Solar, Lunar and Planetary Exploration

Major Lunar Missions — The Story of the Moon

The Moon has always been humanity’s first space destination — simply because it is the nearest. But getting there was never a straight line; it was a clear evolution: first we went just to take photographs, then we attempted soft landings, then we sent humans, and now we are preparing for a permanent presence. Keep this logic in mind as you read:

Flyby/Impact missions → Soft-landing missions → Human landing → Orbiters & sustained presence

Ranger Programme (1960s) — NASA

These were early robotic missions that took close-up photographs of the Moon just before crashing into it.
Ranger 7 (1964) transmitted thousands of detailed images, helping reveal surface structure and crater distribution.

Surveyor Programme (1966–1968) — NASA

The goal here was a soft landing — touching down gently on the Moon rather than crashing.
These missions tested soil strength and confirmed that the lunar surface was firm enough to support a lander and astronauts. This data made the Apollo human landings possible.

Apollo Programme (1969–1972) — NASA

NASA’s human spaceflight mission to land astronauts on the Moon.
Apollo 11 (1969): Neil Armstrong and Buzz Aldrin took the first human steps on the Moon.
In total, six Apollo missions landed successfully, and 12 astronauts walked on the Moon.
These missions brought back lunar rock and soil samples, greatly enhancing our understanding of the Moon’s origin and geology.

Lunar Reconnaissance Orbiter (LRO) (2009–Present) — NASA

A robotic orbiter that maps the Moon’s surface in high resolution.
It studies potential landing sites, polar water-ice deposits, and radiation levels.
It supports future lunar missions, including Artemis.

Artemis Programme (Ongoing) — NASA ★

Aim: to return humans to the Moon after more than 50 years.
It plans to land the first woman and the next man on the Moon.
Goal: establish a sustained human presence, especially near the lunar south pole.
Artemis is also envisioned as a stepping stone toward future human missions to Mars.

Luna Programme (1959–1976) — Soviet Union

This was the Soviet Union’s series of robotic Moon missions, covering flybys, impacts, soft landings, and sample-return operations.

Luna 2 (1959): The first human-made object to reach the Moon — an intentional impact mission. This marked the first time a spacecraft from Earth touched another celestial body.
Luna 9 (1966): Achieved the first successful soft landing on the Moon, transmitting panoramic images and proving the lunar surface was firm enough to support landers.
Luna 16 (1970): A robotic sample-return mission that collected lunar soil and returned it to Earth, demonstrating advanced autonomous landing and ascent technology.

Luna-25 (2023) — Roscosmos ★

Russia’s first lunar mission in nearly five decades.
Important distinction: Luna-25 was not part of the original Soviet-era Luna series — it belongs to Russia’s modern Luna-Glob programme.
It aimed for a soft landing near the lunar south pole, a region of interest due to possible water ice.
However, the spacecraft lost control during orbit adjustment and crashed — the mission failed. Despite the setback, it signalled Russia’s renewed interest in lunar exploration.

Chang’e Programme — China

China’s lunar exploration initiative, named after the Chinese Moon goddess.

Chang’e 3 (2013): China’s first successful soft landing. Deployed the Yutu (Jade Rabbit) rover. China became the third country to achieve a soft landing on the Moon, after the USA and the USSR.
Chang’e 4 (2019): The first spacecraft to land on the far side of the Moon. Because the far side never faces Earth, China used a relay satellite, Queqiao, for communication. It carried the Yutu-2 rover.
Chang’e 5 (2020): A robotic sample-return mission that collected lunar soil and rock and returned it to Earth. China became the third country, after the USA and USSR, to achieve a lunar sample return.

Chandrayaan — India ★

Mission	Year	Outcome
Chandrayaan-1	2008	Confirmed presence of water molecules
Chandrayaan-2	2019	Orbiter successful; lander crashed
Chandrayaan-3	2023	Successful soft landing near the lunar south pole; India became the 4th country to do so

SELENE (Kaguya) (2007) — Japan

SELENE — Selenological and Engineering Explorer — was Japan’s major lunar orbiter mission, launched in 2007.
Kaguya captured high-definition images, significantly improving knowledge of the Moon’s geology.

SLIM (2023–24) — Japan

SLIM (Smart Lander for Investigating Moon) was a technology-demonstration mission for precision landing — landing within a very small target area.
It demonstrated ‘pinpoint landing’ capability, vital for future missions to hazardous regions such as crater edges or polar areas.
It highlighted Japan’s expertise in advanced guidance, navigation, and control systems.

Note: ESA has never independently landed a spacecraft on the Moon. ESA provides scientific instruments, payload components, and technical support to missions led by other agencies.

Major Lunar Milestones — At a Glance

Country	First Lunar Mission	First Successful Soft Landing	First Human Landing
USA	1958 – Pioneer 0/1 (attempts)	1966 – Surveyor 1	1969 – Apollo 11
USSR	1959 – Luna 1	1966 – Luna 9	No
China	2007 – Chang’e 1	2013 – Chang’e 3	No
India	2008 – Chandrayaan-1	2023 – Chandrayaan-3	No
Japan	2007 – SELENE (Kaguya)	2024 – SLIM	No

Major Mars Missions — The Race for the Red Planet

Mars is often called the ‘next frontier.’ Why? Because liquid water once flowed there, and scientists are still searching for signs of microbial life. We will read this section the same way — country-wise and evolution-wise: first flybys, then landers, then rovers, and now preparations for sample return.

Mariner 4 (1965) — NASA

A flyby mission and the first successful Mars mission. It returned the first close-up images of Mars.

Viking 1 & Viking 2 (1976) — NASA

Lander missions, each consisting of an orbiter and a lander.
Viking 1 was the first successful Mars lander mission.
The landers conducted experiments to detect possible signs of microbial life in Martian soil, and provided the first surface images of Mars.

Mars Pathfinder (1997) — NASA

Deployed Sojourner, the first operational rover on another planet, which analysed rocks and soil composition.
Innovation: a low-cost, airbag-based landing system.

Spirit and Opportunity (2004) — NASA

Twin rovers, part of NASA’s Mars Exploration Rover (MER) programme.
They discovered strong evidence of past water activity — mineral formations that only form in the presence of liquid water.

Curiosity Rover (2012–Present) — NASA

Landed in Gale Crater to study whether Mars ever had conditions suitable for life.
Discovered organic molecules and signs of ancient lakebeds.

Perseverance Rover (2021–Present) — NASA

Exploring Jezero Crater, believed to have once contained a river delta.
Searching for evidence of ancient microbial life, and collecting and storing rock samples for a future Mars Sample Return mission.
It deployed Ingenuity, the first helicopter to fly on another planet.

Mars 2 and Mars 3 (1971) — Soviet Union

Mars 2: The lander entered the atmosphere but crashed due to system failure — still, it became the first human-made object to reach the Martian surface, though not a successful landing.
Mars 3: Achieved the first soft landing on Mars, but communication was lost after about 20 seconds, limiting data transmission.

Mars Express (2003–Present) — ESA

ESA’s first mission to Mars — an orbiter studying the Martian atmosphere, surface geology, and subsurface structure.
It provided evidence of large water-ice deposits and detailed mineral mapping of the Martian surface.

ExoMars Programme — ESA and Russia

Trace Gas Orbiter (2016): Studies the Martian atmosphere, focusing on trace gases like methane, which could indicate biological or geological activity.
Rover Component (Delayed): Planned to drill below the Martian surface in search of signs of past life.

Mars Orbiter Mission — Mangalyaan (2013) — ISRO ★

Mangalyaan made India the first Asian nation to reach Mars orbit, and the first country in the world to reach Mars orbit on its maiden attempt. It demonstrated remarkably cost-effective deep-space capability.

Tianwen-1 (2021) — China

Launched in 2020, it successfully entered Mars orbit in 2021.
A combined mission — orbiter, lander, and rover (Zhurong) all in one. China became the first country to deploy an orbiter-lander-rover combination on its very first Mars mission.
China became the second country, after the USA, to successfully operate a rover on Mars.

Hope Probe (2021) — UAE

An orbiter mission designed to study Mars’ atmosphere and climate.
It became the first Arab interplanetary mission.
The UAE became the fifth nation to reach Mars orbit, after the USA, USSR, ESA, and India.

Major International Mars Missions — Summary Table

Country	First Successful Mars Mission	First Lander	First Rover	Notable Achievement
USA	1965 – Mariner 4 (Flyby)	1976 – Viking 1	1997 – Sojourner	Most successful and sustained Mars exploration programme
USSR	1971 – Mars 2/3	1971 – Mars 3 (brief)	No	First spacecraft to soft-land on Mars (short-lived)
ESA	2003 – Mars Express	No (Beagle 2 failed)	No	Trace Gas Orbiter — studying methane
India	2013 – Mangalyaan	No	No	Reached Mars orbit on the maiden attempt itself
China	2021 – Tianwen-1	2021 – Zhurong Lander	2021 – Zhurong Rover	Orbiter + lander + rover in the very first mission
UAE	2021 – Hope Probe	No	No	First Arab interplanetary mission

Major Solar Missions — Understanding the Sun

The Sun is 150 million kilometres away, yet its ‘moods’ — solar storms, solar wind — directly affect our satellites and power grids. Understanding ‘space weather’ is therefore a matter of strategic necessity, and that is exactly what these missions do.

Parker Solar Probe — NASA

Launched in 2018, NASA’s flagship mission to study the Sun.
It is the closest-ever spacecraft to the Sun, travelling directly through the Sun’s outer atmosphere.
The trick: repeated Venus gravity assists were used to gradually reduce its orbital distance.
At closest approach, its speed exceeds 600,000 km/h — making it the fastest human-made object ever!
It withstands extreme heat using a specially designed carbon-composite heat shield.

Solar Orbiter — NASA-ESA Joint

Launched in 2020. It studies the Sun from unique viewing angles.
Notably, it gradually tilts its orbit to obtain views of the Sun’s polar regions — difficult to observe from Earth.
At perihelion, it approaches closer to the Sun than Mercury.

Hinode — JAXA

Hinode means ‘Sunrise’ in Japanese. Launched in 2006.
Also known as Solar-B, since it followed Japan’s earlier solar mission (Solar-A / Yohkoh).
Developed by JAXA in collaboration with NASA and UK research institutions.

SOHO — NASA-ESA

Launched in 1995. It is positioned at the Sun-Earth L1 Lagrange point (~1.5 million km from Earth).
From this location, SOHO has a continuous, unobstructed view of the Sun.

SDO — NASA

Launched in 2010, in a geosynchronous orbit for continuous solar observation.
Part of NASA’s ‘Living with a Star (LWS)’ programme, which focuses on understanding Sun-Earth connections.

Aditya-L1 — ISRO ★

Launched in 2023 — India’s first dedicated solar observation mission.
It too is positioned at the Sun-Earth L1 Lagrange Point, allowing continuous observation of the Sun.
It studies solar activity and its impact on space weather.

Mission	Agency/Country	Launch Year	Location/Orbit	Key Objective
Aditya-L1	India (ISRO)	2023	Sun-Earth L1 Halo Orbit	Study solar corona and space weather
Parker Solar Probe	USA (NASA)	2018	Closest approach to Sun	Study corona and solar wind up close
Solar Orbiter	NASA-ESA	2020	Near-Sun elliptical orbit	Study the Sun’s poles and magnetic field
SOHO	NASA-ESA	1995	Sun-Earth L1	Continuous solar monitoring
SDO	USA (NASA)	2010	Geosynchronous orbit	High-resolution solar imaging
Hinode	Japan (JAXA)	2006	Earth orbit	Study solar magnetic activity

Major Missions to Other Planets

Let us now move beyond Mars and the Sun — toward Venus, Mercury, Jupiter, Saturn, and the outer solar system. Notice a pattern as you read: every planet has a distinct ‘specialty’ that becomes the focus of the mission sent there.

Venus Missions

Venus is often called Earth’s ‘twin’ — but it is an extreme greenhouse hell, with surface temperatures reaching ~460°C. Studying Venus helps scientists understand climate evolution and planetary atmospheres.

Magellan (1990–1994, NASA): Used radar imaging to map Venus’s surface in high detail for the first time — since thick clouds block optical cameras, radar waves penetrate the clouds and reflect back from the surface. Revealed vast volcanic plains and lava flows.
Venus Express (2006–2014, ESA): Studied Venus’s atmosphere and climate system. Confirmed strong greenhouse gases, helping explain the ‘runaway greenhouse effect.’
Akatsuki (2010–Present, JAXA): Focuses on Venusian weather systems — particularly ‘super-rotation,’ where the atmosphere rotates much faster than the planet itself.
Shukrayaan-1 (Planned, ISRO): India’s proposed Venus orbiter mission.

Mercury Missions

Mercury, being closest to the Sun, experiences extreme temperature swings (+430°C to –180°C). Studying Mercury helps us understand planetary formation in extreme environments.

MESSENGER (2004–2015, NASA): The first spacecraft to orbit Mercury (2011). Mapped nearly 100% of its surface. Discovered Mercury’s global magnetic field — indicating an active or partially molten core — and found evidence of water ice in permanently shadowed polar craters.
BepiColombo (2018–Present, ESA-JAXA Joint): Uses multiple gravity assists (Earth, Venus, Mercury) to gradually enter Mercury’s orbit, with arrival expected in the mid-2020s.

Jupiter Missions

Jupiter, the largest planet in the Solar System, is key to understanding gas giants and the icy moons that may host subsurface oceans.

Galileo (1989–2003, NASA): The first spacecraft to orbit Jupiter (1995). Also deployed an atmospheric probe. Studied the four major moons: Io, Europa, Ganymede, and Callisto. Found strong evidence that Europa may have a subsurface ocean, and observed volcanic activity on Io — the most volcanically active body in the Solar System.
Juno (2016–Present, NASA): In a highly elliptical polar orbit to reduce radiation exposure. Studies the atmosphere (including storms like the Great Red Spot), magnetic field, gravity field, and internal structure.
JUICE — Jupiter Icy Moons Explorer (2023–Present, ESA): Scheduled to arrive at Jupiter in the 2030s. Will study the icy moons Europa, Ganymede, and Callisto, and become the first spacecraft to orbit Ganymede — the largest moon in the Solar System.

Saturn Missions

Cassini–Huygens (1997–2017, NASA-ESA Joint): Cassini entered Saturn’s orbit in 2004, becoming the first spacecraft to do so. The mission ended in 2017 with a controlled plunge into Saturn’s atmosphere — the ‘Grand Finale.’
- The Cassini Orbiter detected water-ice plumes erupting from Enceladus, indicating a subsurface ocean. The Huygens Probe made the first-ever landing on Titan, discovering methane lakes, rivers, and a thick nitrogen-rich atmosphere.

Titan is considered one of the most Earth-like bodies in the Solar System in terms of atmospheric processes.

Outer Planets — Uranus and Neptune

Voyager 2 (1977–Present, NASA): Remains the only spacecraft to have visited both Uranus (1986) and Neptune (1989), and continues to operate in interstellar space today. Revealed Uranus’s ~98° axial tilt and new moons and rings. At Neptune, it captured the Great Dark Spot, a massive storm system, and observed the fastest winds in the Solar System.

Dwarf Planet Missions

New Horizons (2006–Present, NASA): The first mission to explore Pluto and the Kuiper Belt. Performed a historic Pluto flyby in 2015, providing humanity’s first close-up images.
- Revealed Pluto as a geologically active world with nitrogen-ice plains (e.g., Sputnik Planitia) and water-ice mountains.
- After Pluto, it explored a Kuiper Belt Object, Arrokoth, in 2019.

Asteroid and Comet Missions

Asteroids and comets are primitive remnants of the early Solar System — essentially time capsules that tell us how it all began.

Hayabusa (2003–2010, JAXA): The first mission to return asteroid samples, from Itokawa.
Hayabusa-2 (2014–2020, JAXA): Collected samples from asteroid Ryugu — organic compounds and water-bearing minerals were found.
OSIRIS-REx (2016–2023, NASA): Returned samples from asteroid Bennu in 2023. Bennu contains carbon-rich material, offering clues about early Solar System chemistry and the origins of life. After sample delivery, the spacecraft was renamed OSIRIS-APEX and is now headed toward asteroid Apophis, with a flyby planned for 2029.