Starship SN8

Starship is a spacecraft and second stage 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. Furthermore, the spacecraft will be used to refuel other Starship vehicles to allow them to reach higher orbits to and other space destinations. Elon Musk, the CEO of SpaceX, estimated in a tweet that 8 launches would be needed to completely refuel a Starship in low Earth orbit, extrapolating this from Starship's payload to orbit and how much fuel a fully fueled Starship contains. To land on bodies without an atmosphere, such as the Moon, Starship will fire its engines and thrusters to slow down.

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. On November 18, 2023, Ship 25 and Booster 9 lifted off the pad, successfully completing hot staging, during the launch, Ship 25 passed the Karman Line, becoming the first Starship ever to reach space, and also became the heaviest single object in space, before exploding at 149km.

History

In November 2005, before SpaceX had launched its first rocket the Falcon 1, CEO Elon Musk first mentioned a long-term and high-capacity rocket concept able to launch 100 tons to low Earth orbit, dubbed the ''BFR''. Later in 2012, Elon Musk first publicly announced plans to develop a rocket surpassing the capabilities of their existing Falcon 9. SpaceX called it the ''Mars Colonial Transporter'', as the rocket was to transport humans to Mars and back.

In 2016, Elon changed the name to ''Interplanetary Transport System'', as he planned the rocket to travel beyond Mars. Made of carbon fiber, this design was to mass over 10,000 tons when fueled and carry 300 tonnes to low Earth orbit, while hoping to be fully reusable. By 2017, the rocket was temporarily re-dubbed the '' BFR'' and had multiple versions announced, such as cargo, tanker and crew. In 2019, the current stainless-steel design was adopted.

Design

The Starship spacecraft is tall, in diameter, and has 6 Raptor engines, 3 of which are optimized for usage in outer space. Future vehicles may have an additional 3 Raptor Vacuum engines for increased payload capacity. The vehicle's payload bay, measuring tall by in diameter, is the largest of any active or planned launch vehicle; its internal volume of is slightly larger than the ISS's pressurized volume. SpaceX will also provide a tall payload bay configuration for even larger payloads.

Starship has a total propellant capacity of 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 do not 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 , 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 facilitates mass production and prevents hot plasma from causing severe damage to the vehicle.

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 nosecone 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 of payload on the Moon per flight.

Starship will be able to be refueled 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

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''

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. Starhopper was repurposed after it completed its testing campaign as a water tank, weather station and equipment mount, it was outfitted with cameras, lights, loudspeakers and a radar system.

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 July 25, a ''Starhopper'' test flight reached about altitude, followed by an August 27 test that rose to and landed about 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 . An Mk3 prototype began construction in late-2019.'Totally Nuts'? Elon Musk Aims to Put a Starship in Orbit in 6 Months. Here's SpaceX's Plan.
Mike Wall, ''Space.com''. September 30, 2019.
Mk1 was in diameter and about tall, with an empty mass of . 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 November 20, 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 . Another tank underwent at least two pressurization tests; the first failed at . After repairs the tank was cryogenic pressure tested (January 29), and ruptured at . The test was considered a success as 8.5 represented a safety factor of 1.4 times the 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 (February 28) due to a design flaw in the lower tank thrust structure.

Hops (SN3–SN6)

SN3 and SN4

SN3 was destroyed during testing on April 3, 2020 due to a failure in the testing configuration.

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

SN5 and SN6

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

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

High-altitude test flights (SN8–SN15)

SN8 and SN9

SN8 was planned to be built out of 304L stainless steel, although some parts may have used 301L steel. In late October and November, SN8 survived four static fires. During the third test (November 12), debris from the pad caused the vehicle to lose pneumatics. Launch took place on December 9. 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 December 11, 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 flight test (February 2). 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 (February 8), followed by a static fire (February 23). After an engine swap came another static fire (February 25).

Two launch attempts were conducted on March 3. 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 (March 12) that included a test of the Reaction control system (RCS), followed by a static fire test (March 15). 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 (March 26). A 10 km flight test was conducted in heavy fog (March 30). 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 (April 9), A cryogenic proof test (April 12), and a header tank cryogenic proof test (April 13). Then a static fire (April 26) and a header tank static fire (April 27) followed. A high-altitude flight test was conducted in overcast weather on May 5, achieving a soft touchdown. A small fire near the base was controlled shortly after landing. After its engines were removed, it was retired on May 31, 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. On July 26, 2023, SN15 was scrapped.

V1 Orbital Launches (SN20/Ship 20–S32)

SN20/Ship 20 – Ship 23

SN20 (Ship 20) resides in the Rocket Garden, previously planned to be launched atop the Super Heavy booster. SN20 was the first vehicle with a complete thermal protection system. SN20 rolled out to the launch mount on August 5, 2021, and was stacked onto 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. However, S20 was retired in March 2022.

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.

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 June 2, 2022, June 6, 2022, and June 7, 2022. On June 9, 2022, Ship 24 was rolled back to the production site for engine installation. On July 5, 2022, Ship 24 was rolled back out to the launch site and lifted onto Suborbital Pad B a day later. Ship 24 then conducted a successful spin prime test on July 18, 2022. On July 20, 2022, Ship 24 completed two successful spin prime tests. On July 21, 2022, Ship 24 again conducted two spin prime tests, the first test only included one engine, while the second test involved two engines. On July 28, 2022, Ship 24 successfully completed a forward flap test. Ship 24 completed two additional successful spin prime tests on August 8, 2022. It was static fired with two engines on August 9, 2022. On August 24, 2022, Ship 24 successfully completed an ignitor test with all 6 of its engines. On August 25, 2022, Ship 24 went through an additional spin prime test. On September 8, 2022, Ship 24 underwent a six engine static fire test, which damaged around 30 of its 18,000 ceramic tiles. The ship was repairs, and was subsequently stacked on top of Booster 7 in mid-October, before being destacked on October 16, 2022, and restacked on October 20, 2022. On November 8, 2022, Ship 24 was destacked again for static fire tests. On December 15, 2022, Ship 24 conducted a single engine static fire. On January 9, 2023, Ship 24 was stacked on Booster 7, and then destacked on January 24, 2023. On January 26, 2023, Ship 24 was rolled back to the production site for final TPS work. On March 31, 2023, Ship 24 was rolled out to the launch site for the final time before launch. On April 5, 2023, Ship 24 had two lift attempts, the first lift attempt was aborted, however the second attempt, less than a few hours after the first, was successful. On April 12, 2023, Ship 24 was destacked for FTS installation before launch. On April 15, 2023, Ship 24 was stacked onto Booster 7 for the final time before launch. On April 20, 2023, it was destroyed in flight along with Booster 7 after spinning out of control.

Ship 25

Ship 25 was a Starship prototype very similar to the destroyed Ship 24. It flew on the second Integrated Flight Test with Booster 9 and was the first Starship to reach pass the Karman Line and reach space. Like Ship 24, S25 featured a heat shield. A payload bay was also built, but was permanently sealed shut. To test its cryogenic testing equipment, it resided for a time at the Massey's site, a nearby former gun range. During the third week of May 2023, Ship 25 was moved to the launch site and lifted onto suborbital pad B in preparation for engine testing. On June 21, 2023, Ship 25 performed a successful spin prime test. On June 24, 2023, it was announced that S25 would be the first vehicle to use hot staging (when the second stage fires its engines while some of the booster's engines are still firing). On June 26, 2023, Ship 25 underwent its first static fire test, igniting all six engines. On August 5, 2023, it was moved to the Rocket Garden for final TPS work. On September 5, 2023, it was moved back to the Orbital Launch Site, followed by stacking onto B9. On September 14, 2023, it was removed from B9. On September 27, 2023, it was lifted back onto B9, before being destacked on October 5, 2023. It was then restacked on October 16, 2023, only to be destacked the next day. This was followed by a restack three days later. On October 24, B9 and S25 completed a WDR. On October 26, 2023, S25 was removed from B9. It was restacked on November 1, 2023, and then destacked on November 2, 2023, followed by FTS installation on November 9, 2023. On November 10, 2023, S25 was stacked onto B9, and then destacked on November 11, 2023. On November 15, 2023, S25 was stacked onto B9 for the Second Integrated Flight Test. Due to a failed grid fin actuator on B9, S25 was destacked on November 16, and restacked on November 17.

On November 18, 2023, Ship 25 was launched atop Booster 9 on the second Integrated Flight Test. Ship 25 successfully separated from Booster 9. Near the end of its burn, the autonomous flight termination system activated, destroying the vehicle.

Ship 26 and 27

Ship 26 and 27 are expendable Starship prototypes, as they lack heat shield tiles and flaps. Ship 26 has no payload bay door, whereas Ship 27 had a reinforced payload dispenser designed to carry Starlink satellites. Ship 26, after several cryo tests, was moved to the engine install stand. Ship 27 was scrapped on July 20, 2023. After the scrapping of S27 was complete, S26 moved to the rocket garden. S27's aft section was then converted into a test article, presumably to test the engine shielding design present on S25. On September 9, 2023, S26 was moved to Suborbital Pad B for static fire testing. On September 27, 2023, S27 was rolled to the Massey's test site. S26 then underwent a cryogenic test on October 9, 2023, followed by a preburner test with a single engine nine days later, a first for vehicles equipped with Raptor 2 engines. This was followed by a single engine static fire on October 20, 2023, simulating a deorbit burn. It was moved back to the rocket garden one week later. On December 7, 2023, S26 was placed on an engine stand, and a crane was attached to S26, potentially indicating an imminent scrapping. However, on December 11, 2023, the crane was detached from S26 and S26 was returned to the Rocket Garden without being scrapped. On December 16, 2023, SpaceX crews began welding large steel pieces onto the stack weld connecting S26's payload bay and forward dome sections, likely an attempt to reinforce the payload bay, although it is currently unclear what the reason behind this reinforcement is, or if this means SpaceX plans to use S26 as a flight article.

Ship 28 – Ship 33

Ships 28 through 32 feature heat shield tiles, as well as reinforced Starlink dispensers. In July 2023, S28 underwent cryogenic testing, before being moved onto the engine install stand. On August 18, 2023, S28 began to have its engines installed. On September 22, 2023, S29 was moved to Masseys for cryogenic testing. On September 26, 2023, S29 was cryogenically tested. On October 13, 2023, S29 was moved to the rocket garden. On November 21, 2023, S29 was moved into the High Bay, followed by the exit of S30 on November 22, 2023. On November 23, 2023, S28 and S30 were moved to the High Bay, presumably for TPS work. On November 24, Musk stated that S32 would be the last of the V1 starships. As of December, 2023, it is unknown what changes will be made to the next version. In late November 2023, S33's components were scrapped. On December 7, 2023, SpaceX confirmed that S28 would be the next vehicle to fly. On December 14, 2023, S28 was moved to the launch site and lifted onto suborbital Pad B for static fire testing. On December 16, 2023, S28 completed a spin prime test.

Test articles

General test articles

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 January 10, 2020, TT1 was filled with water and tested to failure as part of an ambient temperature test, reaching a pressure of .

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

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 (August 23) 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 (January 18), where it burst at an unknown pressure.

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 then back to the production site the next month, after not undergoing any tests. It was later moved from the production site to the Massey's Test site in late September 2022, where it was damaged during a cryogenic pressure test to failure. After repairs, it was tested to destruction in late October 2022.

EDOME 2 is a test tank which is likely designed to continue testing a flatter dome design. As of October 4, 2023, its official designation is unknown. It was tested once, before being scrapped for unknown reasons.

Starship-based test articles

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

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 March 8, 2020.

SN7 was a pathfinder test article for the switch to type 304L stainless steel. A cryogenic proof test was performed on June 15, 2020, achieving a pressure of before a leak occurred. During a pressurize to failure test on June 23, 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 September 23. The bulkhead came apart at a pressure of in ullage and 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 January 26, 2021, SN7.2 passed a cryogenic proof test. On February 4, during a pressurize to failure test, the tank developed a leak. On March 15, SN7.2 was retired.

S26.1 is a test tank designed to test the aft section of ships after S24. It conducted two tests on the can-crusher, before being moved off in July 2023. On September 21, 2023, it was tested to destruction.

S24.2 is test article designed to test the payload bay of Starlink dispenser vehicles. On September 28, 2023, it was moved to the Masseys test site.

Notes

See also

* Artemis Program
* New Glenn
* Private spaceflight
* SpaceX Super Heavy
* Timeline of space exploration

References

{{SpaceX
Proposed reusable launch systems
Reusable spaceflight technology
Reusable spacecraft
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SpaceX Starship
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