This is how Pranjal became a Scientist at ISRO

The below blog post has been contributed by Pranjal Srivastava who is currently a Scientist at ISRO. Pranjal joined IIT Kanpur as an M.Tech student in Computer Science and Engineering. However, since he was selected at ISRO, he dropped out within 2 months to pursue his dream at ISRO. Read the inspiring story of Pranjal below.

Star Trek introduced the popular phrase ‘Space: The Final Frontier’. If this phrase was ever true, that time is now. Space agencies around the world are investing their time, money and resources to gain a competitive advantage in the exciting domain of space science. With plans like Chandrayaan 2 and the ambitious Gaganyaan project to send 3 Indians into space, Indian Space Research Organisation (ISRO) is among the prominent space agencies in the World.

If you are pursuing Computer Science & Engineering (CSE) or already graduated and interested in working at ISRO then this blog post is for you. ISRO recruits engineering graduates every year through the ISRO Centralised Recruitment Board (ICRB) exam for the post of Scientist/Engineer ‘SC’, which is a Level 10 Gazetted officer post. From the last couple of years, they have been carrying on this recruitment process twice a year for CSE graduates. So in short, if you want to work at ISRO, you need to appear for this exam.

In this blog post, we have taken care of everything from the eligibility criteria to the preparation strategy. Let’s begin.

Eligibility Criteria

CSE/IT graduates with a minimum of 65% marks in graduation or CGPA 6.84/10 are eligible to apply. But it is better to have > 70% to be on the safe side as after receiving all the applications ISRO further sets a cutoff percentage and only candidates above that mark are sent admit cards. Since it is a Government organisation, graduates up to the age of 35 can apply. In the recruitment advertisement, it is clearly mentioned whether final year students are eligible to apply or not. Generally, if the recruitment advertisement comes in January then final year students also are free to apply.


There is no properly defined syllabus officially shared by ISRO for the exam. But if you go through the previous year papers it is clear that the syllabus is the same as GATE syllabus with the addition of Software Engineering, Web Technology and C++.

Recruitment Exam Format

The recruitment process is divided into a written exam and interview. The written exam is taken offline on an OMR sheet where candidates have to attempt 80 questions in 90 minutes. There is +3 for the right answer and -1 for negative marking. Candidates are shortlisted for interview on the basis of written exam marks. The important thing to note here is that once you have qualified for the interview, your written exam marks don’t matter and the final selection is done purely on the basis of marks secured in the interview.

Written Exam Preparation

Because of an almost the same syllabus, the preparation for ISRO paper is similar to GATE. Therefore, this blog post would be helpful to anyone preparing for GATE as well.

Books/Internet resources

The written exam is mainly a test of how good you are with basic concepts and your ability to solve questions quickly (80 questions in 90 minutes). To have a good foundation in the subjects, it is important to go through the standard textbooks first. You can follow the relevant chapters suggested from these books:


Book Name

Author Name


Relevant Chapters

Engineering Mathematics

Discrete Mathematics and its Applications

Kenneth Rosen



NCERT Maths 11,12



Relevant Topics from Syllabus

Digital Logic

Digital Design

Morris Mano




The C Programming Language

Dennis Richie



Data Structures and Algorithms

Introduction to Algorithms

Cormen (CLRS)



Theory of Computation

An Introduction to Formal Languages and Automata

Peter Linz



Computer Networks

Computer Networking: A Top-Down Approach

Kurose & Ross



Computer Organisation and Architecture

Computer Organisation and Embedded Systems

Carl Hamacher



Operating System

Operating System Concepts





Database System Concepts




Compiler Design

Compilers: Principles, Techniques and Tools

Aho & Ullman



Once you have gone through the books, you would have a strong foundation in the subjects. For Software Engineering, you can go through this link and solve previous years’ question from the subject. For Web Technology just google and go through syntax and basic concepts in HTML, XML, client-server computing. Similarly, if your programming is decent, you can just go through the basic syntax of C++ and you would be good to go.


  • Start by printing a copy of the syllabus and keeping a soft copy of it at all times in your laptop/mobile.

  • The basic idea for each subject is the same: Go through all the topics in the subject at least once => Start solving last 5 years ISRO and last 10 years GATE papers as and when you are done with each topic. This can’t be stressed enough. This is the biggest question bank you can find and so, solve them with utmost sincerity. In this way, you can continuously practice what you are learning and also get an idea about the types of questions which can be framed from that topic.

  • Join a test series. There are hardly any good ISRO test series, so it's better to join GATE test series. Made Easy online test series is good. It is not very costly and since a lot of serious aspirants give its tests, you get a fair idea about where you stand. There are subject wise tests as well, so you can give those as and when you are finished with the subjects.

  • If you are ever stuck you can post your doubts at GATE Overflow. It is a great place to get your doubts resolved. Also, have a look at GATE CSE. It contains booklist and recommended video lectures.

  • Try learning from the suggested books but if you ever get stuck don’t hesitate to google. The important thing is to learn.

  • Finish reading all the subjects and solving previous years’ papers at least one month before the exam. In the last month, revise, give a mock test every 2-3 days and most importantly analyse your mistakes. Find out the topics in which you need practice and work on them.

  • One last thought is that always prepare short notes from whatever subject you are studying. In the end, there won’t be enough time to go through all the books for revision. That is when you can utilise the short notes for quick revision.

Interview Preparation

Once you make it to the interview the written test marks become irrelevant. Interviews are generally scheduled 2-3 months after the written test. Start by going through all the subjects once more. Also, prepare a list of 4 of your favourite subjects. They may ask about them and if they do then the majority of the questions in the interview will be from those subjects only. If you are in 4th year they may ask about your projects/internships. Similarly, for experienced candidates, they may ask about what you do at work? You may also be asked small numerical questions to solve on the whiteboard. Overall just prepare well and be confident during the interviews.