall, 9 m (30 ft) wide, and is composed of four general sections: the engines, the oxygen tank, the fuel tank, and the interstage. Elon Musk stated in 2021 that the final design will have a dry mass between 160 t (350,000 lb) and 200 t (440,000 lb), with the tanks weighing 80 t (180,000 lb) and the interstage 20 t (44,000 lb).
The propellant tanks on Super Heavy are separated by a common bulkhead, similar to the ones used on the S-II and S-IVB stages on the Saturn V rocket. After Starship's second flight test, the common dome's design was changed to a more elliptical dome, which changed the propellant capacity of both tanks by an unknown, but likely negligible, amount. Both tanks are heavily reinforced, with roughly 74 stringers attached to the interior walls of the tanks. The booster's tanks hold 3,400 t (7,500,000 lb) of propellant, consisting of 2,700 t (6,000,000 lb) of liquid oxygen and 700 t (1,500,000 lb) of liquid methane. Fuel is fed to the engines via a single downcomer, which terminates in a large distribution manifold above the engines.
The oxygen tank terminates with the thrust structure of the vehicle. While the outer 20 engines are mounted to the walls of the aft bay, the inner thirteen are mounted directly to the thrust puck, which is part of the aft dome. A large steel structure is mounted at the bottom of the dome, reinforcing the thrust puck enough to enable its support of the inner thirteen engines, while also providing pathways for methane and oxygen to flow into the engines. Large filters were added in this region as well, beginning on Booster 10. A header tank is used to supply liquid oxygen during the landing burn for the inner thirteen engines. On Booster 15, the header tank has at least nine additional tanks attached, increasing total propellant supply during the landing burn. These tanks may have been present on Boosters 12, 13, and 14, though as of February 2025, this is unconfirmed. Booster 5 was the only 29-engine booster to receive a header tank, which was mounted to the side of the oxygen tank, instead of being integrated with the thrust puck.
The methane downcomer is partially contained within the header tank, as the methane sump is directly below it. On Booster 7 and all subsequent vehicles, four aerodynamic chines are located on the outside of the oxygen tank, providing aerodynamic lift during descent, as well as housing batteries, composite overwrapped pressure vessels (COPVs), and CO2 tanks for fire suppression. On vehicles with hydraulic power units (HPUs), COPVs dedicated to engine ignition, batteries, and communication antennas were located within the HPU cover instead of the chines.
Super Heavy is powered by 33 Raptor engines housed within a dedicated shielding compartment. This compartment is not present before engine installation, thus, boosters are roughly three meters shorter before engine installation. The outer 20 engines, arranged in a single ring, are fixed. To save weight, these engines are started using ground support equipment on the launch mount and cannot be reignited for subsequent burns. The inner thirteen engines are equipped with gimbal actuators and reignite for the boostback and landing burns. After Starship's first flight test, this gimbaling system was switched from a hydraulic system to an electric one, enabling the removal of the hydraulic power units. This change was made to the upper stage after the second flight test. During the ascent and boostback burns, the engines draw propellant from the main tanks, with the liquid oxygen being drawn from a dedicated header tank during the landing burn. Like the thrust vector control system, the engine shielding, which isolates individual engines in the event of a failure, was upgraded after Starship's first flight test, alongside the fire suppression system. The aft bay has eighteen vents visible on the outside of the booster, which are believed to be connected to the outer 20 engines, while the center engines vent directly below the launch pad.
The Raptor engine uses a full-flow staged combustion cycle with oxygen and methane-rich turbopumps. Before 2014, only two full-flow staged-combustion rocket engine designs had advanced enough to undergo testing: the Soviet RD-270 project in the 1960s and the Aerojet Rocketdyne Integrated Powerhead Demonstrator in the mid-2000s. To improve performance, the engines burn super cooled propellant.
The Block 1 version of the booster (used through November 2024) produces a total of 73.5 MN (16,500,000 lbf) just over twice that of the Saturn V first stage, with this total being expected to increase to 80.8 MN (18,200,000 lbf) for Block 2 boosters and later up to 98.1 MN (22,100,000 lbf) with the Block 3 vehicle. These later versions may have up to 35 engines. The combined plume of the engines produces large shock diamonds in the exhaust during the ascent burn.
During unpowered flight in the upper atmosphere, control authority is provided by cold gas thrusters fed with residual ullage gas. Four perpendicular vents are located within the interstage, placed at a 45-degree angle from the hardpoints. Additional vents are located just below the common dome, which point down towards the engines, though at a slight angle.
The interstage is equipped with four electrically actuated grid fins made of stainless steel, each with a mass of roughly 3 t (6,600 lb). The fins remain extended during ascent to save weight, though this results in mild warping during stage separation. The interstage also has protruding hardpoints, located between grid fins, allowing the booster to be lifted or caught by the launch tower. The ability to lift a booster from these hardpoints was proven on August 23, 2022, when Booster 7 was lifted onto OLM A. The first catch of a booster occurred on October 13, 2024, using Booster 12.
After the first Starship test flight, all boosters have an additional 1.8 m tall vented interstage to enable hot staging. During hot staging, Super Heavy shuts down all but the 3 center engines, while the second stage fires its engines before separating, thus the second stage "pushes off" from the first stage giving added thrust. The vented interstage contains a dome to shield the top of Super Heavy from the second stage's engines. Elon Musk in 2023 claimed that this change might result in a 10% increase in the payload to low Earth orbit. Beginning with Booster 11, the vented interstage is jettisoned after completion of the boostback burn, to reduce mass during descent. As of June 2024, SpaceX does not intend to jettison the interstage when flying Block 2 and Block 3 boosters, as the vented section will be directly integrated into the vehicle.
The Block 2 version of Starship is 52.1 m (171 ft) tall, 9 m (30 ft) wide, and is composed of four general sections: the engine bay, the oxygen tank, the fuel tank, and the payload bay. The retired Block 1 was constructed in a similar manner, though it was only 50.3 m (165 ft) tall. Elon Musk stated in 2021 that the vehicle has a dry mass of roughly 100 t (220,000 lb). The windward side is protected by a heat shield, which is composed of eighteen thousand hexagonal black tiles that can withstand temperatures of 1,400 °C (2,600 °F). It is designed to protect the vehicle during atmospheric entry and to be used multiple times with minimal maintenance between flights. The silica-based tiles are attached to Starship with pins, and have small gaps in between to allow for heat expansion. After IFT-4, SpaceX added a secondary ablative layer under the primary heat shield, though this was only added to the flaps of the IFT-6 vehicle. This ablative layer is likely composed of pyron, which is similar in composition to carbon composites. The total mass of the heat shield and ablative layer of a Block 1 ship is 10.5 t (23,000 lb).
The propellant tanks on Starship are separated by a common bulkhead, similar to the ones used on the S-II and S-IVB stages on the Saturn V rocket. While Block 2 vehicles use an elliptical dome, the common and forward domes of the Block 1 design were more conical. Block 1 vehicles only had 24 stringers within the oxygen tank, while Block 2 vehicles hade these added to the methane tanks. The vehicle's tanks hold 1,500 t (3,300,000 lb) of propellant, consisting of 1,170 t (2,580,000 lb) of liquid oxygen and 330 t (730,000 lb) of liquid methane.
Fuel is fed to the engines via four downcomers, with three smaller downcomers feeding the Vacuum Raptors/RVacs and the central downcomer feeding the inner three engines. The central downcomer connects to a large sump, instead of directly to the methane tank itself. The original design only featured a single downcomer. The LOX downcomer extends into the LOX tank, with a small expanded portion of unknown purpose. Two additional downcomers route methane and oxygen from the header tanks. A camera is located on the walls of the tank, pointed towards the payload bay.
The oxygen tank terminates with the thrust structure of the vehicle. The RVacs are mounted directly to the aft dome, which has reinforcements mounted inside of the tank. The three sea level engines are mounted on the thrust puck, which forms the bottom of the aft dome. A conical steel structure is mounted inside the bottom of the dome, reinforcing the thrust puck enough to enable its support of the inner three engines. The propellant lines on the vehicles are all vacuum jacketed, reducing boiloff while in orbit.
Starship is powered by 6 Raptor engines, which are housed within a dedicated shielding compartment. An additional three RVacs will be added to the Block 3 ship design. These engines are equipped with gimbal actuators, and reignite for the landing burns. After Starship's second flight test, this gimbaling system was switched from a hydraulic system to an electric one, enabling the removal of the hydraulic power units. This change was made to the booster after the first flight test. There are four engine chill lines onboard the vehicle, though two of these lines may serve another purpose.
Each engine is protected by a dedicated shielding compartment. Beginning with S25, the Block 1 design had between 14 and 16 such vents. Additional vents were added after flight 7. The fire suppression system, which uses gaseous nitrogen to purge the engine bay during flight was upgraded after flight 7. A similar system on the booster uses CO2 to purge the individual engine compartments during flight and static fires.
The Raptor engine uses a full-flow staged combustion cycle, which has both oxygen and methane-rich turbopumps. Before 2014, only two full-flow staged-combustion rocket engine designs had advanced enough to undergo testing: the Soviet RD-270 project in the 1960s and the Aerojet Rocketdyne Integrated Powerhead Demonstrator in the mid-2000s. To improve performance, the engines burn super cooled propellant.
The Block 1 version of the ship (used through November 2024) produces a total of 12.25 MN (2,750,000 lbf) almost triple the thrust of the Saturn V second stage, with this total being expected to increase to 15.69 MN (3,530,000 lbf) for Block 2 boosters and later up to 26.48 MN (5,950,000 lbf) with the Block 3 vehicle.
During unpowered flight in orbit, control authority is provided by cold gas thrusters fed with residual ullage gas. Four such thrusters are located just below the payload bay, and two on the oxygen tank. Near the top of the nosecone, there are two vents connected to the header tanks. Addtional vents were added at the base of the vehicle after flight two.
The payload bay hosts the nosecone, header tanks, forward flaps, multiple COPVs, and the "pez dispenser". The header tanks are mounted at the tip of the payload bay. The LOX header tank forms the top of the nosecone, with the methane header tank attached directly below it. These tanks terminate in a conical sump, which are attached to the downcomers. Several COPVs are mounted in the space around the methane header tank, providing the startup gas for the engines, with additional COPVs within the base of the payload bay.
The nosecone has substantial internal reinforcement, mainly around the forward flap attachment points and lifting points for the chopsticks. The number of internal stringers was increased between Block 1 and Block 2 vehicles. Additional reinforcements are used to support the pez dispenser on ships equipped with one. Four Starlink antennas are located within the nosecone.
The pez dispenser is used to deploy Starlink satellites into LEO. It was first added to S24, though it was permanently sealed until flight 3. It consists of the dispenser mechanism and the door. The door opens by folding into the payload bay.
The dispenser itself is mounted directly to the forward dome. It has a truss structure for its base, with solid steel used elsewhere. A mobile track is used in the base, enabling the dispenser to push the satellite out of the vehicle. After dispensing a satellite, the next payload is lowered onto the base, and is deployed. The opposite occurs during loading, with the dispenser raising its payloads to receive another satellite. In order to prevent the satellite from floating out of the mechanism during zero-g operations, the dispenser locks the satellites in position using a "retention frame". This is lowered alongside the satellites during operation.
Starship controls its reentry with four flaps, two aft flaps mounted to the sides of the engine bay and LOX tank and two forward flaps on the payload bay. Substantial reinforcements are present in the nosecone for the support of the forward flaps. According to SpaceX, the flaps replace the need for wings or tailplane, reduce the fuel needed for landing, and allow landing at destinations in the Solar System where runways do not exist (for example, Mars). The flap's hinges are sealed in aerocovers because they would otherwise be easily damaged during reentry. Static wicks are present on the flaps, aiding in the discharge of static electricity.
Despite this, damage to the forward flaps was observed on flights four, five, and six, with near complete loss occurring on flight 4. Beginning with Block 2, the design of these forward flaps was significantly changed, moving leeward and becoming thinner and angled. This sets them at an approximately 140-degree angle, compared to the 180-degree angle of the aft flaps and previous version of the forward flaps. This change was made to prevent the damage observed on the last three flights of the Block 1 ship. Both sets of flaps feature cameras in their hinges.
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 3.6:1, lower than the stoichiometric mixture ratio of 4:1 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 2.3 MN (520,000 lbf) at a specific impulse of 327 seconds (3.21 km/s) at sea level and 350 seconds (3.4 km/s) 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 380 seconds (3.7 km/s). The main combustion chamber operates at a pressure of 350 bar (5,100 psi) 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.
On 4 April 2024, Elon Musk provided an update on Starship at Starbase, where two new versions of Starship were announced, Block 2 and Block 3.
Block 1 upper stage vehicles have been retired but were used for the first 6 Flight Tests. As of January 2025, Block 1 boosters are still being used.
Block 2 upper stage vehicles feature a thinner forward flap design, its flaps 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 will be a total of 3.1 m (10 ft) taller than the previous Block 1 vehicle and is planned to have a payload capacity of at least 100 tons to orbit when reused. Additionally, Block 2 vehicles will use Raptor 3, 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. Initial Block 2 upper stage vehicles will use a Block 1 booster. The Block 2 ship first flew on the seventh flight test.
As of June 2024, the Block 3 final configuration is unknown. The most recent configuration, as described in regulatory filings submitted to the FAA, has a height of 150 m (490 ft). The Starship second stage will feature nine Raptor engines, while the Super Heavy booster will have up to 35. It is planned to have a payload capacity of at least 200 tons to orbit when reused.
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 (SQD) arm and booster quick disconnect (BQD). 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 64 km (40 mi), 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 13 October 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 (due to cryogenic propellant boil-off) 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.
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.
In November 2005, before SpaceX had launched its first rocket the Falcon 1, CEO Elon Musk first mentioned a high-capacity rocket concept able to launch 100 t (220,000 lb) to low Earth orbit, dubbed the BFR. Later in 2012, Elon Musk first publicly announced plans to develop a rocket surpassing the capabilities of Space X's existing Falcon 9. SpaceX called it the Mars Colonial Transporter, as the rocket was to transport humans to Mars and back. In 2016, the descriptor was changed to Interplanetary Transport System, as the rocket was planned to travel beyond Mars as well. The conceptual design called for a carbon fiber structure, a mass in excess of 10,000 t (22,000,000 lb) when fully fueled, a payload of 300 t (660,000 lb) to low Earth orbit while being fully reusable. By 2017, the concept was again re-dubbed the BFR.
In December 2018, the structural material was changed from carbon composites to stainless steel, marking the transition from early design concepts of the Starship. Musk cited numerous reasons for the change of material; low cost and ease of manufacture, increased strength of stainless steel at cryogenic temperatures, as well as its ability to withstand high heat. In 2019, SpaceX began to refer to the entire vehicle as Starship, with the second stage also being called Starship, and the booster Super Heavy. They also announced that Starship would use reusable heat-shield tiles similar to those of the Space Shuttle. The second-stage design had also settled on six Raptor engines by 2019: three optimized for sea-level and three optimized for vacuum. In 2019, SpaceX announced a change to the second stage's design, reducing the number of aft flaps from three to two to reduce weight. In March 2020 SpaceX released a Starship Users Guide, in which they stated the payload of Starship to LEO would be over 100 t (220,000 lb), with a payload to GTO of 21 t (46,000 lb).
The first tests started with the construction of the first prototype in 2018, Starhopper, which performed several static fires and two successful low-altitude flights in 2019. SpaceX began constructing the first full-size Starship MK1 and MK2 upper-stage prototypes before 2019, at the SpaceX facilities in Boca Chica, Texas, and Cocoa, Florida, respectively. Neither prototype flew: MK1 was destroyed in November 2019 during a pressure stress test and MK2's Florida facility was deconstructed throughout 2020. Prototypes were built using 301 stainless steel. This was noted for its corrosion resistance and lower cost compared to carbon fiber but faced some challenges, particularly with interlaminar toughness at cryogenic temperatures.
SpaceX then began naming its new Starship upper-stage prototypes with the prefix "SN", short for "serial number". No prototypes between SN1 and SN4 flew either—SN1 and SN3 collapsed during pressure stress tests, and SN4 exploded after its fifth engine firing.
In June 2020, SpaceX started constructing a launch pad for orbital Starship flights. The first flight-capable prototype, SN5, was cylindrical as it had no flaps or nose cone: just one Raptor engine, fuel tanks, and a mass simulator. On 5 August 2020, SN5 performed a 150 m (500 ft) high flight and successfully landed on a nearby pad. On 3 September 2020, the similar-looking Starship SN6 repeated the hop; later that month, a Raptor vacuum engine underwent its first full duration firing at McGregor, Texas.
Starship SN8 was the first full-sized upper-stage prototype, though it lacked a heat shield. It underwent four preliminary static fire tests between October and November 2020. On 9 December 2020, SN8 flew, slowly turning off its three engines one by one, and reached an altitude of 12.5 km (7.8 mi). After SN8 dove back to the ground, its engines were hampered by low methane header tank pressure during the landing attempt, which led to a hard impact on the landing pad and subsequent explosion of the vehicle. SN7 used 304L stainless steel, which is less brittle and more weldable. Later vehicles used a proprietary alloy, 30X, whose composition is proprietary that costs slightly over €3.6/kg.
Because SpaceX had violated its launch license and ignored warnings of worsening shock wave damage, the Federal Aviation Administration investigated the incident for two months. During the SN8 launch, SpaceX ignored FAA warnings that the flight profile posed a risk of explosion. FAA space division chief Wayne Monteith said SpaceX's violation was “inconsistent with a strong safety culture”, and criticized the company for proceeding with the launch "based on 'impressions' and 'assumptions,' rather than procedural checks and positive affirmations".
On 2 February 2021, Starship SN9 launched to 10 km (6.2 mi) in a flight path similar to SN8. The prototype crashed upon landing because one engine did not ignite properly. A month later, on 3 March, Starship SN10 launched on the same flight path as SN9. The vehicle landed hard and crushed its landing legs, leaning to one side. A fire was seen at the vehicle's base and it exploded less than ten minutes later, potentially due to a propellant tank rupture. On 30 March, Starship SN11 flew into thick fog along the same flight path. The vehicle exploded during descent, possibly due to excess propellant in a Raptor's methane turbopump.
In March 2021, the company disclosed a public construction plan for two sub-orbital launch pads, two orbital launch pads, two landing pads, two test stands, and a large propellant tank farm. The company soon proposed developing the surrounding Boca Chica Village, Texas, into a company town named Starbase. Locals raised concerns about SpaceX's authority, power, and a potential threat for eviction through eminent domain.
In early April, the orbital launch pad's fuel storage tanks began mounting. SN12 through SN14 were scrapped before completion; SN15 was selected to fly instead, due to improved avionics, structure, and engines. On 5 May 2021, SN15 launched, completed the same maneuvers as older prototypes, and landed safely. SN15 had a fire in the engine area after landing but it was extinguished. According to a later report by SpaceX, SN15 experienced several issues while landing, including the loss of tank pressure and an engine.
In June 2022, the Federal Aviation Administration determined that SpaceX must address more than 75 issues identified in the preliminary environmental assessment before integrated flight tests could start.
In July 2022, Booster 7 tested the liquid oxygen turbopumps on all 33 Raptor engines, resulting in an explosion at the vehicle's base, which destroyed a pressure pipe and caused minor damage to the launchpad. By the end of November, Ship 24 had performed 2 static test fires, while Booster 7 had performed 6 static test fires and finally on 9 February 2023, a static fire with 31 engines at 50% throttle. In January 2023, the whole Starship stack underwent a full wet dress rehearsal.
After a launch attempt aborted on 17 April 2023, Booster 7 and Ship 24 lifted off on 20 April at 13:33 UTC in the first orbital flight test. Three engines were disabled during the launch sequence and several more failed during the flight. The booster later lost thrust vectoring control of the Raptor engines, which led to the rocket spinning out of control. The vehicle reached a maximum altitude of 24 mi (39 km). Approximately 3 minutes after lift-off the rocket's autonomous flight termination system was activated, though the vehicle tumbled for another 40 seconds before disintegrating. The first flight test blasted large amounts of sand and soil in the air, reaching communities within a 10.7 km (6.6 mi) radius. A brushfire on nearby state parkland also occurred, burning 3.5 acres of state parkland.
After the first test flight, SpaceX began work on the launch mount to repair the damage it sustained during the test and to prevent future issues. The foundation of the launch tower was reinforced and a water-powered flame deflector was built under the launch mount. Ship 25 and Booster 9 were rolled to the suborbital and orbital launch sites in May to undergo multiple tests.
On 18 November 2023, Booster 9 and Ship 25 lifted off the pad. All 33 engines continued to function until staging, where the second stage separated by pushing itself away from the first stage using a hot-staging technique. Following separation, the Super Heavy booster completed its flip maneuver and initiated the boostback burn, but then experienced multiple successive engine failures and exploded. Blockage in a liquid oxygen filter caused one of the engines to fail in a way that resulted in the destruction of the booster, which occurred three and a half minutes into the flight at an altitude of ~90 km over the Gulf of Mexico.
The second stage continued until it reached an altitude of ~149 kilometres (93 mi), after over eight minutes of flight; before engine cutoff, telemetry was lost on the second stage. SpaceX said that a safe command based on flight performance data triggered the flight termination system and destroyed the second stage, before achieving its planned orbit or attempting re-entry. It appeared to re-enter a few hundred miles north of the Virgin Islands, according to NOAA weather radar data.
Following the second flight test (which saw the loss of both stages), significant changes were implemented, including upgrading Starship's thrust vector control system to electric thrust vector control (TVC) and measures to delay liquid oxygen (LOX) venting until after Starship engine cutoff (SECO) has taken place.
Flight 3 launched from the SpaceX Starbase facility along the South Texas coast around 8:25 a.m. CDT on 14 March 2024, coincidentally the 22nd anniversary of its founding. Like IFT-2, all 33 engines on the booster ignited and stage separation was successful. B10 conducted a boostback burn, however, the planned landing in the Gulf of Mexico was not successful, as it exploded at 462 m (1,516 ft) above the surface.
The Starship spacecraft itself, after reaching space and orbital velocity, conducted several tests after engine cutoff, including initiating a propellant transfer demo and payload dispenser test. It attempted to re-enter the atmosphere, and at an altitude of around 65 km (40 mi), all telemetry from Ship 28 stopped, indicating a loss of the vehicle. This flight test demonstrated a cryogenic propellant transfer, by transferring propellant from the Ship's header tanks into its main tanks while in space, a technology which is required for Starship HLS to exit Low Earth orbit (LEO). The result of this test was declared successful by NASA and SpaceX. Additional data analysis is occurring on the fluid dynamics such as slosh and boil-off of the propellant.
The fourth flight test of the full Starship configuration launched on 6 June 2024, at 7:50 a.m. CDT. The goals for the test flight were for the Super Heavy booster to land on a 'virtual tower' in the ocean, and for the Ship to survive peak heating during atmospheric reentry. The flight test was successful in both regards, with Super Heavy achieving a soft splashdown and Ship surviving atmospheric reentry and a controlled splashdown.
In April 2024, Musk stated one of the goals was to attempt a booster tower landing based on successful booster performance in flight 4. Vehicle testing commenced in May 2024. SpaceX claimed that B12 and S30 were ready to launch in early August, in advance of regulatory approval. SpaceX flew S30 and B12 on 13 October 2024, with B12 returning to the launch site for a successful catch for the first time, and S30 successfully splashing down in the Indian Ocean.
Ship 31 completed a successful cryogenic test in July 2024 and a static fire in September. Booster 13 completed similar tests in April and October. Flight 6 was flown on 19 November 2024, with a water landing of the booster rather than a catch. Flight 6 was the first to successfully conduct a Raptor engine relight in the vacuum of space, paving the way for payload deployments on future flights. A stuffed toy banana served as the zero-g indicator, becoming Starship's first payload, though it remained within the vehicle for the duration of the flight. Eric Berger claimed that due to the success of the in-space relight, Starship would likely be "cleared to travel into orbit".
Ship 33 completed a successful cryogenic test in October 2024 and a static fire in late December. Its counterpart, Booster 14, also underwent cryogenic testing in October. Booster 14 rolled out to OLP-1 and conducted a successful spin prime test and static fire in early December. Flight 7 was flown on 16 January 2025; the mission profile for flight test 7 was expected to be similar to the previous launch, targeting a splashdown in the Indian Ocean after attempting an in-space engine relight. Ship 33 was also expected to deploy ten Starlink "simulators," which were also expected to reenter over the Indian Ocean. Contact with Ship 33 was lost shortly before its engines were scheduled to shut down. Subsequently, Ship 33 was seen exploding as it flew over the Turks and Caicos Islands. The booster successfully returned to the launch site and was caught by the chopsticks on OLP-A. As a result of the explosion, numerous commercial airline flights were diverted or delayed.
On March 3, a launch attempt was aborted after multiple holds at T−40 seconds. Shortly before the scheduled launch at 6:45 p.m. CDT, an issue caused a hold for more than five minutes. The hold was briefly lifted, but a new hold was put in place due to issues connected to the Super Heavy booster. SpaceX called for a cancellation of the launch and set 6 March for the launch. The eighth flight test was later launched on 6 March 2025 at 23:30 hours UTC. The Super Heavy booster was successfully caught by the launch tower. During Ship 34's initial burn, four of its six engines experienced premature shutdowns that resulted in a loss of attitude control followed by a total loss of telemetry. The vehicle's breakup was observed from Florida, Jamaica, and the Turks and Caicos Islands. According to SpaceX, communications with the spacecraft ended 9 minutes and 30 seconds after liftoff. The flight was the second of the Block 2 Ship, and attempted to repeat the previous flight's profile. Due to the breakup of the vehicles, the Federal Aviation Administration briefly issued ground stop orders for multiple Florida airports.
SpaceX develops the Starship primarily with private funding. SpaceX Chief Financial Officer Bret Johnsen disclosed in court that SpaceX has invested more than $3 billion into the Starbase facility and Starship systems from July 2014 to May 2023. Elon Musk stated in April 2023 that SpaceX expected to spend about $2 billion on Starship development in 2023. In a 2024 response to a lawsuit, SpaceX stated that the cost of the Starship program was approximately $4 million per day. Adding that any day of delay to the Starship program represented a loss of $100,000.
Musk has theorized that a Starship orbital launch might eventually cost SpaceX only $1 million to launch. Eurospace's director of research Pierre Lionnet stated in 2022 that Starship's launch price to customers would likely be higher because of the rocket's development cost.
As part of the development of the Human Landing System for the Artemis program, SpaceX was awarded in April 2021 a $2.89 billion fixed-price contract from NASA to develop the Starship lunar lander for Artemis III. Blue Origin, a bidding competitor to SpaceX, disputed the decision and began a legal case against NASA and SpaceX in August 2021, causing NASA to suspend the contract for three months until the case was dismissed in the Court of Federal Claims. Two years later Blue Origin was awarded a $3.4 billion fixed-price contract for its lunar lander.
In 2022, NASA awarded SpaceX a $1.15 billion fixed-price contract for a second lunar lander for Artemis IV. The same year, SpaceX was awarded a $102 million five-year contract to develop the Rocket Cargo program for the United States Space Force.
Starship vehicles have been launched 8 times, resulting in 4 successes (50%), and 4 failures. Starship Block 1 was launched six times between April 2023 and November 2024, with the ship retired ahead of the seventh flight. Block 1 boosters are expected to fly further into the future.
SpaceX plans to use Starship to launch the second generation of satellites for SpaceX's Starlink system, which currently delivers high-speed internet to over 70 countries. An analyst at financial services company Morgan Stanley stated development of Starship and Starlink are intertwined, with Starship's planned launch capacity enabling cheaper Starlink launches, and Starlink's profits financing Starship's development costs. In deficit from its inception until the end of 2022, Starlink was first reported to be cash flow positive in the first quarter of 2023, though Elon Musk said that Starlink had only reached "break-even cashflow" in 2023. In December 2023, the FCC issued a final denial of a $885 million Starlink RDOF subsidy because of Starlink's "continuing inability to successfully launch on the Starship rocket".
Starship HLS was initially chosen by NASA as the sole lunar Human Landing System for the planned Artemis III and Artemis IV crewed missions, as part of the Artemis program. Starship HLS is to be launched into a low Earth orbit, and refueled by multiple Starship tanker spacecraft. Once fueled, it would perform a trans lunar injection burn and enter a near-rectilinear halo orbit around the Moon, with a perilune of 1,500 km (930 mi) occurring over the north pole and an apolune of 70,000 km (43,000 mi) occurring over the south pole. The Orion spacecraft would then dock with Starship HLS and two of its four crew would transfer into Starship HLS. Starship HLS would then use its engines to make a powered descent and land near the lunar south pole. After the crew performs the surface portion of its mission, the HLS would ascend with the crew. The crew would then transfer into the Orion spacecraft and return to Earth.
Astronomers have called to consider Starship's larger mass to orbit and wider cargo bay for proposed space telescopes such as LUVOIR, and to develop larger telescopes to take advantage of these capabilities. Starship's 9 m (30 ft) fairing width could hold an 8 m (26 ft) wide space telescope mirror in a single piece, alleviating the need for complex unfolding such as that of the JWST's 6.5 m (21 ft) mirror, which added cost and delays. Ariane 5 imposed a ~6,500 kg limit on the telescope's weight. Starship's low launch cost could also allow probes to use heavier, more common, cheaper materials, such as glass instead of beryllium for large telescope mirrors. With a 5 t (11,000 lb) mirror built using similar methods to the Hubble Space Telescope's mirror, the JWST would represent only 10% of the mass deliverable by a (refueled) Starship to the Sun–Earth L2 point, and therefore minimizing the weight of the telescope would not have been a dominant design consideration.
The National Academies of Science's 2020 survey recommended the Habitable Worlds Observatory (HWO); the space observatory, requiring a super heavy lift launch vehicle, will search for signs of life on exoplanets. The HWO's team hopes for the success of big launchers due to their critical importance to the HWO's mission. Lee Feinberg, NASA HWO lead architect and JWST manager, stays in communication with SpaceX to track Starship's progress and has visited them in 2024 for that same purpose. The NASA Habitable Worlds Observatory will have a 6–8 meter mirror for now, but its design should be flexible to leverage launchers with potentially double the mass and volume by the time it launches in the 2040s. Former NASA JPL architect Casey Handmer believes the HWO to be far too conservative compared to what is possible with Starship. Handmer argues that Starship enables telescopes to scale up to the point of surface-level exoplanet imaging, perhaps big enough to detect seasonal migration patterns.
In January 2022, SpaceX was awarded a $102 million five-year contract to develop the Rocket Cargo program for the United States Space Force. The five-year contract is intended to "determine exactly what a rocket can achieve when used for cargo transport", and will see the Air Force Research Laboratory collect data during commercial launches of Starship. The contract includes an eventual demonstration mission with the launch and landing of a cargo-laden Starship in a point-to-point flight.
The Department of Defense has planned a test with Starship as part of its program to demonstrate the ability to rapidly deploy up to 100 tons of cargo and supplies, a capability it calls point-to-point delivery (P2PD). The test is envisioned to take place in FY25 or FY26.
In 2024, the NASA-ESA Mars Sample Return project, one of NASA's highest priority flagship projects, suffered a setback when an independent review board assessing the project's feasibility concluded that the project could not be completed under its mission profile. In April 2024, the Administrator of NASA then announced that a new mission profile was needed for the project and that NASA would turn to industry for proposals, with responses due in fall 2024, and a high emphasis on lower total cost and lower risk. Starship was widely seen as a leading candidate to serve as a central component of the new mission profile architecture.
SpaceX has proposed using Starship for point-to-point flights (called "Earth to Earth" flights by SpaceX), traveling anywhere on Earth in under an hour. Musk stated that SpaceX would complete hundreds of cargo flights before launching with human passengers.
According to SpaceX, the design of Starship is driven by its requirement to be able to land crews on Mars, though SpaceX has not published technical plans or designs about Starship's life support systems, radiation protection, docking system, or in-orbit refueling system for Mars. The spacecraft would be launched to low Earth orbit and refueled in orbit before heading to Mars. After landing on Mars, the Sabatier reaction could be used to synthesize liquid methane and liquid oxygen, Starship's fuel, in a power-to-gas plant. The plant's raw resources would be Martian water and Martian carbon dioxide. On Earth, similar technologies could be used to make carbon-neutral propellant for the rocket. To date, there has been one proof of concept experiment (MOXIE) demonstrating the extraction of oxygen from Martian carbon dioxide, with George Dvorsky writing for Gizmodo commenting that we are not "remotely close" to turning this "into something practical".
SpaceX and Musk have stated their goal of colonizing Mars to ensure the long-term survival of humanity, with an ambition of having sent one million people to Mars by 2050. In March 2022, he estimated that the first crewed Mars landing could occur in 2029. This timeline has been criticized as unrealistic by Kevin Olsen, a physicist at the University of Oxford, England, who has said that "colony needs to become a factory" to produce air, fuel and water as it is "fundamentally impossible to create a completely closed environment in space", and that the technology to do so is "far, far behind the technology of space flight and habitation construction". Serkan Saydam, a mining engineering professor from the University of New South Wales, Australia, stated that humanity currently lacks the necessary technology to establish a Martian colony, and will likely lack the capacity to establish a Martian city with one million people by 2050.
One future payload is the Superbird-9 communication satellite, which was Starship's first contract for externally made commercial satellites. Another planned payload is the Starlab space station, which Starship will launch in a single piece.
In the future, the spacecraft's crewed version could be used for space tourism—for example, for the third flight of the Polaris program.
Research conducted by Project Lyra determined that with refueling in LEO, a Starship could send a spacecraft to 'Oumuamua on a journey taking 20 years. A gravity assist would be required at Jupiter.
Starbase consists of a manufacturing facility and launch site, and is located at Boca Chica, Texas. Both facilities operate 24 hours a day. A maximum of 450 full-time employees may be onsite. The site is planned to consist of two launch sites, one payload processing facility, one seven-acre solar farm, and other facilities. The company leases Starbase's land for the STARGATE research facility, owned by the University of Texas Rio Grande Valley. It uses part of it for Starship development.
Raptor engines are tested at the Rocket Development facility in McGregor, Texas. The facility has two main test stands: one horizontal stand for both engine types and one vertical stand for sea-level-optimized rocket engines. In the future, a nearby factory, which as of September 2021 was under construction, will make the new generation of sea-level Raptors while SpaceX's headquarters in California will continue building the Raptor Vacuum and test new designs.
At Florida, a facility at Cocoa purifies silica for Starship heat-shield tiles, producing a slurry that is then shipped to a facility at Cape Canaveral. In the past, workers constructed the Starship MK2 prototype in competition with Starbase's crews. The Kennedy Space Center, also in Florida, is planned to host other Starship facilities, such as a Starship launch site at Launch Complex 39A and a production facility at Roberts Road. This production facility is being expanded from "Hangar X", the Falcon rocket boosters' storage and maintenance facility. It will include a 30,000 m (320,000 sq ft) building, loading dock, and a place for constructing integration tower sections. Adjacent to the Kennedy Space Center will be an additional launch site at Cape Canaveral Space Launch Complex 37, likely to service missions for the complex owner, the United States Space Force.
Starbase is planned to host two launch sites, named Pad A and Pad B. A launch site at Starbase has large facilities, such as a tank farm, an orbital launch mount, and an integration tower. Smaller facilities are present at the launch site: tanks surrounding the area containing methane, oxygen, nitrogen, helium, hydraulic fluid, etc.; subcoolers near the tank farm cool propellant using liquid nitrogen; and various pipes are installed at large facilities. Each tank farm consists of eight tanks, enough to support one orbital launch. The current launch mount on Pad A has a water-powered flame diverter, 20 clamps holding the booster, and a quick disconnect mount providing liquid fuel and electricity to the Super Heavy booster before it lifts off.
The integration tower or launch tower consists of steel truss sections, a lightning rod on top, and a pair of mechanical arms that can lift, catch and recover the booster. The decision to catch the booster with the arms was made to reduce the rocket's mass and mechanical complexity by removing the need for landing legs, as well as enabling more rapid reuse by placing the rocket directly back on the launchpad. The mechanical arms are attached to a carriage and controlled by a pulley at the top of the tower. The pulley is linked to a winch and spool at the base of the tower using a cable. Using the winch and the carriage, the mechanical arms can move vertically, with support from bearings attached at the sides of the carriage. A linear hydraulic actuator moves the arms horizontally. On top of the arms are tracks, which are used to position the booster or spacecraft. The tower is mounted with a quick disconnect arm extending to and contracting from the Starship spacecraft; its functions are similar to the quick disconnect mount that powers the booster.
SpaceX has been constructing a Starship launch pad at Kennedy Space Center Launch Complex 39A (LC-39A) since 2021. The site was leased to the company in 2014 and is used to launch Falcon 9 rockets. A Finding of No Significant Impact was issued by SpaceX's environmental impact statement (EIS), with NASA as the lead agency, earlier in September 2019 for the launch pad site. In 2024, the Federal Aviation Administration began the process of preparing an EIS evaluating the potential impacts of the new infrastructure and a higher launch cadence of up to 44 per year at LC-39A.
In June 2024, Blue Origin and United Launch Alliance (ULA) provided comments as part of the EIS process, both objecting to the impact that Starship launch operations may have on their own activities at the site. Blue Origin suggested several mitigations, including allowing other operators to object to a Starship launch that would conflict with one of its own, limiting Starship operations to particular times, or expanding the number of launchpads in the area to reduce the impact of conflicting launches. ULA suggested regulators prevent Starship from launching in Florida altogether because a fully fueled Starship would require an evacuation zone so large that it would prevent other operators from using their facilities, and the noise generated by repetitive launches could be injurious to those who live or work nearby. Elon Musk suggested that the two companies' comments were disingenuous and that their true motivation was to impede SpaceX's progress by lawfare.
The company has also proposed building another Starship launch pad at the nearby Cape Canaveral Space Launch Complex 37 (SLC-37) which became vacant in 2024 after the retirement of the Delta IV rocket. That year, the United States Space Force began the process of preparing an EIS evaluating the potential impacts of new infrastructure and a launch cadence of up to 76 times per year at SLC-37. SpaceX and NASA have also worked on assessing LC-49 to the north of 39A. The Kennedy Space Center's Master Plan One has stated that LC-49 could avoid overflight issues with pad 39B and minimize conflict with the Canaveral National Seashore. On 18 January 2024, NASA does not have activities underway at LC-49.
Both EIS processes must be complete before SpaceX will be cleared to launch Starship from Florida, which likely will not occur until late 2025. The Playalinda Beach has been closed by KSC Police and the National Park Service for many launches from 39A and 39B. The towers and mechanical arms at the sites should be similar to the ones at Starbase.
In order to compete with SpaceX and close their technological gap with the company, the China Aerospace Science and Tech Corp and other aerospace actors in China have reportedly been working on their own equivalent of Starship—the Long March 9 super-heavy lift rocket, which is also designed to eventually be fully reusable. In 2021, the China Academy of Launch Vehicle Technology (CALT) showed a rendered video of a rocket noted to be "strikingly" similar to Starship in appearance and function. In a 2022 event organized by the International Astronautical Federation and the Chinese Society of Astronautics, the CALT communicated performing research on a crewed launch vehicle powered by LOX-methane propellant, with a second stage that was very similar to Starship's.
SpaceNews noted that the Chinese start-up Space Epoch and engine maker Jiuzhou Yunjian were developing a smaller Starship-like rocket with a methane-LOX engine similar to Raptor, stainless steel tanks, and an iterative design. Starship's reusability and stainless-steel construction might also have inspired Project Jarvis, a reusable upper stage for Blue Origin's New Glenn heavy-lift launch vehicle intended to replace New Glenn's expendable upper stage in the future.
In 2021, members of Congress voiced concerns about the FAA's response to SpaceX's launch license violations following the explosion of SN8, calling on the FAA to "resist any potential undue influence on launch safety decision-making". In 2023, prior to Starship's second test flight, SpaceX's vice president and ex-NASA engineer Bill Gerstenmaier made statements at the U.S. Senate on the importance of innovation in light of "strategic competition from state actors like China". He said SpaceX was under a contract with NASA to use Starship to land American astronauts on the moon before China does, and that the Starship test flights campaign was being held up by "regulatory headwinds and unnecessary bureaucracy" unrelated to public safety.
Following the second integrated flight test of Starship, the Government Accountability Office (GAO) made recommendations to the FAA to "improve its mishap investigation process", finding that historically they have allowed the launch operator to conduct their investigation with the FAA supervising. Several environmental groups have filed lawsuits against the FAA and SpaceX, claiming that environmental reviews were bypassed due to Musk's political and financial influence.