Innovation in Space Tech
Sh. S Somanath
The author is the Chairman, Indian Space Research Organisation (ISRO), Space Commission, and the Secretary, Department of Space, GoI.
The exploration of space has always been a driving force for technological innovation, pushing the boundaries of what is possible and opening up a myriad of opportunities for research and development. From the early days of the space race to the present day, the pace of innovation in space technology has been rapid and transformative. Space applications, transportation systems, and infrastructure are a few verticals of the ISRO programme that have witnessed many technological innovations. It is actively pursuing the maiden human spaceflight mission - Gaganyaan to send astronauts to space and safely return to Earth.
In our country, the Indian Space Research Organisation (ISRO) has been at the forefront of space technology and exploration since its inception. On 21 November 1963, the first rocket took off from Thumba, a fishing hamlet near Thiruvananthapuram, announcing the birth of India’s space programme. The then rocket, payload, radar, and computer all that was required for the first launch, came from outside the country.
Over the years, leveraging its key resources, the organisation has made several strides in space technologies, making India a major player in the global space arena. In ISRO, the evolution of space technology and innovation had taken place in various technological frontiers. It is beyond the scope of the present article to touch upon every innovation in space technology that has taken birth at ISRO in the journey of 53+ years.Nevertheless, the spectrum of technological innovations, in this article, will cover the major verticals of Space Transportation System, Space Infrastructure, Space Science and Inter-Planetary Missions, Space Applications, Human Space Exploration, Space Robotics, Artificial Intelligence, Quantum Technologies, among others.
Space Transportation System
The 1970s marked the beginning of space transportation system with the development of solid-propulsion-based Sounding Rockets, which are capable of putting 30 kg of payload in 120 km of altitude, soon followed by the subsequent development of first generation launch vehicles, i.e., Satellite Launch Vehicles (SLV) and Augmented SLV (ASLV) with the induction of liquid-propulsion technology. The integration of solid and liquid propulsion and the development of various key technologies in the areas of Aerodynamics, Manufacturing, Composites, Mission Simulation, Avionics, Pyros, Mechanisms, Materials, Structural Engineering, Payload Integration, and System Reliability have resulted in the development of the second generation workhorse launch vehicle, which is none other than the Polar Satellite Launch Vehicle (PSLV), with the capability of placing a 1700 kg payload into polar orbit.
The indigenous development of a Cryogenic propulsive engine was the major technology leap in the development of third generation rockets i.e., GSLV launch vehicles, which have the capability of placing a 2000 kg payload in Geo-Synchronous Transfer Orbit (GTO).
Launching of high-throughput communication satellites necessitated the development of a further advanced launch vehicle, i.e., Launch Vehicle MK3 (LVM3). Powered by the world’s 3rd largest solid boosters, high-capacity liquid and cryogenic engines, LVM3 has the capability of putting 4000 kg payload in GTO.
The latest member of ISR O’s rocket family is the Small Satellite Launch Vehicle (SSLV), a three stage launch vehicle. Solid stages and a liquid propulsion based velocity trimming module made SSLV capable of launching a 500 kg satellite into a 500 km planar orbit in a quick turn-around time. Figure 1 shows the generations of ISR O rockets, from the sounding rocket era to the latest SSLV timeline.
Figure 1: Evolution of ISRO rockets
Space Infrastructure
Like the space transportation system, the early 1970s were the formative years of the Space Infrastructure of ISRO, which led to the foundations for design, building and operation of spacecraft. Soon, the first satellite of the country, ‘Aryabhata’ was realised and launched on 19 April 1975. Subsequently, experimental missions like Bhaskara and APPLE were executed and geared towards remote sensing, meteorology, and communications technologies.
Further momentum was gained with the indigenous development of key technologies for spacecrafts such as Advanced Propulsion, Power Systems, Thermal Systems, Deployable Structures, Space Bus Systems, Communication Systems, Ground Infrastructure, Optical, Microwave, Scientific & Communication Payloads, Unfurlable Antennas, High Throughput Satellite Systems, Multi-SpectralOptical Satellite Systems, High Resolution Cameras, Multi-Wavelength observations of the Universe, Stationary Plasma Thruster etc., for the self-reliance in spacecraft technology.
Capability in the remote sensing has grown from the coarse resolution of 1 km to the fine resolution of 28 cm with day & night and all-weather capability. The communication transponders have also proportionally grown from a mere single unit to 317 numbers. Altogether, ISRO has mastered the capability of making satellites of 2000 kg with 1 kW power to 6000 kg with 14 kW power, operating in various frequency bands and with wide, shaped, and highly focused spot capability for communications, sub-metre resolution, optical, multi-spectral, and microwave imaging for earth observations, and progressing from payload-based navigation solutions to a satellite constellation - NavIC (Navigation with Indian Constellation). The present space infrastructure includes 25 Earth observation satellites, 22 communication satellites, 7 navigation satellites, 2 space science satellites and experimental, small and student satellites. The evolution of satellites in ISRO is outlined in Figure 2.
Figure 2: Evolution of ISRO satellites
Space Science and Inter-planetary missions
Entrusted by confidence and technicalexpertise gained from satellites and launch vehicletechnologies, ISRO has sailed successfully to thereach of the Moon and Mars, opening the era ofplanetary explorations and beyond. Chandrayaan-1,the first lunar orbiter mission has brought newexperiences in hosting international payloads,calibration, data interpretation, adopting globalstandards in science data formats, etc. The scienceoutcomes of the maiden mission have providednew perspectives about the Moon.Successful findings of water on theMoon was the scientific breakthroughachieved by Chandrayaan-1. Then,Rover and Landercraft technologieswere developed, leading to theconception of a second missionto our nearest celestial neighbour.Chandrayaan-2 mission wasaltogether a highly complex mission,consisting of an Orbiter, Lunar Roverand Lunar Landercraft, as compared toits predecessor.
ISRO continues to explore Marswith the first ever interplanetarymission to the red planet,calledMars Orbiter Mission (MOM), akaMangalyaan. It made India the firstAsian nation to reach the Martianorbit and the first nation in the worldto do so on its maiden attempt.MOM explored Mars’ surfacefeatures, morphology, mineralogy,and Martian atmosphere with fiveonboard scientific instruments. Thekey technologies required for designing, planning,management and operations of an interplanetarymission were developed during MOM, whichcomprised - Orbit raising Manoeuvres, Trans-MarsInjection, Trajectory Correction Maneuvers, MarsOrbit Insertion, Development of Force Models andAlgorithms for Orbit and Attitude (Orientation)Computations and Analysis, Navigation in all phases,etc. The spacecraft was monitored from ISTRAC,ISRO-Bengaluru with support from the Indian DeepSpace Network (IDSN) antennae in Karnataka. MOMhas yielded unprecedented technical insights intothe Martian atmospheric composition and manyother aspects of the planet.
The multi-wavelength space astronomymission, AstroSat has served astronomers fromnearly 50 countries. One of the breakthroughfindings of the mission is the detection of UVemission from star formation in a galaxy that is 9.4billion years away, providing the first measurementsin the redshift range, near to the peak of the cosmicstar-formation history of the Universe. Figure 3shows a few glimpses of ISRO’s space science andplanetary mission.
Figure 3: Glimpses of ISRO’s space science and planetary missions
Space Applications
Space Applications is yet another vertical ofthe ISRO programme, which has witnessed manytechnological innovations. Earth Observation (EO)applications are institutionalised across many userMinistries/Departments, towards National security,Agriculture, Agro-forestry, Disaster management,Fishery, Land Use Land Cover (LULC), ResourceMapping, Planning, Monitoring & Evaluation anddecision support for major Flagship Programmes ofthe Government.
In order to meet the gamut of aforementionedrequirements for remote sensing/EO applications,a great deal of development had taken place inground infrastructure and imaging technologies.
Ground technologies for tracking multipleobjects in space, including the establishment ofmulti-object tracking radar, an integrated multimissionground segment for earth observationsatellites, Polarimeteric Doppler Weather Radar,state-of-the-art advanced ground station for EarthObservation satellites at Bharti station, AntarcticaMulti-Frequency Earth Stations, and a DistressAlert Transmitter have facilitated the uninterruptedusage of satellite services.
The revolution in imaging technologies suchas Pushbroom, 3-Tier Imaging, Step-Stare, StereoImaging, Scatterometer, Synthetic Aperture Radar(SAR), Ground Penetrating Radar (GPR) Altimeter,TDI imaging, VHR imaging, etc., in the domain ofEarth Observation served to accomplish 47 missionswith capabilities of spatial resolution from 1 km to28 cm, temporal resolution of 24 days to 2.5 days,and spectral resolution of 7 bits to 14 bits.
Human Space Exploration
Human Space Exploration is the latest entrantto programmatic verticals of ISRO. At present, ISROis actively pursuing the maiden human spaceflightmission - Gaganyaan to send astronauts to space andsafely return to Earth. Gaganyaan is yet another verycomplex mission, involving development of majortechnology elements such as human-rated launchvehicle, Crew escape systems, Habitable orbitalmodule, Life support system, Crew managementactivities for the safety of humans onboard, to namea few. Demonstration of re-entry flight of CrewModule i.e., Crew Module Atmospheric Re-entryExperiment (CARE) mission and Pad abort test forcrew escape systems, and testing of human-ratedlaunch vehicle propulsive stages i.e. solid boosters,liquid and cryo engines have been successfullyaccomplished. A new vehicle i.e., Test Vehicle (TV)has been developed to test critical crew associatedsystems. ISRO conducted a major developmenttest, ‘Integrated Main Parachute Airdrop Test (IMAT)’of the crew module deceleration system to simulatedifferent failure conditions of the parachute systembefore it is deemed qualified to be used in the firsthuman spaceflight mission. Gaganyaan is at anadvanced stage of its mission realisation.
Figure 4: PAD Abort Test (PAT-01) for Gaganyaan
Technology Innovation Continues…
Apart from the aforementioned five majorprogrammatic verticals of ISRO, strides in spacetechnology innovation continue in the thrust areasof Reusable Launch Vehicles, Stage Recovery andReuse, Vertical Take-off Vertical landing (VTVL), LOXMethaneEngine, Air breathing/ Hybrid Propulsion,3D printing, Artificial Intelligence, Space Robotics,Humanoid robots, On-orbit servicing, AdvancedMaterials & Manufacturing, Chemicals and EnergySystems, miniaturised Avionics system, AdvancedInertial systems, Low Cost Spacecrafts, Inter SatelliteLink (ISL) Networks, Space Based Solar Power,Quantum Communication, Quantum Radar, ElectricPropulsion, Advanced Scientific Payloads, SpaceBased Surveillance, Advanced Data processing,Atomic Clock, Travelling Wave Tube Amplifiers,In-Situ Resource Utilisation, Flexible SatellitePayloads, Inter-planetary Space Exploration,Space Tourism, Low-temperature Energy Systems,Intelligent Satellite, Self-destructing Satellite, SpaceBio-mimetic, Technologies for sustained Humanspace missions namely, Regenerative Life supportsystems, Rendezvous and Docking, Inflatablehabitats, Human factor and Engineering studies, etc.
In an effort to develop technologies for low-costaccess to space and space travel, ISRO conceiveda Reusable Launch Vehicle (RLV) programme todevelop space planes and shuttles that can ascentto orbit, stay there, re-enter, and land on a runwaylike an aeroplane. Having accomplished suborbitalflight and sea landing in 2016, recently, ISRO madea significant development in RLV technologies withRLV landing experiment (RLV-LEX) demonstratingautonomous landing of a winged vehicle on arunway. The experiment was demonstrated at ATRChitradurga,Karnataka, on 02 April 2023. Currently,ISRO is working on the Orbital Re-entry Experiment(ORE) which will be carried out with RLV flown atopan updated version of GSLV.
