SpaceX Starship

Starship is a rocket made out of stainless steel by SpaceX, a company that works in the atmosphere and space. The rocket is made of two stages: Super Heavy and Starship. Both of these stages can be used again. This is unusual for a rocket. The rocket can lift  of people and things to orbit. It can also travel to the Moon and Mars. There are many different ways Starship can be used. It can do many things from serving space tourists, to helping humans going to Mars.

Before launch, liquid oxygen and liquid methane fill Starship's tanks. Then, 33 Raptor engines fire and lift the rocket up. Super Heavy and Starship will then separate. After that, the Starship spacecraft boosts itself into orbit. The booster then descends and lands on the launch tower's arms. When Starship lands, the spacecraft will glide using its flaps. At the last few seconds, the spacecraft flips up and land.

Since 2005, SpaceX has been working on ideas similar to Starship. The company then checks the design with a series of tests: from flying  high in July 2019, to flying  high in May 2021. , Starship is going to do it's first spaceflight sometime in 2022.

Parts 
Starship has two parts: the Super Heavy booster and the Starship spacecraft. Both Super Heavy and Starship should be able to land and launch many times quickly. That is the reason why the Starship rocket is often called a fully-reusable rocket. As of November 2021, no other rockets except Falcon 9 and Falcon Heavy's booster can do this. Most of the rocket is made from SAE 304 stainless steel, the most common type of all. 

Starship may become the tallest, heaviest, and most powerful rocket in the world. It can carry  of cargo to low Earth orbit. The Space Shuttle could only carry  to the International Space Station, however. In this example, the International Space Station has an even lower orbit than Starship.{{Efn|The International Space Station orbits  high at 51.64° inclination. Starship in this case orbits  high at 98.9° inclination. The Starship spacecraft can also carry cargo to higher Earth orbits, the Moon, and Mars. 

Super Heavy and Starship must pass many tests before launch. Firstly, they are filled with nitrogen gas to check for leaks. Then, cold liquid nitrogen fills and drains from Starship and Super Heavy to check the tanks' strength. Finally, propellant fills their tanks, and the Raptor engines are fired.

Super Heavy booster 
Below the rocket is a  tall Super Heavy booster. This booster can hold about  of propellant. Super Heavy and Starship's propellants are liquid methane and liquid oxygen. The booster is made from stainless steel rings. These rings are  thick,  tall, and  diameter.

At the bottom of the booster are 33 Raptor rocket engines. They can make  of thrust, twice more than the Saturn V. The thrust speeds up the rocket to .

On top of Super Heavy are four boxes containing fins in a grid pattern. These boxes are usually called grid fins, like those of the Falcon 9. Grid fins rotate to control and guide the booster while falling from the sky. When it is just a few kilometers or miles above ground, Super Heavy fires its engines and lands on the tower arms, which will 'catch' it.

Starship spacecraft 

On top of the booster sits a  tall Starship spacecraft. The spacecraft can hold about  of propellant. Its propellant is the same as Super Heavy's, which are liquid methane and liquid oxygen. The Starship spacecraft is made from stainless steel rings, similar to Super Heavy.

At the bottom of the spacecraft are six rocket engines. Three of them are regular Raptor engines; three others are Raptor Vacuum engines. These regular Raptor engines work inside the air, while Raptor Vacuum engines work inside the vacuum.

There are two kinds of propellant tanks inside Starship: these are main tanks and header tanks. The main tanks store propellant for almost all functions of the spacecraft. The only exception here is when Starship lands when it uses its header tanks instead.

There are four flaps that connect to Starship's body. Two large flaps are at the bottom of the spacecraft, and two small flaps are at the top of the spacecraft. They are made from stainless steel sheets and bend to a trapezoid shape. The flaps can control Starship's falling speed and direction.

A black heat shield covers one side of the spacecraft. The heat shield is made from ceramic hexagon tiles and sheets of ceramic wool. They help to protect Starship from hot plasma, made when the spacecraft enters Earth's atmosphere. Starship's heat shield could be durable and used many times.

Types of Starship 
In the past, the Starship spacecraft was planned to only bring cargo and astronauts to Mars. However, as of 2021, SpaceX is planning many kinds of Starships that do different tasks. They are different from each other by having parts added, removed, or changed.

Some Starships might transport people between different cities without leaving Earth's orbit. It could go from New York City to Shanghai in 39 minutes, much faster than an airplane's 15 hours. SpaceX thinks that Starship flights might be as cheap as a business class ticket in the far future. As of January 2021, the United States Air Force is interested in this idea.

However, most Starships would carry satellites, cargo, and humans to Earth orbit. They would have a large door that rotates along a hinge. These Starships could catch space debris as well.

Some Starships would carry propellant instead of cargo. These spacecraft can fuel another spacecraft in orbit. Via fueling, these spacecraft would have more range and can go further.

Starship HLS (Starship Human Landing System) will land astronauts on the Moon during the Artemis program. It can take propellant from other Starships to have more range. The spacecraft would not have a heat shield or body flaps. However, it will have solar panels and landing engines. Starship HLS can be fueled and connected to the Orion spacecraft.

Starships going to Mars also need fueling as well. That spacecraft might have forty rooms, a storage room, and a shelter. The shelter protects astronauts from the Sun's ionizing radiation.

Launch and landing places 

The rocket might launch from Starbase, boats, or LC-39A. Starbase at Texas is where SpaceX makes and tests most Super Heavy and Starship. The launch boats are named Phobos and Deimos after the moons of Mars. They were oil platforms owned by Valaris.

All Starship launch and landing places will have a tower. It has a large crane placed on top that can lift Super Heavy and Starship. That tower also has a pair of steel arms that rotate at a hinge similar to claws. The claws can catch Super Heavy as well.

Some people living near Starbase blamed SpaceX for harming wildlife, building and testing things without permission, and making too much noise. However, many people come to visit and stay there. When asked, they said that watching and imagining Starships sending humans to Mars made them love the place.

Raptor rocket engine 

Both Super Heavy and Starship have SpaceX's Raptor rocket engines at the bottom. Each engine can make about  of thrust. It has a full-flow staged combustion cycle design and burns liquid methane with liquid oxygen. These Raptor engines will be made in a new factory at McGregor.

Also at the bottom of the Starship spacecraft are the Raptor Vacuum engines. They are Raptor engines with larger nozzles. The Raptor Vacuum only works in space and is more efficient than the normal Raptor engine. The Raptor 2 engine is the next generation of the Raptor and Raptor Vacuum engines. They will be used in Super Heavy and Starship sometime in the future. Both the Raptor Vacuum and Raptor 2 are going to be made in another factory at Hawthorne.

This is how a full-flow staged combustion cycle engine works. First, liquid methane and oxygen flow into the engine's turbopumps. The turbopumps increase the liquids' pressure. Then, the methane and oxygen evaporate into hot gases in two preburners. One preburner gets more methane, and another gets more oxygen. The gas then turns the turbines and turbopumps by a shaft. These spinning turbines and turbopumps pump more propellant to the engine. This hot and mixed gas is then burned in a combustion chamber. Finally, the engine nozzle directs the ignited gas to make thrust.

Missions

Planned 

SpaceX wants Starship to replace the Falcon 9, Falcon Heavy, and Dragon 2. Musk guessed a Starship launch should cost $2 million (United States dollars) and the mission's propellant cost should be about $900,000. Starship could carry 400 Starlink satellites into orbit. A Falcon 9 can carry only 60 Starlink satellites.

The dearMoon project is planned for no earlier than 2023. Previously, in 2018, Japanese entrepreneur Yusaku Maezawa announced that private space mission. Its crew are Maezawa himself and eight other people. The plan is to use Starship as the main spacecraft. The spacecraft launch them toward the Moon, circle around it, and then return back to Earth.

On 16 April 2021, NASA (a government agency) selected Starship HLS as the Moon lander for the Artemis program. The other options were the Integrated Lander Vehicle by the National Team and Dynetics HLS by the Dynetics company. NASA then awarded SpaceX $2.89 billion to make Starship HLS. NASA wants Starship HLS to do a landing on the Moon without humans first. Then, Starship will send astronauts for the Artemis 3 mission.

Failed protest about not getting a contract 
Ten days later, Blue Origin sent a protest to NASA. Blue Origin blamed NASA for not allowing Blue Origin to compete. Blue Origin said NASA did not keep its promise. The original plan was that NASA would choose two Moon landers. On 30 July 2021, NASA denied Blue Origin's protest. NASA said they could only choose one lander because they did not have enough money. The government said NASA did not break the competition's rules.

Colonizing other planets 
SpaceX wants to start Mars colonization and terraforming. It would do so by sending humans to Mars. Musk's life goal is to ensure that humans are still around after a mass extinction on Earth. He also talked about Starships going to Enceladus, Europa, Pluto, and the Oort cloud. The Starship rocket on those missions could launch from Mars.

SpaceX thinks sending humans to Mars needs many steps. First, some Starships might carry many important things to Mars' surface. Inside them are fertilizer factories, propellant factories, and building materials. The propellant factory takes in carbon dioxide from Mars's air and hydrogen from the ice below. Then, the factory uses the Sabatier reaction. Hydrogen reacts with carbon dioxide with hydrogen to create methane and oxygen. Methane and oxygen are Starship's propellants. Filled up with the factory's methane and oxygen, Starship can return from Mars back to Earth. Building materials are used to make domes. They protect farmland from Mars's weather and atmosphere.

Musk has guessed that a city with a million people on Mars is enough to keep itself running. It should be able to create everything that the people need. The city does not need shipments from Earth by then. He guessed that the city needs at least ten thousand Starships full of humans. Each Starship can carry 100 passengers on board. To give the colony enough equipment and food, a hundred thousand Starships carrying cargo might launch to Mars. This guess does not have population growth.

History

Early ideas 

In 2005, Elon Musk talked about a launch vehicle named BFR, later known as the Falcon XX. The Falcon XX was never built. Unlike Starship, it could only fly up once. Falcon XX was going to use Merlin 2 engine, a larger version of the Merlin engine. The engines burns kerosene and liquid oxygen.

In September 2016, at the 67th IAC (International Astronautical Congress), Elon Musk talked about the ITS (Interplanetary Transport System). It was going to be  tall and  wide. The booster was going to have 42 Raptors, and the spacecraft was going to have 9 Raptors. Both the booster and spacecraft are made from carbon composites, and could launch many times. The ITS can carry humans to Mars and other places inside the Solar System. When the spacecraft enters Mars's atmosphere, it cools by transpiration. Transpiration here means the spacecraft flows propellant to the front side and evaporates the heat.

At the next IAC in September 2017, Musk announced the Big Falcon Rocket. It is sometimes called Big Fucking Rocket. In that IAC, he talked about moving people around Earth quickly with a Big Falcon Rocket. He called it Earth to Earth.

In November 2018, Musk tweeted about a new spacecraft design. It had three bottom flaps and two top flaps. Around that time, the present names of Starship parts were first used:

 the booster stage was named Super Heavy;
 the spacecraft stage was named Starship; and
 the whole rocket was named Starship system or Starship.

In January 2019, Musk tweeted that Starship will be made from stainless steel instead of carbon composite. He explained that a stainless steel Starship is stronger than a carbon composite Starship. In March 2019, Musk tweeted again that Starships will have a heat shield made of tiles. The heat shield replaces transpiration cooling.

Hops 
On 27 August 2019, Starhopper, the first vehicle to use the Raptor, flew  high. In October 2019, Starship's design had three Raptors and three Raptor Vacuum engines. There are only two bottom flaps in the new design. They are close to the heat shield’s edges. In September 2019, Starship Mk1 (Mark 1) was the first built Starship. The next vehicle, named Mk2, was built in Florida five months later. Mk1 failed [testing at cold temperature, or] the cryogenic proof test, while SpaceX recycled Mk2. Both of them did not fly.

In early 2020, SpaceX changed Mk3's name to SN1 (serial number 1). On 28 February 2020, SN1 crushed itself during a cryogenic proof test. It is because of a leak in the bottom tank. On 8 March 2020, SN2's tank completed its only cryogenic proof test. On 3 April 2020, during the SN3 cryogenic proof test, a valve leaked liquid nitrogen inside its bottom tank. This causes the vehicle to lose pressure and crush itself. On 29 May 2020, SN4 had its fifth successful static fire test. But, after the test, the connected propellant pipe made SN4 explode.

On 4 August 2020, SN5 completed a flight with one Raptor. The rocket went to  before coming down. It is the first Starship to complete a flight intact. On 24 August 2020, SN6 repeated SN5's flight and did not explode. As of October 2021, the company is testing and experimenting with SN7’s tanks.

Test flights and other testing 
SN8 was the first complete Starship. In October and November 2020, SN8 survived four static fire tests. The first, second, and fourth tests were successful, but the third test failed. In the third test, SN8's Raptors destroyed the mount. The concrete layer melted, splashed, and hit a Raptor.

On 9 December 2020, the FAA (Federal Aviation Administration) warned SN8 could explode if it was flown as planned. SpaceX ignored its warnings. SN8 then flew up, making it the first Starship to fly. It goes as high as , then comes back down. While landing, SN8's methane header tank did not pump enough methane to the Raptors. This causes one engine to burn itself. So, SN8 hit the ground fast and exploded.

On 2 February 2021, SN9 flew  high. During the landing, a Raptor does not work. So, SN9 lands at an angle and exploded as well. On 3 March 2021, SN10 repeated SN9's flight. It then landed with all Raptors working. But, because SN10 was damaged, it blew up eight minutes later. On 8 March 2021, the first Super Heavy booster named BN1 (booster number 1) was finished.

On 30 March 2021, SN11 exploded in dense fog. No one knows why it exploded. A possible explanation is that a Raptor burned SN11's computer. This could let too much propellant flow into the engine's turbopump. When the engine is lit, the pressure inside the chamber is too much, making SN11 explode.

SpaceX then skipped SN12, SN13, SN14, and BN2. Their improvements were added to SN15 instead. On 5 May 2021, SN15 flew the same flight and landed. It did not explode after launch. On 20 July 2021, BN3 static fired for the only time. As of October 2021, SN15, SN16, and BN3 have not been used since.

Launches into space 
As of October 2021, SpaceX again skipped some Starship and Super Heavy. They are SN16, SN17, SN18, and SN19. Now, there are plans to launch SN20 and BN4 into space. On 22 October 2021, SN20 static fired one Raptor Vacuum.

A plan by NASA to see Starship entering the atmosphere showed the launch could happen near March 2022. In SpaceX's plan, SN20 and BN4 will go above the Straits of Florida. BN4 is then going to separate about three minutes after. The booster then goes back into the Gulf of Mexico, about  from the shore. SN20 then speeds up close to the orbital speed. It then splashes down ninety minutes later. It will be at about  northwest of the Hawaiian island Kauai.

The FAA has not allowed SpaceX to launch SN20 and BN4 however. The company must finish a proposal about how Starship launches affect the area around it. Some experts said the proposal missed an important detail. It is how SpaceX gets a large volume of methane for Starship's propellant. A professor writes this might be illegal under United States' environmental acts from Congress.

Timeline 
Note: The start dates are when rocket stages were first seen, and the end dates are when they are destroyed or not used anymore.

Notes and references 

Rockets
Spacecraft
SpaceX