ISRO IRNSS-1I Navigation Satellite Mission: Objectives, Launch Date, Status, UPSC Notes

India’s space programme, led by the Indian Space Research Organisation (ISRO), has evolved from modest beginnings into one of the most respected space agencies in the world. Over the years, ISRO has designed and executed a range of missions—from satellite navigation, Earth observation, interplanetary exploration, to solar studies—that have not only enhanced India’s technological self-reliance but also contributed to global scientific collaboration. Its cost-effective approaches and mission diversity—from Chandrayaan and Mangalyaan to Aditya-L1 and the upcoming Gaganyaan—have become case studies in innovation.

For UPSC aspirants, ISROs journey is more than current affairs—it directly intersects with the syllabus of General Studies Paper 3 (Science & Technology), provides examples for GS Paper 2 (International Relations, Governance), and can enrich perspectives in the Essay Paper, Ethics, and even Optional subjects like Geography or PSIR. In this article, we will explore detailed insights about ISRO IRNSS-1I Navigation Satellite Mission —its objectives, timelines, key technologies, and strategic implications.

ISRO IRNSS-1I Navigation Satellite Mission Overview

ISRO launched IRNSS-1I Navigation Satellite to support objectives related to Navigation.The IRNSS-1I Navigation Satellite mission was designed to operate in Earth.

• The mission was launched using the PSLV-C41, as per the mission plan.
• The vehicle was launched from Satish Dhawan Space Centre.
• IRNSS-1I Navigation Satellite was mainly intended to Regional navigation services.
• Supporting long-term development, IRNSS-1I Navigation Satellite worked toward Augment NavIC constellation in addition to its main objective.
• As per ISRO documentation, the mission is Operational.

IRNSS-1I Navigation Satellite Space Mission Overview for UPSC
Mission Name	IRNSS-1I Navigation Satellite
Mission Abbreviation	IRNSS-1I
Mission Type	Navigation
Target Celestial Body or Orbit	Earth
Primary Objective	Regional navigation services
Secondary Objectives	Augment NavIC constellation
Mission Status	Operational

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Timeline & Milestones of ISRO IRNSS-1I Navigation Satellite Mission

• The scheduled launch date for IRNSS-1I Navigation Satellite was April 12, 2018.

Timeline & Milestones
Proposal Date	N/A
Critical Design Review (CDR) Date	N/A
Assembly Complete Date	N/A
Launch Date	April 12, 2018
Landing / Flyby Date	N/A
End of Primary Mission Date	N/A

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ISRO IRNSS-1I Navigation Satellite Mission Technical Specifications

Key subsystems and architecture of IRNSS-1I Navigation Satellite were built around I-1K bus, Rubidium atomic clocks.Following its launch on April 12, 2018 via PSLV-C41, the spacecraft was deployed into Geosynchronous Orbit (GSO).

• The mission architecture included Navigation and ranging payloads that would support both operational needs and scientific data acquisition.
• The communication systems onboard IRNSS-1I Navigation Satellite operated using L5-band, S-band, allowing reliable data transmission throughout the mission.
• IRNSS-1I Navigation Satellite made use of key technologies such as Satellite navigation technology.

Technical Specifications
Spacecraft Technical Specifications	I-1K bus, Rubidium atomic clocks
Scientific Payloads	Navigation and ranging payloads
Orbit Details	Geosynchronous Orbit (GSO)
Communication Frequencies / Band	L5-band, S-band
Key Technologies Used	Satellite navigation technology

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IRNSS-1I Navigation Satellite Launch Information

• IRNSS-1I Navigation Satellite was launched on April 12, 2018.
• The launch of IRNSS-1I Navigation Satellite was carried out by the PSLV-C41.
• The launch took place at Satish Dhawan Space Centre.

Launch Information
Launch Vehicle	PSLV-C41
Launch Site	Satish Dhawan Space Centre

Who are the Stakeholders & Collaborators?

Key roles in the mission were handled by ISRO.

Stakeholders & Collaboration
Agencies Involved	ISRO
Commercial Partners	N/A
International Partners	N/A
Payload Contributions by Partners	N/A
Data Sharing Policy	N/A

Outputs, Applications & Impact of ISRO IRNSS-1I Navigation Satellite Mission

ISRO marked Successfully augmented the NavIC constellation, ensuring its full operational capability and providing redundancy for the system through the successful execution of IRNSS-1I Navigation Satellite.Scientific analysis and public services were enabled through outputs like Navigation and timing data.

• ISRO has noted that IRNSS-1I Navigation Satellite contributes to public services including Navigation, tracking, disaster management, timing services.
• The mission was conceptualized in line with broader policy directions, including Strengthens NavIC constellation, ensures regional navigation autonomy.
• To ensure continuity in the missions goals, ISRO has proposed follow-up programs such as NVS series (second generation NavIC satellites), which will expand the operational scope of the original initiative.

Outputs, Applications & Impact of IRNSS-1I Navigation Satellite Mission
Data Outputs and Applications	Navigation and timing data
Major Achievements	Successfully augmented the NavIC constellation, ensuring its full operational capability and providing redundancy for the system
Applications in Civilian Life	Navigation, tracking, disaster management, timing services
Impact on Policy & Global Collaboration	N/A
Environmental Impact & Sustainability	N/A
Strategic Significance & Policy Alignment	Strengthens NavIC constellation, ensures regional navigation autonomy
Follow-up Missions or Extensions	NVS series (second generation NavIC satellites)
Cost Estimate	N/A

ISRO IRNSS-1I Navigation Satellite Space Mission Risks, Failures & Mitigation

Risks, Failures & Mitigation
Challenges Faced	N/A
Risk Mitigation Measures	N/A
Failures or Anomalies	N/A
Corrective Actions Taken	N/A
Lessons Learned	N/A

UPSC Relevance of ISRO IRNSS-1I Navigation Satellite Space Mission

• ISRO missions are frequently asked in the UPSC Prelims examination, especially under the Science and Technology section, where candidates are expected to know key facts like launch dates, objectives, and agencies involved.
• Missions like RISAT, Cartosat, and Oceansat illustrate how space technology supports internal security, agriculture, coastal monitoring, and environmental protection, all of which are topics in General Studies papers.
• ISRO’s space missions offer rich content for UPSC essays on themes like innovation, scientific temper, national self-reliance, or institutional excellence.
• Anthropology or Sociology students can reference ISRO’s outreach programs and applications for tribal development, education, and telemedicine.

Past UPSC Mains PYQs on ISRO Space Missions

Q1. Discuss the role of the private sector in the growth of the space industry in India. How has the governments policy of 2023 affected it? (2023, GS Paper 3 - Science & Technology)

Q2. What is India’s plan to have its own space station and how will it benefit our space programme? (2022 & 2019, GS Paper 3 - Science & Technology)

Q3. Space has been the next big frontier for mankind after sea and land. In this context, discuss Indias policy and preparedness for space wars. (2019, GS Paper 3 - Science & Technology)

Q4. Discuss the utility of the Mars Orbiter Mission (MOM) for India. (2016, GS Paper 3 - Science & Technology)

Q5. What do you understand by Standard Positioning Systems and Precision Positioning Systems in the GPS era? Discuss the advantages India perceives from its ambitious IRNSS programme employing just seven satellites. (2015, GS Paper 3 - Science & Technology)

Past UPSC Prelims PYQs on ISRO Space Missions

Q1 [2025]: GPS-Aided Geo Augmented Navigation (GAGAN) uses a system of ground stations to provide necessary augmentation. Which of the following statements is/are correct in respect of GAGAN?

I. It is designed to provide additional accuracy and integrity.
II. It will allow more uniform and high quality air traffic management.
III. It will provide benefits only in aviation but not in other modes of transportation.

Select the correct answer using the code given below.

(a) I, II and III
(b) II and III only
(c) I only
(d) I and II only

Correct Answer: (d) I and II only

Explanation: Statements I and II correctly describe the core purpose and benefit of the GAGAN system. (I) GAGAN is designed to augment GPS signals by correcting for errors, which provides much greater accuracy and guarantees the integrity (reliability) of the positioning information. (II) This enhanced accuracy and reliability directly enables more precise aircraft routing and landing procedures, thus improving the uniformity and quality of air traffic management.

Q2 [2022]: If a major solar storm (solar flare) reaches the Earth, which of the following are the possible effects on the Earth?

1. GPS and navigation systems could fail.
2. Tsunamis could occur at equatorial regions.
3. Power grids could be damaged.
4. Intense auroras could occur over much of the Earth.
5. Forest fires could take place over much of the planet.
6. Orbits of the satellites could be disturbed.
7. Shortwave radio communication of the aircraft flying over polar regions could be interrupted.

Select the correct answer using the code given below:

(a) 1, 2, 4 and 5 only
(b) 2, 3, 5, 6 and 7 only
(c) 1, 3, 4, 6 and 7 only
(d) 1, 2, 3, 4, 5, 6 and 7

Answer: The correct answer is (c).

Explanation: A major solar storm can disrupt GPS, power grids, satellite orbits, polar radio communication, and cause auroras, but cannot trigger tsunamis or forest fires.

Q3 [2020]: The experiment will employ a trio of spacecraft flying in formation in the shape of an equilateral triangle that has sides one million kilometres long, with lasers shining between the craft.” The experiment in question refers to

(a) Voyager-2
(b) New horizons
(c) Lisa Pathfinder
(d) Evolved LISA

Answer: The correct answer is (d) Evolved LISA.

Explanation: Evolved LISA (Laser Interferometer Space Antenna) is a planned space-based gravitational wave observatory by ESA and NASA, using three spacecraft in a triangular formation with laser beams to detect cosmic gravitational waves.

Q4 [2016]: Consider the following statements:

The Mangalyaan launched by ISRO

1. is also called the Mars Orbiter Mission
2. made India the second country to have a spacecraft orbit the Mars after USA
3. made India the only country to be successful in making its spacecraft orbit the Mars in its very first attempt

Which of the statement(s) given above is/are correct?

(a) 1 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3

Answer: c) 1 and 3 only

Explanation: Mangalyaan is the informal name of Mars Orbiter Mission (MOM), launched by ISRO on 5 November 2013 and India is the only nation to date to have succeeded on its maiden attempt.

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UPSC Practice Questions on ISRO Space Missions

Q1. In which of the following years was Indias first experimental remote sensing satellite launched?
1. 1981
2. 1978
3. 1979
4. 1980
Answer: 3
Solution: The correct answer is 1979. Bhaskara-I was an experimental Earth observation satellite launched by the Indian Space Research Organisation ISRO on June 7, 1979. It was part of Indias efforts to develop remote sensing technology for various applications like land and water management, forestry, and environmental monitoring. The Bhaskara-I was followed by the Bhaskara-II satellite, furthering the remote sensing capabilities of the country. These early satellites played a vital role in shaping Indias remote sensing program, leading to more advanced satellites like the IRS Indian Remote Sensing series.

Q2. What is the name of the abort mission that ISRO is scheduled to launch recently?
1. Flight Test Vehicle Abort Mission-1 TV-D1
2. Crew Escape System Test Mission-1 CES-T1
3. Gaganyaan Abort Mission-1 GAM-1
4. Both 1 and 2
Answer: 1
Solution: The correct answer is Flight Test Vehicle Abort Mission-1 TV-D1. ISRO is all set to launch the Flight Test Vehicle Abort Mission TV-D1, a key part of its ambitious human space mission Gaganyaan. The TV-D1 is a single-stage liquid rocket that will carry a crew module and crew escape systems to an altitude of 17 km. The abort sequence will then be executed, with the crew escape systems separating from the rocket and deploying parachutes to bring the crew module safely to the ground. The success of the TV-D1 test flight will be a significant milestone for the Gaganyaan programme, as it will demonstrate the ability of the crew escape system to safely transport astronauts away from a failing rocket. This test flight will be followed by three more tests of the same nature in the coming days. The Gaganyaan mission aims to launch a crew of three Indian astronauts to an orbit of 400 km for a three-day mission, and bring them back safely to Earth. If successful, India will become the fourth nation to launch a manned spaceflight mission, after the US, Russia, and China.

Q3. What is the name of the point where the Chandrayaan lander landed on the Moon?
1. Shiv Shakti Point
2. Ganga Point
3. Sadbhavana Point
4. Vikram Site
Answer: 1
Solution: The correct answer is Shiv Shakti Point. The landing site of Chandrayaan-3, the third lunar mission of the Indian Space Research Organisation ISRO, is named Shiv Shakti Point. The missions lander, Vikram, and rover, Pragyan, landed 600 km from the south pole of the Moon on 23 August 2023. The landing site was named on 26 August 2023 at the ISTRAC headquarters in Bengaluru. India became the fourth nation to make a successful soft landing on the Moon and the first country to land on the lunar south pole. Shiv Shakti Point is located at the coordinates 69.373S 32.319E and lies between the lunar craters Manzinus C and Simpelius N.

Q4. Who or what is Vyommitra?
1. ISROs secondary space capsule
2. ISROs humanoid robot
3. ISROs first manned space flight
4. ISROs space travel kit
Answer: 2
Solution: The correct answer is ISROs humanoid robot. The word Vyommitra is made up of two words of the Sanskrit language Vyom and Mitra which means space and friend respectively. This is the prototype of the Half-Humanoid female robot developed by ISRO. It was unveiled on 22 January 2020. Vyommitra is planned to be sent on the manned space mission in December 2021 which will help the male astronauts. Under the Gaganyaan program, Vyommitra will be sent to unmanned missions at the end of this year and also next year before the astronauts left. The aim of its creation is that ISRO does not want to fly animals on board for its experiments like other nations do to find out how the human body reacts during long-duration in space. This humanoid robot will understand what weightlessness and radiation can do to a human body.

Q5. As a part of which ISROs mission is the Bharatiya Antariksh Station BAS being developed?
1. Chandrayaan Mission
2. Gaganyaan Program
3. Mangalyaan Mission
4. Aditya-L1 Mission
Answer: 2
Solution: The correct answer is Gaganyaan Program. The Bharatiya Antariksh Station BAS is a part of ISROs Gaganyaan Programme, which is Indias human spaceflight mission to Low Earth Orbit LEO. The Gaganyaan Programme was approved in December 2018 and aims to launch human spaceflight missions, laying the foundation for further space exploration. The development of BAS is a key component of the Gaganyaan Programme, extending its scope to include long-duration human space missions and the establishment of Indias own space station. The first module of BAS is expected to be launched by December 2028, with an operational space station by 2035.

Q6. In which of the following places is the Indian Deep Space Network ISDN located?
1. Byalalu
2. Vedaranyam
3. Kulathur
4. Veppanthattai
Answer: 1
Solution: The correct answer is Byalalu. The Indian Deep Space Network ISDN is a network of large antennas and communication facilities that support interplanetary spacecraft missions. It is operated by the Indian Space Research Organisation ISRO. The primary function is to track and communicate with Indian space missions, including Mars Orbiter Mission Mangalyaan and Chandrayaan missions. Byalalu is a village located near Bangalore in Karnataka, India. The ISDN was established here to take advantage of the remote location, which minimizes radio frequency interference. It houses large parabolic antennas, including a 32-meter and an 18-meter antenna used for deep space communication.

Q7. What is the name of the inflatable habitat used in Indias first analog space mission in Ladakh?
1. Hab-1
2. Luna-1
3. Space-Dome
4. Ski-Dome
Answer: 1
Solution: The correct answer is Hab-1. ISRO has started Indias first analog space mission at Leh in Ladakh using a habitat named Hab-1. The analog space mission aims to simulate life in an interplanetary habitat as part of preparations for future lunar missions. Ladakh was chosen for the mission due to its dry, cold climate and high-altitude terrain resembling Martian and lunar landscapes. The Hab-1 habitat is designed to provide a self-sustaining environment with essential facilities for the crew. This mission will help gather data for long-duration space missions to the Moon, Mars, and beyond.

Q8. Consider the following statements about Women Engineered Satellite WESAT:
I. WESAT is the first Indian satellite to be fully designed and developed by women students of Lal Bahadur Shastri Institute of Technology for Women, Kerala.
II. WESAT was launched aboard the PSLV-C58/XPoSAT Mission as one of the secondary payloads on 1st January, 2024.
III. WESAT is meant to study how rainfall refills underground water in rural areas of India.
Which among the above statements are correct?
1. I and II only
2. II and III only
3. I and III only
4. All the above
Answer: 1
Solution: The correct answer is Option 1: I and II only. WESAT is the first Indian satellite to be fully designed and developed by women students of Lal Bahadur Shastri Institute of Technology for Women, Kerala. WESAT was launched aboard the PSLV-C58/XPoSAT Mission as one of the secondary payloads on 1st January, 2024. WESAT aims to inspire more women to participate in the field of aerospace engineering and satellite technology. The mission is a significant milestone in promoting gender diversity and inclusion in the space sector.

Q9. The location of the planned prime landing site for Vikram Lander on Chandrayaan-2 was SLS54, which is located at 70.9S and 22.8E on the Moon. Consider the following statements regarding the selection of the potential landing site.
(i) Visible to Earth for radio communication.
(ii) Water ice has been mapped at the site earlier by Lunar Reconnaissance Orbiter mission.
(iii) Local terrain features such that they dont shadow the site for long durations.
Which of the following statements above is/are correct?
1. (ii) and (iii)
2. (i) and (iii)
3. (i), (ii) and (iii)
4. (iii) only
Answer: 2
Solution: The correct answer is Option 2. Statement (i): The planned landing site for Vikram Lander was designed to ensure uninterrupted radio communication with Earth, which is crucial for the success of the mission. Statement (iii): The selection of the site took into account local terrain features, ensuring that they do not shadow the site for long durations, which could impact operations and power generation. The sites location in the polar region helps in maximizing scientific exploration opportunities, including research on water ice and lunar geology. The mission aimed to achieve a soft landing near the Moons South Pole, a previously unexplored region, marking a significant milestone in space exploration. Statement (ii): While water ice has been mapped at the Moons South Pole by missions such as NASAs Lunar Reconnaissance Orbiter LRO, there is no conclusive evidence that it was specifically mapped at the SLS54 site. The Moons South Pole is of great interest to scientists due to the presence of permanently shadowed regions that may harbor water ice, which could be a resource for future lunar missions.

Q10. Aditya-L1 is a landmark Indian mission aimed at understanding solar phenomena. What specific celestial target is Aditya-L1 focused on studying from the Lagrangian point L1?
1. Moon
2. Mars
3. Venus
4. Sun
Answer: 4
Solution: The correct answer is Sun. Aditya-L1 is Indias first dedicated mission to study the Sun. It is designed to provide insights into the solar atmosphere and its impact on the interplanetary space environment. The mission is named after the Sun god Aditya in Hindu mythology and L1 denotes its placement at the Lagrange point 1 L1, which is about 1.5 million kilometers from Earth towards the Sun. The L1 point is a strategic location for continuous solar observations because objects at this point maintain a stable position relative to the Earth and the Sun. Aditya-L1 will observe the solar corona, which is the outermost layer of the Suns atmosphere, and study its dynamics and impact on space weather. The mission aims to understand the origin and development of coronal mass ejections CMEs and solar flares, which can affect satellite operations, communications, and power grids on Earth. Aditya-L1 will carry seven payloads to observe the photosphere, chromosphere, and the outermost layers of the Sun the corona using electromagnetic and particle detectors.

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