1. LANDING ON THE MOON 

Though the USSR took the first initiative to reach the moon, it was the US’s Apollo 11 mission which succeeded in landing a small capsule named Eagle, carrying three astronauts, on the Sea of Tranquillity region of the moon. Two astronauts were on that Lunar Module. On July 20, 1969, Neil Armstrong became the first human to set foot on the moon, which was in his words “one small step for man, one giant leap for mankind” (picture right). Later on, Edwin Aldrin joined him. The two conducted basic experiments, deployed scientific instruments and collected lunar soil samples. 

2. HUBBLE SPACE TELESCOPE

Due to the blurring effect of the earth’s atmosphere, observing space through earth-based telescopes has limitations. In the 1980s, an idea was mooted to send a large telescope above the atmosphere, to circle the earth. The Hubble Space Telescope was sent into space in 1990 with a 2.4m mirror and four major instruments which could observe simultaneously in different wavelength bands of the electromagnetic spectrum. Suddenly the sky became transparent in near-ultraviolet, visible and near-infrared spectra, unfolding images of the universe which earlier no mind could have imagined. With one single instrument, our inventory of cosmos increased manifold. The Hubble Space Telescope was not flawless in the beginning but thanks to continuous upgrades, it remains active till today.

3. SPACE STATION 

The need for a space station was felt to procure knowledge about space environment, effects on life and materials under zero-gravity situation and build work capabilities in near-vacuum. For starters, Zaria was launched in 1998. It is the largest artificial body in orbit around the earth and can be seen with the naked eye under favourable viewing conditions. This 419 tonne marvel floating at a height of 410km, with an orbital period of 92.69 minutes, has completed more than 1,00,000 orbits as of July 2016.

This space station was the collaborative effort of NASA, ROSCOSMOS (Russian space agency), Japanese Space Agency (JAXA), European Space Agency (ESA) and Canada (CSA). A separate module named Zvezda added sleeping quarters, toilet, kitchen, dehumidifier, oxygen generators, exercise equipment plus voice, data, television communication with vision control. The first crew reached the space station in November 2000. Since then, many astronauts have stayed for six months to more than two years.
Recently, scientists on board have grown vegetables at the station, raising hope for human colonies outside earth.

4. SPACE SHUTTLE 

The concept of space shuttle was mooted in the early 1980s to cut cost and allow a spacecraft’s return to earth after a mission. A manned launch vehicle along with an orbiter capable of gliding back to earth was fabricated. Its mission was to carry large technical payloads, including satellites, through orbits around the earth and recover such payloads and return them to earth. The first mission with a fully functional orbiter, Columbia, was launched on April 12, 1981. Four more space shuttles — Challenger, Discovery, Atlantis and Endeavour — were operational in course of the programme, which ended in 2011. It was a shuttle mission which put the Hubble Space Telescope in its orbit. 
Sadly, two orbiters Columbia and Challenger suffered fatal accidents, with the loss of 14 astronauts. Kalpana Chawla was one of them. The longest shuttle mission was by Columbia; lasting more than 17 days. The final space shuttle launch was that of Atlantis on July 8, 2011.

5. LARGE HADRON COLLIDER 

is the world’s largest and most powerful particle collider, the most complex experimental facility ever built and has the distinction of the largest single machine in the world. A collaboration of more than 10,000 scientists from 100-plus countries, it was built by European Organisation of Nuclear Research (CERN) between 1998 and 2008.

In a collider, two oppositely directed beams of particles continuously move through a huge number of powerful magnets, increasing their energy continuously. These beams are then made to collide with each other, as if to break the particles apart. Analysis of the by-products of these collisions gives scientists an idea of the structure of the subatomic world and the laws of nature governing them.

LHC consists of a tunnel 27 km in circumference at a depth of 175m beneath the France-Switzerland border near Geneva. The plan is to accelerate two beams of protons moving opposite to each other acquiring huge energy by passing through circular magnets and ultimately colliding at four points of the accelerator where four detectors are positioned to see the result of the collisions. 

It was used to test the existence of a hypothetical particle called Higgs Boson and if discovered, to identify its properties. This hypothetical Higgs Boson, first proposed by Prof. Peter Higgs, in the 1960s, was found out to be of immense importance by particle physicists. Through a mechanism involving the boson, they theorised that every other particle acquires their mass through an interaction with these Bosons. This prediction was on the basis of a proposed structure of the particle universe defined through decades of scientific inputs called the Standard Model. The Standard Model was also based on the fact that the Big Bang hypothesis is a description of the actual progression of events of the birth and evolution of the universe. So, the prevalent ideas of not only the particle world but also the truth about the formation of the universe depended upon the discovery of the Higgs Boson. That is the reason it was termed by some people as the “God Particle”. LHC became fully operational in November 2009. On July 4, 2012, a huge collaboration of scientists announced the positive identification of the Higgs Boson in the LHC. The facility was closed down in 2013 for upgradation and has become operational since mid-2015. Subsequent experiments have supported the presence of Higgs Boson, which has made the scientific community aware of the truth about the Standard Model. LHC will continue to present us with a more transparent view of nature at its smallest.

6. CHANDRAYAAN  

The objective was to send an orbiter with scientific instruments to the moon. This orbiter would go round the earth’s satellite and produce data to help in building a future human colony in moon. Chandrayaan was sent into space on October 22, 2008, with 11 instruments on board. Upon reaching, it threw an impactor on the moon surface creating materials to be ejected out, which were later analysed for the presence of water. Initially keeping a height of 100km from the surface every 117 minutes, Chandrayaan went round the moon for over 10 months after which communication was lost. By then, Chandrayaan observed huge reservoirs of silicon, magnesium, aluminium and iron on the surface. Its most important finding was a reservoir of around six thousand crore litres of water ice near the north pole of the moon. 

7. MANGALYAAN 

On August 15, 2012, the Mangalyaan project was announced in Parliament. According to the declaration, Indian space scientists within 15 months, on a paltry budget of Rs 460 crore could be producing a satellite mission capable of putting a satellite on Mars orbit. Thus the concept of Mars Orbiter Mission (MOM) or Mangalyaan was formulated. The world waited in disbelief. On November 5, 2013 the Mangalyaan was sent into space with five instruments, atop a PSLV X 25 rocket, at 2.38pm. After 44 minutes of flight, it was put on an earth parking orbit. Then, after raising the orbit repeatedly it was directed onto an elliptical orbit around the sun on December 1, so as to reach the red planet Mars on September 24, 2014. This was done because of paucity of fuel on the spacecraft and therefore to take the help of gravity, first from the earth and then from the sun. It was a mission whose success depended heavily on the precision guidance of the spacecraft. ISRO scientists were successful. The country erupted in joy when on September 24 at 8.02am Mangalyaan was injected into the predetermined orbit. Since then, it has regularly sent spectacular images of Martian features and have collected valuable data, which is now being analysed. Though its working life was earlier determined as six months, it is still going strong. The success of Mangalyaan has motivated Indian scientists to plan for Mangalyaan 2, a mission with an orbiter and a lander rover which would be moving on Mars.

8. ASTRONOMICAL OBSERVATORY IN SPACE 

The global trend is to observe the cosmos at multi-wavelengths. Telescopes and detectors in gamma, ultraviolet, infrared and x-ray are being commissioned regularly. Since the radiation in these wavelengths are absorbed by the earth’s atmosphere, these detectors are installed on satellites orbiting the earth. In 2000, Indian scientists decided to put such a satellite on earth orbit. The uniqueness of this plan was not to have a single type of telescope on a satellite but to have a multi-wavelength observatory in space — a first in the world. On September 28, 2015, India successfully launched a dedicated scientific exploration observatory, Astrosat. This 1,500 kg satellite has on it five main instruments, which would provide much sought data on deep field survey of the universe and help asses the evolution, physical properties and characteristics of distant stars, binary star systems, white dwarfs, pulsars and the enigmatic black holes. In its exploratory stay, it has discovered a new gamma ray burst, solved problems of peculiar properties of stars in distant star clusters and would start functioning for research purposes from October 2016. India thus entered an elite club of countries with their own astronomical observatory in space. 

9. GRAVITY WAVE

Albert Einstein showed that two extremely dense objects going round each other and ultimately colliding would cause a rippling effect on space and time which would be propagated through out the universe ‘gravitational waves’. Since the intensity of such waves mostly coming from the vast distances of the universe will be extremely weak, it was technologically not possible to detect them. Rather, the idea of building large scale interferometers looked promising. Two very large rectangular cavities, perpendicular to each other, act as light tunnels. The idea was if gravitational waves pass through these arms, definitive signatures of gravity waves could be proved. Ligo is one of the largest gravity wave detectors in the US. Research institutes of the US, UK, Germany and Australia are the stakeholders of this observatory. The two detectors are in Livingstone, Louisiana and in Hanford in Richmond, Washington, with 2 to 4km arms at right angles to each other. On February 11, 2016, scientists of the observatory declared that Ligo had detected gravitational waves, simultaneously at both its units on September 14, 2015. This was a momentous occasion. India too has started work on the Indigo (Indian Initiative in Gravitational Wave Observation) project. Once built, this would strengthen the search for this illusive cosmic signal. Plans are afoot even to build space-based interferometers.

10. JUNO REACHES JUPITER

According to the Solar Nebular Hypothesis, our solar system originated from a cloud of gas and dust. Because of gravity, the central region of this cloud became dense and the temperature rose to such a level that the nuclear fusion process started, giving birth to our sun. At the outer periphery of this cloud, dust and gas condensed and coalesced to form planets. In general, such a gas cloud gives birth to two stars. But in the case of the solar system because of the absence of enough material, in place of the second star, the gas giant Jupiter was born. A spacecraft named Juno was launched on August 5, 2011 to rendezvous with Jupiter in 2016 and get data to help us understand not only Jupiter but also the early stages of the solar system. Never before was such a solar-powered spacecraft sent to a great distance. After five years, Juno entered the orbit around Jupiter, a prelude to 20 months of scientific data collection, to be followed by a planned de-orbiting. Juno would also search for clues about how the planet was formed, whether it has a rocky core, its mass distribution and the amount of water present within the deep atmosphere. 

11. EYE ON PLUTO

To gather data about the ninth planet Pluto, which has recently become a dwarf planet, and about the region beyond Pluto, where comets and multitudes of rocks prevail, NASA planned and launched New Horizons spacecraft in January 2006. After a journey over an enormous distance, on July 14, 2015, New Horizon flew 12,500km above the surface of Pluto, making it the first spacecraft to explore the dwarf planet. At present, it is on its way for a fly-by of a Kuiper belt object, the region from where the cometary heads originate. The spacecraft has sent very vivid images of Pluto’s surface. They show mountain ranges like the Himalayas but made up of carbon dioxide ice. It has also provided us a close look at Pluto’s atmosphere.