23 Apr

ISRO Launchers Operational

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Content

• ISRO Launchers (Operational)
  1. PSLV (Polar Satellite Launch Vehicle)
  2. GSLV (Geosynchronous Satellite Launch Vehicle)
  3. Sounding Rockets
• Other Engines and related projects in News
  1. ISRO’s Next-Gen Launch Vehicle (NGLV) may assume PSLV’s Role
  2. Semi-cryogenic Engine (Under development)
  3. Differences between Cryogenic Engine and Semi-Cryogenic Engine
  4. Reusable Rockets: Revolutionizing Access to Outer Space
  5. Low-Cost Small Satellite Launcher (SSLV)

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1) ISRO LAUNCHERS (OPERATIONAL)

PSLV, GSLV, Sounding Rockets are three broad categories of rockets (launchers) that
ISRO has developed over the years

• Both PSLV (Polar Satellite Launch Vehicle) and GSLV (Geosynchronous
  Satellite Launch Vehicle) are the satellite launch vehicles (rockets) developed by ISRO.

1) PSLV (POLAR SATELLITE LAUNCH VEHICLE)

• The PSLV is the third-generation satellite launch vehicle of India. It is an expandable system and was the first Indian Launch Vehicle to be equipped with Liquid Stage.
  • Note: ISRO has over the years realized 5 generations of rockets – SLV, ASLV, PSLV, GSLV, and GSLV-MK-III.
• Where is PSLV used?
  • It was developed to allow India to launch its Indian Remote Sensing (IRS) satellite into Sun synchronous orbit, a service that was, until the advent of the PSLV, commercially available only from Russia.
  • PSLV can also launch small size satellites into Geostationary Transfer Orbit.
• It is one of the world’s most reliable launch vehicles.

• Launches So Far
  • Developed in early 1990s, its first launch in 1993 was a failure.
  • First successful launch of PSLV took place in 1994 and till Sep 2023 (i.e., PSLV C 57), PSLV has had 59 launches with only two failures.
• Technical Specifications of PSLV
  • Capabilities
    • Payload to SSPO (sun synchronous polar orbit): 1,860 Kg
• Expansion of capabilities: Strap on Motors
• PSLV uses 6 solid rocket strap-on motors to augment the thrust provided by the first stage in its PSLV-G (1678 kg in SSPO) and PSLV-XL (1750 kg to SSPO) variants. PSLV-DL, PSLV-QL versions use 2 and 4 straps on motors respectively. PSLV-CA (1100 kg in LEO) uses no strap on motors.
• Key Significance and Achievements of PSLV
  • Reliability: Only 2 failures in almost 3 decades of service and 60 launches.
  • Commercial use: PSLV has launched more than 350 foreign satellites from 34 different countries so far.
  • It has played significant role in various major ISRO missions (including Chandryaan-1, MOM, IRNSS system etc.)
  • Strengthen India’s Soft Power
  • Many learnings from the development of PSLV has helped scientists develop several non-space applications like fire resistant tiles, better engines for missiles

A)  Solid Fuel Engine vs Liquid Fuel Engine (Extra Gyan)

• A solid rocket fuel has its fuel and oxidant mixed together as fine powders and then pressed into solid cake.
• Key characteristics
  • Higher Thrust -> Higher force to launch the vehicle.
  • Less volume
  • One time burn -> all fuel burns at the same time, i.e., once it has been lit it will carry on burning until it is used up.
  • Produces a lot of smoke -> large particles when fired
• A liquid fuel engine uses liquid fuel which can have following advantages
  • Controlling Thrust
  • Engine can be shut down and restarted
  • Higher energy density (joules per kg of propellant) is higher.
  • Higher Specific Impulse (impulse (in Newton second) per kg of propellent)
  • E.g., a modern solid fuel rocket has specific impulse of around 2500 N s Kg^-1, while a good liquid fuel rocket produces an impulse of about 4500 N s Kg^-1.
  • Disadvantage: More complicated Engine requirements and thus more expensive and heavier engine -> pumps, piping, separate storage for the fuel and oxidant means that extra mass has to be carried by the launch vehicle.
• Why Hybrid Engines
  • Vastly reduce overall system weight and cost. It increases reliability (a smaller number of components which can fail)

B) PSLV C-58

• ISRO’s PSLV C-58 has launched XPOSAT Satellite into an eastward low inclination orbit on 1^st Jan 2024.
• After injection of XPOSAT, the PS4 stage was restarted twice to reduce the orbit into 350 km circular orbit for orbital platform (OP) experiments. The PSLV Orbital Experiment Module-3 (POEM-3) experiment was executed to meet the objective of 10 identified payloads, supplied by ISRO and IN-SPACe.
  • These 10 payloads are developed by start-ups, education institutions and ISRO Centres.
  • They are:
    • The Radiation Shielding Experimental Module (RSEM) by TakeMe2Space;
    • Women Engineered Satellite (WESAT) by LBS Institute of Technology for Women;
    • BeliefSa-t0 Amateur radio satellite by K.J. Somaiya Institute of Technology;
    • Green Impulse TrAnsmitter (GITA) by Inspecity Space Labs Private Limited;
    • Launching Expeditions for Aspiring Technologies -Technology Demonstrator (LEAP-TD) by Dhruva Space Private Limited
    • RUDRA 0.3 HPGP by Bellatrix Aerospace Private Limited;
    • ARKA-200 by Bellatrix Aerospace Private Limited;
    • Dust Experiment (DEX) by PRL;
    • ISRO Fuel cell Power System (FCPS) by VSSC, ISRO and;
    • FCPS payload is significant as it has potential applications in India’s space station which is proposed to come up by 2035.
    • Si-based High Energy cell by VSSC, ISRO
• Note: This is the third time ISRO has operated the PSLV fourth stage in this way.
• Thus, it can be said that the PSLV-C58 mission represents a union of the aspirations of professional scientists, aspiring students of science, and India’s private spaceflight sector.

ISRO successfully tests Polymer Electrolyte Membrane Fuel Cell On PSLV’s-C58’s orbital Platform POEM3 (Jan 2024)

• ISRO successfully tested a 100 W class Polymer Electrolyte Membrane Fuel Cell based power system in its orbital platform, POEM-3 which was launched onboard PSLV-C58 on 1^st Jan 2024.
• The objective of the experiment was to assess Polymer Electrolyte Membrane Fuel Cell operation in space and to collect data to facilitate the design systems for future mission.
• Outcome of the test:
  • • pressure vessels. It provided a wealth of data on performance of various static and dynamic systems.During the short duration test onboard POEM, 180 W power was generated from Hydrogen and Oxygen gases stored onboard in high pressure vessels. It provided a wealth of data on performance of various static and dynamic systems.

C) PSLV C-57/ Aditya-L1 Mission (Sep 2023) 

D) PSLV-C56 / DS-SAR Mission (July 2023)

• The launch of PSLV C-56 carrying DS-SAR satellite, along with 6 co-passengers [all 7 Singaporean satellites] was accomplished successfully on July 30, 2023.
• PSLV C-56 was configured in core alone model, similar to C-55.
• DS-SAR is a 360 kg satellite into a Near-equatorial Orbit (NEO) at 5 degrees inclination and 535 km altitude.
  • DS-SAR satellite is used for satellite imagery requirements of various agencies within the government of Singapore.
  • It carries a Synthetic Aperture Radar (SAR) payload developed by Israel Aerospace Industries (IAI). This allows DS-SAR to provide all weather day and night coverage, and capable of imaging at 1m-resolution at full polarimetry.
• After the launcher placed all the seven satellites into a 535 km circular orbit, PS4 stage was brought back to a lower orbit of 295 km X 300 orbit. This has been done so that the stage spends less time in space, reducing its duration from over two decades to less than two months, before re-entering into the earth’s orbit.

E)  PSLV C-55/TeLEOS-2 Mission (April 2023)

• PSLV C-55/ TeLEOS-2 was launched successfully on April 22, 2023, from SDSC-SHAR, Sriharikota.
• This is a dedicated commercial mission through NSIL with TeLEOS-2 as primary satellite and Lumelite-4 as a co-passenger satellite.
• The satellite weigh about 741 kg and 16 kg Both belong to Singapore.

POEM-2: The mission has the PSLV Orbital Experiment Module (POEM), where the spent PS4 stage of the launch vehicle would be utilized as an orbital platform to carryout scientific experiment through non-separating payloads. The payloads belong to ISRO, Bellatrix, Dhruva Space, and Indian Institute of Astrophysics.

2)  GSLV (Geosynchronous Satellite Launch Vehicle)

• Background of GSLV
  • GSLV is an expandable launch system operated by ISRO.
  • First launch in 2001. First successful flight in 2003: successfully placed GSAT-2 in 2003.
  • Main Purpose: GSLV was primarily developed to launch INSAT class of satellites into Geosynchronous Transfer Orbit GSLV is being used for launching GSAT series of satellites.
  • Payload to GTO: Presently GSLV-mk-II can inject 5 ton (GSLV Mk-2) of communication satellite into Geosynchronous Transfer Orbit.
  • Payload to LEO: GSLV’s capability of placing up to 5 tonnes in LEO broadens the scope of payloads from heavy satellite to multiple smaller satellites.
• Three Stage Launcher (GSLV-Mk-2) (one solid motor stage (expandable with four liquid engine strap ons), one earth Storable Liquid stage, and one cryogenic stage)
• Third Stage: CUS
  • Developed under Cryogenic Upper Stage Project (CUSP), the 5 is India’s first cryogenic engine, developed by Liquid Propulsion Systems Centre in Mahendragarh, Tamil Nadu. CE-7.5 has a staged combustion operating cycle.
    • Fuel: LOX + LH₂ (Liquid Oxygen + Liquid Hydrogen)
    • Max Thrust: 75 KN
• Variants
  • GSLV Mk 1(a,b,c) – Not important
  • GSLV Mk 2 (Operational)

• This variant uses an Indian cryogenic engine, the CE-7.5, and is capable of launching 2500 Kg into Geostationary transfer orbit. Previous GSLV vehicles (GSLV Mk1) have used Russian cryogenic engines.

A)  Launch Vehicle Mark 3 (LMV3 or GSLV Mark 3)

• LVM3 is a 3-stage heavy lift launch vehicle developed by ISRO.
  1. Solid Rocket Boosters: S200 – GSLV MK III uses two S200 solid rockets boosters to provide the huge amount of thrust required for lift off. Fuel: HTPB.
  2. A liquid Propellant core stage (L110): The L110 liquid stage is powered by 2 Vikas engines.
  3. A Cryogenic Stage (C25): The C25 is an improvement on CE-20 Cryogenic engine, India’s largest cryogenic engine, designed and developed by the Liquid Propulsion System Center
     1. Fuel: LOx + LH₂
• Capability: GSLV-Mk III can launch 4 tons class of satellites to Geosynchronous Transfer orbit (GTO) or about 8-10 tons to LEO, which is twice the capability of GSLV Mk II.
• GSLV MK-III Flights so far:
  • GSLV-Mk III – D1 (2017): GSAT-19 to GTO
  • GSLV-MK III – D2 (2018): GSAT-29 to GTO
  • GSLV-MK III – M1 (2019): Chandrayaan-2
  • GSLV-MK III – M2 (2022): OneWeb India-1 Mission
  • GSLV MK III – M3 (2023): OneWeb India-2 Mission
  • GSLV MK III – M4 (2023): Chandrayaan-3
• GSLV MK-III – M2/ OneWeb India-1 Mission (Oct 2022)
• It was only the second operational flight of LVM3 (after Chandryaan-2 mission). It was a dedicated commercial satellite mission of NewSpace India Limited (NSIL). This mission was undertaken as part of the commercial arrangement between NSIL and m/s Network Access Associates Limited (m/s OneWeb Ltd), a UK based company. A total of 36 OneWeb Gen-1 satellites of about 150 Kg each totaling about 5,796 Kg were launched to a circular LEO of about 601 km with a 87.4 degree inclination.
• This was one of the biggest commercial orders executed by ISRO.
• Note: Some Unique features of the Mission
  • First Commercial Mission of LVM3
  • First multi-satellite mission with 36 OneWeb Satellites onboard
  • First launch of LVM3 to LEO
  • First Indian rocket with six-ton payload
  • First NSIL Mission with LVM3
  • First OneWeb Mission with NSIL/DoS

LVM3 M3/ OneWeb India-2 Mission Accomplished Successfully (March 2023)

• In its sixth consecutive successfully flight of LVM3, the vehicle placed 36 satellites belonging to the OneWeb Group company in their intended 450 km circular orbit with an inclination of 87.4 degrees.
• The total weight of the payload was 5,805 kg.

LVM3 M4/ Chandrayaan 3.0 Mission was accomplished in July 2023 

B)  India’s Journey towards developing its own cryogenic engine

• Basics about Cryogenic Engine
  • Cryogenic engine is a rocket engine that uses cryogenic fuel or oxidizer, i.e. its fuel or oxidizer (or both) are gases liquified and stored at very low temperatures.
  • Note: All Cryogenic engines are also, liquid propellent rocket engines or hybrid rocket engines.
  • Fuel: Combination of Liquid hydrogen and Liquid Oxygen is the most commonly used propellant in cryogenic engine. The fuel provides very high specific impulse.
• Difficulties in developing Cryogenic engine: Burning super cooled fuel at extremely high temperature; Developing material that can withstand high temperature and pressure during combustion.
  • Advantages
    • More efficient and provides more thrust for every kg of propellant it burns.
  • Current status
    • CE-7.5 being used in GSLV MK-II.
    • CE-20 is being used in GSLV MK-III. It is indigenously developed for LVM-3.
• Further upgradation:
  • In Nov 2022, ISRO has successfully conducted a hot test of CE20 cryogenic engine. This successful hot test was at an uprated thrust level of 21.8 tonne for the first time.
  • This will enhance the LVM3 payload capability upto 450 Kg with additional propellant loading. The major modification carried out on this test article compared to previous engines was introduction of Thrust Control valve (TCV) for thrust control.
  • In addition to the hot test, a 3D printed LOX and LH2 turbine exhaust casings were also inducted in the engine for the first time.

3) Sounding Rockets

• Sounding rockets are one or two stage solid propellant rockets used for probing the upper atmospheric regions and for space research.
• They also serve as easily affordable platforms to test or prove prototypes of new components or subsystems intended for use in launch vehicles and satellites.
• With the establishment of the Thumba Equatorial Rocket Launching Station (TERLS) in 1963 at Thumba, a location close to the magnetic equator, there was a quantum jump in the scope for aeronomy and atmospheric sciences in India.
  • The launch of the first sounding rocket from Thumba near Thiruvananthapuram, Kerala on 21 November 1963, marked the beginning of the Indian Space Programme. The rocket was US Nike Apache.
• Operational Sounding Rockets
  • Currently 3 versions are offered as operational sounding rockets, which cover a payload range of 8-100 Kg and an apogee range of 80-475 Km.

Vehicle	RH-200	RH-300-Mk-II	RH-560-MK-II
Payload (in kg)	10	60	100
Altitude (in km)	80	160	470
Purpose	Meteorology	Aeronomy	Aeronomy
Launch Pad	Thumba, Kerala	SDSC-SHAR	SDSC-SHAR

• Rohini (Rocket Family) is a series of sounding rockets developed by ISRO for meteorological and atmospheric study.
• ISRO’s RH-200 sounding rocket records 200^th consecutive successful flight (Nov 2022)
  • The small rocket lifted off from the launchpad at the Thumba Equatorial Rocket Launching Station (TERLS) at the Vikram Sarabhai Space Centre (VSSC).
• Example of Experiment: Air Breathing Propulsion Experiment using RH-560 rocket fitted with a supersonic combustion (Scramjet) engine on Aug 28 from Sriharikota. (Aug 2016)

2)  Other Engines and related projects in News

1)  ISRO’s Next-Gen Launch Vehicle (NGLV) may assume PSLV’s Role

• ISRO is developing a Next-Gen Launch Vehicle (NGLV), which will one day replace operational systems like PSLV. Here ISRO is planning a three stage to orbit, reusable heavy lift vehicle with payload capacity of 10 tons to GTO.
• It will feature semi-cryogenic propulsion; simple and robust design (allowing bulk manufacturing, modularity and minimal turnaround time)

2)  Semi-cryogenic Engine (Under development) 

• Semi-Cryogenic Engine is an Indian Liquid fuel rocket engine using a combination of liquid oxygen (LOX) and refined kerosene (Isrosene) as propellants. It is being developed for future heavy lift launch vehicles and reusable launch vehicles.
• It is being developed by Liquid Propulsion System Centre, a subsidiary of ISRO.
  • Project Codename: SCE-200
• Where will it be used?
  • Immediate Application: One of the immediate applications will be to replace the liquid core (L110) engine of GSLV Mark-3 with the SCE-200 to boost the payload capacity of the rocket from 4 to six tonnes.
• SCE-200: Other Details
  • Cost of project: 1800 crore (Cabinet cleared the project in 2008).
  • Currently, only US and Russia have this technology.
  • In 2015, ISRO signed an MoU with Russian Space Agency to boost its plan for Semi-Cryogenic Launch Vehicle

3)  Differences between Cryogenic Engine and Semi-Cryogenic Engine

	Cryogenic	Semi-Cryogenic
Fuel	Liquid Hydrogen + Liquid Oxygen	Isrosene + Liquid Oxygen
Temperature	Liquid hydrogen required to be stored at -253-degree celsius	Kerosene can be stored at normal temperatures
Weight	LH2 + LO2 is heavier than Kerosene and has to be stored at freezing temperature of -253 degree celsius.	Lighter than liquid fuel and can be stored at normal temperature. Therefore, kerosene occupies less space, and more propellant can be packed in the semi-cryogenic engine’s fuel compartment.
Specific Impulse	Cryogenic engine offers higher specific impulse then SCE
Thrust to weight Ratio		It offers better thrust to weight ratio upto 180. Higher density of the exhaust gas in case of the SCE contribute to high mass flow rates making it easier to develop high thrust engines.
Stage	Higher specific impulse is valuable for upper stage, where mass comes at a premium price. So Cryogenic is used at upper stage.	·        SCE have been preferred in lower stages when high thrust is must-have over specific impulse.

4)  Reusable Rockets: Revolutionizing Access to Outer Space 

• Details
  • Reusable launch system is a launch system that includes the recovery of some or all of the component stages and reuse of these components in another launch.
  • Till now, several fully reusable sub-orbital system and partially reusable orbital systems have been flown. During 21^st century, the interest in reusable launch system has grown considerably, with several active launchers.
    • SpaceX’s Falcon 9 rocket has a reusable first stage and expendable second stage. Plans for the second stage of the Falcon 9 to be made reusable, creating a fully reusable system, have been cancelled, with the SpaceX starship being planned as a fully reusable launch vehicle.
  • If ISRO is able to develop this technology, it will reduce the cost of launch by 70-80% and increase the competitiveness of ISRO in satellite launch market.
• Steps taken by ISRO to develop RLV.
  • In May 2016, ISRO successfully test fired its first indigenous winged reusable satellite launch vehicle.
    • In this experimental mission, the HS9 solid rocket booster carrying RLV-TD lifted off form the First Launch Pad at Satish Dhawan Centre, Sriharikota.
    • The RLV-TD re-entered the earth after reaching a height of 70 km.
    • It was a baby step towards developing reusable launch vehicle.
    • Ultimate Aim: Ultimate aim of the project is to put satellite into orbit around earth and then reenter the atmosphere.
  • The final version would take another 10-15 years to get ready.

5)  Low-Cost Small Satellite Launcher (SSLV)

• Introduction
  • The Indian SSLV (Small Satellite Launch Vehicle) is a small launch vehicle which serves small satellite launches.
  • It is the smallest vehicle at 110-ton mass at ISRO.
  • Low turnaround time: It takes only 72 hours to assemble (unlike around 70 days needed for PSLV).
  • Low Human Resource requirement: Only 6 people are required to do assembly (unlike 60 people for the PSLV).
  • Cost Effective: The overall cost of building the SSLV will only be Rs 30 crores.
  • Capability: Payload capacity of 500 Kg to 500 km planar orbit or 300 kg to SSPO. Using PSLV for these small satellites was an overkill.
  • It uses three solid fuel-based stages and a liquid fuel-based velocity trimming module (VTM) to place the satellite in orbit.
  • It is ideal for on-demand, quick turn-around launch of small satellites.
  • Major technologies developed as part of SSLV are flexible nozzle control with electro-mechanical actuators for all stages, miniaturized avionics, and a velocity trimming module in the upper stage for precise satellite injections.
• Need
  • The global demand for launch of small satellite is increasing. It is being demanded by businesses, government agencies, universities, and various research labs.
• First Developmental Flight  
  • The maiden flight of SSLV in Aug 2022 can be considered a partial success.  
    • When it came to the stage when the satellite had to be set in orbit, there was a glitch which resulted in the satellite being lost forever. ISRO announced that there was a malfunction of a sensor which resulted in placing the satellites in an elliptical orbit, rather than a circular orbit.
    • It placed the satellites into 356 km X 76 km elliptical orbit instead of 356 km circular orbit.
• 2nd Developmental Flight: SSLV-D2/ EOS-07 Mission (Feb 2023)
  • The 2^nd developmental flight of SSLV-D2 was successfully launched on Feb 10, 2023.
  • It intended to inject EOS-07, Janus-1 and AzaadiSAT-2 satellite into 450 km circular orbit, in its 15 minutes flight.
    • EOS-07 is 3 kg satellite designed, developed and realized by ISRO. New experiments include mm-wave Humidity Sounder and Spectrum Monitoring payload.
    • Janus-1, a 10.2 kg satellite belongs to Antaris, USA.
    • AzaadiSAT-2 is a combined effort of about 750 girl students across India guided by SpaceKids India, Chennai.