Computers & Internet — Digital World Fundamentals

Why This Chapter Matters

Science and technology current affairs bridge two sections of the RRB Group D paper at once, general science and general awareness, which means a single well-remembered fact here can answer questions from either section. ISRO missions alone have generated 3 to 4 questions across recent RRB and SSC papers in a single exam cycle, making this one of the highest-return topics per hour of study in the entire syllabus.

The single biggest mistake aspirants make is treating every space or technology headline as equally important and trying to memorise all of it in equal detail. That approach burns your limited revision time on trivia while missing the handful of missions and technologies that examiners actually draw questions from repeatedly: Chandrayaan, Aditya-L1, Gaganyaan, and basic definitions of AI and 5G. This chapter sorts the signal from the noise, going deep on what gets tested and light on what does not.

1. ISRO and Indian Space Missions

Chandrayaan-3: India's Lunar Landmark

Chandrayaan-3 launched on July 14, 2023, aboard the LVM3 (Launch Vehicle Mark-3) rocket from the Satish Dhawan Space Centre, Sriharikota. Its lander, named Vikram, touched down successfully near the Moon's south pole on August 23, 2023, making India the fourth country to achieve a soft lunar landing after the USA, Russia (then Soviet Union), and China, and the first country ever to land specifically near the lunar south pole region.

The mission carried a rover named Pragyan, which means "wisdom" in Sanskrit, and which explored the lunar surface, confirming the presence of sulphur and detecting other elements through its onboard spectrometer instruments. August 23 is now observed as National Space Day in India, commemorating this achievement.

Exam trap: Do not confuse Vikram (the lander) with Pragyan (the rover). A simple way to keep them straight: Vikram means "valour," fitting for the vehicle that braves the risky landing; Pragyan means "wisdom," fitting for the rover that then explores and learns about the surface.

Chandrayaan-3 followed Chandrayaan-2, launched in 2019, whose orbiter succeeded but whose lander, also named Vikram, crashed during its final descent. Chandrayaan-3 was designed specifically to fix the failure points identified from that earlier attempt, which is why examiners sometimes ask which mission succeeded where the previous one failed.

Aditya-L1: Watching the Sun

Aditya-L1, India's first dedicated solar observation mission, launched on September 2, 2023, aboard a PSLV rocket. It travelled roughly 1.5 million kilometres from Earth, far short of reaching the Sun itself, to a gravitationally stable point called Lagrange Point 1 (L1), where it settled into a halo orbit in January 2024. From this vantage point, Aditya-L1 continuously observes the Sun without any eclipse interruption, studying the solar corona, solar wind, and space weather phenomena that can affect satellites and power grids on Earth.

Think of L1 as a parking spot exactly balanced between Earth's gravity pulling one way and the Sun's gravity pulling the other, letting a spacecraft sit there using minimal fuel to stay in place, rather like balancing a coin exactly on the edge of a table where two forces cancel out.

Gaganyaan: India's Human Spaceflight Ambition

Gaganyaan is ISRO's mission to send Indian astronauts into low Earth orbit using an entirely Indian-built launch vehicle and crew capsule, a goal that would make India only the fourth nation to independently send humans to space, after Russia, the USA, and China. Through 2024 and 2025, the programme continued its uncrewed test flights and safety validation stages, including tests of the crew escape system designed to pull the capsule away from the rocket in case of a launch emergency. The astronaut candidates selected for the eventual crewed mission underwent training, including sessions in Russia, ahead of the mission's planned crewed flight.

Memory hook: Gaganyaan comes from Sanskrit, roughly "sky vehicle." Pair it mentally with Chandrayaan ("Moon vehicle") and Mangalyaan ("Mars vehicle"), India's three flagship "yaan" missions, each named for its destination, sky, Moon, and Mars respectively.

Mangalyaan: The Mars Legacy Mission

Mangalyaan, formally the Mars Orbiter Mission, launched in November 2013 and reached Mars orbit in September 2014, making India the first country to reach Mars orbit on its very first attempt and the fourth nation overall to reach Mars, after the USA, Russia, and the European Space Agency. Though the mission's operational life eventually ended, it remains a landmark reference point in current affairs discussions about India's growing space capability, often cited alongside Chandrayaan-3 as proof of ISRO's cost-efficient mission design; Mangalyaan famously cost less than the production budget of some Hollywood space films.

PSLV, GSLV, and LVM3: Know Your Rockets

RRB and SSC papers frequently test which rocket launched which mission, so keep this distinction clear. The Polar Satellite Launch Vehicle (PSLV) is ISRO's reliable workhorse, used for most satellite launches including Mangalyaan and Aditya-L1. The Geosynchronous Satellite Launch Vehicle (GSLV) handles heavier payloads meant for geostationary orbit. The LVM3, previously called GSLV Mk III, is ISRO's most powerful operational rocket, used for Chandrayaan-2, Chandrayaan-3, and planned for Gaganyaan's crewed flights, because it can carry the heaviest payloads to the needed orbits.

Memory hook: Think of PSLV as a reliable auto-rickshaw, frequent and dependable for regular trips. GSLV is a bigger taxi for heavier loads. LVM3 is the heavy truck, brought out only when the cargo, like a Moon lander or a human crew capsule, is too big and heavy for anything smaller.

NavIC and Other ISRO Applications

NavIC (Navigation with Indian Constellation), India's own regional satellite navigation system, similar in concept to the American GPS but focused on India and its surrounding region, continued expanding its civilian applications through this period, including integration into smartphones and vehicle tracking systems. This reduces India's dependence on foreign satellite navigation systems for critical applications.

2. Renewable Energy Initiatives

India's Solar Power Push

India continued its rapid expansion of solar power capacity through 2024 and 2025, driven by schemes like the PM Surya Ghar: Muft Bijli Yojana, launched in 2024, which aims to provide free electricity to households by subsidising rooftop solar panel installation, targeting one crore households. The scheme offers direct subsidy support, making solar installation affordable for middle and lower-income households who previously found the upfront cost prohibitive.

India's large-scale solar parks, including facilities in Rajasthan, Gujarat, and Karnataka, continued expanding capacity, with India ranking among the top few countries globally for installed solar power capacity. The logic behind India's solar push is straightforward: India receives abundant sunlight across most of the year, making solar one of the most naturally suited renewable sources for the country compared to, say, wind-dependent nations with less consistent sunlight.

Wind Energy and Hybrid Projects

Alongside solar, India continued developing wind energy capacity, particularly along its western and southern coastlines where wind patterns are most favourable, states like Gujarat, Tamil Nadu, and Rajasthan lead in installed wind capacity. Hybrid renewable projects, combining solar and wind generation at the same site to balance output across different times of day and seasons, gained more traction during this period as a way to make renewable power supply more consistent.

International Solar Alliance and Global Commitments

India co-founded the International Solar Alliance (ISA) alongside France, launched in 2015 at the Paris climate conference, and the alliance continued expanding its membership through this period, working to promote solar energy adoption particularly among sun-rich developing nations. India also continued progress toward its stated target of a substantial share of its installed power capacity coming from non-fossil fuel sources, a commitment made at international climate forums and tracked closely in government energy reports.

Exam trap: Do not confuse installed renewable capacity (the maximum power plants can generate) with actual generation (the power actually produced), since solar and wind generation varies by weather and time of day, a nuance examiners sometimes test through carefully worded questions.

Green Hydrogen Mission

The National Green Hydrogen Mission, launched in 2023, aims to make India a global hub for producing, using, and exporting green hydrogen, hydrogen produced using renewable electricity rather than fossil fuels. Green hydrogen is seen as a crucial fuel for hard-to-electrify sectors like heavy industry, shipping, and long-haul transport, where batteries alone are less practical due to weight and charging-time constraints.

3. Notable Scientific Achievements

Indigenous Vaccine and Health Technology

India's pharmaceutical and biotechnology sector, having demonstrated its manufacturing scale during the COVID-19 pandemic through vaccines like Covaxin, developed by Bharat Biotech in collaboration with the Indian Council of Medical Research, continued building on that momentum through 2024 and 2025, expanding vaccine research for other diseases and strengthening India's position as a major global vaccine manufacturer, sometimes referred to informally as the "pharmacy of the world."

Quantum Computing and the National Quantum Mission

India's National Quantum Mission, approved in 2023, aims to develop quantum computing, quantum communication, and quantum sensing capabilities over the following years, positioning India among the nations investing seriously in this emerging technology field. Quantum computers use principles of quantum mechanics to process certain types of information dramatically faster than traditional computers for specific problem types, though the technology remains in relatively early development stages worldwide, India included.

Semiconductor Manufacturing Push

Through 2024 and 2025, India's semiconductor manufacturing ambitions gained momentum, with government incentive schemes attracting investment in chip fabrication and assembly plants in states like Gujarat and Assam. Semiconductors, the tiny chips that power everything from smartphones to cars to railway signalling systems, became a strategic priority globally after supply chain disruptions during the pandemic exposed how dependent most countries, including India, were on a small handful of chip-manufacturing nations.

4. Emerging Technology Explained Simply

Artificial Intelligence (AI)

Artificial Intelligence refers to computer systems designed to perform tasks that normally need human intelligence, recognising images, understanding language, making predictions, or playing strategic games. You do not need deep technical knowledge for this exam, but you should understand the basic idea clearly: AI systems learn patterns from large amounts of data rather than being programmed with explicit step-by-step instructions for every situation.

A simple analogy: imagine teaching a child to recognise a mango not by describing every possible shape, colour, and size a mango can have, but by showing them hundreds of mango photos until they naturally learn to spot one anywhere. That is roughly how a large chunk of modern AI, called machine learning, works, learning from examples rather than following a fixed rulebook.

India's own AI push includes the IndiaAI Mission, approved in 2024, aimed at building domestic AI computing infrastructure, supporting Indian language AI models, and encouraging AI adoption across government services and industry. This mission recognises that AI trained primarily on English-language, Western data does not always serve India's linguistically diverse population well, so building India-specific AI capability, including support for Indian languages, became a stated national priority.

5G and Telecommunications

5G, the fifth generation of mobile network technology, rolled out across Indian cities starting in October 2022 and continued expanding to smaller towns and rural areas through 2024 and 2025. Compared to the earlier 4G network, 5G offers dramatically faster data speeds, much lower latency (the delay between sending and receiving data), and the capacity to connect far more devices simultaneously in the same area.

Think of 4G as a two-lane road that gets congested during peak hours, while 5G is a wide multi-lane highway built for both current traffic and the much heavier traffic expected in the future, including connected devices beyond just phones, like smart factory sensors, connected vehicles, and remote surgery equipment that need near-instant data transfer.

India's 5G rollout was notably fast by global standards, reaching a large share of districts within about two years of launch, partly credited to the indigenous development of core 5G technology by Indian telecom companies and research institutions, reducing dependence on foreign telecom equipment suppliers for critical network infrastructure.

Exam trap: Do not confuse 5G (a mobile network generation, about how data travels wirelessly) with fibre broadband (a wired internet technology). Both offer high speed, but 5G is specifically about mobile and wireless connectivity, a distinction examiners occasionally test through option wording.

Electric Vehicles and Battery Technology

India's electric vehicle sector continued growing through 2024 and 2025, supported by government schemes offering purchase incentives and by expanding charging infrastructure in major cities. Electric two-wheelers and three-wheelers, being cheaper and simpler than electric cars, led adoption numbers in India, reflecting the country's price-sensitive vehicle market. Battery technology, particularly lithium-ion batteries, remains the primary cost driver for electric vehicles, which is why India also began investing in domestic battery manufacturing capacity to reduce reliance on imported battery cells.

5. Why These Topics Cluster Together in Exams

Notice a pattern across this chapter: nearly every development ties back to two national themes, self-reliance (reducing dependence on imported technology, whether rockets, chips, batteries, or telecom equipment) and inclusive access (bringing technology benefits, from free electricity to AI in local languages, to ordinary citizens rather than just urban elites). Once you see this pattern, individual facts become easier to place, because you can ask yourself "which theme does this belong to?" rather than memorising each fact as an isolated trivia point.

This is also why science and technology current affairs overlap so heavily with the general current affairs and economy topics elsewhere in this book. An exam question about India's semiconductor push, for instance, could appear in a "science" section or an "economy" section depending on how the paper is structured, so do not silo your revision by chapter title alone; revise the underlying facts and be ready for them from either angle.

6. Common Question Formats and How to Prepare

Science and technology current affairs questions in RRB papers usually follow one of four formats, and recognising the format helps you prepare more efficiently. First, "first/only" questions: "Which country was the first to land near the Moon's south pole?" Second, date-matching questions: "In which year did Aditya-L1 reach L1 orbit?" Third, naming questions: "What is the lander of Chandrayaan-3 called?" Fourth, comparison questions: "How does 5G differ from 4G?"

Notice that each format tests a different kind of memory. "First/only" questions test whether you know the significance of an event, not just its date. Date-matching tests raw recall of a number. Naming tests recall of a proper noun tied to a mission. Comparison tests conceptual understanding rather than memorisation. When you revise this chapter, deliberately quiz yourself in all four formats for each major fact, rather than only reading passively, since passive reading builds recognition but not the active recall the exam actually demands.

A useful trick for space missions specifically: build a simple timeline in your notebook with just five entries, Mangalyaan (2013), Chandrayaan-2 (2019), Chandrayaan-3 (2023), Aditya-L1 (2023), and Gaganyaan (ongoing). Five entries are far easier to hold in memory than fifteen scattered facts, and once the timeline is solid, the surrounding details, rocket names, achievements, lander names, attach themselves more easily to their correct year.

7. Connecting Science Current Affairs to the Static Science Chapters

This book's earlier science chapters cover foundational physics, chemistry, and biology concepts that rarely change. This chapter, by contrast, covers the fast-moving edge of that same science, current missions, current technology rollouts, current research directions. The two halves reinforce each other. When you read about Aditya-L1 studying the solar corona, that connects to solar system concepts from your basic astronomy revision. When you read about lithium-ion batteries in electric vehicles, that connects to basic chemistry concepts about electrochemical cells covered elsewhere in this book.

Treat this chapter as the "what's new" layer sitting on top of the "what's always true" layer from your static science chapters. Exam papers often draw one question from each layer on the same broad topic, for instance one static question on how a solar cell works and one current-affairs question on India's solar capacity targets, so strong preparation in one layer supports the other rather than competing with it for your study time.

8. A Final Word on Staying Current

Because this is a "current developments" chapter, some of its cutting-edge facts, particularly around Gaganyaan's crewed flight date, ongoing quantum computing milestones, and the latest EV adoption figures, will keep evolving after this book reaches you. Treat the missions and technologies named here as your confirmed foundation. In your final weeks of preparation, spend a short, focused session checking specifically for: any newly announced ISRO mission, any updated Gaganyaan timeline, and any major new government technology scheme announced in the months closest to your exam date. This targeted approach protects your revision time far better than re-reading unrelated general news each day.

Quick Revision — One-Line Facts

• Chandrayaan-3 launched on July 14, 2023, aboard the LVM3 rocket.
• Vikram lander touched down near the Moon's south pole on August 23, 2023.
• August 23 is observed as National Space Day in India.
• Pragyan, meaning "wisdom," was the rover carried by Chandrayaan-3.
• India became the fourth country to achieve a soft Moon landing and the first near the south pole.
• Chandrayaan-2's lander, also named Vikram, crashed during its 2019 landing attempt.
• Aditya-L1 launched on September 2, 2023, aboard a PSLV rocket.
• Aditya-L1 reached its halo orbit around Lagrange Point 1 in January 2024.
• L1 is a gravitationally balanced point roughly 1.5 million km from Earth toward the Sun.
• Gaganyaan aims to make India the fourth nation to independently send humans to space.
• Mangalyaan (Mars Orbiter Mission) launched in November 2013, reached Mars orbit in September 2014.
• India was the first country to reach Mars orbit on its first attempt.
• PSLV is ISRO's reliable workhorse rocket for most regular satellite launches.
• LVM3 (formerly GSLV Mk III) is ISRO's most powerful rocket, used for Chandrayaan missions and Gaganyaan.
• NavIC is India's own regional satellite navigation system, similar in purpose to GPS.
• PM Surya Ghar: Muft Bijli Yojana, launched in 2024, subsidises rooftop solar for free household electricity.
• India ranks among the top countries globally for installed solar power capacity.
• International Solar Alliance was co-founded by India and France, launched in 2015.
• National Green Hydrogen Mission, launched in 2023, aims to make India a global green hydrogen hub.
• Covaxin, developed by Bharat Biotech with ICMR, was India's indigenous COVID-19 vaccine.
• National Quantum Mission was approved in 2023 to build India's quantum computing capability.
• India's semiconductor manufacturing push gained momentum through 2024-2025 with new fab investments.
• Artificial Intelligence systems learn patterns from data rather than following fixed step-by-step rules.
• IndiaAI Mission, approved in 2024, supports domestic AI infrastructure and Indian language AI models.
• India's 5G rollout began in October 2022 and expanded rapidly to rural areas by 2024-2025.
• 5G offers faster speed, lower latency, and greater device capacity compared to 4G.
• 5G is a wireless mobile network technology, distinct from wired fibre broadband.
• Electric two-wheelers and three-wheelers lead India's EV adoption due to lower cost.
• Lithium-ion batteries remain the primary cost driver for electric vehicles.
• Science and technology current affairs often overlap with economy and general current affairs sections.

Memory Tables

Table 1: ISRO's Major "Yaan" Missions

Mission	Meaning	Launch Year	Key Achievement
Mangalyaan	Mars vehicle	2013 (reached Mars 2014)	First nation to reach Mars orbit on first attempt
Chandrayaan-2	Moon vehicle (2nd)	2019	Orbiter succeeded; lander crashed
Chandrayaan-3	Moon vehicle (3rd)	2023	First successful landing near lunar south pole
Gaganyaan	Sky vehicle	In progress (test flights through 2024-2025)	Aims for India's first indigenous human spaceflight
Aditya-L1	Sun mission (not "yaan" named)	2023	India's first dedicated solar observation mission

Table 2: Emerging Technology Quick Reference

Technology	What It Means	India-Specific Initiative
Artificial Intelligence	Systems that learn from data to perform human-like tasks	IndiaAI Mission (2024)
5G	Fifth-generation mobile network, faster and lower latency than 4G	Rollout began October 2022
Green Hydrogen	Hydrogen produced using renewable electricity	National Green Hydrogen Mission (2023)
Quantum Computing	Computing using quantum mechanics principles for select problem types	National Quantum Mission (2023)
Electric Vehicles	Vehicles powered by batteries instead of fossil fuel engines	Purchase incentive and charging infra schemes

Practice MCQs

Q1. On which date did Chandrayaan-3's Vikram lander touch down near the Moon's south pole? (a) July 14, 2023 (b) August 23, 2023 (c) September 2, 2023 (d) January 2024

Q2. What is August 23 observed as in India, commemorating Chandrayaan-3's success? (a) Republic Day (b) National Technology Day (c) National Space Day (d) ISRO Foundation Day

Q3. What was the name of the rover carried by Chandrayaan-3? (a) Vikram (b) Pragyan (c) Mangal (d) Surya

Q4. Which rocket carried Chandrayaan-3 into space? (a) PSLV (b) GSLV (c) LVM3 (d) SLV

Q5. Aditya-L1 settled into orbit around which point in January 2024? (a) Earth's geostationary orbit (b) Lagrange Point 1 (c) Lunar orbit (d) Mars orbit

Q6. What was the outcome of Chandrayaan-2's landing attempt in 2019? (a) It succeeded fully (b) The orbiter succeeded but the lander crashed (c) The mission was cancelled before launch (d) It never reached the Moon's vicinity

Q7. India's Mars Orbiter Mission, Mangalyaan, achieved which notable first? (a) First country to land on Mars (b) First country to reach Mars orbit on its first attempt (c) First country to send humans to Mars (d) First country to launch a Mars mission

Q8. Which ISRO rocket is described as the most powerful, used for Chandrayaan missions and planned Gaganyaan flights? (a) PSLV (b) GSLV (c) LVM3 (d) ASLV

Q9. NavIC is best described as what? (a) India's national highway network (b) India's regional satellite navigation system (c) India's nuclear power programme (d) India's cybersecurity agency

Q10. PM Surya Ghar: Muft Bijli Yojana, launched in 2024, primarily supports which technology? (a) Wind turbines (b) Rooftop solar panels (c) Electric vehicle charging (d) Nuclear power plants

Q11. The International Solar Alliance was co-founded by India along with which country? (a) Germany (b) France (c) Japan (d) United Kingdom

Q12. Green hydrogen, the focus of India's National Green Hydrogen Mission, is defined as hydrogen produced using what? (a) Coal-based electricity (b) Renewable electricity (c) Nuclear power only (d) Natural gas reforming exclusively

Q13. In basic terms, how does much of modern Artificial Intelligence, specifically machine learning, function? (a) By following fixed step-by-step rules for every case (b) By learning patterns from large amounts of data (c) By copying instructions from a fixed manual (d) By requiring no data at all

Q14. Compared to 4G, what does 5G primarily offer? (a) Slower speed but wider coverage (b) Faster speed, lower latency, and greater device capacity (c) Only wired connectivity (d) No difference in performance

Q15. Which of the following correctly distinguishes 5G from fibre broadband? (a) They are identical technologies (b) 5G is wireless mobile network technology; fibre broadband is wired (c) Fibre broadband is a mobile network generation (d) 5G only works indoors

Answer Key

Q	Answer	One-line reason
1	(b) August 23, 2023	This date is now marked as National Space Day, making it one of the most tested dates in this chapter.
2	(c) National Space Day	The observance directly commemorates the successful lunar landing achieved on this date.
3	(b) Pragyan	Pragyan (wisdom) was the rover; Vikram (valour) was the lander, a pairing worth remembering by meaning.
4	(c) LVM3	LVM3, ISRO's most powerful operational rocket, was needed for Chandrayaan-3's heavier payload.
5	(b) Lagrange Point 1	L1 is the gravitationally balanced point that lets Aditya-L1 continuously observe the Sun.
6	(b) The orbiter succeeded but the lander crashed	Chandrayaan-3 was specifically designed to fix the landing failure from Chandrayaan-2.
7	(b) First country to reach Mars orbit on its first attempt	This remains Mangalyaan's most frequently tested distinguishing achievement.
8	(c) LVM3	LVM3 (formerly GSLV Mk III) is reserved for ISRO's heaviest and most critical payloads.
9	(b) India's regional satellite navigation system	NavIC serves a similar purpose to GPS but is focused on India and its surrounding region.
10	(b) Rooftop solar panels	The scheme subsidises rooftop solar installation to provide free electricity to households.
11	(b) France	India and France jointly launched the International Solar Alliance in 2015 at the Paris climate conference.
12	(b) Renewable electricity	Green hydrogen is defined specifically by its renewable-electricity production method, unlike hydrogen from fossil fuels.
13	(b) By learning patterns from large amounts of data	This data-driven learning approach is the core distinguishing feature of machine learning within AI.
14	(b) Faster speed, lower latency, and greater device capacity	These three improvements define 5G's advantage over the earlier 4G standard.
15	(b) 5G is wireless mobile network technology; fibre broadband is wired	This distinction is a common source of confusion that examiners specifically test.