History of Space Exploration

Space Exploration Foundations

• Humans are naturally fascinated by the night sky and celestial bodies.
• Ancient astronomers combined observation with religious interpretations of the heavens.
• Stonehenge demonstrates ancient cultures' awareness of celestial events, aligning with solstices.

The Drive to Explore

• Modern humans began exploring 150,000 years ago, leaving East Africa.
• By 1000 CE, Polynesians reached Hawaii, and humans populated all continents except Antarctica, using Paleolithic technology.
• From 1405-1433, Chinese fleets, led by Zheng He, explored as far as Africa but were discontinued due to a change in Imperial policy after the Emperor died.
• European explorers in smaller, sturdy ships with lateen sails and advanced navigational tools discovered and subjugated new lands 500 years ago.
• Christopher Columbus famously sailed west for Spain in 1492, encountering civilizations in the Americas, who still used stone tools at the time.
• Vasco da Gama sailed for Portugal, reaching India in 1498 by going south around Africa.
• The first circumnavigation of the world was achieved by Ferdinand Magellan, sailing for Spain, starting on September 20, 1519.
• Magellan died during the voyage, and only one ship, the Victoria, returned in 1522 with 18 survivors, marking high casualty rates of 80% for ships and 92% for crew.
• Exploration voyages persisted, varying in success and sometimes disappearing.
• The Royal Observatory in Greenwich, England, was founded in 1675 to improve navigation by accurately mapping the stars and determining longitude.
• British Captain James Cook led scientific voyages, combating scurvy by providing his crew with vitamin C-rich foods.
• Cook's first voyage (1768-1771) aimed to observe the transit of Venus for data to calculate the Earth's distance from the Sun, leading to the discovery of New Zealand and Australia.
• Cook's second voyage (1772-1775) circumnavigated the Antarctic region.
• Cook's third voyage (1776-1780) sought a Northwest Passage, encountering native Hawaiians.
• Robert Peary reached the North Pole in 1909.
• Roald Amundsen reached the South Pole in 1911.
• Sir Edmund Hillary and Tenzing Norgay summited Mount Everest in 1953, using oxygen tanks, at 8.8 km above sea level.
• The US Navy bathyscape Trieste reached the Challenger Deep in 1960, with Jacques Piccard and Don Walsh, which is 10.9 km deep.

Speculations on Life Beyond Earth

• The discovery of unique creatures on Earth fostered speculation about extraterrestrial life.
• Ancient Egyptians saw the Milky Way as a celestial Nile River.
• Babylonian astronomers charted planets around 700 BCE, and the zodiac was developed around 400 BCE, assigning religious meaning to celestial bodies.
• Lucian of Samosata wrote True Histories in 165 CE, considered an early work of science fiction.
• The Incan and Aztec cultures built observatories and developed calendars, including the Aztec 365-day year count and 260-day ritual cycle.
• Bernard Le Bovier de Fontelle suggested the possibility of extraterrestrial life in his 1686 book.
• Johannes Kepler proposed that lunar craters might be city walls in a 1634 science fiction story.
• Aristarchus of Samos proposed a heliocentric model, but it wasn't widely accepted at the time.
• Claudius Ptolemy's geocentric model was accepted by Christian and Islamic faiths, though it had inaccuracies.
• Nasir al-Din Tusi and other astronomers worked to refine the Ptolemaic model.
• Nicolaus Copernicus developed a heliocentric model, published posthumously to avoid conflict with the Roman Catholic Church.
• Galileo Galilei discovered Jupiter's moons, supporting the Copernican system which led to his house arrest.
• Galileo's publication of telescopic observations in Sidereal Messenger stimulated science fiction, some used their stories to comment on contemporary issues.
• Cyrano de Bergerac's The Voyage to the Moon (1649) featured a rocket, marking one of the first uses of rockets in science fiction.
• Edward Everett Hale's "The Brick Moon" (1869) described an artificial moon.
• Jules Verne wrote From the Earth to the Moon (1865) and Around the Moon (1866).
• H.G. Wells' The War of the Worlds (1897) is about a Martian invasion of Earth.

The Origins of Rocketry in War

• The Chinese used rockets in warfare during the time of Genghis Khan (1162-1227).
• Albertus Magnus provided a gunpowder recipe in On the Wonders of the World (1193-1290).
• Chinese troops used gunpowder rockets against the Mongols in 1232.
• Rockets briefly appeared in Europe around 1400 but were replaced by cannons.
• The Sultanate of Mysore used rockets against the British East India Company in the late 1700s.
• Sir William Congreve developed gunpowder rockets for the British military in the early 19th century.
• Congreve rockets were used in various battles, including the bombardment of Fort McHenry in 1814.
• Rocket-assisted whaling harpoons and rocket-launched rescue lines were developed in the 1820s.

Investigating Space with Rocket Devices

• Konstantin Eduardovich Tsiolkovsky (1857-1935) was a key Russian space theorist.
• Tsiolkovsky's 1898 article outlined how rockets could put spaceships in orbit and introduced the rocket equation.
• The Soviet Union recognized Tsiolkovsky by granting him a lifetime pension in 1921.

The Technology of Rockets

• Thrust is the product of propellant mass flow and exhaust velocity (T=mC).
• Rockets can attain speeds exceeding 17,500 mph to achieve Earth orbit.
• Thrust direction is usually longitudinal, but some rockets use gimbaled nozzles.
• Thrust magnitude depends on the rocket's efficiency and power.
• Pressure and temperature of exhaust gases are determined by rocket propellant.
• Solid fuel rockets use combustible fuel with an oxidizing agent, which can operate outside Earth's atmosphere.
• Liquid fuel rockets use separate liquid fuel and oxidizer (often liquid oxygen) tanks that are pumped into the combustion chamber, which can operate outside Earth's atmosphere.
• Rockets often have adjustable tail fins, vernier thrusters, and thrust-vector technology.
• Liquid fuel rockets can be shut off and restarted, unlike solid fuel rockets.
• Isaac Newton's theory of gravity (1646-1727) states that all objects with mass exert gravitational attraction.
• Newton's Three Laws of Motion include inertia, acceleration, and equal/opposite forces.

First Liquid Fueled Rocket

• Robert Goddard (1882-1945) experimented with liquid and solid rocket propellants.
• Goddard developed turbopumps, engine nozzles, cooling systems, and launching devices.
• In 1919, Goddard wrote "A Method of Reaching Extreme Altitudes.”
• Goddard's first liquid fuel rocket flight occurred in 1926 in Auburn, Massachusetts.

The Beginnings of German Rocketry

• Hermann Oberth (1894-1989) wrote about the possibility of long range rockets, first as a doctoral thesis, and then as the book, The Rocket into Interplanetary Space, in 1923.
• Oberth mentored the Society for Spaceship travel, founded in 1927.
• The Society developed a rocket-powered race car and launched a liquid oxygen-methane rocket in 1931.

Selling Space Exploration

• George Méliès created the first science film, A Trip to the Moon, in 1902.
• The Soviet film Aelita (1924) depicted rockets to Mars.
• Fritz Lang's Woman in the Moon (1929) featured Hermann Oberth as a consultant.
• Buck Rogers first appeared in 1928.

Rocket Societies around the World

• Rocket clubs emerged worldwide in the 1930s, including the American Interplanetary Society.
• Caltech students, led by Frank Malina, formed the Suicide Squad to develop sounding rockets.
• The British Interplanetary Society (BIS) was founded in 1933.
• Robert Esnault-Pelterie advocated for space exploration in France.
• Sergei Pavlovich Korolev founded GIRD in the Soviet Union in 1930.