Gaganyaan is India’s first human spaceflight, ensuring crew safety and employing advanced technology.
THIRUVANANTHAPURAM: In an exclusive conversation, TNI’s Vivek Narayanan speaks to Dr. S Unnikrishnan Nair, the Director of Vikram Sarabhai Space Centre (VSSC) and a launch vehicle specialist, about India’s ambitious space missions: Gaganyaan and Chandrayaan 3. These groundbreaking ventures signify India’s unwavering commitment to exploring the cosmos and cementing its position among the leading space-faring nations of the world.
India’s Gaganyaan and Chandrayaan 3 missions mark pioneering strides in space exploration. Gaganyaan is India’s first human spaceflight, ensuring crew safety and employing advanced technology. Chandrayaan 3 faces the challenge of a soft Moon landing, overcoming distance and gravity, tells Dr Nair.
ISRO excels in launch vehicles like PSLV and GSLV, and technologies like reusable launch vehicles and scramjet propulsion which has drawn the attention of the international community that observes India’s progress closely.
Excerpts from the interview
VIVEK NARAYANAN: We have Dr. S Unnikrishnan Nair with us, the Director of VSSC and also the launch vehicle specialist. Can you explain the significance of the upcoming Gaganyaan Mission and the challenges it faces?
Dr S UNNIKRISHNAN NAIR: The Gaganyaan Mission is a milestone for ISRO and VSSC (Vikram Sarabhai Space Centre). It marks the first time India is embarking on a mission involving human spaceflight, where astronauts will be sent into space and brought back safely. This requires a different approach, with a primary focus on the security and safety of the crew. Special considerations are being made for their living environment, including provisions for food, water, waste management, and maintaining the appropriate pressure.
The launch vehicle, LVM 3, is being made human-rated, adding robustness, reducing redundancies, and reliability. The typical payload firing section will be replaced with an orbital module featuring a crew escape system at the tip. The vehicle will be equipped with advanced avionics and a vehicle health management system to monitor vital parameters and make appropriate decisions in case of any issues during the mission depending upon the health conditions of the crew.
VIVEK NARAYANAN: How many crew members are expected to be part of the Gaganyaan Mission, and when is it expected to take place?
Dr S UNNIKRISHNAN NAIR: Currently, four astronaut trainees are undergoing training. The number of crew members for the first mission will be decided based on the situation, but the capacity of the crew module is designed to accommodate a maximum of three crew members. As for the timeline, the Chairman has already mentioned it. We are currently focusing on qualifying the system, and several tests need to be conducted. One of the most important tests coming up in a couple of months is demonstrating the performance of the escape system in flight conditions. For this, we will use a small vehicle with the escape system mounted on it, taking it to the appropriate altitude and transonic condition (from subsonic to supersonic). We’ll activate the escape system during this condition to assess its performance and ensure the parameters are acceptable for human safety. Following this, there will be a series of tests, including an unmanned flight somewhere in the next year, leading up to multiple unmanned flights before the manned mission.
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VIVEK NARAYANAN: Can you explain the challenges faced in the Chandrayaan 3 mission and its significance for the country?
Dr S UNNIKRISHNAN NAIR: Chandrayaan 3 is a challenging mission as it involves traveling a vast distance of approximately 3,80,000 kms to the Moon, where gravity is only one-sixth of that on Earth. The end-to-end mission management of the spacecraft throughout the journey is a significant challenge. The initial part involves VSSE’s role in injecting the spacecraft into a precise orbit with the right initial conditions, allowing for a gradual increase in velocity to escape Earth’s gravitational field. Subsequently, it will enter the Moon’s gravitational influence and then perform a soft landing on the Moon. The absence of an atmosphere on the Moon makes energy management during landing particularly challenging, as it requires firing thrusters in the opposite direction to control the spacecraft. Overall, the mission involves complex engineering, managing payloads, and addressing the challenges of space, radiation, temperature extremes, and sensor operations.
VIVEK NARAYANAN: What are the main missions and projects currently underway at VSSC?
Dr S UNNIKRISHNAN NAIR: As for the future, VSSC serves as the mother center of ISRO, where all launch vehicles are designed, realized, and launched from Sriharikota. Several centers, including LPSC for propulsion systems, ISU for inertial sensors, and Mahendragiri, play a vital role in the launch vehicle program. The center is involved in various missions and projects related to space exploration and satellite launches. ISRO is actively working on several launch vehicles. We have the PSLV (Polar Satellite Launch Vehicle), which is in production mode and operational. The GSLV (Geosynchronous Satellite Launch Vehicle) had some issues with the last to last flight, related to the cryogenic stage, but those have been rectified, and a successful flight has recently been conducted. The SSLV (Small Satellite Launch Vehicle) is also progressing well, with two successful flights and preparations for the next one. The GSLV Mk III, which was used for the Chandrayaan mission, will be modified for the Gaganyaan and manned flights. Additionally, ISRO is involved in technology development activities, such as the reusable launch vehicle and scramjet propulsion technology.
VIVEK NARAYANAN: Could you explain the process of human rating the LVM three rocket for the Gaganyaan mission?
Dr S UNNIKRISHNAN NAIR: Human rating a rocket involves ensuring the safety and confidence of both the vehicle and the crew. Launch vehicles have numerous components, and their reliability is typically around 0.97 to 0.98, which is not sufficient for human missions. To address this, ISRO focuses on designing, testing, and demonstrating a higher reliability escape system. This system ensures that if anything goes wrong during the launch, the escape system will be activated to rescue the crew. Moreover, they improve redundancy in the launch vehicle, such as using quad systems instead of dual systems for avionics and having multiple seals. The launch vehicle and ground systems are closely monitored with fully instrumented measurements to assess vehicle health and make real-time decisions during the flight. The human rating process encompasses various aspects to ensure maximum safety for the crew.
VIVEK NARAYANAN: What other technology development activities are ongoing at ISRO, and what is the focus of these activities?
Dr S UNNIKRISHNAN NAIR:: In addition to the launch vehicle development, ISRO is actively engaged in multiple technology development activities. Some of these include reusable launch vehicle technology, where they have successfully achieved a perfect landing of a winged aircraft autonomously. Scramjet propulsion technology is also being developed. Sounding rockets are used for various technology tests, including avionic system development and inflatable aerodynamic decelerators. Long duration flight programs and hundreds of other new technology development activities are being pursued in parallel by various entities within ISRO.
VIVEK NARAYANAN: What measures are being taken to ensure the safety of the crew in the Gaganyaan mission?
Dr S UNNIKRISHNAN NAIR:: Ensuring the safety of the crew is of utmost importance in the Gaganyaan mission. One approach is the integrated approach called “human rating.” This involves flying on a shallow trajectory, even at the cost of payload, to ensure that the escape system can be activated at any time during the trajectory to protect the crew’s physiological conditions. Various safety measures are implemented, such as a higher reliability escape system and redundant systems in the launch vehicle. The focus is on crew safety and reliability rather than just machine success.
VIVEK NARAYANAN: How is ISRO contributing to startup missions and projects?
Dr S UNNIKRISHNAN NAIR: ISRO actively supports startup missions and projects through the interface called In-SPACe, where startups approach the space agency. Depending on the capability of each center, support is provided in areas like solid motor, liquid engine testing, aerodynamic testing, avionic systems, and consultancy services. ISRO extends technical advice and facilities to startups, fostering innovation and collaboration. This involvement of private firms and startups is making the space program more dynamic and cutting-edge.
VIVEK NARAYANAN: How are youngsters reacting to ISRO’s space missions, and is there an increase in interest among the youth?
Dr S UNNIKRISHNAN NAIR: The response from youngsters has been highly enthusiastic. Thousands of students and youngsters attended the last PSLV launch, with overflowing galleries and excitement, taking photos. Young people get inspired by such events and express interest in joining ISRO or other scientific endeavors. The space missions are creating awareness about science and technology and encouraging more youth to join such advanced technology development programs.
VIVEK NARAYANAN: How are other countries looking at India’s Gaganyaan mission?
Dr S UNNIKRISHNAN NAIR: The Gaganyaan mission has garnered international attention and interest. Only a few countries are conducting human spaceflight missions, and India’s capabilities and technologies are being noticed globally. Countries like the US, Russia, and China have been actively involved in human spaceflight programs, and India’s entry into this domain is seen as a significant development. International collaboration also takes place in certain areas, such as wind tunnel tests and procurement of certain components.
VIVEK NARAYANAN: What is the expected time for Chandrayaan 3?
Dr S UNNIKRISHNAN NAIR: The targeted landing date for Chandrayaan 3 is August 23rd, with further adjustments possible depending on the progress of the mission. The timeline is set around August 10th, and the mission aims to achieve a soft landing on the Moon. However, it is a dynamic process, and any unforeseen challenges may affect the landing date.