Rocket Science and History

Rocket Science Overview

• Rocket science involves the design, construction, and operation of rockets and spacecraft.
• It applies physics and engineering principles to enable space travel.
• Rockets operate based on Newton's third law of motion: every action has an equal and opposite reaction.
• Expelled gas from a rocket's nozzle creates a force that propels the rocket forward.
• Designing efficient, safe, and reliable rockets requires knowledge of aerodynamics, thermodynamics, and Material Science.
• Achieving escape velocity is a key challenge, requiring sufficient speed to overcome Earth's gravity.
• Escape velocity depends on the rocket's mass and the gravitational force of the planet.
• Private companies like SpaceX and Blue Origin aim to make space travel more accessible and affordable.

History of Rocketry

• Rockets have been used for centuries in warfare, entertainment, and scientific exploration.
• Ancient China: First rockets were invented, made of bamboo tubes filled with gunpowder, used for fireworks.
• 13th Century: Rockets used in warfare by the Chinese against Mongol armies.
• 16th Century: Rockets used for military purposes in Europe.
• Napoleonic Wars: British army used rockets effectively, including the Congreve rocket named after its inventor.
• 20th Century: V2 rocket developed by Nazi Germany during World War II, the first long-range ballistic missile.
• Post-World War II: The United States and the Soviet Union used V2 technology for their rocket programs.
• 1950s and 1960s: Rocketry became a key part of the space race.
• 1957: The Soviet Union launched Sputnik, the first artificial satellite.
• 1961: Yuri Gagarin was the first human in space, launched by the Soviet Union.
• 1969: The United States Apollo program sent astronauts to the moon.

Rocketry Evolution and Applications

• Rocketry has evolved significantly since the early space wars
• Rockets are now used for satellite launches
• Rockets are used for planetary exploration
• Rockets are used to power missiles and spacecraft

Types of Rockets

• Rockets come in various shapes and sizes for different applications

Solid Fuel Rockets

• Solid fuel rockets use a solid propellant packed into the motor.
• The propellant burns to produce hot gases expelled through a nozzle
• Solid fuel rockets are simple and reliable

Liquid Fuel Rockets

• Liquid fuel rockets use liquid propellants stored in separate tanks
• Propellants mix and react chemically to produce hot gases
• Liquid fuel rockets are more versatile and can be throttled.

Hybrid Rockets

• Hybrid rockets combine solid fuel and liquid oxidizer.
• They mix in the rocket motor
• Hybrid rockets have higher specific impulse than solid fuel rockets

Experimental Rockets

• Some rocket types like nuclear and electric rockets remain experimental

Nuclear Rockets

• Nuclear rockets heat a propellant using nuclear reactions for thrust.
• They can achieve higher speeds with less propellant than chemical rockets
• Nuclear rockets pose safety and regulatory challenges.

Electric Rockets

• Electric Rockets ionize a propellant and accelerate it, generating thrust
• Electric rockets are very efficient, reaching high speeds over long distances.
• Electric rockets have a low thrust-to-weight ratio,
• Electric Rockets are used for in-space propulsion, satellite maneuvering, and interplanetary missions

Newton's Laws of Motion

• Newton's laws apply to planetary movement and rocket launches

Newton's First Law

• Objects at rest stay at rest and objects in motion stay in motion unless acted upon by a force
• This is also known as the law of inertia
• Inertia explains why rockets need to overcome resistance to escape Earth's gravity.

Newton's Second Law

• An object's acceleration is proportional to the net force and inversely proportional to its mass
• Expressed as f = ma, where f = force, m = mass, a = acceleration
• The law explains the force needed to propel a spacecraft and overcome gravity.

Newton's Third Law

• For every action, there is an equal and opposite reaction
• This law explains how rockets lift off by expelling hot gases.

Rocket Engine Categories

• Rocket engines are classified as chemical or non-chemical

Chemical Rocket Engines

• Chemical rocket engines use chemical reactions to generate thrust

Solid Propellant Rocket Engines

• Solid propellant engines burn a solid propellant to produce thrust.
• Solid rocket engines are simple and reliable but cannot be turned off
• Solid propellant engines are used in boosters

Liquid Propellant Rocket Engines

• Liquid propellant engines mix and burn liquid propellant for thrust
• Liquid rocket engines are more powerful, throttleable, and can be turned on/off

Hybrid Propellant Rocket Engines

• Hybrid propellant engines use a combination of solid and liquid propellants

Non-Chemical Rocket Engines

• Non-chemical rocket engines use other energy sources to generate thrust

Nuclear Rockets

• Nuclear rockets use nuclear reactions to produce heat and thrust
• Nuclear rocket engines are powerful and can operate for extended periods

Electric Rockets

• Electric rocket engines use electric fields to accelerate charged particles for thrust
• Electric rocket engines are efficient and can operate for long periods

Solar Rockets

• Solar rocket engines use solar energy to produce thrust
• Solar rocket engines are efficient but are typically used for small spacecraft

Kepler's Laws of Planetary Motion

• Kepler's laws describe the motion of objects in orbit around a star.
• Kepler's laws are used in space exploration and technology today.

Kepler's First Law

• Planets orbit a star in an ellipse, with the star at one of the foci
• Provides a framework for understanding planet motion

Kepler's Second Law

• A line connecting a planet to its star sweeps equal areas in equal time
• Planets move faster when closer to the star and slower when farther away
• Provides a means to calculate a planet's speed and direction.

Kepler's Third Law

• The square of a planet's orbital period is proportional to the cube of its semi-major axis
• The farther a planet is from its star, the longer it takes to revolve
• Allows scientists to calculate a planet's distance given its revolution period

Satellites

• Satellites are man-made objects that orbit celestial bodies
• Satellites have purposes from communication and navigation to research.

Geostationary Satellites

• Geostationary satellites orbit at 35,786 km, in a fixed position to Earth
• Orbital speed is synchronized with Earth's rotation
• Geostationary satellites are used for telecommunications, broadcasting, and weather.

Low Earth Orbit Satellites

• Low Earth Orbit (LEO) satellites orbit at 160-2,000 km altitude
• LEO satellites are used for remote sensing, surveillance, and research
• The International Space Station is an example of a LEO satellite

Medium Earth Orbit Satellites

• Medium Earth Orbit (MEO) satellites orbit at 2,000-35,786 km altitude.
• MEO satellites are used for GPS

Polar Orbiting Satellites

• Polar orbiting satellites orbit Earth from pole to pole
• Polar orbiting satellites are used for weather forecasting and monitoring

Sun Synchronous Satellites

• Sun-synchronous satellites orbit at 600-800 km altitude
• Satellites maintain a constant angle with the Sun
• Sun-synchronous satellites pass over a point on Earth at the same local solar time

Communication Satellites

• Communication satellites are in geostationary or LEO orbits
• Communication satellites are used for telecommunications, broadcasting, and internet
• Equipped with transponders for relaying radio signals

Navigation Satellites

• Navigation satellites are used for global positioning systems (GPS)
• Satellites are in MEO orbits and equipped with atomic clocks and receivers

Earth Observation Satellites

• Satellites are commonly used for remote sensing and environmental monitoring
• Earth observation satellites, equipped with cameras and sensors, are typically placed in LEO or polar orbits

Military Satellites

• Military Satellites are used for intelligence, reconnaissance, and communication
• Military Satellites are typically placed in LEO or geostationary orbits

Orbital Mechanics for Satellites

• Orbital mechanics is essential for determining satellite behavior/trajectory
• A satellite's orbit is defined by orbital elements, including semi-major axis and eccentricity.
• A satellite must balance centripetal and gravitational forces.

Achieving Stable Orbit

• Satellites get to and maintain stable orbits depending on the desired goal
• Satellites need regular adjustments to maintain orbit

Homan Transfer

• The Homan transfer is a two-burn maneuver to transfer a satellite between circular orbits, through an elliptical orbit

Bioelliptic Transfer

• The bioelliptic transfer involves two burns,
• The initial burn raises the satellite altitude and the second circularizes its orbit

Satellite Launch Methods

• Rockets are a common method for launching satellites
• Carrier planes, specialized aircraft, can launch small satellites at high altitudes.

Challenges of Satellite Launch

• Getting satellites into the correct orbit, essential for their performance
• Engineers calculate speed and trajectory for rocket or carrier plane launches

Mechanical Properties of Aerospace Materials

• Materials behave different when exposed to external forces.
• Strength, elasticity, ductility, toughness, and hardness are important in Aerospace materials

Strength

• Strength is the ability of a material to withstand external forces
• Aerospace materials need to have optimal strength for high forces
• Strength can be measured in tensile, compressive, or shear strength.

Elasticity

• Elasticity is the ability of a material to return to its original shape after being exposed to external forces
• Aerospace materials need elasticity for repeated stresses.
• Elasticity is determined by the modulus of elasticity

Ductility

• Ductility is the ability of a material to deform without breaking when external forces are applied
• Aerospace materials need ductility for bending/flexing

Toughness

• Toughness is the ability of a material to withstand external forces without breaking
• Aerospace materials need to be able to withstand impact
• Toughness is determined by impact strength,

Hardness

• Hardness is the ability of a material to resist deformation
• Aerospace materials need to withstand wear and tear
• Hardness is measured with resistance to indentation/scratching

Aluminum

• Aluminum is lightweight with a good strength-to-weight ratio
• Aluminum is easy to work with and inexpensive
• Aluminum has poor thermal conductivity

Titanium

• Titanium has a high strength-to-weight ratio and corrosion resistance
• It can withstand high temperatures and radiation

Carbon Fiber

• Carbon fiber is strong and lightweight
• Carbon fibers are bonded with resin
• Carbon fiber has a high strength-to-weight ratio

Ceramics

• Ceramics withstand high temperatures and harsh environments
• Ceramics are commonly used in rocket engines and heat shields
• Ceramics are lightweight with excellent thermal/electrical insulation

Refractory Metals

• Refractory metals have high melting points and withstand high temperatures.
• Tungsten is used in rocket engines for its high melting point and density.

In Kernel

• Inconel is a nickel-based alloy, used in high-temperature and high-stress applications
• Inconel has excellent corrosion oxidation resistance

Material Selection for Aerospace Applications

• Performance requirements, weight, cost, and availability are important when selecting aerospace materials

Performance Requirements

• Materials must meet strict performance requirements, including strength and heat resistance
• Materials must withstand extreme stresses from takeoff/re-entry

Wait

• A critical factor, reducing weight in a vehicle can benefit performance
• Vehicle and material must be lightweight to ensure maximum efficiency

Cost

• Materials must be cost-effective.

Availability

• The limited availability of some raw materials must be taken into account

Human Space Flight

• Human spaceflight involves sending humans into space for scientific research or exploration
• A spacecraft needs to be specialized to sustain human life

Vostok Spacecraft

• Designed by the Soviet, carried Yuri Gagarin in 1961
• It was a small, single-person

Soy Spacecraft

• The Soy spacecraft is designed by the Soviet Union
• The Soy spacecraft is used to transport humans
• The Soy spacecraft carries three passengers
• It has environmental control, life support, and waste management

Space Shuttle and SpaceX

• Space shuttle (1981-2011): Reusable spacecraft for satellite launches, and experiments
• Private companies: SpaceX and Boeing, have designed spacecraft
• SpaceX Crew Dragon: Four-person capsule, can be launched on a Falcon 9 rocket

Protecting Astronauts in Space

• Spacecraft and rockets must have ways to protect astronauts
• Radiation is a major risk in space
• Spacecraft are built with shielding materials, such as water to combat radiation

Spacecraft Life Support Systems (LSS)

• Spacecraft are isolated, so they need life support systems
• Life suppor systems provide conditions for astronauts
• Life Support systems provide air, water, food, & waste management
• The performance and reliability of LSS are crucial

Components of a Life Support System

• Air, water, food and waste management systems.

Air Management System

• Air management systems continuously monitor CO2
• Air is filtered to remove dust and microorganisms
• Oxygen supply system provides breathable air, using oxygen generators

Water Management System

• Water management systems are critically important for space flight
• Water systems recycle water to reduce the need for water

Food Management System

• The food management system provides safety, and nutrition during launch

Waste Management System

• Collects, stores, processes solid & liquid waste
• Processes can include incineration and compaction
• The life support systems development requires consistent and rigorous testing
• Private firms launch people into space for tourism currently
• Much is still undiscovered in space
• Human space flight and space exploration hold both promise and challenges in the future

Mars Exploration

• NASA plans to send humans to explore, conduct research, and maybe establish a permanent base
• Missions to Mars have been planned for decades
• Robotic missions have studied Mars

Required Technological Advancements

• New spacecraft and propulsion systems are needed for long-distance space travel
• Lightweight, durable materials must withstand space and Martian conditions
• Life support systems must sustain humans for extended periods in space and on Mars
• Advanced robotics and AI are critical for exploring Mars and other planets

Space Debris Challenges

• Space debris risks current and future missions, and astronauts on the ISS
• Thousands of satellites have become defunct, creating substantial debris
• New technologies must track and remove space debris
• Spacecraft should be designed to resist impacts from space debris

Alternative Destinations

• Asteroids and moons of Jupiter and Saturn may be explored
• These destinations offer opportunities to study the solar system's origins and find new resources

Commercialization of Space

• Space tourism is becoming a reality through companies like SpaceX and Blue Origin
• Space-based manufacturing and resource extraction have potential economic and technological benefits

Inspiration and Investment

• Significant investment is needed in technology, research, and development
• International cooperation and collaboration are essential
• Exploring space advances scientific knowledge and creates economic opportunities