Starhopper

Starship

Starship prototype SN20 at the SpaceX Starbase in Boca Chica (Texas). The distinctive stainless steel structure is visible as well as the edges of the dark thermal protection tiles that cover the other side of the vehicle.
Manufacturer	SpaceX
Country of origin	United States
Applications	Crew and cargo interplanetary transport Point-to-point transport on Earth
Website	https://www.spacex.com/vehicles/starship/
Specifications
Spacecraft type	Crewed, reusable
Launch mass	1320 tons (120 tons dry)
Payload capacity	100t - 150t
Crew capacity	Up to 100 (planned)
Dimensions
Height	50 m (164 ft)
Diameter	9 m (30 ft)
Wingspan	17 m (56 ft)
Production
Status	In development
Failed	0
Lost	1 (prototype)
Maiden launch	April 20th, 2023
Related spacecraft
Derivatives	Starship HLS
Flown with	SpaceX Super Heavy

Starship is a spacecraft currently under development by American aerospace company SpaceX. Stacked atop its booster, Super Heavy, it composes the identically named Starship super heavy-lift space vehicle. The spacecraft is designed to transport both crew and cargo to a variety of destinations, including Earth orbit, the Moon, Mars, and potentially beyond. It is intended to enable long duration interplanetary flights for a crew of up to 100 people. It will also be capable of point-to-point transport on Earth, enabling travel to anywhere in the world in less than an hour

Development began in 2012, when Elon Musk, CEO of SpaceX, described a plan to build a reusable rocket system with substantially greater capabilities than the Falcon 9 and the planned Falcon Heavy. The rocket evolved through many design and name changes. On July 25, 2019, the Starhopper prototype performed the first successful flight at SpaceX Starbase near Boca Chica, Texas. The SN15 prototype became the first full-size test spacecraft to take off and land successfully in May 2021. On April 20, 2023, Ship 24 and Booster 7 lifted off the pad, the first time the booster and starship flew together as a fully integrated stack.

Design

The Starship spacecraft is 50 m (160 ft) tall, 9 m (30 ft) in diameter, and is fitted with 3 Raptor and 3 Raptor Vacuum engines for increased thrust in the vacuum of outer space. Future vehicles may have 6 Raptor Vacuum engines. The vehicle's payload bay, measuring 17 m (56 ft) tall by 8 m (26 ft) in diameter, is the largest of any active or planned launch vehicle; its internal volume of 1,000 m³ (35,000 cu ft) is slightly larger than the ISS's pressurized volume. SpaceX also provides a 22 m (72 ft) tall payload bay configuration for even larger payloads.

Starship has a total propellant capacity of 1,200 t (2,600,000 lb) across its main tanks and header tanks. The header tanks are better insulated due to their position and are reserved for use to flip and land the spacecraft following reentry. A set of reaction control thrusters, which use the pressure in the fuel tank, control attitude while in space.

The spacecraft has four body flaps to control the spacecraft's orientation and help dissipate energy during atmospheric entry, composed of two forward flaps and two aft 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 don't exist (for example, Mars). Under the forward flaps, hardpoints are used for lifting and catching the spacecraft via mechanical arms. The flap's hinges are sealed in aero-covers because they would be easily damaged during reentry.

Starship's heat shield, composed of thousands of hexagonal black tiles that can withstand temperatures of 1,400 °C (2,600 °F), is designed to be used many times without maintenance between flights. The tiles are made of silica and are attached with pins rather than glued, with small gaps in between to counteract heat expansion. Their hexagonal shape facilitate mass production and prevent hot plasma from causing severe damage to the vehicle.

Diagram of Starship's internal structure. Not shown in this diagram are the flaps: the aft flaps are placed at the bottom (or left in this orientation), and the forward flaps are placed at the top (here, right) portion of the spaceship. From the FAA environmental reassessment.

Variants

For satellite launch, Starship will have a large cargo door that will open to release payloads and close upon reentry instead of a more conventional jettisonable nose-cone fairing. Instead of a cleanroom, payloads are integrated directly into Starship's payload bay, which requires purging the payload bay with temperature-controlled ISO class 8 clean air. To deploy Starlink satellites, the cargo door will be replaced with a slot and dispenser rack, whose mechanism has been compared to a Pez candy dispenser.

Crewed Starship vehicles would replace the cargo bay with a pressurized crew section and have a life support system. For long-duration missions, such as crewed flights to Mars, SpaceX describes the interior as potentially including "private cabins, large communal areas, centralized storage, solar storm shelters, and a viewing gallery." Starship's life support system is expected to recycle resources such as air and water from waste.

Starship Human Landing System (HLS) is a crewed lunar lander variant of the Starship vehicle that is extensively modified for landing, operation, and takeoff from the lunar surface. It features modified landing legs, a body-mounted solar array, a set of thrusters mounted mid-body to assist with final landing and takeoff, two airlocks, and an elevator to lower crew and cargo onto the lunar surface. Starship HLS will be able to land more than 100 t (220,000 lb) of payload on the Moon per flight.

Starship will be able to be refuelled by docking with separately launched Starship propellant tanker spacecraft in orbit. Doing so would increase the spacecraft's mass capacity and allow it to reach higher-energy targets, such as geosynchronous orbit, the Moon, and Mars. A Starship propellant depot could cache methane and oxygen on-orbit, and will be used by Starship HLS to replenish its fuel tanks.

Development

A complete Starship launch vehicle on the launch pad. The Starship spacecraft (recognisable by the black color of its thermal protection tiles) is stacked on top of the Super Heavy booster.

Videos of Starship flight tests
From NASASpaceFlight.com and SpaceX
Starhopper 150m hop
Starship SN5 150m hop
Starship SN6 150m hop
Starship SN8 12.5km test flight
Starship SN9 10km test flight
Starship SN10 10km test flight
Starship SN11 10km test flight
Starship SN15 10km test flight
Starship S24/B7 Orbital test flight

Starship's development is iterative and incremental, using frequent—and often destructive— tests on a series of rocket prototypes.

SpaceX prototypes are subjected to many tests before they can be launched. Proof pressure tests come first. The tanks are filled with a liquid or gas to test their strength and safety factor. SpaceX tests some tanks beyond the specified limit, to find the point at which they burst. The engines were tested in later prototypes, while the vehicle remained tethered to the ground (static fire). After passing these tests vehicles launch, either flying within the atmosphere, or reaching orbit.

Starhopper

Starhopper in March 2019

Starhopper configuration as flown in August 2019

Construction on the initial steel test article—Starship Hopper,Hopper, Hoppy, or Starhopper began at Boca Chica in 2018. Starhopper had a single engine and was test flown to develop landing and low-altitude/low-velocity control algorithms.

Starhopper used LOX and liquid methane fuel.

Testing

It passed tanking tests, wet dress rehearsals, and pre-burner tests. A storm blew over and damaged Starhopper's nose cone. SpaceX continued testing without one.

It then passed a static fire test, and in a tethered test reached 1 meter altitude. On 25 July, a Starhopper test flight reached about 20 m (66 ft) altitude, followed by a 27 August test that rose to 150 m (490 ft) and landed about 100 m (330 ft) from the launchpad, the Raptor's first use in flight.

Mark series (Mk1 - Mk4)

SpaceX began building two high-altitude prototypes simultaneously, Mk1 in Texas and Mk2 in Florida, using competing teams that shared progress, insights, and build techniques. These vehicles featured three Raptor methalox engines and were meant to reach an altitude 5 km (3.1 mi). An Mk3 prototype began construction in late-2019.

Starship Mk1 in September 2019

Mk1 was 9 m (30 ft) in diameter and about 50 m (160 ft) tall, with an empty mass of 200 t (440,000 lb). It was intended for testing flight and reentry profiles, in pursuit of a suborbital flight. When announced, it boasted three sea-level Raptors, two fins each at the front and back, and a nose cone containing cold-gas reaction control thrusters,. all of which were removed thereafter.

Mk4 construction began in Florida in October, but was scrapped after a few weeks.

On 20 November 2019, Mk1 blew apart during a pressure test. Mk2 was never completed.

In December 2019, Musk redesignated Mk3 as Starship SN1 and predicted that minor design improvements would continue through SN20. In January 2020, SpaceX performed pressurization tests in Boca Chica. One test intentionally destroyed the tank by over-pressurizing it to 7.1 bar (103 psi). Another tank underwent at least two pressurization tests; the first failed at 7.5 bar (109 psi). After repairs the tank was cryogenic pressure tested (29 January), and ruptured at 8.5 bar (123 psi). The test was considered a success as 8.5 represented a safety factor of 1.4 times the 6 bar (87 psi) operational pressure.

SpaceX began stacking SN1 in February 2020 after successful pressurization tests on propellant tank prototypes. SN1 was destroyed during a cryogenic pressurization test (28 February) due to a design flaw in the lower tank thrust structure.

Hops (SN3 - SN6)

SN3 and SN4

Static fire of SN4

SN3 was destroyed during testing on 3 April 2020 due to a bad testing configuration.

SN4 passed cryogenic pressure testing (26 April) and two static fires (5 and 7 May): one tested the main tanks, while the other tested the fuel header tank. After uninstalling the engine, a new cryogenic pressure test was conducted (19 May). A leak in the methane fuel piping ignited, causing significant damage to the rocket's base, destroying the control wiring. SN4 was destroyed (29 May), due to a failure with the Ground Support Equipment's quick-disconnect function.

SN5 and SN6

After a static fire test (30 July), SN5 completed a 150-meter flight (4 August) with engine SN27. SN6 completed a static fire (24 August) and a 150-meter hop test flight with engine SN29 (3 September).

In January 2021, SN6 was scrapped, followed by SN5 in February.

High-altitude test flights (SN8 - SN15)

SN8 shortly after taking off during its test flight

Starship SN8 remains after it crashed to the ground

SN9 on Suborbital Pad B, with the production facility in the background

SN8 and SN9

SN8 was planned to be built out of 304L stainless steel, although some parts may have used 301 steel. In late October and November, SN8 survived four static fires. During the third test (12 November), debris from the pad caused the vehicle to lose pneumatics. Launch took place on 9 December. Launch, ascent, reorientation, and controlled descent were successful, but low pressure in the methane header tank kept the engines from producing enough thrust for the landing burn, destroying SN8 on impact.

On 11 December, the stand beneath SN9 failed, causing the vehicle to tip and contact the walls inside the High Bay. SN9 then required a replacement forward flap. SN9 conducted 6 static fires in January 2021, including three separate static fires. Engines 44 and 46 had to be replaced. After struggling to gain FAA permission, SN9 conducted a 10 km (6.2 mi) flight test (2 February). Ascent, engine cutoffs, reorientation and controlled descent were stable, but one engine's oxygen pre-burner failed, sending SN9 crashing into the landing pad. The landing pad was then reinforced with an additional layer of concrete. After the SN9 failure, all three engines were used to perform the belly flop landing sequence. This offered a failsafe should one fail to ignite.

SN10 - SN14

SN10's first cryogenic proof test succeeded (8 February), followed by a static fire (23 February). After an engine swap came another static fire (25 February).

Two launch attempts were conducted on 3 March. The first attempt was automatically aborted after one engine produced too much thrust while throttling up. After a 3-hour delay to increase the tolerance, the second attempt landed without exploding. The test ended with a hard landing-at 10 m/s-most likely due to partial helium ingestion from the fuel header tank. Three landing legs were not locked in place, producing a slight lean after landing. Although the vehicle initially remained intact, the impact crushed the legs and part of the leg skirt. Eight minutes later the prototype exploded.

SN11 accomplished a cryogenic proof test (12 March) that included a test of the Reaction Control System (RCS), followed by a static fire test (15 March). Immediately after ignition, the test was aborted. Another static fire attempt led to reports that one of the three engines had been removed for repairs. A replacement engine was installed and a third static fire was attempted (26 March ). A 10 km flight test was conducted in heavy fog (30 March). The test included engine cutoffs, flip maneuver, flap control and descent, along with a visible fire on engine 2 during the ascent. Just after the defective engine was re-ignited for the landing burn, SN11 lost telemetry at T+ 5:49 and disintegrated. SN12 through SN14 never launched.

SN15 - SN19

SN15 introduced improved avionics software, an updated aft skirt propellant architecture, and a new Raptor design and configuration. A Starlink antenna on the side of the vehicle was another new feature. SN15 underwent an ambient temperature pressure test (9 April), A cryogenic proof test (12 April), and a header tank cryogenic proof test (13 April). Then a static fire (26 April) and a header tank static fire (27 April) followed. A 10 km (33,000 ft) high-altitude flight test was conducted in overcast weather on 5 May, achieving a soft touchdown. A small fire near the base was controlled shortly after landing. After its engines were removed, it was retired on 31 May, the first Starship prototype to fly, land and be recovered. It took its place in the Rocket Garden. SN16 and SN17 were scrapped, and SN18 and SN19 were never completed.

Orbital launches (SN20/Ship 20-)

SN20/Ship 20 - Ship 23

SN20 getting its heat shield inspected

Static fire test of SN20 on 21 November 2021

SN20 (Ship 20) resides in the Rocket Garden, previously planned to be launched atop the Super Heavy booster. SN20's thermal protection system covers much of the vehicle.

SN20 rolled out to the launch mount on 5 August 2021 and was the first to be stacked on a booster. It used Booster 4 for a fit test. FCC filings in May 2021 by SpaceX stated that the orbital flight would launch from Boca Chica. After separation, Starship would enter orbit and around 90 minutes later attempt a soft ocean landing around 100 km off the coast of Kauai.

Ship 21 was scrapped, Ship 22 moved out to the Rocket Garden in late February 2022. Ship 23 was scrapped and partially recycled in Ship 24 which was targeted for an orbital flight as of September 2022. As of now Ship 22's forward flaps have been attached to Ship 29's nosecone.

Ship 24

As of December 2022, Ship 24 was planned to make an orbital test flight atop Booster 7. It was first spotted in November 2021, and made cryogenic proof tests on 2, 6, and 7 June 2022. Starship 24 then conducted spin prime tests on 18, 20, and 21 July 2022, with an additional one on 8 August 2022. It was static fired with two engines on 9 August 2022. On 8 September 2022, Ship 24 underwent a static fire test where all six of its engines; three sea level and three vacuum engines, endured an 8-second test. The test damaged/destroyed around 30 of its 25,000 ceramic tiles. The ship went through repairs and was subsequently stacked on top of Booster 7 in late October ahead of further testing. As of 26 January 2023, Ship 24 is rolled back to the production site for final TPS work for orbital test flight. On April 20, 2023, it was intentionally destroyed in flight along with Booster 7 after spinning out of control.

In response to the launch damage caused by the first orbital flight attempt, SpaceX plan to put steel plates cooled by a water-system underneath the launch mount for the next Starship launch. According to Elon Musk, the launch tower has no meaningful damage although it was struck by large chunks of concrete.

Ship 25

Ship 25 is a Starship prototype very similar to the destroyed Ship 24. Like Ship 24, it features a heat shield. A payload bay was also built, but it was sealed permanently shut. To test its cryogenic testing equipment, it currently resides at the Massey's site, a former nearby gun range. As of May 2023, the fate of Ship 25 is unknown.

Ship 26-27

Ship 26 and 27 are expendable Starship prototypes spacecrafts as they do no have heat shield tiles and no forward and aft flaps. Ship 26 has no payload bay door, whereas Ship 27 does feature a reinforced payload dispenser designed to carry Starlink satellites.

Ship 28-29

Ships 28 and 29 feature heat shield tiles, as well as reinforced Starlink dispensers.

Test tanks

General test tanks

Test Tank 1 (TT1) was a subscale test tank consisting of two forward bulkheads connected by a small barrel section. TT1 was used to test new materials and construction methods. On 10 January 2020, TT1 was filled with water and tested to failure as part of an ambient temperature test, reaching a pressure of 7.1 bar (103 psi).

Liquid Oxygen Header Test Tank (LOX HTT) was similar to TT1, but was based on the LOX Header tank inside a nosecone section. On 24 January 2020, the tank underwent a pressurization test which lasted several hours. The following day it was tested to destruction.

Test Tank 2 (TT2) was another subscale test tank similar to TT1. On 27 January 2020, TT2 underwent an ambient temperature pressure test where it reached a pressure of 7.5 bar (109 psi) before a leak occurred. Two days later, it underwent a cryogenic proof test to destruction, bursting at 8.5 bar (123 psi).

EDOME is a test tank created to test flatter domes, possibly used on future Starship prototypes. It was moved to the launch site in July 2022, and back to the production site the next month, and never received testing. It was later moved from the production site to the new Masseys site on 22 September 2022, which conducts non-flight hardware testing. On 30 September 2022, it burst during a cryogenic pressure test to failure. After repairs, it was tested to destruction in late October 2022.

Starship-based test tanks

SN2 was a half-size test tank used to test welding quality and thrust puck design. The thrust puck is found on the bottom of the vehicle where in later Starship tests up to three sea-level Raptor engines would be mounted. SN2 passed a pressure test on 8 March 2020.

SN7 was a pathfinder test article for the switch to type 304L stainless steel. A cryogenic proof test was performed on 15 June 2020, achieving a pressure of 7.6 bar (110 psi) before a leak occurred. During a pressurize to failure test on 23 June 2020, the tank burst at an unknown pressure.

SN7.1 was the second 304L test tank, with the goal of reaching a higher failure pressure. The tank was repeatedly tested in September, and tested to destruction on 23 September. The bulkhead came apart at a pressure of 8 bar (115 psi) in ullage and 9 bar (130 psi) at base.

SN7.2 was created to test thinner walls, and therefore, lower mass. It is believed to be constructed from 3 mm steel sheets rather than the 4 mm thickness of its predecessors. On 26 January 2021, SN7.2 passed a cryogenic proof test. On 4 February, during a pressurize to failure test, the tank developed a leak. On 15 March, SN7.2 was retired.

Ground support equipment-based test tanks

GSE 4.1 was first spotted in August 2021, and was the first ground support equipment (GSE) test tank built, made from parts of GSE 4. It underwent a cryogenic proof test (23 August) before it was rolled to Sanchez site. It was rolled back to the launch site in November 2021 and underwent an apparent cryogenic proof test to failure (18 January), where it burst at an unknown pressure.

See also

• Blue Origin v. United States & Space Exploration Technologies Corp.
• Rocket Cargo