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SpaceX Starship Rocket; Design Specification, Variants, Features, Launches and cost

SpaceX relentless race in space exploration and the tussle to reach Mars birthed the revolutionary Starship space shuttle. It’s of high expectations that it would land the next human crew to the moon since the last time astronauts visited the moon during the Apollo program. The Rocket’s design specifications, development, test flights, planned orbital launches with all the proposed variants and component features are detailed herein.

The Starship is a fully reusable spacecraft with super heavy rocket booster, the two‑stage‑to‑orbit super heavy‑lift launch vehicle is been developed by the American company SpaceX. The vehicle is composed of a booster first stage named “Super Heavy”, and a second stage, also called “Starship”. Starship is the most powerful launch vehicle ever built and is expected to be the first to demonstrate total reusability.

Unusually for traditional second stages, the Starship second stage is being designed as a long‑duration cargo and passenger‑carrying spacecraft to carry both crew and cargo to Earth orbit, the Moon, Mars and beyond. It serves as a self-contained spacecraft while in orbit.

Both stages are powered by Raptor engines, which burn liquid oxygen and liquid natural gas (methane) propellants in a highly efficient full-flow staged combustion power cycle. Both rocket stages are designed for rapid reuse by landing vertically. The Super Heavy booster can perform a boost back burn and Starship can reenter the atmosphere for a belly-first descent.

Starship Design

Starship is designed to be a fully reusable and orbital rocket, aiming to drastically reduce launch costs and maintenance between flights. It will consist of a Super Heavy first stage or a booster and a Starship second stage or spacecraft, powered by Raptor and Raptor Vacuum engines. The bodies of both rocket stages are made from stainless steel, giving Starship its shine and strength for atmospheric entry. The rocket’s reusability and stainless-steel construction has influenced other rockets such as the Terran R and Project Jarvis.

Manufacturing of the Starship rocket starts with rolls of steel. They are then unrolled, cut, and welded along the cut edge to create a cylinder 9m (30 ft) in diameter, 2m (7 ft) in height, and around 1,600 kg (4,000 lb) in mass. To make the outer layer of the Starship spacecraft, seventeen of these cylinders and nose cones are stacked and welded along their edges. Between the methane and oxygen tanks are domes, made by robots welding at a rate of ten minutes per seam, equal to four hours per dome. These welds are later inspected with an X-ray machine.

When stacked and fueled, Starship is about 5,000t (11,000,000 lb) by mass, 9m (30 ft) wide, and 120m (390 ft) high. It is taller than the Saturn V the rocket that was used for the NASA Apollo program of the 1960s and 1970s. by 9 m (30 ft), With Super Heavy’s peak thrust of 72 MN (16,000,000 lbf), the rocket has a thrust-to-weight ratio of about 1.45 at liftoff. One launch may deliver 100 t (220,000 lb) to low Earth orbit, which would formally classify the rocket as a super heavy-lift launch vehicle.

Starship Raptor engine

Raptor is a family of rocket engines developed by SpaceX exclusively for use in Starship and Super Heavy. It is fueled by liquid oxygen and methane, burning them in a highly efficient full-flow staged combustion power cycle. It is the third engine that uses such a cycle and the first that powered a flight vehicle. The Raptor engine uses methane as the fuel of choice over other rocket propellants, including the facts that methane burns ‘cleaner’, produces less soot, and can be directly synthesized from carbon dioxide and water. These properties make the engine highly practical, efficient and long-lasting.

Raptor1 and Raptor2 at Starbase

The engine structure itself is mostly made out of aluminum, copper and steel; oxidizer-side turbo pumps and manifolds subject to incredibly corrosive oxygen-rich flames are manufactured out of an Inconel-like SX500 super alloy. A small number of parts are 3Dprinted.

At sea level, the standard Raptor engine produces 2.3 MN (520,000 lbf) at a specific impulse of 327 sec, increasing to 350 sec in vacuum. Raptor Vacuum, used exclusively 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 vacuum specific impulse to 380 sec. Another engine variant, Raptor Boost, isused exclusively on the Super Heavy booster, it lacks gimbal actuators and has limited throttle capability in exchange for increased thrust.

Super Heavy booster

Super Heavy is a first stage or booster stage, forming the lower part of the rocket. The booster is 70 m (230 ft) tall, 9 m (30 ft) wide, and houses up to thirty-three sea level-optimized Raptor engines. The engines are arranged in concentric rings, with three engines in the innermost ring, ten in the middle ring, and twenty in the outermost ring. The two inner rings are filled with conventional Raptor engines possessing gimbal actuators for thrust steering. The outermost ring is filled with Raptor Boost engines with gimbal actuators removed to save mass. Collectively, they produce 72 MN (16,000,000 lbf) at full power, more than twice as powerful as the Saturn V.

Superheavy Booster transfer to launch pad

The booster’s tanks can hold 3,600 t (7,900,000 lb) of propellant, consisting of 2,800 t (6,200,000 lb) of liquid oxygen and 800 t(1,800,000 lb) of liquid methane. Super Heavy also stores 280 L (74 US gal) of hydraulic fluid for its operations. The final design of Super Heavy is estimated to 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).

Superheavy booster static fire on launch pad

The booster is equipped with four electrically actuated grid fins, each of which has a mass of 3 t (6,600 lb). The grid fins are unevenly spaced to allow the craft to obtain more pitch control and can only rotate in the roll axis. Between the grid fins are Super Heavy’s hard points, which are used for lifting and catching by the mechanical arms on the integration tower. The booster’s orientation can be controlled using cold gas thrusters, fed with evaporated propellant inside the tanks. The booster’s separation from the spacecraft is done by the Raptor engines and releasing the latches.

Starship spacecraft

Starship is a second stage or long-duration spacecraft, forming the upper part of the rocket. The spacecraft is 50 m (160 ft) tall and has a dry mass of less than 100 t (220,000 lb). Starship’s pay load volume is about 1,000 m3 (35,000 cu ft), larger than the International Space Station’s pressurized volume by 80 m3 (2,800 cu ft), and can be even bigger with an extended 22 m (72 ft)-tall volume. By refueling the Starship spacecraft in orbit using tanker spacecraft, Starship will be able to transport larger payloads and more astronauts to other Earth orbits, the Moon, and Mars.

Cross section Anatomy of SpaceX Starship

Starship has a total propellant capacity of 1,200 t (2,600,000 lb), divided into 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. About 130 L (34 US gal) of hydraulic fluid is used for the spacecraft’s operations.

At the aft end of the Starship spacecraft are six Raptor engines, three of which are designed for operation in the lower atmosphere, and the other three Raptor Vacuum engines are optimized to operate in the vacuum of space. A set of reaction control thrusters mounted at the spacecraft’s exterior to control the spacecraft’s attitude while in space.

The spacecraft has four body flaps to control the spacecraft’s orientation and help to dissipate energy during atmospheric entry, composed of two forward flaps and two aft flaps. Under the forward flaps are hard points, used for lifting and catching the spacecraft via mechanical arms. To prevent damage of the flap’s hinges, they are sealed with metal because they are easily damaged during reentry otherwise.

SpaceX Starship beside fully stacked ship on launch tower at Starbase

Starship’s heat shield, composed of thousands of hexagonal black tiles, is designed to be used many times, ultimately with no maintenance between flights. The tiles are made of silica and are more uniform in shape than the Space Shuttle’s heat shield tiles. They are attached with pins, not glued, with small gaps in between to counteract heat expansion. Their hexagonal shape is designed to enable mass production and prevent hot plasma from causing severe damage, allowing the tiles to withstand temperatures of 1,400 °C (2,600 °F).

History and Development of the Starship

Before the present known version of the Starship, In November 2005, before SpaceX launched its first rocket (Falcon 1), the company’s main founder Elon Musk first referenced a long-term and high-capacity rocket concept named BFR (Big Falcon Rocket) that would be able to launch 100t (220,000 lb) to low Earth orbit. It would use the proposed Merlin 2 kerosene-oxygen rocket engine, which is in direct lineage to the Merlin engines used on the Falcon 9. The Merlin 2’s thrust would have been comparable to the F-1 engines used on the Saturn V.

Around 2012, the company first mentioned the Mars Colonial Transporter rocket concept in public, designed for Mars colonization. The rocket was going to be able to carry 100 people or 100t (220,000 lb) of cargo to Mars and be powered by the in development methane-oxygen Raptor engines. It had seemed that the Raptor engine had superseded the Merlin 2 and the Mars Colonial Transporter rocket today shows off as the Starship.

The Starship’s development is iterative and incremental, marked by tests on rocket prototypes. The first of such prototypes was the Star hopper, which performed several static fires and low-altitude flights. Then, seven of Starship’s upper stage prototypes were flight tested between August 2020 and May 2021. The last of which, a full-size Starship SN15, successfully landed after launching to an altitude of 10 kilometers (6.2 mi). A full-scale orbital test flight of the rocket is currently expected to take place in late 2022.

The Starship prototype tests can generally be classified into three main types.

In proof pressure tests, the vehicle’s tanks are pressurized with either gases or liquids to test its tank strength. Sometimes, the vehicle is deliberately over pressurized resulting in a burst.
The vehicle then performs mission rehearsals, with or without propellant, to check both the vehicle and ground infrastructure.
Before a test flight, SpaceX loads the vehicle prototype with propellant and fires its engines briefly, conducting a static fire test. Alternatively, the engines’ turbo pump spinning can be tested without firing the engines, referred to as a spin prime test.

After these tests are deemed successful, flight tests and launches may commence. During a suborbital launch, Starship prototypes fly to a high altitude and descend, landing back at either near the launch site, sea, or offshore platforms. During an orbital launch, Starship performs procedures as described in its mission profile. Due to the company’s openness to the space news industry, Starship rocket tests, flights, and launches have received significant media coverage.

Starship’s Low Altitude Test Flights

Through the developmental process, the starship went through some series of low altitude test flights with its first prototype the Starhopper using a Raptor engine. The vehicle had three non-retractable legs and was shorter than the final spacecraft design. As of August 2021, the vehicle has been retired and repurposed; it is now a mounting point for communication, weather monitoring and tracking equipment, and becoming a water tank.

The first full-size Starship Mk1 and Mk2 upper-stage prototypes never flew, as Mk1 was destroyed November 2019 during a pressure stress test and Mk2’s Florida facility was abandoned and deconstructed throughout 2020. After the Mk prototypes, SpaceX began naming its new Starship upper-stage prototypes with the prefix “SN”, short for “serial number”. No prototypes between SN1 and SN4 flew either, as SN1 and SN3 collapsed during pressure stress tests and SN4 exploded after its fifth engine firing.

In June 2020, SpaceX started construction of a launch pad for orbit-capable Starship rockets. Starship SN5 was built with no flaps or nose cone, giving it a cylindrical shape. The test vehicle consisted of one Raptor engine, propellant tanks, and a mass simulator. On 5 August 2020, SN5 performed a 150m (500 ft)-high flight, successfully landing on a nearby pad. The company ended low altitude test with the SN6 on 3 September 2020.

A week later, SpaceX stress-tested SN7.1 fuel tank, whichwas constructed from SAE 304L stainless steel rather than SAE 301 by earlier tanks. In the same September, the company fired its Raptor Vacuum engine in full duration.

Starship’s High Altitude Test Flights

For the Starship’s high altitude test, SN8 was the first fully complete Starship upper stage prototype. Before its flight, it underwent four static fire tests between October and November 2020. On 9 December 2020, SN8 flew, slowly turning off its three engines one by one, and reaching to an altitude of 12.5km (7.8 mi). The craft then performed the belly-flop maneuver and dove back through the atmosphere.

Low methane header tank pressure during the prototype’s landing attempt caused its engines to underperform, which led to a hard impact with the landing pad. Because SpaceX had violated its launch license and ignored warnings of worsening shock wave damage, the Federal Aviation Administration performed a two-month investigation of the incident. On 2 February 2021, Starship SN9 launched to 10 km (6.2 mi) and crashed upon landing as a result of one of its engines failing to properly ignite.

A month later, on 3rd March 2021, after an initially aborted launch three hours earlier, Starship SN10 launched on the same flight path as its two predecessors. The vehicle then landed hard and crushed its landing legs, leaning to one side, and a fire was seen at the vehicle’s base. Less than ten minutes later, it exploded, probably due to a propellant tank rupture.

A few weeks later on 30 March 2021, Starship SN11 flew into thick fog along the same flight path. About twenty-five seconds after lift-off, fire could be spotted at an engine, though it did not impact the ascent. During descent, the vehicle exploded, scattering debris up to 8 km (5 mi) away. It was suspected that a methane leak damaged the vehicle’s avionics, causing excess propellant in a Raptor’s methane turbo pump, leading to the vehicle’s explosion.

Starship prototypes SN12, SN13, and SN14 were scrapped before completion, and Starship SN15 was selected to fly instead. The prototype features general improvement on its avionics, structure, and engines, learning from the failures of prior prototypes. On 5 May 2021, SN15 launched, completed the same maneuvers as older prototypes, and landed softly after six minutes.

Even though SN15 had a small fire in the engine area after landing, like SN10, it was extinguished, completing the first successful high-altitude test. Further prototypes such as Starship SN16 were built, but plans for flying them were abandoned.

Starship Planned orbital launches

In July 2021, Super Heavy BN3 conducted its first full-duration static firing, lighting three engines. Around this time, SpaceX changed their naming scheme from “SN” to “Ship” for Starship crafts, and from “BN” to “Booster” for Super Heavy boosters. A month later, using cranes, Ship 20 was stacked atop Booster 4 for the first time.

Ship 20 was the first to include a body-tall heat shield, made of standardized hexagonal heat tiles. In October 2021, the catching mechanical arms were installed onto the integration tower, and the first tank farm’s construction was completed. Two weeks later, NASA and SpaceX announced their plans to construct Kennedy Space Center’s Launch Complex 49.

At the start of 2022, the Raptor 2 engine was first spotted by the public. Raptor 2 is intended to be an upgrade to the original engine with a much more simplified design, decrease in mass, widening of the throat, and increase in main combustion chamber pressure from 250bar (3,600 psi) to 300bar (4,400 psi). This lead to an increase in thrust from 1.85MN (420,000 lbf) to 2.3MN (520,000 lbf), with a 3 seconds of specific impulse decrease trade off.

In February 2022, after stacking Ship 20 on top of Booster 4 using mechanical arms, Elon Musk gave a presentation on Starship development at Starbase; he updated progress on Raptor 2 production, mentioned a possible move to the Florida facility, and confirmed many technical information speculations.

On 11 July 2022, Booster 7 tested spinning the liquid oxygen turbo pumps on all of its thirty-three Raptor engines, referred to as a spin prime test. The test resulted in a violent explosion at the prototype’s base, though the prototype’s body remains somewhat intact. As of July 2022, Booster 7 was expected to pair up with Ship 24 for the first orbital flight. Elon Musk confirmed that this is still planned on 24 October 2022, stating that this could change if any damage occurs during testing.

Although SpaceX has not received an orbital launch license as of 30 October 2022, the company had described the planned trajectory in a report sent to the Federal Communications Commission. During the orbital test flight, the rocket is planned to launch from Starbase, after which the Super Heavy booster will separate and perform a soft water landing around 30 km (20 mi) from the Texas shoreline. The spacecraft will continue flying with its ground track passing through the Straits of Florida and then softly land in the Pacific Ocean around 100 km (60 mi) northwest of Kauai in the Hawaiian Islands. The spaceflight will last ninety minutes.

SpaceX Starship Applications and launches

The Starship is designed to be a human space craft for professional and recreational purposes and also for variety of payload deployment to low Earth Orbit and distant deep space locations.

Starship’s reusability is expected to reduce launch costs, expanding space access to more payloads and entities. Musk has stated that a Starship orbital launch will eventually cost $1 million (or $10 per kilogram). However, Euro space’s director of research Pierre Lionnet stated that Starship’s launch cost will likely be higher because of the rocket’s high development cost.

Starship is also expected to be able to launch up to three times per day and replace the company’s Falcon 9 and Falcon Heavy rockets. Such a launch cadence is necessary for Starship’s profitability and may cause the current space industry to become saturated. One way for Starship to meet its demand is to launch rideshare missions that carry many satellites at once.