Rockets and Launch Systems

Rockets are vehicles that propel themselves by expelling gas at high velocity, generated by burning their fuel under high temperature and pressure, in accordance with Newton’s third law of motion—the principle of action and reaction. Launch systems, on the other hand, are comprehensive infrastructures and technological components designed to deliver a payload—such as a satellite, scientific instrument, crewed capsule, or military system—to a specific orbit, region, or target.

These systems play a critical role in numerous fields, ranging from space research to the establishment of global communication networks, from scientific exploration to the defense industry. Their fundamental objective is to deliver the payload safely, efficiently, and precisely to the intended destination.

Basic Working Principles

The operation of rockets is based on Isaac Newton’s laws of motion. A rocket engine produces high-temperature, high-pressure gas by combining fuel and oxidizer in a combustion chamber. The resulting gas is expelled at high speed through a nozzle at the rear of the engine. This expulsion creates a thrust force. In response, an equal and opposite reaction force is applied to the rocket, propelling it forward.

The acceleration of a rocket can be explained by Newton’s second law (F=ma). As fuel is consumed, the rocket’s mass decreases, causing acceleration to increase even if the thrust force remains constant. Consequently, rockets continuously gain speed during launch. Although the rocket’s acceleration is lower than that of the expelled gases due to its greater mass, the final velocity achieved is sufficient for orbital insertion.

History of Rockets and Launch Systems

The theoretical foundations of rocket technology were laid in the early 20th century by Konstantin Tsiolkovsky, who demonstrated that liquid-fueled rockets could enable spaceflight. The first person to translate this theory into practice was American Robert Goddard, who successfully launched the world’s first liquid-fueled rocket in 1926, marking the beginning of modern rocketry.

During World War II, rocket technology made significant military advances. The V-2 rocket, developed under the leadership of German engineer Wernher von Braun, became the world’s first ballistic missile and the first vehicle to achieve suborbital flight. After the war, both the United States and the Soviet Union incorporated V-2 technology into their respective space programs.

The 1950s and 1960s were defined by the “Space Race,” an extension of the Cold War. In 1957, the Soviet Union launched Sputnik 1, initiating the race. The United States responded in 1958 with the launch of Explorer 1. In 1961, Soviet cosmonaut Yuri Gagarin became the first human to enter space aboard Vostok 1. The pinnacle of this era was the Saturn V rocket, developed under NASA’s Apollo program, which enabled crewed lunar missions.

From the 1970s onward, commercial satellite launch activities gained importance. The Ariane rocket family, developed by the European Space Agency (ESA), established a significant position in the commercial market. NASA’s Space Shuttle program brought the concept of reusable launch systems into practice. In the 2000s, the private sector’s role expanded significantly. SpaceX developed reusable launch technologies with its Falcon series, substantially reducing launch costs. Companies such as Blue Origin and Virgin Galactic created new markets in space tourism and commercial transportation.

Staged Systems

The speed and energy required for a rocket to reach orbit are too great to be achieved in a single stage. Therefore, rockets are typically designed with staged systems that reduce the vehicle’s mass during flight, enabling more efficient acceleration.

Single Stage to Orbit (SSTO) Rockets

Single-stage rockets are designed to reach orbit using only one stage, with no parts jettisoned during the mission. While this design offers theoretical simplicity and potential reusability, practical implementation is extremely challenging.

SSTO rockets must carry all their fuel, engines, and payload from liftoff, making them very heavy. This increases the difficulty of achieving sufficient thrust and exacerbates aerodynamic losses. Additionally, efficiency decreases because empty tanks and engines continue to be carried after fuel depletion.

With current technology, SSTO systems lack the performance necessary to safely and economically deliver payloads to orbit. Consequently, the vast majority of modern space missions rely on multi-stage systems.

Multi-stage Rockets

The majority of modern launch vehicles are multi-stage. Each stage, after consuming its fuel, separates, allowing the remaining stages to continue the mission with reduced mass. This method improves fuel efficiency and enables the rocket to reach higher velocities.

• First stage: Provides maximum thrust to penetrate the dense lower atmosphere.
• Second stage: Carries the load from the first stage through thinner atmospheric conditions.
• Upper stages: Place the payload into its target orbit or transfer trajectory.

Stage separation mechanisms in multi-stage systems require high precision. These mechanisms are designed to prevent damage to upper stages. Examples of multi-stage rockets include Saturn V, Falcon 9, Ariane 5, and Soyuz.

Launch System Components

A payload launch system consists of numerous complex components that operate in coordinated harmony. These components are critical to mission success.

Payload

The payload is the primary cargo carried by the launch system. It may include telecommunications or observation satellites, scientific instruments, space telescopes, crewed spacecraft, or military systems. The payload’s mass, dimensions, and target orbit directly influence the design of the launch vehicle.

Launch Vehicle

The launch vehicle, typically a multi-stage rocket, is the primary platform that transports the payload from Earth’s surface to the target orbit. Rockets are designed using the staging principle to reduce mass and improve efficiency. Stages that have exhausted their fuel are jettisoned during flight. Launch vehicles are categorized into two types based on reusability: expendable launch vehicles are single-use and disintegrate upon reentry after mission completion, while reusable launch vehicles are designed to return safely to Earth for reuse.

Space Launch System (SLS)

The SLS is a super-heavy launch vehicle developed by NASA for deep space missions. Its core stage is powered by four RS-25 engines and supported by two five-segment solid rocket boosters. This configuration generates approximately 7.2 million pounds of total thrust, providing the capacity required for missions to the Moon, Mars, and beyond.

The SLS can be manufactured in modular configurations. Block 1 is designed to carry the Orion spacecraft to the Moon. Future configurations will increase payload capacity to support Mars missions. Booster separation occurs during the first minutes of flight, and the separation mechanisms require high precision.

Saturn V

The Saturn V is historically renowned as the launch vehicle of NASA’s Apollo program, which carried humans to the Moon. This three-stage rocket, 110 meters tall, had a capacity to deliver 140,000 kilograms to low Earth orbit. The first two stages generated immense thrust to overcome Earth’s gravity, while the third stage performed the trans-lunar injection. The Saturn V’s design incorporated the most advanced engineering solutions of its time to ensure safe stage separation. Today, it remains the most powerful launch vehicle ever built by humanity.

Falcon 9

The Falcon 9 is a two-stage launch vehicle developed by SpaceX. Its first stage is reusable; after liftoff, it returns to Earth using controlled engine burns. This technology has significantly reduced launch costs. Falcon 9 is frequently used for commercial satellite launches, International Space Station resupply missions, and crewed spaceflights. The second stage precisely places the payload into its target orbit.

Soyuz

Soyuz rockets are multi-stage launch vehicles long used by Russia. They are renowned for their reliability in both crewed and uncrewed missions. The majority of crewed missions to the International Space Station (ISS) have been conducted using Soyuz rockets.

Ariane 5 and Ariane 6

The European Space Agency’s Ariane series plays a critical role in the commercial satellite launch market. Ariane 5 can carry dual payloads, launching two satellites simultaneously. The next-generation Ariane 6 offers greater flexibility and cost efficiency.

Long March

China’s Long March rocket series forms the backbone of the country’s space program. Various configurations cover a broad mission spectrum, from low Earth orbit to geosynchronous orbit and lunar missions.

GSLV Mk III

India’s GSLV Mk III launch vehicle has enhanced the country’s independent space launch capability through its high payload capacity. This vehicle is used for lunar and Mars missions and can deliver heavy satellites to geosynchronous orbit.

Thrust and Propulsion Systems

Rockets are classified by fuel type into solid-fueled, liquid-fueled, hybrid, and electric propulsion systems. Each system has distinct engineering requirements, advantages, and limitations.

Solid-Fueled Rockets

Solid-fueled rockets are among the oldest and simplest systems. Fuel and oxidizer are pre-mixed and loaded as a solid propellant grain into the combustion chamber. Once ignited, they burn continuously and cannot be stopped. These systems are durable, easy to store, and provide high thrust at liftoff. However, thrust control is difficult. Therefore, they are typically used as boosters.

The five-segment solid rocket boosters on NASA’s SLS are an example. They provide more than 75% of the total thrust at liftoff, helping the main rocket penetrate the dense lower atmosphere.

Liquid-Fueled Rockets

This is the most common system in modern launch vehicles. Fuel and oxidizer are stored in separate tanks and delivered to the combustion chamber via pump-turbopump systems. Engines can be shut down, reignited, and throttled. This capability grants liquid-fueled engines high maneuverability and precise orbital insertion.

The most commonly used propellant combination is liquid hydrogen and liquid oxygen. This combination has been used in the main stages of heavy launch vehicles such as Saturn V and SLS.

Hybrid Rockets

Hybrid systems typically use a solid fuel and a liquid oxidizer. The solid fuel resides in the combustion chamber while the liquid oxidizer is injected from tanks. Engines can be shut down, and combustion rate can be partially controlled. These systems are safer and simpler but are still under development.

Electric Propulsion Systems

Ion and plasma thrusters use electrical energy to accelerate ions. They produce very low thrust but provide high specific impulse through prolonged operation. They are used outside the atmosphere for long-duration deep space missions and in-orbit maneuvers.

Control and Guidance Systems

These systems ensure the rocket remains on the correct trajectory from launch until orbital insertion. Modern rockets control their orientation by vectoring engine nozzles (thrust vector control) or using small auxiliary thrusters mounted on the vehicle body. Avionics systems, inertial navigation units, Global Positioning System (GPS) receivers, and telemetry systems continuously communicate with ground control centers to track the rocket’s real-time position, velocity, and status, enabling precise guidance.

Ground Support Systems

Ground support systems consist of infrastructure located at the launch platform, including fueling facilities, hold-down arms, fire and explosion prevention mechanisms, data and power connections, launch towers, and telemetry antennas.

These systems perform multiple functions, from holding the rocket in a vertical position on the pad to safely loading cryogenic propellants and controlling vibrations and acoustic loads generated at liftoff.

Launch Pads

Launch pads are complex facilities where rockets are erected vertically, fueled, and prepared for launch. They include anchoring structures, fueling systems, flame trenches, fire safety mechanisms, telemetry infrastructure, and emergency systems.

Kennedy Space Center (KSC)

Located in Florida, KSC is a major center for NASA’s Apollo, Space Shuttle, and current SLS launches. Launch Complex 39A has hosted numerous historic missions, from Apollo 11 to modern Falcon 9 and Falcon Heavy flights. Launch Complex 39B has been modernized for SLS missions.

Cape Canaveral Space Force Station

Adjacent to Kennedy Space Center, Cape Canaveral Space Force Station is a critical hub for U.S. military and commercial launch activities. Launch Pads LC-40 and LC-41 are used for SpaceX’s Falcon 9 and ULA’s Atlas V missions. Cape Canaveral’s geographic location provides strategic access to low-inclination orbits, such as equatorial orbits.

Vandenberg Space Force Base

Vandenberg Space Force Base in California is preferred for polar and sun-synchronous orbit launches. This site is ideal for missions requiring orbits aligned along Earth’s north-south axis. Military reconnaissance satellites and scientific observation satellites are frequently launched from Vandenberg.

Wallops Flight Facility

The Wallops Flight Facility in Virginia is used for smaller-scale satellite launches, research rockets, and atmospheric science missions. Wallops plays a significant role in NASA’s educational and scientific research launch activities.

Launch Operations

Launch operations encompass a complex set of activities extending from rocket assembly through launch and even post-launch tracking. These operations require high precision and coordination and are successfully completed only after months of preparation and the integrated functioning of hundreds of subsystems.

Pre-Launch Preparations

The launch process begins in the rocket assembly building, where different stages, engines, and auxiliary systems are integrated. Each component undergoes extensive individual and integrated testing. After assembly, the rocket is transported at very low speed to the launch pad using specialized transporters, such as NASA’s Crawler-Transporter. At the pad, the rocket is raised to a vertical position and secured with hold-down arms. Mechanical stability is ensured, and electrical and data connections are established with ground support systems. The rocket’s avionics, engines, telemetry links, and thrust vector control mechanisms are thoroughly inspected. Payload integration typically occurs at this stage. The payload is installed into the upper section of the rocket using specialized equipment that minimizes vibration and electrostatic risks under controlled conditions.

Fueling and Final Tests

Shortly before launch, cryogenic propellants—such as liquid hydrogen and liquid oxygen—are loaded into the tanks. These propellants are stored at extremely low temperatures (around -250 °C), so fueling occurs very close to launch time. During fueling, tank pressures, temperatures, and levels are continuously monitored. Simultaneously, the rocket’s electrical systems, guidance sensors, and telemetry links are retested. If any anomaly is detected in critical subsystems, the launch can be halted, and the issue addressed before rescheduling.

Countdown Process

The countdown is the most critical phase of launch operations. It can last hours or even days, depending on mission complexity. During this time, the launch team continuously evaluates weather conditions, the rocket’s technical status, and the flight plan. Scheduled holds may be implemented to address potential technical or environmental issues. These holds allow necessary corrections to be made within the launch window. Once all systems are confirmed as “ready,” the countdown resumes, and the rocket’s engines are ignited at the final seconds.

Liftoff and Initial Flight Phase

Upon engine ignition, the rocket separates from the hold-down arms on the launch pad. To ensure stability at liftoff, the launch tower and hold-down systems continue to support the vehicle for several seconds. As the rocket passes through the dense lower atmosphere, the first stage provides maximum thrust. After fuel depletion, the first stage separates and the second stage takes over. Safe operation of the separation mechanisms ensures the rocket’s balance and flight continuity.

Post-Launch Tracking

Until the rocket reaches orbit, it is continuously tracked by ground control centers. Telemetry systems transmit real-time data on the rocket’s position, velocity, orientation, and subsystem status. Once the upper stages release the payload into its target orbit, the launch operation is officially complete. Depending on mission type, the payload may perform its own orbit adjustment maneuvers or begin transmitting scientific data.

Rocket and Launch System Development in Türkiye

Türkiye is taking significant steps toward achieving independent access to space. The most important project in this domain is the Micro Satellite Launch System (MUFS) Development Project, led by Roketsan under the direction of the Presidency of Defense Industries (SSB). Launched in 2018, the project aims to develop a launch vehicle (MUFA) capable of placing 100-kilogram microsatellites into low Earth orbit at an altitude of 400 kilometers.

Under this project, numerous technologies critical to space launch systems have been developed using national capabilities. These include solid and liquid-fueled rocket engines with thrust vector control, systems for precise attitude control, indigenous inertial navigation systems, and stage separation mechanisms designed for space environments. Successful test launches have been conducted using Sonda Rockets to validate these technologies. During these tests, capabilities such as controlled flight outside the atmosphere and stage separation were successfully demonstrated. Türkiye plans to conduct its first satellite launch from a domestic launch center under the MUFS project beginning in 2026.