Scientific & Technological Developments — Space Program, Nuclear Program & Basics of Computers

Free study material · concepts, shortcuts & solved questions

✍️ Select any text to highlight or save it

Part A: India's Space Program (ISRO)

ISRO (Indian Space Research Organisation): established 1969, HQ Bengaluru; successor to INCOSPAR (Indian National Committee for Space Research, 1962), founded under the vision of Dr. Vikram Sarabhai ("Father of Indian Space Program").
Satish Dhawan Space Centre: main launch site, Sriharikota, Andhra Pradesh.
First Indian satellite: Aryabhata, launched 1975 (from a Soviet cosmodrome).
First Indian in space: Rakesh Sharma (1984, aboard Soviet Soyuz T-11).

SLV (Satellite Launch Vehicle): India's first launch vehicle.
PSLV (Polar Satellite Launch Vehicle): ISRO's workhorse, highly reliable, used for Chandrayaan-1, Mangalyaan.
GSLV (Geosynchronous Satellite Launch Vehicle): for heavier payloads to geostationary orbit; uses indigenous Cryogenic engine technology.
LVM3 (GSLV Mk III): heaviest lift vehicle, used for Chandrayaan-2 and Chandrayaan-3.

Chandrayaan-1 (2008): discovered evidence of water molecules on the Moon.
Chandrayaan-2 (2019): orbiter successful; Vikram lander crash-landed.
Chandrayaan-3 (2023): successful soft landing near the Moon's south pole (23 August 2023) — India became the first country to land near the lunar south pole and the 4th country to achieve a soft lunar landing (after USA, Russia/USSR, China). The landing site was named "Shiv Shakti Point"; 23 August is now celebrated as National Space Day.
Mangalyaan / Mars Orbiter Mission (MOM, 2013-14): India became the first country to reach Mars orbit in its very first attempt, and the first Asian nation to reach Mars orbit; also one of the cheapest interplanetary missions ever undertaken.
Aditya-L1 (2023): India's first mission to study the Sun, placed in a halo orbit around the Sun-Earth Lagrange Point 1 (L1).
Gaganyaan: India's first indigenous human spaceflight mission (under development), would make India the 4th nation to independently send humans to space.
NavIC (Navigation with Indian Constellation): India's own regional satellite navigation system (like GPS), developed by ISRO.
RISAT, Cartosat, INSAT, GSAT series: remote sensing, mapping, and communication satellite series.
Antrix Corporation / NewSpace India Limited (NSIL): commercial arms of ISRO.

Department of Atomic Energy (DAE): established 1954.
Dr. Homi J. Bhabha: "Father of the Indian Nuclear Program," founder of Tata Institute of Fundamental Research (TIFR) and the Atomic Energy Establishment, Trombay (later renamed Bhabha Atomic Research Centre — BARC).
Nuclear tests:
- Smiling Buddha (Pokhran-I, 1974): India's first nuclear test, described as a "peaceful nuclear explosion."
- Pokhran-II (1998): series of 5 nuclear tests under PM Atal Bihari Vajpayee; led India to declare itself a nuclear weapons state.
Three-Stage Nuclear Power Programme: conceived by Homi Bhabha, aims to utilise India's large thorium reserves (India has one of the world's largest thorium reserves).
Nuclear Power Plants: Tarapur (Maharashtra — India's first), Kalpakkam (Tamil Nadu — home to Fast Breeder Reactor), Kudankulam (Tamil Nadu, largest, Indo-Russian collaboration), Rawatbhata (Rajasthan), Narora (UP).
NPCIL: Nuclear Power Corporation of India Limited, operates nuclear power plants.
Civil Nuclear Deal (Indo-US, 123 Agreement): 2008, allowed India access to civilian nuclear technology/fuel despite not being an NPT signatory.

DRDO (Defence Research and Development Organisation): 1958, develops missiles (Agni, Prithvi, Akash, BrahMos — jointly with Russia, supersonic cruise missile), Tejas fighter aircraft (indigenous Light Combat Aircraft), Arjun tank.
CSIR (Council of Scientific and Industrial Research): 1942, largest chain of publicly funded R&D institutions in India.
Missile names & categories: Agni series (Intermediate/Intercontinental Ballistic Missiles), Prithvi (short-range ballistic), Akash (surface-to-air), Nag (anti-tank), BrahMos (supersonic cruise missile, India-Russia joint venture).

Computer: an electronic device that processes data according to a set of instructions (a program) to produce output.
Charles Babbage: "Father of the Computer," designed the Analytical Engine.
Generations of Computers:
1. 1st Gen (1940s-50s): Vacuum tubes.
2. 2nd Gen (1950s-60s): Transistors.
3. 3rd Gen (1960s-70s): Integrated Circuits (ICs).
4. 4th Gen (1970s-present): Microprocessors.
5. 5th Gen: Artificial Intelligence-based.

Hardware: physical components — CPU (Central Processing Unit, "brain" of computer, contains ALU and Control Unit), RAM (Random Access Memory, volatile, temporary), ROM (Read Only Memory, non-volatile), Hard Disk/SSD (permanent storage), Input devices (keyboard, mouse, scanner), Output devices (monitor, printer).
Software:
- System Software: Operating System (Windows, Linux, macOS, Android, iOS) — manages hardware and provides platform for applications.
- Application Software: MS Word, Excel, PowerPoint, browsers, etc.
Memory units: Bit (smallest unit) → Byte (8 bits) → Kilobyte (KB) → Megabyte (MB) → Gigabyte (GB) → Terabyte (TB) → Petabyte (PB).

Internet: global network of interconnected computer networks.
WWW (World Wide Web): invented by Tim Berners-Lee (1989/1991) — a system of interlinked documents accessed via the internet (distinct from the internet itself).
IP Address: unique numerical identifier for a device on a network.
URL, HTTP/HTTPS, browser: HTTP (HyperText Transfer Protocol), HTTPS is the secure version.
LAN (Local Area Network — small area like an office), WAN (Wide Area Network — large geographical area, e.g., the internet itself), MAN (Metropolitan Area Network).
Common file extensions: .doc/.docx (Word), .xls/.xlsx (Excel), .ppt/.pptx (PowerPoint), .pdf (Portable Document Format), .jpg/.png (images), .mp3 (audio), .mp4 (video).

MS Word: word processing; shortcut Ctrl+B (bold), Ctrl+I (italic), Ctrl+U (underline), Ctrl+S (save), Ctrl+P (print), Ctrl+Z (undo).
MS Excel: spreadsheet software; uses formulas (SUM, AVERAGE), cells identified by column letter + row number (e.g., A1).
MS PowerPoint: presentation software.

Virus, Malware, Ransomware: malicious software; Antivirus protects against them.
Cloud Computing: storing/accessing data over the internet rather than local hard drives.
Artificial Intelligence (AI): simulation of human intelligence by machines.
Cryptocurrency/Blockchain: decentralised digital ledger technology (Bitcoin — first and most well-known cryptocurrency, created by pseudonymous "Satoshi Nakamoto").
Search Engines: Google, Bing, Yahoo — index and retrieve information from the web.
E-mail: electronic mail; common providers — Gmail, Outlook.

Alan Turing: "Father of Computer Science/AI," Turing Machine concept, codebreaking in WWII.
Bill Gates: co-founder of Microsoft.
Steve Jobs: co-founder of Apple.
Tim Berners-Lee: inventor of the World Wide Web.
Vint Cerf: "Father of the Internet," co-designed TCP/IP.