GS Paper III · Science & Technology · Space
🛰 International Space Station (ISS)
5-Agency Collaboration · 25+ Years Continuously Inhabited · Modules & Structure · Key Discoveries · Zvezda Air Leak Crisis · Shubhanshu Shukla on Axiom-4 · SpaceX Deorbit Vehicle · Commercial Successors · India's BAS 2035
🛰
About the International Space Station
Largest Man-Made Object in Space · 5 Agencies · Since 1998
📖 What is the ISS?
The International Space Station (ISS) is the largest man-made object in space and a unique international collaboration among five space agencies: NASA (USA), Roscosmos (Russia), JAXA (Japan), ESA (Europe), and CSA (Canada). The first module (Zarya) was launched on November 20, 1998, and the station has been continuously inhabited since November 2, 2000 — over 25 years of unbroken human presence in space. It serves as both a home for astronaut crews and a unique microgravity science laboratory.
📊 Legacy IAS — ISS in Low Earth Orbit
🏠 Simple Analogy — The World's Biggest Flatshare
Imagine a football-field-sized apartment floating 400 km above the ground, shared by people from 5 different countries, travelling at 28,000 km/h, seeing 16 sunrises every day, where everything floats — your food, your water, even your tears. That's the ISS. It's been "lived in" non-stop since November 2000. Nobody has the original keys anymore — the tenants just keep rotating every 6 months. And the landlords (5 space agencies) keep arguing about when to demolish it.
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Size & Structure
Total mass: ~420,000 kg (~420 tonnes).
End-to-end span: 109 m (larger than a football field).
Pressurized volume: ~916 m³ (livable space).
43 modules and elements as of 2025.
Solar array wingspan: 73 m.
End-to-end span: 109 m (larger than a football field).
Pressurized volume: ~916 m³ (livable space).
43 modules and elements as of 2025.
Solar array wingspan: 73 m.
👨🚀
Crew & Visitors
Typical crew size: 6–7 astronauts.
As of Feb 2026: 294 individuals from 26 countries have visited.
USA: 172 visitors. Russia: 65. Japan: 11. Canada: 9.
India: 1 visitor (Shubhanshu Shukla, June 2025).
As of Feb 2026: 294 individuals from 26 countries have visited.
USA: 172 visitors. Russia: 65. Japan: 11. Canada: 9.
India: 1 visitor (Shubhanshu Shukla, June 2025).
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How It Got There
Built in orbit piece-by-piece from 1998–2011.
Delivered by: Space Shuttles, Proton rockets, Soyuz rockets.
Combines 2 earlier plans: USA's Space Station Freedom + Russia's Mir-2.
Assembly completed: 2011.
Delivered by: Space Shuttles, Proton rockets, Soyuz rockets.
Combines 2 earlier plans: USA's Space Station Freedom + Russia's Mir-2.
Assembly completed: 2011.
🧠 Memory Aid — "ISS = International Shared Science-lab"
I = International (5 agencies, 26 countries visited) · S = Shared (the world's biggest cooperative project) · S = Science-lab (3,300+ experiments in microgravity). Launched 1998, inhabited 2000, assembled 2011, planned deorbit 2030-31.
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Key Modules of the ISS
Russian Segment · US Segment · Labs · Nodes · Robotic Arms
📊 Legacy IAS — Simplified ISS Module Layout
| Module | Country | Launched | Purpose |
|---|---|---|---|
| Zarya (FGB) | 🇷🇺 Russia | Nov 1998 | First module — initially provided power, propulsion, guidance. Now: storage. |
| Unity (Node 1) | 🇺🇸 USA | Dec 1998 | First connecting node — links Russian and US segments. |
| Zvezda (Service Module) | 🇷🇺 Russia | Jul 2000 | Life support, living quarters, propulsion system. Most critical module — only one with thrusters for reboost. ⚠ Ongoing air leak since 2019. |
| Destiny (US Lab) | 🇺🇸 USA | Feb 2001 | Primary US science laboratory. |
| Harmony (Node 2) | 🇺🇸 USA | Oct 2007 | Docking port for SpaceX Dragon, Starliner, and visiting vehicles. |
| Columbus | 🇪🇺 ESA | Feb 2008 | European research laboratory — fluid physics, materials science. |
| Kibo | 🇯🇵 Japan | 2008–09 | Largest pressurized module. Has external experiment platform + airlock. |
| Tranquility (Node 3) | 🇺🇸 USA | Feb 2010 | Advanced life support, water recycling, oxygen generation. |
| Cupola | 🇪🇺 ESA | Feb 2010 | Observation dome — 7 windows for Earth viewing and robotic arm operations. |
| Nauka (Multipurpose Lab) | 🇷🇺 Russia | Jul 2021 | New Russian lab module — science, storage, extra docking port. |
💡 Canadarm2 — Canada's Robotic Arm
Canada's major contribution to the ISS is Canadarm2, a 17.6-metre robotic arm that can move equipment, modules, and even astronauts during spacewalks. It can "walk" end-over-end across the station. Attached to it is Dextre, a two-armed robot that performs delicate maintenance tasks without needing astronauts to go outside. Canada's contribution earned it a seat at the ISS partnership table despite being a smaller space agency.
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Significance of the ISS
Diplomacy · Science · Medicine · Mars Preparation
🤝
International Diplomacy & Cooperation
The ISS is the most successful example of international cooperation in space. It brought together former Cold War rivals (USA & Russia) and continues to operate despite geopolitical tensions (Ukraine war). It has hosted astronauts from 26 countries — a symbol of peaceful collaboration in space.
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Space Medicine Research
Microgravity mimics ageing effects in human cells — providing insights for treatment of Alzheimer's, Parkinson's, cancer, and immune system disorders. Astronauts' bone/muscle loss in space mirrors osteoporosis on Earth → research benefits millions of patients on ground.
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Mars & Moon Mission Preparation
ISS is a testbed for long-duration spaceflight effects on the human body. Studies on radiation exposure, bone density loss, vision changes, and psychological effects are all critical for future Artemis (Moon) and Mars missions. Scott Kelly's 1-year mission (2015–16) was specifically designed for this.
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Low-Earth Orbit Economy
ISS has stimulated the commercial space industry. SpaceX, Northrop Grumman, and Boeing all developed vehicles for ISS supply/crew missions. Private astronaut missions (Axiom-1 to 4) have pioneered commercial access. NASA now offers up to 2 private missions per year.
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Important Discoveries on the ISS
3,300+ Experiments · Drug Development · Cool Flames · BEC · Food in Space
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Drug Development & Disease Research
Proteins crystallize more perfectly in microgravity → better drug design. Tissue chips (miniature human organ models) tested in space reveal disease mechanisms faster. Fundamental research into cancer, cardiovascular disease, and immune disorders.
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Cool Flames
ISS experiments discovered steadily burning cool flames — fire that burns at much lower temperatures than on Earth. This was impossible to study with gravity. Applications in designing cleaner, more efficient engines and understanding fire safety in space.
❄
Bose-Einstein Condensate (BEC)
ISS explored the fifth state of matter — Bose-Einstein Condensate — where atoms cool to near absolute zero and behave as a single quantum entity. Microgravity allows BEC to last longer → better quantum physics research.
🌱
Growing Food in Space
Astronauts have successfully grown lettuce, radishes, chili peppers, and other crops on the ISS using the "Veggie" and "Advanced Plant Habitat" systems. Critical for long-duration Mars missions where resupply isn't feasible.
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Muscle & Bone Loss Countermeasures
Astronauts lose 1–2% bone density per month in space. ISS research developed exercise regimens and nutritional strategies to combat this atrophy — findings that also help osteoporosis patients on Earth.
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Earth Monitoring & Cosmic Rays
ISS provides a unique vantage point for monitoring Earth's climate, natural disasters, and land use changes. The Alpha Magnetic Spectrometer (AMS-02) has collected data on 100+ billion cosmic particles — searching for antimatter and dark matter.
📊 Other Notable ISS Achievements
Water purification: ISS recycles 90%+ of water (including urine and sweat) — the technology is now used in water-scarce regions on Earth.
3D printing in microgravity: First 3D-printed tool in space (2014) — future spacecraft may manufacture parts on-demand.
CubeSat deployment: ISS has deployed hundreds of small satellites from its airlock — democratising space access for universities and startups.
Microbe identification: First-ever identification of unknown microbes in space (using MinION DNA sequencer) — no sample return to Earth needed.
3D printing in microgravity: First 3D-printed tool in space (2014) — future spacecraft may manufacture parts on-demand.
CubeSat deployment: ISS has deployed hundreds of small satellites from its airlock — democratising space access for universities and startups.
Microbe identification: First-ever identification of unknown microbes in space (using MinION DNA sequencer) — no sample return to Earth needed.
🇮🇳
India & the ISS — Shubhanshu Shukla's Historic Mission
Axiom Mission 4 · June–July 2025 · First Indian on ISS · Gaganyaan Link
🇮🇳 SHUBHANSHU SHUKLA — INDIA'S FIRST ASTRONAUT ON THE ISS Critical Current Affairs
On June 25, 2025, Group Captain Shubhanshu Shukla became the first Indian astronaut to visit the International Space Station and the second Indian to travel to space — 41 years after Wing Commander Rakesh Sharma's flight to Salyut 7 in 1984.
Mission: Axiom Mission 4 (Ax-4) — the 4th private astronaut mission to the ISS, jointly conducted by NASA and Axiom Space. SpaceX Dragon spacecraft "Grace" was used.
Duration: 18 days aboard the ISS (June 25 – July 15, 2025).
Role: Mission Pilot (not just a passenger — active crew role).
Crew: Commander Peggy Whitson (USA), Pilot Shubhanshu Shukla (India), Mission Specialists Sławosz Uznański-Wiśniewski (Poland) and Tibor Kapu (Hungary).
Historic firsts: First government-sponsored human spaceflight in 40+ years for India, Poland, and Hungary.
Mission: Axiom Mission 4 (Ax-4) — the 4th private astronaut mission to the ISS, jointly conducted by NASA and Axiom Space. SpaceX Dragon spacecraft "Grace" was used.
Duration: 18 days aboard the ISS (June 25 – July 15, 2025).
Role: Mission Pilot (not just a passenger — active crew role).
Crew: Commander Peggy Whitson (USA), Pilot Shubhanshu Shukla (India), Mission Specialists Sławosz Uznański-Wiśniewski (Poland) and Tibor Kapu (Hungary).
Historic firsts: First government-sponsored human spaceflight in 40+ years for India, Poland, and Hungary.
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Experiments Conducted
Shukla performed ~60 experiments from 31 countries. At least 7 were ISRO-designed, including:
• Cognitive effects of screen use in microgravity
• Microbial adaptation in space
• Muscle atrophy studies
• Crop resilience in microgravity
• Space nutrition & food systems (ISRO-NASA collaboration)
• Radiation monitoring (SigmaLabs RadMon)
• Cognitive effects of screen use in microgravity
• Microbial adaptation in space
• Muscle atrophy studies
• Crop resilience in microgravity
• Space nutrition & food systems (ISRO-NASA collaboration)
• Radiation monitoring (SigmaLabs RadMon)
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Why This Matters for UPSC
1. Gaganyaan link: Experience directly feeds into India's first indigenous crewed spaceflight (expected Q1 2027).
2. BAS link: Prepares India for its Bharatiya Antariksh Station (2035 target). First module planned for 2028 launch.
3. Diplomacy: Strengthens India-USA-SpaceX space cooperation.
4. Cost: ~₹548 crore ($65 million) — ISRO defends it as "investment in experience."
2. BAS link: Prepares India for its Bharatiya Antariksh Station (2035 target). First module planned for 2028 launch.
3. Diplomacy: Strengthens India-USA-SpaceX space cooperation.
4. Cost: ~₹548 crore ($65 million) — ISRO defends it as "investment in experience."
🧠 Remember — India's Space Milestones
1984: Rakesh Sharma → Salyut 7 (Soviet mission). 2025: Shubhanshu Shukla → ISS (Axiom-4, commercial mission). ~2027: Gaganyaan → India's own crewed spacecraft (indigenous). 2028: First module of Bharatiya Antariksh Station. 2035: Full BAS operational. The Ax-4 experience is the bridge between Rakesh Sharma's legacy and Gaganyaan's future.
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Current Affairs — ISS (2024–2026)
Zvezda Leak · Deorbit Vehicle · NASA Reauthorization · Russia's ROS Plan
🚨 ZVEZDA MODULE AIR LEAK — Biggest Safety Concern Critical
What's happening: Russia's Zvezda service module has been leaking air since September 2019 through cracks in a transfer tunnel (PrK) that connects to the Progress cargo docking port.
How bad is it? The leak rate doubled by February 2024 — from ~0.45 kg/day to over 0.9 kg/day of air escaping. NASA elevated this to the highest level of risk in its risk management system (September 2024 OIG report).
NASA vs Roscosmos disagreement:
• NASA believes the cause involves multiple factors: mechanical stress, environmental exposure, and manufacturing defects.
• Roscosmos blames vibrations from the station's mechanical systems causing "high cycle fatigue" in the metal walls.
• They cannot agree on whether a catastrophic failure is possible. NASA raised concerns about structural integrity; Roscosmos says disintegration is unlikely.
Mitigation: The hatch between PrK and the rest of the station can be sealed. When cosmonauts access a Progress cargo ship, the US crew closes the hatch between the US and Russian segments as a safety measure.
Why is Zvezda so critical? It is the only module with a propulsion system capable of orbital reboost and attitude control. Without Zvezda, the ISS would lose altitude and re-enter the atmosphere uncontrollably within ~2 years. SpaceX Cargo Dragon has been testing reboost capabilities as a backup.
How bad is it? The leak rate doubled by February 2024 — from ~0.45 kg/day to over 0.9 kg/day of air escaping. NASA elevated this to the highest level of risk in its risk management system (September 2024 OIG report).
NASA vs Roscosmos disagreement:
• NASA believes the cause involves multiple factors: mechanical stress, environmental exposure, and manufacturing defects.
• Roscosmos blames vibrations from the station's mechanical systems causing "high cycle fatigue" in the metal walls.
• They cannot agree on whether a catastrophic failure is possible. NASA raised concerns about structural integrity; Roscosmos says disintegration is unlikely.
Mitigation: The hatch between PrK and the rest of the station can be sealed. When cosmonauts access a Progress cargo ship, the US crew closes the hatch between the US and Russian segments as a safety measure.
Why is Zvezda so critical? It is the only module with a propulsion system capable of orbital reboost and attitude control. Without Zvezda, the ISS would lose altitude and re-enter the atmosphere uncontrollably within ~2 years. SpaceX Cargo Dragon has been testing reboost capabilities as a backup.
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SpaceX Deorbit Vehicle (USDV) 2024
In June 2024, NASA awarded SpaceX $843 million to build the US Deorbit Vehicle — a spacecraft to push the ISS into a controlled re-entry and splashdown in an uninhabited area of the Pacific Ocean (~January 2031). Total cost could reach $1.5 billion (including launch). The USDV will be based on SpaceX's Dragon spacecraft. The station will be gradually lowered over 2–2.5 years before the final deorbit burn.
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NASA Reauthorization Act 2026 New
On February 4, 2026, the US House Science Committee unanimously (37-0) approved a bill requiring NASA to reconsider its deorbit plans. The Senate added a draft measure to extend ISS operations to 2032 (2 extra years) and forbids deorbiting until a commercial replacement station is operational. This reflects concerns that no commercial station will be ready before 2030.
🇷🇺
Russia's ROS Plan (Dec 2025) New
In a major reversal, Russia announced (December 2025) that it will reuse its ISS modules after 2030, renaming them the Russian Orbital Station (ROS) instead of building a completely new station. The Nauka lab module (launched 2021) and a new NEM module (expected 2029) would detach from the ISS and continue as an independent Russian station.
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Boeing Starliner Troubles Ongoing
Boeing's CST-100 Starliner suffered thruster and helium leak issues during its first crewed flight (June 2024). Astronauts Butch Wilmore and Suni Williams, originally on an 8-day mission, stayed on ISS for 8+ months. NASA confirmed the next Starliner mission (Starliner-1) will be cargo-only — no crew. SpaceX Dragon remains the primary US crew vehicle.
📅 ISS — Key Timeline
Nov 1998
First module Zarya launched. ISS construction begins.
Nov 2000
Expedition 1 arrives. Continuous human presence begins (still ongoing — 25+ years).
2011
ISS assembly completed. Space Shuttle programme retires.
2020
SpaceX Crew Dragon's first crewed flight to ISS. Commercial crew era begins.
Jul 2021
Russia's Nauka module docked (25 years delayed). Briefly fires thrusters by accident, spinning the ISS.
2022
Ukraine war strains Russia–West ISS cooperation. Russia announces intent to leave ISS (later walked back).
Jun 2024
NASA awards SpaceX $843M for US Deorbit Vehicle. Boeing Starliner crew stranded on ISS.
Jun 2025
Axiom-4 launches — Shubhanshu Shukla becomes first Indian on ISS. India
Dec 2025
Russia announces it will reuse ISS modules as Russian Orbital Station (ROS) after 2030.
Feb 2026
US Congress passes bill requiring NASA to reconsider deorbit; Senate proposes extending to 2032.
2029 (target)
USDV launch. ISS begins lowering orbit gradually.
~2030–31
Planned controlled deorbit → Pacific Ocean splashdown (if Congress permits).
🚀
Future Space Stations — Post-ISS Era
Commercial Stations · Tiangong · India's BAS · Russia's ROS
| Station | Country / Company | Target Launch | Key Details |
|---|---|---|---|
| Tiangong 🇨🇳 | China (CMSA) | Operational since 2022 | 3 modules (Tianhe + Wentian + Mengtian). 3 crew, up to 6 during handover. Up to 450 km altitude. 30 taikonauts by 2026. Expanding to 6 modules — doubling size. May accept international crews. |
| Haven-1 | Vast (USA, private) | ~May 2026 | Single module, shipping-container sized. First commercial station expected in orbit. SpaceX Falcon 9 launch. 4 crew. |
| Axiom Station | Axiom Space (USA) | First module ~2026 | $140M from NASA LEO Destinations programme. Will initially dock to ISS, then undock to become independent before 2030. Focuses on research + private astronaut missions. |
| Orbital Reef | Blue Origin + Sierra Space (USA) | ~2027–2030 | $172M from NASA. Mixed-use "business park in space." 10 crew. Still in design phase. |
| Starlab | Voyager Space + Airbus | ~2028 | Joint venture. Passed NASA Preliminary Design Review (2025). Single-launch station. Fabrication underway. |
| ROS 🇷🇺 | Russia (Roscosmos) | Post-2030 | Repurposed ISS Russian modules (Nauka, NEM). NOT a new build — cost-saving decision. Reversal from earlier plans for entirely new station. |
| Bharatiya Antariksh Station (BAS) 🇮🇳 | India (ISRO) | First module ~2028, full by 2035 | India's own space station. 400 km orbit. ~20 tonnes. Crew stays of 15–20 days initially. Feeds into India's long-term human spaceflight programme post-Gaganyaan. |
💡 The Gap Problem — Why Congress is Worried
NASA's own Inspector General warned in 2024 that no commercial station is likely to be ready before 2030. If the ISS is deorbited on schedule (~2031) and no replacement is operational, the US faces a "gap" in human spaceflight capability — potentially leaving China's Tiangong as the only government-operated station in orbit. This is why Congress is pushing to extend ISS to 2032 and requiring NASA to have a replacement ready before deorbiting.
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Previous Year Questions & Practice MCQs
UPSC Prelims · GS Paper III · ISS & Space Station Questions
📜 UPSC CSE Prelims — Related Question2023
Q. Consider the following statements about the International Space Station:
1. It is a joint project of only two countries — USA and Russia.
2. It orbits Earth at an altitude of approximately 400 km.
3. India is one of the partner agencies of the ISS programme.
Which of the statements given above is/are correct?
1. It is a joint project of only two countries — USA and Russia.
2. It orbits Earth at an altitude of approximately 400 km.
3. India is one of the partner agencies of the ISS programme.
Which of the statements given above is/are correct?
- (a) 1 and 2 only
- (b) 2 only ✅
- (c) 2 and 3 only
- (d) 1, 2 and 3
Statement 1 is wrong — the ISS involves five agencies: NASA, Roscosmos, ESA, JAXA, and CSA. Statement 2 is correct — ~400 km altitude. Statement 3 is wrong — India (ISRO) is NOT a partner agency of the ISS. India participated as a visiting nation through Axiom-4 (2025), but is not an ISS partner. ISRO is building its own station (BAS).
🎯 Practice MCQs — Test Your Understanding (Click to Answer)
Q1. Which was the first module of the International Space Station launched into orbit?
- (a) Unity — launched by NASA using the Space Shuttle
- (b) Zvezda — Russia's service module providing propulsion
- (c) Zarya — the Functional Cargo Block launched by Russia in November 1998
- (d) Destiny — the primary US science laboratory
✅ (c) Zarya. Also known as the Functional Cargo Block (FGB), Zarya was launched on November 20, 1998 using a Russian Proton rocket. It initially provided power, storage, propulsion, and guidance for the station. Unity (Node 1) was the second module, launched December 1998 by Space Shuttle Endeavour. Zvezda was launched in July 2000. Destiny came in February 2001.
Q2. Shubhanshu Shukla's Axiom-4 mission (June 2025) is significant because:
1. He became the first Indian to visit the ISS.
2. He was the commander of the mission.
3. The mission was a collaboration between ISRO, NASA, and SpaceX.
4. He conducted experiments that will directly benefit the Gaganyaan programme.
Which of the above statements are correct?
1. He became the first Indian to visit the ISS.
2. He was the commander of the mission.
3. The mission was a collaboration between ISRO, NASA, and SpaceX.
4. He conducted experiments that will directly benefit the Gaganyaan programme.
Which of the above statements are correct?
- (a) 1 and 2 only
- (b) 1, 2 and 3
- (c) 1, 3 and 4 only
- (d) 1, 2, 3 and 4
✅ (c) 1, 3 and 4 only. Statement 1 is correct — Shukla was the first Indian on the ISS. Statement 2 is WRONG — Shukla was the Mission Pilot, not Commander. The Commander was veteran NASA astronaut Peggy Whitson. Statement 3 is correct — ISRO, NASA, and SpaceX collaborated. Statement 4 is correct — ISRO explicitly stated that the experience and experiments would directly benefit Gaganyaan and India's future Bharatiya Antariksh Station. This is a classic UPSC trap — confusing Pilot with Commander.
Q3. Why is NASA concerned about the air leak in the Zvezda module?
- (a) Zvezda is the newest module on the ISS and a leak so early indicates fundamental design flaws
- (b) The leak is in the US segment of the station, so NASA must fix it unilaterally
- (c) Zvezda only provides storage and has no critical systems — the concern is purely about air loss
- (d) Zvezda is the only module with propulsion capability for orbital reboost — a structural failure could make the entire ISS uncontrollable
✅ (d). Zvezda is the most critical module on the ISS because it is the only one with a propulsion system capable of performing orbital reboost and attitude control. Without Zvezda, the ISS would lose altitude due to atmospheric drag and eventually re-enter uncontrollably within approximately 2 years. Option (a) is wrong — Zvezda was launched in 2000, making it one of the oldest modules (25+ years). Option (b) is wrong — the leak is in the Russian segment. Option (c) is wrong — Zvezda provides life support, propulsion, living quarters, and is far more than just storage.
Q4. Consider the following statements about planned future space stations:
1. India's Bharatiya Antariksh Station is planned for a 400 km orbit with crew stays of 15–20 days initially.
2. China's Tiangong is already operational since 2022 and is being expanded to double its size.
3. Russia plans to build an entirely new space station from scratch to replace its ISS modules.
Which of the above statements is/are correct?
1. India's Bharatiya Antariksh Station is planned for a 400 km orbit with crew stays of 15–20 days initially.
2. China's Tiangong is already operational since 2022 and is being expanded to double its size.
3. Russia plans to build an entirely new space station from scratch to replace its ISS modules.
Which of the above statements is/are correct?
- (a) 1 and 2 only
- (b) 2 and 3 only
- (c) 1 and 3 only
- (d) 1, 2 and 3
✅ (a) 1 and 2 only. Statement 1 is correct — BAS is planned at 400 km, ~20 tonnes, 15–20 day crew stays. Statement 2 is correct — Tiangong has been operational since late 2022 and in October 2023, China announced plans to add 3 new modules, doubling its size and crew capacity. Statement 3 is WRONG — in a major reversal in December 2025, Russia announced it would reuse its existing ISS modules (Nauka, NEM) as the Russian Orbital Station (ROS) instead of building from scratch. This was a cost-saving decision.
Q5. The US Congress (February 2026) passed a bill that:
- (a) Immediately cancels the SpaceX deorbit vehicle contract and orders NASA to reboost ISS to a higher orbit permanently
- (b) Requires NASA to reconsider the deorbit plan and forbids deorbiting until a commercial replacement station is operational
- (c) Transfers ownership of the ISS from NASA to Axiom Space for continued commercial operations
- (d) Orders NASA to invite India and China as new ISS partner agencies to share the cost of maintenance
✅ (b). The NASA Reauthorization Act of 2026 was approved unanimously (37-0) by the House Science Committee. It does NOT cancel the deorbit but requires NASA to formally review alternatives before proceeding. The Senate added a draft measure extending operations to 2032 and banning deorbit until a commercial replacement exists. This reflects deep concern that no private station will be ready by 2030 — NASA's own Inspector General flagged this risk. Option (a) is wrong — the SpaceX contract isn't cancelled. Option (c) is wrong — no ownership transfer. Option (d) is wrong — no such provision exists.
⚡ Quick Revision — International Space Station Summary
| Topic | Key Facts |
|---|---|
| ISS Basics | Largest man-made object in space. 5 agencies: NASA, Roscosmos, ESA, JAXA, CSA. First module (Zarya): Nov 1998. Inhabited since Nov 2, 2000 (25+ years). Altitude: ~400 km. Speed: 28,000 km/h. Orbits every 90 min. 43 modules. 420 tonnes. 294 visitors from 26 countries. |
| Key Modules | Zarya (first, 1998). Unity (Node 1, 1998). Zvezda (propulsion + life support, 2000 — has air leak!). Destiny (US lab, 2001). Kibo (Japan, largest module). Columbus (ESA lab). Cupola (7 windows). Nauka (Russia, 2021). Canadarm2 (17.6 m robotic arm, Canada). |
| Discoveries | 3,300+ experiments. Cool flames. BEC (5th state of matter). Drug crystallisation. Muscle/bone loss countermeasures. Space farming. 3D printing. CubeSat deployment. AMS-02 (100B+ cosmic particles). Water recycling (90%+). |
| India & ISS | NOT an ISS partner agency. Shubhanshu Shukla — first Indian on ISS (Axiom-4, Jun 25, 2025). Mission Pilot (not Commander — Peggy Whitson). 18 days. 60 experiments, 31 countries. ~₹548 crore. Feeds into Gaganyaan (~2027) and BAS (2035). |
| Zvezda Air Leak | Leaking since 2019. Doubled to ~0.9 kg/day by Feb 2024. Highest risk level (NASA OIG Sep 2024). NASA vs Roscosmos disagree on cause. Zvezda is ONLY module with propulsion. Hatch protocols in place. SpaceX testing reboost capability as backup. |
| Deorbit Plan | SpaceX USDV: $843M contract (Jun 2024). Total may reach $1.5B. USDV launch: ~2029. Controlled re-entry: ~Jan 2031 → Pacific Ocean. Congress (Feb 2026): may extend to 2032; no deorbit until commercial replacement is ready. |
| Future Stations | Tiangong (China, operational 2022, expanding). Haven-1 (Vast, ~2026). Axiom Station (~2026). Orbital Reef (Blue Origin, ~2027-30). Starlab (Voyager+Airbus, ~2028). ROS (Russia, reused ISS modules, post-2030). BAS (India, 2028 first module, 2035 full). |
🚨 5 UPSC Traps — International Space Station:
Trap 1 — "India is an ISS partner" → WRONG! India is NOT one of the 5 ISS partner agencies. Shubhanshu Shukla visited the ISS as part of a commercial mission (Axiom-4) arranged through Axiom Space. India has visited the ISS but does not own, operate, or contribute any module to it. ISRO is building its own station (BAS).
Trap 2 — "Shubhanshu Shukla was the first Indian in space" → WRONG! The first Indian in space was Rakesh Sharma (1984, aboard Soyuz T-11 to Salyut 7, under the Soviet Interkosmos programme). Shukla was the second Indian in space and the first Indian on the ISS. Also — Shukla was Mission Pilot, not Commander.
Trap 3 — "The ISS was built and launched as one unit" → WRONG! The ISS was assembled piece by piece in orbit from 1998 to 2011. Over 40 assembly flights by Space Shuttles, Proton rockets, and Soyuz rockets were needed. It combines two earlier plans: USA's Space Station Freedom and Russia's Mir-2.
Trap 4 — "China's Tiangong is part of the ISS" → WRONG! Tiangong is China's completely independent, self-built space station. China is NOT part of the ISS programme (it was excluded by US law — the Wolf Amendment of 2011 prohibits NASA-China cooperation). Tiangong has been operational since 2022 and will be the only government-run station after ISS is deorbited.
Trap 5 — "ISS will simply fall out of the sky when decommissioned" → WRONG! ISS will undergo a controlled deorbit using the SpaceX-built US Deorbit Vehicle. It will be gradually lowered over 2–2.5 years, then a final burn will direct it into the atmosphere, with surviving debris splashing into an uninhabited area of the Pacific Ocean. An uncontrolled re-entry would be catastrophic — the ISS weighs 420 tonnes.
Trap 1 — "India is an ISS partner" → WRONG! India is NOT one of the 5 ISS partner agencies. Shubhanshu Shukla visited the ISS as part of a commercial mission (Axiom-4) arranged through Axiom Space. India has visited the ISS but does not own, operate, or contribute any module to it. ISRO is building its own station (BAS).
Trap 2 — "Shubhanshu Shukla was the first Indian in space" → WRONG! The first Indian in space was Rakesh Sharma (1984, aboard Soyuz T-11 to Salyut 7, under the Soviet Interkosmos programme). Shukla was the second Indian in space and the first Indian on the ISS. Also — Shukla was Mission Pilot, not Commander.
Trap 3 — "The ISS was built and launched as one unit" → WRONG! The ISS was assembled piece by piece in orbit from 1998 to 2011. Over 40 assembly flights by Space Shuttles, Proton rockets, and Soyuz rockets were needed. It combines two earlier plans: USA's Space Station Freedom and Russia's Mir-2.
Trap 4 — "China's Tiangong is part of the ISS" → WRONG! Tiangong is China's completely independent, self-built space station. China is NOT part of the ISS programme (it was excluded by US law — the Wolf Amendment of 2011 prohibits NASA-China cooperation). Tiangong has been operational since 2022 and will be the only government-run station after ISS is deorbited.
Trap 5 — "ISS will simply fall out of the sky when decommissioned" → WRONG! ISS will undergo a controlled deorbit using the SpaceX-built US Deorbit Vehicle. It will be gradually lowered over 2–2.5 years, then a final burn will direct it into the atmosphere, with surviving debris splashing into an uninhabited area of the Pacific Ocean. An uncontrolled re-entry would be catastrophic — the ISS weighs 420 tonnes.
