First Rocket And Space Shuttle
Ancient China is credited with the invention of the first rockets.
Over time, Chinese engineers and alchemists refined rocket technology, leading to the development of more powerful and sophisticated rockets.
The knowledge of rocket technology eventually spread to other parts of the world, influencing the development of rockets in Europe and elsewhere.
In Ancient China, They were used primarily as weapons, propelled by gunpowder. These early rockets were simple devices, often consisting of a tube filled with gunpowder and attached to a stick. When ignited, the gunpowder would produce thrust, propelling the rocket forward.
While these early rockets were effective as weapons, they were not capable of reaching great heights or distances. It wasn't until the 20th century that rockets began to be developed for space exploration. Robert H. Goddard is often credited with launching the first liquid-fueled rocket in 1926. His work laid the foundation for modern rocket technology, which has enabled us to explore the Moon, Mars, and beyond.
NASA's First Rocket
The first rocket launched by NASA was the Bumper 2. It was a two-stage rocket launched on July 29, 1950, from Cape Canaveral, Florida.
Robert H. Goddard: An American physicist and engineer, Goddard conducted groundbreaking experiments in rocketry.
Hermann Oberth: A German rocket scientist, Oberth's work on rocket theory and design influenced the development of rocket technology in both Germany and the United States
Werner von Braun: A German rocket engineer who worked for Nazi Germany during World War II, von Braun was captured by American forces and brought to the United States.
Theory of Rocket
The principle on which rocket propulsion works is based on Newton's third law of motion. Here, the fuel is forcibly ejected from the exit such that an equal and opposite reaction occurs.
Rocket Propulsion Diagram
In a liquid-fuel rocket, the following things are found:
- Liquid rocket fuel such as liquid oxygen, liquid nitrogen
- An oxidizer
- Pumps to carry the fuel and the oxidizer
- A combustion chamber where the two liquids mix and burn
- A hot exhaust choke
- Exit from where the exhaust is removed
Acceleration of Rocket
The acceleration of the rocket is given as:
F = m * a- Where:
- F = Force (thrust in the case of a rocket)
- m = Mass of the rocket
- a = Acceleration of the rocket
Δv = Ve * ln(m0 / mf) - g * tWhere:
- Δv = Change in velocity
- Ve = Exhaust velocity
- m0 = Initial mass
- mf = Final mass
- g = Acceleration due to gravity
- t = Time
Factors Affecting Acceleration
- Thrust: A higher thrust will result in a faster acceleration, even against the force of gravity.
- Mass ratio: A higher mass ratio (initial mass divided by final mass) means the rocket can carry more propellant, leading to a greater change in velocity.
- Exhaust velocity: A higher exhaust velocity means the rocket can expel propellant at a higher speed, resulting in a greater thrust.
The acceleration of a rocket in gravity depends on the balance between its thrust and the force of gravity. As the rocket ascends, the force of gravity decreases, allowing it to accelerate more rapidly.
The Space Shuttle was a reusable spacecraft that flew to space for many years. It was launched from Florida and landed at a special runway. It carried astronauts and cargo, like satellites and experiments.
The Shuttle had three main parts: the orbiter, the external tank, and the solid rocket boosters. The orbiter was the part that flew back to Earth. The external tank held fuel for the orbiter. The solid rocket boosters helped the Shuttle get into space.
There were five Shuttles: Columbia, Challenger, Discovery, Atlantis, and Endeavour. Two of them, Challenger and Columbia, were lost in accidents. The remaining three Shuttles were retired in 2011.
Outer space (or simply space) is the expanse that exists beyond Earth's atmosphere and between celestial bodies. It contains ultra-low levels of particle densities, constituting a near-perfect vacuum - Ultra-high vacuum (UHV) is the vacuum regime characterised by pressures lower than about 1×10−6 pascals (1.0×10−8 mbar; 7.5×10−9 Torr).of predominantly hydrogen and helium plasma, permeated by electromagnetic radiation, cosmic rays, neutrinos, magnetic fields and dust. The baseline temperature of outer space, as set by the background radiation from the Big Bang, is 2.7 kelvins (−270 °C; −455 °F).
The plasma between galaxies is thought to account for about half of the baryonic (ordinary) matter in the universe, having a number density of less than one hydrogen atom per cubic metre and a kinetic temperature of millions of kelvins. Local concentrations of matter have condensed into stars and galaxies. Intergalactic space takes up most of the volume of the universe, but even galaxies and star systems consist almost entirely of empty space. Most of the remaining mass-energy in the observable universe is made up of an unknown form, dubbed dark matter and dark energy.
Outer space does not begin at a definite altitude above Earth's surface. The Kármán line, an altitude of 100 km (62 mi) above sea level, is conventionally used as the start of outer space in space treaties and for aerospace records keeping. Certain portions of the upper stratosphere and the mesosphere are sometimes referred to as "near space". The framework for international space law was established by the Outer Space Treaty, which entered into force on 10 October 1967. This treaty precludes any claims of national sovereignty and permits all states to freely explore outer space. Despite the drafting of UN resolutions for the peaceful uses of outer space, anti-satellite weapons have been tested in Earth orbit.
The concept that the space between the Earth and the Moon must be a vacuum was first proposed in the 17th century after scientists discovered that air pressure decreased with altitude. The immense scale of outer space was grasped in the 20th century when the distance to the Andromeda galaxy was first measured. Humans began the physical exploration of space later in the same century with the advent of high-altitude balloon flights. This was followed by crewed rocket flights and, then, crewed Earth orbit, first achieved by Yuri Gagarin of the Soviet Union in 1961. The economic cost of putting objects, including humans, into space is very high, limiting human spaceflight to low Earth orbit and the Moon. On the other hand, uncrewed spacecraft have reached all of the known planets in the Solar System. Outer space represents a challenging environment for human exploration because of the hazards of vacuum and radiation. Microgravity harms human physiology and causes both muscle atrophy and bone loss.
The Space Suit
A space suit (or spacesuit) is an environmental suit used for protection from the harsh environment of outer space, mainly from its vacuum as a highly specialized pressure suit, but also its temperature extremes, as well as radiation and micrometeoroids. Basic space suits are worn as a safety precaution inside spacecraft in case of loss of cabin pressure. For extravehicular activity (EVA) more complex space suits are worn, featuring a portable life support system.
Pressure suits are in general needed at low-pressure environments above the Armstrong limit, at around 19,000 m (62,000 ft) above Earth. Space suits augment pressure suits with complex systems of equipment and environmental systems designed to keep the wearer comfortable, and to minimize the effort required to bend the limbs, resisting a soft pressure garment's natural tendency to stiffen against the vacuum. A self-contained oxygen supply and environmental control system is frequently employed to allow complete freedom of movement, independent of the spacecraft.
The Apollo/Skylab space suit (sometimes called the Apollo 11 Spacesuit because it was most known for being used in the Apollo 11 Mission) is a class of space suits used in Apollo and Skylab missions. The names for both the Apollo and Skylab space suits were Extravehicular Mobility Unit (EMU). The Apollo EMUs consisted of a Pressure Suit Assembly (PSA) aka "suit" and a Portable Life Support System (PLSS) that was more commonly called the "backpack". The A7L was the PSA model used on the Apollo 7 through 14 missions.
The subsequent Apollo 15-17 lunar missions, Skylab, and Apollo–Soyuz used A7LB pressure suits. Additionally, these pressure suits varied by program usage. For the Skylab EMU, NASA elected to use an umbilical life support system named the Astronaut Life Support Assembly.
The suits used during lunar EVAs had a weight of about 81.6 kg (180 lb) and under lunar surface gravity a weight equivalent to 13.6 kg (30 lb). The low surface gravity and suit pressurization put considerable constraints on its use. The (21 kg) suit without a life support backpack, and costs only a fraction of the standard US$12,000,000 cost.
Primary life support system - life support backpack
A primary (or portable or personal) life support system (or subsystem) (PLSS), is a device connected to an astronaut or cosmonaut's spacesuit, which allows extra-vehicular activity with maximum freedom, independent of a spacecraft's life support system. A PLSS is generally worn like a backpack. The functions performed by the PLSS include:
Regulating suit pressure
- Providing breathable oxygen
- Removing carbon dioxide, humidity, odours, and contaminants from breathing oxygen
- Cooling and recirculating oxygen through the pressure garment, and water through a Liquid Cooling and Ventilation Garment or Liquid Cooling Garment.
- Two-way voice communication
- Display or telemetry of suit health parameters
- Telemetry of an indicator of the wearer's immediate health (e.g. heart rate)
The air handling function of a PLSS is similar to that of a diving rebreather, in that exhaled gases are recycled into the breathing gas in a closed loop.
When used in a microgravity environment, a separate propulsion system is generally needed for safety and control, since there is no physical connection to a spacecraft.
The portable life support system used in the Apollo lunar landing missions used lithium hydroxide to remove the carbon dioxide from the breathing air, and circulated water in an open loop through a liquid-cooled garment, expelling the water into space, where it turned to ice crystals. Some of the water was also used to remove excess heat from the astronaut's breathing air, and collected for dumping into the spacecraft's wastewater tank after an EVA. The PLSS also contained a radio transceiver and antenna for communications, which were relayed through the spacecraft's communication system to Earth. PLSS controls were provided in the Remote Control Unit (RCU) mounted on the astronaut's chest. Oxygen and water were rechargeable for multiple EVAs from the spacecraft's environmental control system.
Lunar surface EVA times for the first four missions (Apollo 11 through 14) were limited to 4 hours, with oxygen stored at 1,020 pounds per square inch (7.0 MPa), 3.0 pounds (1.4 kg) of lithium hydroxide, 8.5 pounds (3.9 litres) of cooling water, and a 279 watt-hour battery. For the extended missions of Apollo 15 through 17, the EVA stay time was doubled to 8 hours by increasing oxygen to 1,430 pounds per square inch (9.9 MPa), lithium hydroxide to 3.12 pounds (1.42 kg), cooling water to 11.5 pounds (5.2 litres), and battery capacity to 390 watt-hours.
An emergency backup was provided in case the main system failed, by a separate unit called the Oxygen Purge System (OPS), mounted on top of the PLSS, immediately behind the astronaut's helmet. The OPS maintained suit pressure and removed carbon dioxide, heat and water vapour through a continuous, one-way airflow vented to space. When activated, the OPS provided oxygen to a separate inlet on the pressure suit, once a vent valve on a separate suit outlet was manually opened. The OPS provided a maximum of about 30 minutes of emergency oxygen for breathing and cooling. This could be extended to 75 to 90 minutes with a "buddy system" hose that used the other astronaut's functional PLSS for cooling (only). This allowed the vent valve to be partly closed to decrease the oxygen flow rate.
The PLSS was 26 inches (66 cm) high, 18 inches (46 cm) wide, and 10 inches (25 cm) deep. It was tested at the Houston Flight Center by James P. Lucas, working for Hamilton Standard, and by various astronauts in neutral buoyancy tanks at Dallas. It was tested in space for the first time by Rusty Schweickart in a stand-up EVA in Earth orbit on Apollo 9. His PLSS weighed 84 pounds (38 kg) on Earth, but only 14 lb (equivalent to the Earth weight of 6.4 kg) on the Moon. The OPS weighed 41 pounds (19 kg) on Earth (6.8 lb (equivalent to the Earth's weight of 3.1 kg) on the Moon).
Space Shuttle/International Space Station PLS
Similar systems have been used by Space Shuttle astronauts, and are currently used by International Space Station crews.
The primary life support system for the EMU suit used on the Space Shuttle and International Space Station is manufactured by Hamilton Sundstrand. It is mounted to the back of the Hard Upper Torso (HUT) assembly.
Oxygen (O2), carbon dioxide (CO2) and water vapour are drawn from the extremities of the suit by the liquid cooling and ventilation garment or LCVG, which sends the gas to the PLSS. When the gas enters the PLSS, activated charcoal removes odours and lithium hydroxide (LiOH) removes carbon dioxide. Next, the gas passes through a fan which maintains a flow rate of about six cubic feet per minute. A sublimation then condenses water vapour, which is removed by a "slurper" and a rotary separator. The removed water is stored and used to supplement the water supply used in the LCVG. The sublimation also cools the remaining oxygen to about 55 °F (13 °C). A flow sensor monitors the flow rate.
Extra oxygen is added to the flow from a storage tank as necessary, downstream of the flow sensor. The oxygen is then returned to the suit at the back of the head, where it flows down over the astronaut's face. By delivering oxygen to the helmet and drawing gas from the extremities, the suit is designed to ensure that the suit occupant breathes the freshest possible oxygen.
The operating pressure of the space suit is maintained at 4.3 psi (30 kPa) (0.3 atm ~ one-third of Earth atmospheric pressure) during extravehicular operations, and 0.7 psi (4.8 kPa) relative to external pressure while in intravehicular mode (i.e., inside the pressurized spacecraft).
The material of Space suit
It is composed of an inner and outer shell of Beta cloth, seven layers of aluminized Kapton film separated by six layers of Beta Marquisette, and a liner of two layers of Neoprene-coated nylon Ripstop. A layer of Chromei-R (a woven metal) is added to the knee, elbow, and shoulders to protect the suit against abrasion.
1. A water-cooled Nylon undergarment.
2. A multi-layered Pressure suit:
- Inside Layer: Lightweight nylon with fabric vents.
- Middle-Layer: Neoprene-coated Nylon to hold pressure.
- Outer-Layer: Nylon to restrain the pressurized layers beneath.
3. Five Layers of Aluminized Mylar interwoven with four layers of Dacron for heat protection.
4. Two Layers of Kapton for additional heat protection.
5. A layer of Teflon-coated cloth (non-flammable) for protection from scrapes.
6. A layer of White-Teflon coated cloth (non-flammable)
It is a set of Nylon Tricot and Spandex, ”long underwear” that is laced with thin plastic tubes through which, cool water flows which eliminates the excess body heat produced by the astronaut.
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