4-20-2023 - Spacex Starship stage seperation fail and blast. Possible causes. Part 1

Congratulations to Spacex for the first integrated test flight of #Starship with the Super Heavy booster.

Disclaimer: The below information are collected from ChatGPT and the internet (as of now only OpenAI's ChatGPT). This is NOT OFFICIAL information from SpaceX. It is possible that these information could be very wrong. The intention of this blog post is purely interest and curiosity to know about Starship, and the time spent on this blog is very very very tiny (no extensive research, at all).

Note: The purpose of this blog post is only truly interest but nothing else. The purpose of this blog post is only to talk about any spacecraft, in general.

1. Propellant mixing: If the fuel and oxidizer tanks from the Super Heavy remain attached to the rocket after separation, it can cause a mixture of propellants that can lead to an explosion.

This is because the fuel and oxidizer need to be kept separate until they are ignited in the combustion chamber to create the thrust necessary to power the rocket. If they are allowed to mix prematurely, it can cause an uncontrolled reaction that could damage or destroy the rocket. This is why it's critical to ensure that the separation process is designed and executed properly to prevent any potential mixing of the propellants.

2. Overpressure: If the separation process causes a sudden overpressure in the fuel or oxidizer tanks of the Super Heavy, it can cause a rupture or explosion.

3. Structural damage: If the separation process causes structural damage to the Super Heavy, it can lead to a loss of control, which can result in an explosion.

4. Other unforeseen factors: There could be other unforeseen factors that contribute to the failure and subsequent explosion, such as equipment failure, human error, or environmental factors.

It's important to note that each situation is unique and requires a thorough investigation to determine the root cause of the failure and explosion. SpaceX has a rigorous testing and quality control process in place to ensure the safety and reliability of its spacecraft, and the company will conduct a thorough investigation to determine the cause of any incidents and take appropriate steps to address any issues and improve future missions.

SpaceX's Starship separation process is designed to ensure a clean separation of the two stages and prevent any mixing of the propellants. The separation process is based on a pneumatic system that uses compressed gas to push the stages apart after separation.

The process begins with the release of the locking mechanisms that hold the two stages together. Once the locks are released, the pneumatic system activates and pushes the two stages apart. This process is designed to be smooth and controlled to prevent any sudden movements that could cause structural damage or lead to propellant mixing.

To further prevent propellant mixing, the Starship is equipped with a system that purges the residual propellant from the engines and tanks after separation. This system helps to ensure that any remaining propellant is safely vented away from the rocket and does not mix with the propellant from the next stage.

Overall, SpaceX's separation process is designed to be robust, reliable, and safe to ensure the success of the Starship missions.

The SpaceX Starship's pneumatic system is an essential component of the rocket's separation process. It is responsible for providing the force necessary to separate the different stages of the rocket during flight.

The system works by using compressed gas, usually helium, to drive pistons that push the stages apart. The compressed gas is stored in high-pressure tanks located within the rocket, and it is directed to the separation pistons through a network of valves and plumbing.

The use of compressed gas in the separation process has several advantages. It is a reliable and well-understood technology that has been used in the aerospace industry for decades. It is also lightweight, which is important for a rocket that needs to carry large payloads into space.

One of the key design considerations for the pneumatic system is ensuring that it can generate enough force to separate the stages quickly and reliably.

There are several factors that could potentially affect the ability of a pneumatic system to generate enough force to separate the stages quickly and reliably. Here are a few possibilities:

1. Insufficient air pressure is one of the most common reasons why a pneumatic system may fail to generate enough force to separate the stages effectively. When air pressure is too low, the force generated by the pneumatic cylinder will also be reduced, resulting in slower and less reliable stage separation.

A malfunctioning compressor could be the cause of low air pressure. The compressor is responsible for pressurizing the air that is used in the pneumatic system. If it is not working properly, it may not be able to generate enough pressure to meet the system's requirements. This could be due to a variety of factors, such as a damaged piston or cylinder, a worn-out motor, or a malfunctioning pressure switch.

Another potential cause of low air pressure is a leak in the pneumatic system. Even small leaks can have a significant impact on the performance of the system, as they can cause the air pressure to drop over time. Common places for leaks to occur include fittings, hoses, and valves.

Finally, a pressure regulator that is set too low can also cause insufficient air pressure. The pressure regulator is responsible for controlling the amount of pressure that is supplied to the pneumatic system. If it is set too low, the pressure in the system will be insufficient to generate the necessary force for stage separation.

To address this issue, it is important to conduct a thorough inspection of the pneumatic system to identify the root cause of the low air pressure. This may involve checking the compressor, identifying and repairing leaks, or adjusting the pressure regulator to ensure that it is set at the appropriate level.

2. Inadequate cylinder size:

The size of the cylinder used in a pneumatic system is a critical factor in determining the force that can be generated for stage separation. If the cylinder is too small, it may not be able to generate enough force to separate the stages effectively, resulting in slower or unreliable separation.

The size of the cylinder required for stage separation depends on several factors, including the weight of the stages, the required separation force, and the stroke length required to achieve the desired separation distance. If the cylinder is too small, it may not be able to generate enough force to overcome the frictional forces and the weight of the stages. This can result in slow or incomplete stage separation, or even complete failure of the system.

In this case, it may be necessary to use a larger cylinder or multiple cylinders to achieve the desired force for stage separation. A larger cylinder will have a greater surface area and will be able to generate more force than a smaller cylinder, all other factors being equal. Multiple cylinders can be used in tandem to generate greater force, by using the combined force of each cylinder to achieve the desired separation force.

It is important to carefully evaluate the requirements for the pneumatic system and select the appropriate cylinder size to ensure that it can generate enough force for reliable and effective stage separation. The size of the cylinder should be selected based on the weight of the stages, the desired separation force, and the stroke length required to achieve the desired separation distance.

3. Faulty valve operation:

The valve in a pneumatic system is responsible for controlling the flow of compressed air to the cylinder that generates the force required for stage separation. If the valve is not functioning correctly, it may not be allowing enough air to reach the cylinder, which can result in insufficient force being generated for reliable and effective stage separation.

There are several factors that can affect the operation of the valve, including malfunctions, clogs, and incorrect adjustment. A malfunctioning valve can be caused by a variety of factors, such as a damaged valve body, a stuck valve spool, or a broken valve spring. If the valve is clogged or dirty, it may not be able to operate correctly, as the flow of air to the cylinder may be restricted. In some cases, the valve may not be properly adjusted, resulting in an insufficient flow of air to the cylinder.

To address this issue, it is important to first identify the root cause of the faulty valve operation. This may involve inspecting the valve for damage or wear, checking for clogs or dirt, or adjusting the valve to ensure that it is operating correctly. In some cases, it may be necessary to replace the valve or clean it to restore proper function.

Regular maintenance and inspection of the valve can help prevent issues with faulty valve operation in a pneumatic system. This can include cleaning or replacing the valve as needed, and checking for proper adjustment to ensure that it is delivering the correct flow of air to the cylinder for reliable and effective stage separation.

4. Incorrect air flow direction:

In a pneumatic system, the direction of air flow is critical to generating the necessary force for stage separation. If the air flow direction is incorrect, the system may not be able to generate enough force to separate the stages effectively, resulting in slower or unreliable separation.

There are several factors that can affect the direction of air flow in a pneumatic system, including the installation of the valve, blockages in the air lines, and misalignment of the cylinder. If the valve is not installed correctly, it may not be directing air flow in the proper direction, which can result in insufficient force being generated for stage separation.

Blockages in the air lines can also prevent proper air flow direction, as the restricted air flow can reduce the amount of force generated by the system. Finally, misalignment of the cylinder can cause air flow to be directed improperly, which can also result in insufficient force being generated for stage separation.

To address this issue, it is important to identify the root cause of the incorrect air flow direction. This may involve inspecting the valve and air lines for proper installation and alignment, checking for blockages in the air lines, and ensuring that the cylinder is properly aligned for proper air flow direction.

Regular maintenance and inspection of the pneumatic system can help prevent issues with incorrect air flow direction. This can include checking for blockages in the air lines, inspecting the valve and cylinder for proper installation and alignment, and ensuring that the system is generating enough force for reliable and effective stage separation.

5. Mechanical issues can be a common cause of problems with a pneumatic system's ability to generate sufficient force to separate stages effectively. These issues can arise from a range of factors such as wear and tear, improper maintenance, or damage from external sources.

Wear and tear can cause components to become worn out or damaged over time, leading to reduced performance and eventual failure. This can be particularly problematic for components that are subjected to repeated stress or pressure, such as valves, cylinders, or hoses. If these components are not properly maintained or replaced when necessary, they can fail to generate enough force for stage separation.

Improper maintenance can also contribute to mechanical issues in a pneumatic system. If the system is not regularly inspected, cleaned, and lubricated, components may become dirty or clogged, leading to reduced performance. Additionally, failure to perform routine maintenance tasks such as tightening bolts or checking fluid levels can also contribute to mechanical issues over time.

External sources of damage can also impact the performance of a pneumatic system. For example, exposure to extreme temperatures or moisture can cause components to corrode or rust, which can reduce their effectiveness. Similarly, exposure to shock or impact from other equipment or objects can cause damage to components, which can also impact their ability to generate sufficient force for stage separation.

To address mechanical issues in a pneumatic system, it is important to regularly inspect and maintain all components, replace worn or damaged parts as necessary, and protect the system from external sources of damage. By taking these steps, it is possible to ensure that the system is operating at peak performance and generating enough force for reliable and effective stage separation.

The system needs to be designed to handle the weight and acceleration of the rocket and overcome any frictional forces that may be present.

SpaceX has conducted extensive testing of the pneumatic system to ensure that it meets the necessary performance and safety requirements. This testing includes both computer simulations and physical tests using prototype rockets. SpaceX engineers have also made continuous improvements to the system over time, based on data gathered from test flights and actual missions.

Overall, the pneumatic system is a critical component of the Starship's separation process, and its reliability is essential to the success of the rocket's missions.