Important missions of NASA | Science & Technology for UPSC CSE PDF Download

In this article, You will read Important Missions of NASA for UPSC IAS Exam. Important Space Missions Launched by NASA include JUNO, NEW HORIZON, INSIGHT, MESSENGER, OSIRIS-REX, PARKER SOLAR, Voyager mission, etc.National Aeronautics and Space Administration (NASA)
The National Aeronautics and Space Administration (NASA) is an independent agency of the executive branch of the United States federal government responsible for the civilian space program, as well as aeronautics and aerospace research.

• Established under the National Aeronautics and Space Act 1958
• Headquarters: Washington, DC, USA

History – NASA

Following World War II, the United States was in direct competition with the erstwhile Soviet Union (the superpower that was disbanded into several sovereign nations including the Russian Federation, Kazakhstan, Ukraine, etc. in 1991). That period was called the “Cold War”.
It was the Soviet Union’s launch of Sputnik on October 4, 1957, that first put an object into orbit around Earth.
It was followed in November by the even larger Sputnik II, which carried the dog Laika.
Only in late January 1958, the United States could launch Explorer 1, hoisted aloft by the Army’s rocket team, using rocket technology developed from World War II.

• Though a small spacecraft weighing only 30 pounds, it discovered what is now known as the Van Allen radiation belts, named for the University of Iowa scientist Dr. James Van Allen, launching the new discipline of space science.
• Explorer 1 was followed in March 1958 by the Navy’s Vanguard 1, 6 inches in diameter and weighing only 3 pounds.

NASA’s birth was directly related to the launch of the Sputniks and the ensuing race to demonstrate technological superiority in space.
Driven by the competition of the Cold War, on July 29, 1958, President Dwight D. Eisenhower signed the National Aeronautics and Space Act, providing for research into the problems of flight within Earth’s atmosphere and in space.
After a protracted debate over military versus civilian control of space, the act inaugurated a new civilian agency designated the National Aeronautics and Space Administration (NASA).

Objectives of NASA

• To expand human knowledge of space
• To lead the world in space-related technological innovation
• To develop vehicles that can carry both equipment and living organisms into space
• To coordinate with international space agencies to achieve the greatest possible scientific advancements.

Important Missions of NASA

JUNO Mission

• Determine how much water is in Jupiter’s atmosphere, which helps determine which planet formation theory is correct (or if new theories are needed)
• Look deep into Jupiter’s atmosphere to measure composition, temperature, cloud motions, and other properties
• Map Jupiter’s magnetic and gravity fields, revealing the planet’s deep structure
• Explore and study Jupiter’s magnetosphere near the planet’s poles, especially the auroras – Jupiter’s northern and southern lights – providing new insights into how the planet’s enormous magnetic force field affects its atmosphere

New Horizon

• The First Mission to the Pluto System and the Kuiper Belt
• The New Horizons mission is helping us understand worlds at the edge of our solar system by making the first reconnaissance of the dwarf planet Pluto and by venturing deeper into the distant, mysterious Kuiper Belt – a relic of solar system formation.
• The Kuiper Belt is a region of space. The known icy worlds and comets in both regions are much smaller than Earth’s Moon.
• The Kuiper Belt is a doughnut-shaped ring of icy objects around the Sun, extending just beyond the orbit of Neptune from about 30 to 55 AU.

Cassini Mission

The Cassini–Huygens mission, commonly called Cassini, was a collaboration between NASA, the European Space Agency, and the Italian Space Agency to send a probe to study the planet Saturn and its system, including its rings and natural satellites.

InSight

• InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) is a NASA Discovery Program mission that will place a single geophysical lander on Mars to study its deep interior.
• But InSight is more than a Mars mission – it is a terrestrial planet explorer that will address one of the most fundamental issues of planetary and solar system science – understanding the processes that shaped the rocky planets of the inner solar system (including Earth) more than four billion years ago.

Punch & Tracers Mission 

NASA has selected two new missions to advance our understanding of the Sun and its dynamic effects on space. One of the selected missions will study how the Sun drives particles and energy into the solar system and a second will study Earth’s response.

• The Polarimeter to Unify the Corona and Heliosphere, or PUNCH, the mission will focus directly on the Sun’s outer atmosphere, the corona, and how it generates the solar wind. Composed of four suitcase-sized satellites, PUNCH will image and track the solar wind as it leaves the Sun.
• The spacecraft also will track coronal mass ejections – large eruptions of solar material that can drive large space weather events near Earth – to better understand their evolution and develop new techniques for predicting such eruptions.
• The second mission is Tandem Reconnection and Cusp Electrodynamics Reconnaissance Satellites, or TRACERS.
• The TRACERS investigation was partially selected as a NASA-launched rideshare mission, meaning it will be launched as a secondary payload with PUNCH.
• TRACERS will observe particles and fields at the Earth’s northern magnetic cusp region – the region encircling Earth’s pole, where our planet’s magnetic field lines curve down toward Earth.
• Here, the field lines guide particles from the boundary between Earth’s magnetic field and interplanetary space down into the atmosphere.

Messenger

Understanding Mercury, the smallest, densest and least-explored of the terrestrial planets.
The spacecraft was launched aboard a Delta II rocket in August 2004 to study Mercury’s chemical composition, geology, and magnetic field.
New observations by the MESSENGER spacecraft provide compelling support for the long-held hypothesis that Mercury harbors abundant water ice and other frozen volatile materials in its permanently shadowed polar craters.
The instruments carried by MESSENGER were used on a complex series of flybys – the spacecraft flew by Earth once, Venus twice, and Mercury itself three times, allowing it to decelerate relative to Mercury using minimal fuel. During its first flyby of Mercury in January 2008, MESSENGER became the second mission after Mariner 10’s 1975 flyby to reach Mercury.
The MESSENGER mission was designed to study the characteristics and environment of Mercury from orbit. Specifically, the scientific objectives of the mission were:

• To characterize the chemical composition of Mercury’s surface.
• To study the planet’s geologic history.
• To elucidate the nature of the global magnetic field (magnetosphere).
• To determine the size and state of the core.
• To determine the volatile inventory at the poles.
• To study the nature of Mercury’s exosphere.

Kessler Syndrome 

• The Kessler Syndrome is a theory proposed by NASA scientist Donald J. Kessler in 1978, used to describe a self-sustaining cascading collision of space debris in LEO. It’s the idea that two colliding objects in space generate more debris that then collides with other objects, creating even more shrapnel and litter until the entirety of LEO is an impassable array of super-swift stuff. At that point, any entering satellite would face unprecedented risks of headfirst bombardment
• Matter in orbit travels at ridiculously high speeds, say 22,000km/h, just as an example. If this matter were to travel in the same plane and direction indefinitely, it would be impossible for any matter to collide, like cars going straight on a highway at the same speed, never endeavoring to switch lanes or get off on an exit.
• But in space, uncontrolled objects do not follow a straight path. Instead, each piece of debris is subject to drift and decay. The variation in Earth’s gravitation field causes drift or the gradual movement of an object to a different orbital plane. The friction of an object with Earth’s atmosphere causes decay or the slow decrease in an object’s altitude.
• Live satellites can be repositioned using onboard thrusters to counteract natural drift and keep to their intended orbits, but dead ones. Those just keep on floating, unrestrained, drifting and decaying and, at any moment, knocking into other drifters.

Orbital Decay

• In orbital mechanics, decay is a process that leads to the gradual decrease of the distance between two orbiting bodies at their closest approach over many orbital periods.
• These orbiting bodies can be a planet and its satellite, a star and any object orbiting it, or components of any binary system. The orbital decay can be caused by a multitude of mechanical, gravitational, and electromagnetic effects. For bodies in a low Earth orbit, the most significant effect is the atmospheric drag.
• If left unchecked, the decay eventually results in termination of the orbit where the smaller object strikes the surface of the primary; or for objects where the primary has an atmosphere, it burns, explodes, or otherwise breaks up in its atmosphere; or for objects where the primary is a star, ends with incineration by the star’s radiation (such as for comets), and so on.
• Causes of Orbital Decay include Atmospheric drag, Tidal effects, Mass concentration, light, and thermal radiation, and gravitational radiation.

Osiris- Rex 

• OSIRIS-Rex stands for Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer.
  It is a NASA asteroid study and sample-return mission.
  OSIRIS-REx is the third mission in NASA’s New Frontiers Program, which previously sent the New Horizons spacecraft zooming by Pluto and the Juno spacecraft into orbit around Jupiter.

Why was Bennu chosen?

• Bennu was selected for a the OSIRIS-REx mission from over 500,000 known asteroids, due to it fitting a number of key criteria. These include:
  Proximity to Earth: In order for OSIRIS-REx to reach its destination in a reasonable timeframe, NASA needed to find an asteroid which had a similar orbit to Earth.
• Size: Small asteroids, those less than 200m in diameter, typically spin much faster than larger asteroids, meaning the regolith material can be ejected into space. Bennu is around 500m in diameter, so rotates slowly enough to ensure that the regolith stays on its surface.
• Composition: Bennu is a primitive asteroid, meaning it hasn’t significantly changed since the beginning of the Solar System (over 4 billion years ago). It is also very carbon-rich, meaning it may contain organic molecules, which could have been precursors to life on Earth.

Additionally, Bennu is of interest as it is a Potentially Hazardous Asteroid (PHA). Every 6 years, Bennu’s orbit brings it within 200,000 miles of the Earth, which means it has a high probability of impacting Earth in the late 22nd Century.

Voyager 1

• It is a space probe launched by NASA on September 5, 1977. Part of the Voyager program to study the outer Solar System. It is in interstellar space.

Interstellar Space

• In astronomy, the interstellar medium (ISM) is the matter and radiation that exists in the space between the star systems in a galaxy. This matter includes gas in ionic, atomic, and molecular form, as well as dust and cosmic rays. It fills interstellar space and blends smoothly into the surrounding intergalactic space.
• Once you arrive in interstellar space, there would be an increase of “cold” particles around you. There would also be a magnetic field that does not originate from our sun.
  
  Interstellar Space

Voyager-2

• Like Voyager 1, Voyager 2 was designed to find and study the edge of our solar system.
• It is the only spacecraft to study all four of the solar system’s giant planets- Jupiter, Saturn, Uranus, and Neptune at close range.
• Voyager 2 is 11.5 billion miles from the Earth and, at that distance, light takes 17 hours to reach it or for messages from it to reach mission control on Earth.
• Voyager gets its power from a radioisotope thermoelectric generator (RTG) which turns heat from the decay of radioactive material into electricity.
• It officially entered ‘interstellar space’ in November 2018. It joined its twin—Voyager 1—as the only human-made object to enter the space between the stars.
• This space between the stars is dominated by the plasma that was ejected by the death of nearby giant stars millions of years ago.
• The sun sends out a constant flow of charged particles called the solar wind, which ultimately travels past all the planets to some three times the distance to Pluto before being impeded by the interstellar medium.
• This forms a giant bubble around the sun and its planets, known as the heliosphere.

Parker Solar 

• Parker Solar is NASA’s robotic spacecraft to probe the outer corona of the Sun. It is part of NASA’s Living with a Star Program
• NASA renamed the spacecraft from the Solar Probe Plus to the Parker Solar Probe in honor of astrophysicist Eugene Parker. This was the first time NASA named a spacecraft for a living individual.
• NASA’s Parker Solar Probe lifted off on 12th August 2018 from a pad here at Cape Canaveral Air Force Station, its powerful United Launch Alliance Delta IV Heavy rocket carving an arc of orange flame into the predawn sky.
• The Parker Solar Probe carries a lineup of instruments to study the Sun both remotely and in situ, or directly. Together, the data from these instruments should help scientists answer three foundational questions about our star.
• Parker Solar Probe will explore the corona, a region of the Sun only seen from Earth when the Moon blocks out the Sun’s bright face during total solar eclipses. The corona holds the answers to many of scientists’ outstanding questions about the Sun’s activity and processes.
• Parker Solar Probe is World’s first mission to touch the Sun.

James Webb Telescope 

• Webb is an international collaboration between NASA, the European Space Agency (ESA), and the Canadian Space Agency (CSA).
• The James Webb Space Telescope (sometimes called JWST or Webb) will be a large infrared telescope with a 6.5-meter primary mirror. The telescope will be launched on an Ariane 5 rocket from French Guiana in Spring 2019.
• The James Webb Space Telescope will not be in orbit around the Earth, like the Hubble Space Telescope is – it will actually orbit the Sun, 1.5 million kilometers (1 million miles) away from the Earth at what is called the second Lagrange point or L2.
• Webb will be the premier observatory of the next decade, serving thousands of astronomers worldwide. It will study every phase in the history of our Universe, ranging from the first luminous glows after the Big Bang, to the formation of solar systems capable of supporting life on planets like Earth, to the evolution of our own Solar System.

Kepler Space Telescope

• NASA’s Kepler Space Telescope was an observatory in space dedicated to finding planets outside our solar system with a particular focus on finding planets that might resemble Earth.
• During its over nine year’s life, Kepler had observed 530,506 stars and detected 2,662 planets.
• It used the transit photometry detection method for searching for an exoplanet, which looked for periodic, repetitive dips in visible light of stars caused by planets passing or transiting in front of its host star.
• Recently NASA retired its Kepler space telescope as it ran out of fuel.

Hubble Telescope

• It was built by the United States space agency NASA, with contributions from the European Space Agency.
• NASA named the world’s first space-based optical telescope after American astronomer Edwin P. Hubble (1889 — 1953).
• Dr. Hubble confirmed an “expanding” universe, which provided the foundation for the big-bang theory.
• It is a large space telescope and was launched in 1990 and is still operational. It is expected to decay by 2030-2040
• Hubble features a 2.4-meter mirror, and its four main instruments include ultraviolet, visible, and near-infrared regions of the electromagnetic spectrum
• It is the only telescope that has been designed in a manner that it can be serviced by astronauts in space. Till date 5 Space Shuttle missions have been conducted to repair and upgrade the parts of the telescope

LIGO (Laser Interferometer Gravitational-Wave Observatory)

• It is the world’s largest gravitational wave observatory and wonder of precision engineering.
• It comprises of two enormous laser interferometers located thousands of kilometers apart, each having two arms which are 4 km long.
• It exploits the physical properties of light and of space itself to detect and understand the origins of Gravitational Waves (GW).
• Gravitational waves are created when two black holes orbit each other and merge.
• the first gravitational wave was actually detected by LIGO only in 2015.

LIGO detectors

• Two LIGO detectors work as one unit to ensure a remarkable precision, which is needed to detect a signal as weak as a gravitational wave.
• Its detector components are completely isolated and sheltered from the outside world.
• Unlike optical or radio telescopes, it does not see electromagnetic radiation (e.g., visible light, radio waves, and microwaves) because gravitational waves are not part of the electromagnetic spectrum.
• It doesn’t need to collect light from stars; it doesn’t need to be round or dish-shaped like optical telescope mirrors or radio telescope dishes, both of which focus EM radiation to produce images.

LIGO Project at a global level

• Two LIGO detectors are already operational in the U.S., at Livingston and Hanford.
• The Japanese detector, KAGRA, or Kamioka Gravitational-wave Detector, is expected to join the international network soon.

LIGO India

• LIGO India will come up in Maharashtra, which will also have two arms of 4 km in length.
• The project aims to move one Advanced LIGO detector from Hanford to India.
• This project is a collaboration between the LIGO Laboratory and three lead institutions in the IndIGO consortium: Institute of Plasma Research (IPR) Gandhinagar, Inter-University Centre for Astronomy and Astrophysics (IUCAA), Pune and Raja Ramanna Centre for Advanced Technology (RRCAT), Indore.
• It is an ultra-high precision large-scale apparatus, which is expected to show a unique “temperament” determined by the local site characteristics.

Event Horizon Telescope

The Event Horizon Telescope (EHT) is a large telescope array consisting of a global network of radio telescopes (used to detect radio waves from space).
Event horizon telescope consists of eight radio observatories around the world, including telescopes in Spain, the US and Antarctica.

• The EHT project combines data from several very-long-baseline interferometry (VLBI) stations around Earth with angular resolution sufficient to observe objects the size of a supermassive black hole’s event horizon.
• The project’s observational targets include the two black holes with the largest angular diameter as observed from Earth: the black hole at the center of the supergiant elliptical galaxy Messier 87 (M87), and Sagittarius A* (Sgr A*) at the center of the Milky Way.

The first image of a black hole, at the center of galaxy Messier 87, was published by the EHT Collaboration on April 10, 2019, in a series of six scientific publications.

• The EHT is composed of many radio observatories or radio telescope facilities around the world, working together to produce a high-sensitivity, high-angular-resolution telescope.
• Through the technique of very-long-baseline interferometry (VLBI), many independent radio antennas separated by hundreds or thousands of kilometers can act as a phased array, a virtual telescope that can be pointed electronically, with an effective aperture which is the diameter of the entire planet.

The Event Horizon Telescope Collaboration announced its first results in six simultaneous press conferences worldwide on April 10, 2019. The announcement featured the first direct image of a black hole, which showed the supermassive black hole at the center of Messier 87, designated M87*
General Theory of Relativity (Einstein) predicts that photons emitted by the gas falling into a black hole should travel along curved trajectories, forming a ring of light around a “shadow” corresponding to the location of the black hole. While we often use the term “shadow,” it isn’t technically correct.

• What we are hoping to observe with the EHT is rather a “silhouette” of a black hole: its dark shape on a bright background of light coming from the surrounding matter, deformed by strong spacetime curvature.

Event Horizon Telescope Array

Outer Space Treaty

• The Outer Space Treaty, formally the Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies, is a treaty that forms the basis of international space law.
• The Treaty was opened for signature by the three depository Governments (the Russian Federation, the United Kingdom, and the United States of America) in January 1967, and it entered into force in October 1967.

The Outer Space Treaty provides the basic framework on international space law, including the following principles:

• The exploration and use of outer space shall be carried out for the benefit and in the interests of all countries and shall be the province of all mankind.
• Outer space shall be free for exploration and use by all States;
• outer space is not subject to national appropriation by claim of sovereignty, by means of use or occupation, or by any other means;
• States shall not place nuclear weapons or other weapons of mass destruction in orbit or on celestial bodies or station them in outer space in any other manner.
• The Moon and other celestial bodies shall be used exclusively for peaceful purposes;
• Astronauts shall be regarded as the envoys of mankind;
• States shall be responsible for national space activities whether carried out by governmental or non-governmental entities;
• States shall be liable for damage caused by their space objects; and
• States shall avoid harmful contamination of space and celestial bodies.

Space Tourism

• Space tourism is space travel for recreational, leisure, or business purposes. A number of startup companies have sprung up in recent years, such as Virgin Galactic and XCOR Aerospace, hoping to create a sub-orbital space tourism industry.
• Recently a winged spaceship designed to take tourists on excursions beyond Earth’s atmosphere exploded during a test flight over the Mojave Desert, killing a pilot in the second fiery setback for commercial space travel.
• It raises serious questions about the viability of such programs.

Space Elevator 

• A space elevator is a proposed type of space transportation system. It is a highly ambitious program inspired by sci-fi stories.
• Its main component will be a ribbon-like cable anchored to the surface and extending into space. It is designed to permit vehicle transport along the cable from a planetary surface, such as the Earth’s, directly into space or orbit, without the use of large rockets.
• An Earth-based space elevator would consist of a cable with one end attached to the surface near the equator and the other end in space beyond geostationary orbit.
• It will carry humans and other objects to space without rockets.

Sofia -Stratospheric Observatory  For Infrared Astronomy

• The Stratospheric Observatory for Infrared Astronomy (SOFIA) is a joint project of NASA and the German Aerospace Center (DLR) to construct and maintain an airborne observatory.
• NASA awarded the contract for the development of the aircraft, operation of the observatory, and management of the American part of the project to the Universities Space Research Association (USRA) in 1996.
• SOFIA is the largest airborne observatory in the world, capable of making observations that are impossible for even the largest and highest ground-based telescopes. During its planned 20-year lifetime, SOFIA also will inspire the development of new scientific instrumentation and foster the education of young scientists and engineers.

Orbiting Carbon Observatory

• The Orbiting Carbon Observatory (OCO) is a NASA satellite mission intended to provide global space-based observations of atmospheric carbon dioxide (CO₂).
• The original spacecraft was lost in a launch failure on February 24, 2009, when the payload fairing of the Taurus rocket which was carrying it failed to separate during ascent.
• The added mass of the failing prevented the satellite from reaching orbit. It subsequently re-entered the atmosphere and crashed into the Indian Ocean near Antarctica. The replacement satellite, Orbiting Carbon Observatory-2, was launched on July 2, 2014.
• OCO will fly in a near-polar orbit which enables the instrument to observe most of Earth’s surface at least once every sixteen days.
• It is intended to fly in loose formation with a series of other Earth-orbiting satellites known as the Earth Observing System Afternoon Constellation, or the A-train.
• This coordinated flight formation was intended to enable researchers to correlate OCO data with data acquired by other instruments on other spacecraft.

Solar Dynamic Observatory (SDO)

• SDO is NASA’s project initiated in 2010 to observe the influence of the Sun on the Sun-Earth System.
• This project is part of the Living with a Star (LWS) program of NASA
• SDO’s goal is to understand the solar variations that influence life and society on Earth.

SPHEREx

NASA will launch a new space telescope mission Spectro-Photometer for the History of the Universe, Epoch of Reionization and Ices Explorer (SPHEREx) in 2023.

• The launch could help astronomers understand how the Universe evolved in the first place and how common the ingredients for life are within it.

Missions’ Objective

• SPHEREx will survey the sky in optical as well as near-infrared light.
• Astronomers will use the mission to gather data on more than 300 million galaxies, as well as more than 100 million stars in Milky Way.
• The mission will create a map of the entire sky in 96 different colour bands.

Significance

• SPHEREx’s main goal is to search for the fundamentals of life — water and organic matter within the Milky Way.
• Beyond Milky Way, it will also be looking at the wider regions of the universe, where stars are born.
• This will give scientists targets for more detailed study in future missions, like NASA’s James Webb Space Telescope and Wide-Field Infrared Survey Telescope.
• It will deliver an unprecedented galactic map containing ‘fingerprints’ from the first moments in the universe’s history.
• It will provide new clues to one of the greatest mysteries in science that what made the universe expand so quickly less than a nanosecond after the Big Bang.

Icon and Gold 

• By NASA- The Global-scale Observations of the Limb and Disk, or GOLD and the Ionospheric Connection Explorer, or ICON- Study of the ionosphere
• GOLD in Geostationary orbit over Western Hemisphere
• ICON- Low-Earth Orbit
• The ionosphere is located between 60 and 400 km above the mesopause.
• It contains electrically charged particles known as ions, and hence, it is known as the ionosphere. Radio waves transmitted from the earth are reflected back to the earth by this layer and is used for radio propagation to distant places on the Earth. In this layer, the temperature starts increasing with height.

NASA – Crewed programs

Artemis Mission

NASA wants to send the first woman and the next man to the Moon by the year 2024, which it plans on doing through the Artemis lunar exploration program.
ARTEMIS stands for Acceleration, Reconnection, Turbulence, and Electrodynamics of Moon’s Interaction with the Sun.
The mission was named Artemis after the Greek mythological goddess of the Moon and twin sister to Apollo, the namesake of the program that sent 12 American astronauts to the Moon between 1969 and 1972.
Objective: The main objective is to measure what happens when the Sun’s radiation hits our rocky moon, where there is no magnetic field to protect it.

The mission: For the Artemis program, NASA’s new rocket called the Space Launch System (SLS) will send astronauts aboard the Orion spacecraft a quarter of a million miles away from Earth to the lunar orbit.
Once astronauts dock Orion at the Gateway — which is a small spaceship in orbit around the moon — the astronauts will be able to live and work around the Moon, and from the spaceship, astronauts will take expeditions to the surface of the Moon.

Lunar missions- key facts:

• Before the US sent the Apollo 11 mission to the Moon, it sent three classes of robotic missions between 1961 and 1968. 
• On July 20, 1969, Neil Armstrong became the first human to step on the Moon as part of the Apollo 11 mission.
• After July 1969, 12 American astronauts walked on the surface of the Moon until 1972.
• In 1959, the Soviet Union’s uncrewed Luna 1 and 2 became the first rover to visit the Moon. Since then, seven nations have followed suit.
• In the 1990s, the US resumed lunar exploration with robotic missions Clementine and Lunar Prospector.
• In 2009, it began a new series of robotic lunar missions with the launch of the Lunar Reconnaissance Orbiter (LRO) and the Lunar Crater Observation and Sensing Satellite (LCROSS).
• In 2011, NASA began the ARTEMIS (Acceleration, Reconnection, Turbulence, and Electrodynamics of the Moon’s Interaction with the Sun) mission using a pair of repurposed spacecraft and in 2012 the Gravity Recovery and Interior Laboratory (GRAIL) spacecraft studied the Moon’s gravity.
• Apart from the US, the European Space Agency, Japan, China, and India have sent missions to explore the Moon.
• China landed two rovers on the surface, which includes the first-ever landing on the Moon’s far side in 2019.
• The Indian Space Research Organisation (ISRO) recently announced India’s third lunar mission Chandrayaan-3, which will comprise a lander and a rover.

NASA’s Gateway Lunar Orbit outpost

The Gateway is a small spaceship that will orbit the Moon, meant for astronaut missions to the Moon and later, for expeditions to Mars.

It will act as a temporary office and living quarters for astronauts distanced at about 250,000 miles from Earth. The spaceship will have living quarters, laboratories for science and research, and docking ports for visiting spacecraft.
Once docked to the Gateway, astronauts will be able to stay there for three months at a time, conduct science experiments and take trips to the surface of the Moon.
Compared to the ISS, the Gateway is much smaller. It is a critical component of NASA’s Artemis programme.

Features of the Gateway

• One of the most unique features of the Gateway is that it can be moved to other orbits around the Moon to conduct more research.
• The Gateway will act as an airport, where spacecraft bound for the lunar surface of Mars can refuel or replace parts and resupply things like food and oxygen, allowing astronauts to take multiple trips to the Lunar surface and exploration of new locations across the Moon.

How is it different from ISS?

• Astronauts will use the Gateway at least once per year and not stay around the year as they do on the International Space Station (ISS).
• Compared to the ISS, the Gateway is much smaller (the size of a studio apartment), while the ISS is about the size of a six-bedroom house.

Dawn Mission

• Dawn mission was launched by NASAdeploying spacecraft to study the asteroid Vesta and dwarf planet Ceres.
• It is the only mission ever to orbit two extraterrestrial targets and will characterize the early solar system and the processes that dominated its formation.
• Vesta and Ceres are celestial bodies believed to have accreted early in the history of the solar system.
• Dawn orbited giant asteroid Vesta for 14 months from 2011 to 2012, then continued on to Ceres, where it has been in orbit since March 2015.
• The spacecraft is likely to run out of a key fuel known as hydrazine which keeps it oriented and in communication with Earth.

Ceres and Vesta

• Ceres is the earliest known and smallest of the dwarf planet.
• It is also the largest object in the asteroid belt between Mars and Jupiter.
• Thus Ceres is both a dwarf planet and an asteroid.
• Vesta is the second most massive body in the asteroid belt, surpassed only by Ceres.

DART (Double Asteroid Redirection Test)

• The DART is a planetary defense-driven test of technologies for preventing an impact of Earth by a hazardous asteroid.
• DART would be NASA’s first mission to demonstrate what’s known as the kinetic impactor technique – striking the asteroid to shift its orbit – to defend against a potential future asteroid impact.

Planetary Missions

Asteroids

• Asteroid Redirect Initiative
• Dawn
• Osiris-REX

Comets

• Deep Impact
• EPOXI
• Rosetta
• Stardust-NExT

Jupiter

• Europa Mission
• Galileo
• Hubble
• Juno
• Pioneer
• Voyager

Mars

• Hubble
• InSight
• Mars Exploration Rover
• Mars Global Surveyor
• Mars Odyssey
• Mars Pathfinder
• Mars Reconnaissance Orbiter
• Mars Science Laboratory, Curiosity
• MAVEN
• Phoenix
• Viking

Mercury

• MESSENGER

Moon

• Apollo
• Clementine
• GRAIL
• LADEE
• LCROSS
• LRO (Lunar Reconnaissance Orbiter)
• Mini-RF
• Moon Mineralogy Mapper
• Ranger
• Surveyor

Neptune

• Hubble
• Voyager

Pluto

• Hubble
• New Horizons

Saturn

• Cassini
• Hubble
• Pioneer
• Voyage

Uranus

• Hubble
• Voyager

Venus

• Magellan
• Pioneer