I believe that the sky is greatly responsible for the birth of philosophy, religion and science – if not the most.  

The Sun and the clouds no doubt had immense practical implications so the ancients could not help but try to understand and interpret it in a utilitarian sense, but the dark night sky with specks of white lights must have triggered an even greater curiosity in man.

Hidden by the grandeur of the Sun, the sky at day time looks limited and practical, but at night the same sky looks monstrous and vague. Immense and vast. Beautiful and Impractical. Abstract. It must have been crucial to raising that elusive question for the first time:

Where are we?

Astronomy is the name given to the study of that vast expanse of space above our heads. It is one of the oldest sciences. Every advanced society we know of has had interest and works done on it. Mesopotamian, Egyptian, Indus-Valley, MesoAmerican, Chinese, Greek- all these civilizations have some kind of interpretation on the sky above and our positions relative to it. They all have questioned Space.

Space in the simplest of terms is the region beyond earth.

Exploration has a deep meaning:

an act or instance of exploring or investigating; examination.

It is not just limited to physically being available at the site of exploration. In that regard, every form of investigation or inquiry is an exploration. But what we will be concerned with here is only the physical exploration of the sky and space above us. That is the immediate developments leading to and activities in space. Let us begin.

As mentioned above, space is the region beyond the Earth. This immediately begs a question- Where does it begin?

For this, a system called Karman Line is used. Named after engineer and physicist Theodore Von Karman, this hypothetical line lies 100 kms above earth’s mean sea level.

Another approach taken towards determining the boundary is: The U.S. Armed Forces definition of an astronaut is a person who has flown higher than 50 miles (80 km) above mean sea level, approximately the line between the mesosphere and the thermosphere.

The first spacecraft to cross the Karman Line was the German A-4/V-2 rocket MW 18014 launched in June 1944. It was the first manmade object to cross the line and attained the apogee of 176 kms. It was a test launch as a follow up to multiple A-4 rockets which had managed to reach an altitude of 90 kms. But those rockets weren’t convincing enough. The MW 18014 was in fact a series of launches designed to monitor the rockets’ behavior in vacuum. This paved a way for post-war rockets and eventual satellites. But this was by no means the beginning of rockets. But it had the same use rockets’ conception had: Military.    

The transportation technology for space travels is called rockets. 

It was a British mathematician William Moore in 1813, who contributed significantly towards thrusting ourselves upwards seriously. He developed rocket theory and developed a rocket equation. Where he

...described the relevant dynamics for constant thrust and constant propellant consumption rate acting on a rocket with the varying mass. Moore however did not relate thrust and the exhaust velocity and, therefore, did not relate the rocket velocity increment and the exhaust velocity of the propellant flow. 

British inventor Henry Trengrouse then developed a rocket apparatus in 1818. It’s purpose was to project a lifeline from a wrecked ship to the shore. It was supposed to save lives for a change and not the other way around.   

The next few decades saw many developments and improvements on military rocketing. But it was a Russian-Soviet self-taught genius Konstantin Tsiolkovsky born in 1857 who was to focus and work on the space beyond in such a way that it changed rocketry and the possibilities of space exploration forever.  

Dedicated to scientific agendas from an early age, he had already begun to fantasize space travels.  Based on his vision of solar-system, galaxy colonization and a human controlled Universe, he studied motion of rocket apparatus, rocket propulsion and eventually derived the now famous Tsiolkovsky equation. The equation described motions of rocket-vehicles as:

a device that can apply acceleration to itself using thrust by expelling part of its mass with high velocity can thereby move due to the conservation of momentum… 

Konstantin Tsiolkovsky

His main technical contributions were in liquid fuels and staging. He also discussed space-suits. 

Along with him, Robert Esnault-Pelterie, Robert Goddard, Herman Oberth, others independently derived the equation too. All this paved way for seriously leaving the earth. Pelterie presented papers calculating energy required to reach moon and other planets.   Goddard built the world’s first liquid-fueled rocket. Oberth wrote, discovered and worked in many aspects of space travels.  

Rocket Scientist such as Wernher Von Braun, who was immensely influencial to the developments of rockets in both Nazi Germany (V2) and later in the US space program; and engineers/designers such Valetin Glushko and Sergey Korolev were influenced by Tsiolkovsky and the latter two may have even worked to realize his vision. 

In May of 1924 the Society for Studies of Interplanetary Travelwas founded in Moscow by Konstantin Tsiolkovsky, Friedrich Zander and 200 other space and rocket experts to discuss space travels majorly. 

1927 saw the amateur space organization Society for Space Travel established in Germany which helped push things there.

Around the same time Ukrainian/Soviet visionary Yuri Kondratyuk  circulated his book The Conquest of Interplanetary Spaces where he discussed many ideas on space travels among which he talked of lunar orbits and the concept of gravitational slingshots which were to be influential later.

Another key figure around this time was a Solvene engineer named Herman Potočnik. He published a book The Problems of Space Travels in 1928 where he discussed human settlements in space, space stations, use of space for communication, etc. He also expressed skepticism on the potential military use of space.

With all these technical, scientific and philosophical ideas, rockets started to blast off in 1928 with the Lippisch Ente (German for Lippisch duck). The struggling aircraft flew 4900 feet in its second attempt in its first flight and met with an accident in its second flight. This was a part of the Opel company’s program. 

Opel RAK.1, world’s first public flight of a rocket-powered aircraft.

The Opel-RAK program in Germany saw a series of rocket aircrafts. It helped advance rocket and aviation greatly.

EA-41 developed during 1931-1942 saw the development of the first French liquid fuelled rockets. It was a part of the French Space Program, the third national program after the USSR and US. There were multiple launches in 1941-42 with the fifth one reaching 60 kms.

Multiple experiments with JETO (Jet assisted Take Off)/RATO (Rocket Assisted Take Off) were conducted in the US in 1941. 

This takes us to the V2 rockets mentioned earlier. 

After the Second World-War,  the V2 systems came into the hands of the US and thus began the proper take-off of exploratory programs. In 1946 the first research flight took place from the US with V2 for cosmic radiation experiments. The same year also saw the flight of the Nike Missile. 

A landmark achievement saw V2 No. 13 take the first photograph of Earth from the Space. It was taken from 105 kms. The project was launched on 24th October 1946. 

First Photograph of Earth from Space

In 1949 the RTV-G-4 Bumper (Bumper-5), a combination of V2 and the American WAC Corporal sounding rocket attained the altitude of 392.68 kilometers. 

1949 also saw the publication of the influential book The Conquest of Space by William Ley. The book talked about the prospects of Solar System exploration. 

Wernher von Braun published The Mars Project in 1952 which highlighted the technical specification on the human expedition to Mars. It has often been deemed an influential and important book.  He talked about a scientific expedition of 10 spacecrafts, 70 crew members spending 443 days on the surface of Mars.  He also talked about nitric acid/hydrazine propellant and  reusable heavy-lift launch vehicles. 

In 1956 the American Jupiter-C program saw the first rocket to enter the Exosphere. It went to a height of 1097.57 kms and achieved Mach 18 velocity. von Braun was influential in the development of these vehicles. 

Jupiter C

The same year saw the first launch of PGM-17 Thor, a US ballistic missile which paved the way for Delta space launch rockets. 

21 August 1957 saw the launch of the first ICBM (Intercontinental Ballistic Missiles) through(8K71) or SS-6 Sapwood. These missiles have a minimum range of 5500 kms.

Thus the Cold War Space Race gathered serious momentum. While it had political motivations, it helped develop technologies and mechanisms that changed space travel and explorations forever. 

1957 saw the launch of USSR’s Sputnik-1, the first artificial satellite which also sent the first signals from space. It orbited for three weeks.  The same year in the month of November the first mammal -Laika the dog was sent to the orbit in Sputnik-2. A decade earlier fruit flies were sent as the first organisms in space in V2 by the US. 

1958 saw the US send its first artificial satellite in Explorer 1 mission. It confirmed the existence of Van Allen Radiation Belt which is a zone of charged particles held by Earth’s magnetosphere. The same year the US also launched its first ISBM in Atlas B. 

In 1959, the Luna 1 spacecraft reached the vicinity of the Moon as it missed its surface by only about 6000 kms. Luna 1 also became the first spacecraft to detect solar wind and reach Earth’s escape velocity. The same year American Satellite Explorer 6 took the first photograph of Earth from Orbit.

Explorer 6’s photograph

The same year also saw Luna 2 become the first human spacecraft to reach the surface of the Moon. It has impacted the Moon at the speed of 3.3 kms per second. Next month Luna 3 brought the first photograph of the far side of the moon. 

Luna 3’s Image of Moon

The 1960s saw the most revolutionary decade in human Space-Exploration. First, the US mission Pioneer 5 launched a space probe to investigate the regions between the orbits of Earth and Venus. It confirmed the existence of interplanetary magnetic fields. In August, the Korabl-Sputnik 2 mission saw the USSR send two dogs, two rats, forty mice and plants to orbit and bring them back. 

Strelka. Made it into Space way before the billionaires!

October saw the failed attempt at first shot at Mars through USSR’s Mars 1M.  

1961 began with US sending the astrochimp, Ham in MR (Mercury Redstone) 2. A dozen days later USSRs Venera 1 achieved the first spin-stabilization of a space vehicle. Then a landmark moment in 12th April saw USSRs Vostok 1 send Yuri Gagarin to space in what was to become the first instance of a human orbiting the Earth. US followed with the first human-piloted space flight Freedom 7 with Alan Shepard becoming the 2nd man to reach space. The spacecraft was launched on a ballistic trajectory suborbital flight. A couple of weeks later USSRs Venera 1 reached within 100,000 kms of Venus. 

In 1962 USA with its OSA (Orbiting Solar Observatory)-1 initiated the first orbital solar observatory. The same year the US launched Mercury MA-6 (Friendship 7) where John Glenn put US in orbit. In August, Norway with Ferdinand 1 launched the first auroral research rocket into the ionosphere. USSRs Mars 1 reached 11,000 kms to Mars and in December, USs Mariner 2 reached 34,773 kms to Venus. 

In 1963, USSR launched Vostok 6 where Valentina Tereshkova became the first woman and first civilian to orbit earth. US X-15 Flight 90, the first reusable manned spacecraft (suborbital) reached space which pioneered reusability and carried out launch and glide landings.

In March of 1964, Alexei Leonov performed the first space walk. 

Ranger 8 in 1965 yielded over 7,000 photos of the lunar surface. The Soviet probe Venera 3 became the 1st artificial probe to impact on the surface of another planet, Venus. USSR Proton rocket, a highly successful launch vehicle was launched with notable payloads, Salyut 6 & Salyut 7, Mir & ISS components. US Mariner 4 took the first close-up photograph of Mars in July. 

Source – NASA

In 1966, the USSR Luna 9 made the first soft landing on the Moon. Later the USSR launched Soyuz spacecrafts. Vanera 3 in March made the first impact on Venus. In August, Lunar Orbita 1 became the first mission to map the moon. 

1967 saw Surveyor 3, scoop and test lunar soil. Mariner 5’s mission to Venus saw it reach solar orbit and achieved the closest Venus flyby which paved the way for obtaining readings of Venus atmosphere.

In 1968 the Apollo 8 became the first space mission to enter the gravitational influence of another celestial body (Moon). 

1969 saw Mariner 6 reach within ~ 3200 of Mars where it collected photos and other data. American mission Apollo 11, sent the first men on the Moon. It also brought the first sample from the moon. In August, Mariner 7 took the first photograph of Phobos, the moon of Mars. 

In 1970 Venera 7, the Soviet probe became the first to land safely on the surface of Venus. Earlier the American satellite Uhuru became the first X-ray orbital observatory

In 1971, the Soviet Salyut 1, the first Space Station was established. Mariner 9 in November became the first spacecraft to orbit Mars.  Later, Soviets with Mars 2 and 3 had the first impact on Mars and the first soft landing there with photographs of its surface, respectively. 

Pioneer 10 in 1972 passed Jupiter and it took readings on Jupiter’s composition finding that the planet is composed mostly of hydrogen. It also became the first craft to escape in a trajectory away from the Sun and also the first mission to escape the inner Solar System into the asteroid belt. American SAS 2 also became the first orbital gamma ray observatory. 

In 1973, Pioneer 11 passed Jupiter and then Saturn in 1979. It discovered an additional ring around Saturn and also 2 moons. The same year the Mariner 10 mission to Venus and Mercury began. It passed Venus in 1974 and arrived at Mercury in 1974. It also took readings of clouds and wind patterns of Venus’ atmosphere.

Viking 1 took off for Mars in 1975 and landed there in 1976. It was the first probe to land safely on Mars. There it performed chemical analysis of soil.

Panoramic photo of Mars from Viking 1 lander.

Viking 2, the sister probe of Viking 1 took off in 1975 and landed on Mars 1976. The year 1975 also saw the establishment of ESA, the European Space Agency. Soviet Venera 9 became the first to orbit Venus and took photographs of its surface. 

 1976 saw Helios 2, the joint venture between US (NASA) and West Germany’s DFVLR fly closest to the Sun at 43.432 million kilometers. It also recorded the highest speed by any aircraft at 252,792 km/h. Later, Viking Lander took photos and soil samples from the surface of Mars. 

The legendary Voyager 2 in 1977 left for Jupiter, Saturn,Uranus and Neptune. It eventually encountered Jupiter in 1979, Saturn in 1981, Uranus 1986 and Neptune in 1989. It provided evidence of  rings around Neptune and its great dark spot. It entered into the boundary area of the solar system in 2007.

Voyager 1 left for Jupiter and Saturn 16 days after Voyager 2. It had encountered Jupiter 1979, providing evidence of rings around it and passed Saturn in 1980. 

The Voyagers contain sounds and images portraying the diversity of life and culture on Earth, and are intended for any intelligent extraterrestrial life form who may find them. 

Towards the end of the decade the Pioneer Venus 1 in 1978 entered Venus’ orbit, studied its atmosphere, magnetic field, weather, and surface. Pioneer Venus 2 was a multiprobe which entered the Venus atmosphere, took its readings and impacted on its surface.

In 1981, US space shuttle STS 1 pioneered reusability and glide landings. 

The next year, Vanera 13 took sound recordings of Venus. 

This Is What The Surface Of Venus Sounds Like! Venera 14 Sound Recording 1982 (4K UHD) – YouTube

In 1983, IRAS became the first Infrared orbital observatory.

In 1986 USSRs Mir was the first constantly inhabited space station. The same year ESAs Giotto made a close observation of Halley’s Comet at a mere 596 kms. 

Giotto: Halley’s Comet Flyby Animation (1986.03.14) [720p] – YouTube

In 1989, ESAs Hipparcos became the first astrometric satellite in that its work was to precisely measure positions of celestial bodies in the sky. Magellan left for Venus the same year and landed in 1990. It then mapped over 99% of its surface. Observed volcanoes. Galileo used Earth’s gravity to propel itself toward Jupiter. The COBE launched in November was the orbital cosmic microwave observatory. 

1990 saw Voyager send the first Solar System image and the launch of the legendary Hubble Space Telescope as a joint venture of NASA (USA) and ESA. 

In 1991 USA Galileo experienced 951 Gaspra, which was the closest flyby to an asteroid at 1600 kms. 

In 1992 Ulysses, a joint venture of NASA and ESA began a journey to orbit around the Sun. It made scans of the Sun in 1995, 2005 and 2008. 

Mars Global Surveyor in 1996 began orbiting Mars. It began mapping its entire surface in 1999. Discovering a weak magnetic field on the planet and finding evidence of liquid water of sometime in the past. Mars Pathfinder took off and landed on Mars in 1997, it sent surface images. 

Cassini-Huygens headed for Saturn in 1997 and began orbiting in 2004. It was a mission to study the planet’s atmosphere, rings, and moons. It managed to spot a subterranean ocean and other astounding discoveries. Mars Pathfinder headed to Mars. 

In 1998, the first multinational space station ISS, was established as a joint venture of- Russia (FKA) USA (NASA)  Europe (ESA)  Japan (JAXA) and Canada (CSA). Russia launched the Zarya module as the first part of the ISS.  Lunar Prospector began orbiting and mapped 11 elements on its surface. It also  discovered evidence of water ice at both lunar poles. Deep Space 1 saw the comet Borrelly fly by within 2414 kms.  It used an ion thruster for propulsion. 

Deep Space 1 Encounters a Comet – Video File – Borrelly (AVC-2001-131) – YouTube

Stardust in 1999 headed for the comet Wild-2. It reached there in 2004 and gathered its dust samples. 

Taken by Stardust in 2004

The 21st Century began with NEAR Shoesmaker orbiting the asteroid 433 Eros first in 2000 then in 2001. 

2001 Mars Odyssey reached Mars and detected evidence of water ice near its South Pole. It also aimed to identify minerals on Mars.  Genesis in 2001 orbited The Sun and collected particles from solar wind. 

Mars Express/ Beagle 2 arrived at Mars in 2003 and performed remote sensing. 

Mars Exploration Rovers Spirit and Opportunity landed on Mars in 2004. There they found further evidence that water existed on its surface. 

2004 also saw Cassini-Huygens orbit Saturn. The following year it had the first soft landing on Titan

and then in the outer Solar System. MESSENGER in 2004 left for Mercury and flew by in 2008. It managed to provide images of 20% of Mercury’s surface. 

Deep Impact in 2005 headed for the Comet Tempel 1. It did reach and deployed an impact probe which slammed into the comet. Japan’s Hayabusa managed the first asteroid ascent on 25143 Itokawa.

Mars Reconnaissance Orbiter launched in 2005 reached there in 2006. It took detailed images of the Martian surface. Later it discovered salt deposits. 

In 2006 India’s Chandrayaan -1 from ISRO discovered lunar water in ice-form. 

2009 saw the launch of the much anticipated Kepler telescope. It’s function being to search for Earth-like exoplanets. 

Hayabusa brought sample returns in 2010. 

MESSENGER had its orbit of Mercury in 2011. The same year the Dawn probe managed to orbit Vesta. It later went on to orbit the dwarf planet (Ceres).

In 2012 Voyager 1 reached Interstellar Space. 

2014 saw ESA Rosetta soft-land on the comet 67P/Churyumov–Gerasimenko.

New Horizons flew by Pluto in 2015. 

In 2017 Hawaii Haleakalā Observatory detected Oumuamua, the first known interstellar object. 

This very deep combined image shows the interstellar asteroid ‘Oumuamua at the centre of the picture.

Hayabusa 2 in 2018 sent a rover on the asteroid Ryugu 162173.

2019 saw New Horizon exploring contact binary 486958 Arrokoth, the trans-Neptunian object in the Kuiper Belt. It also saw Chang’e 4 land on the far side of the moon. Event Horizon, the telescopic network provided the first direct photograph of Black Hole Sagittarius A*. 

In 2021, Ingenuity had aerodynamic flight on Mars. 

There are numerous missions today headed for the future. We can talk about it sometime later. 

The story of human success in space exploration is the story of the success of human will.

How do we measure how much of an influence the gaze, awe and curiosity of ancient wonderers have had on the present successful human venture into the vast unknown?

I also wonder what those ancient musers would be more surprised by:

• The fact that their progenies have managed to physically reach to that vast, dark unknown above OR
• How that vast, dark unknown turned out to be?