ISRO uses Liquid Hydrogen (LH2) as fuel and Liquid Oxygen (LOX) as the oxidizer in their cryogenic stages. Theseare stored in propellant tanks which are arranged in tandem with the intertank structure in the middle. These intertanks can have several construction techniques like truss/framed, monocoque, closely stiffened, etc.Presently ISRO intertank structures are made of truss rods, as shown in Fig. 1. These truss rods are meant to allow radial contraction through spherical joints at both ends since the intertank is at ambient temperature, contrary to the low temperature of cryogenic tanks. However, this configuration introduces large, concentrated loads at the truss interfaces, which in turn results in local buckling. Additionally, in this configuration, components on the dome are left open to the aerodynamic flow and acoustic loads.ISRO is thus working on developing a closely stiffened intertank structure (see Fig. 2) that will allow a uniform distribution of stresses at the joint4. However, this configuration will lead to an increase in mass and thus is a non-economical solution. It was found that the closely stiffened intertank contributed to approximately an extra 100 Kg of mass. Therefore, the concept of a common bulkhead seems a plausible approach to minimise mass and overcome the above-mentioned problems of concentrated stresses.
Hardware development and testing at a small scale can be done though it seems very expensive and complex. LN2 may be used instead of LO2 for safety and operational reasons for these experiments. Several core materials are available to be explored (experimentally) for these applications, which may offer better manufacturing feasibility.The manufacturing feasibility for foam-filled honeycomb is another challenging task, along with determining suitable foam and honeycomb combinations. The design of connecting region (transition of CBH dome to external tank) is yet another design area to be worked on. The probable solution to it may be a decoupled ring interface.ISRO has been using such ring interfaces, but modifications are required in maximizing conduction path and minimizing conduction area when it comes to its usage in CBH cryogenic tanks. The manufacturing feasibility and the NDI techniques for each component need to be explored for full-scale development.
GSLV Mk3 roadmap. Semi-cryogenic state would be inducted in GSLV Mk3 M4 mission.Source:
Very interesting. Isn't GSLV Mk3 equipped with SC120 no longer a new rocket different from GSLV Mk3? I'm surprised that it's not named Mk4, but I'm extremely surprised that the mission number is M instead of D.
GROWTH POTENTIAL OF 6 TONS TO GTO IN FUTUREThe payload capability of GSLV MKIII will be increased upto 6 tons to GTO by induction of a High Propulsive Stage (Semi-Cryogenic stage SC120) in lieu of the present L110 and also by increased propellant loading of Cryogenic stage.
To meet ISRO’s objective of achieving higher payloads of 5 tonnes and above in GTO, a powerful, efficient and eco friendly stage was envisaged and this led to the development of Semi cryogenic engine and stage. LPSC has configured and designed a semi-cryogenic core stage, dimensionally optimized to replace the L110 stage of GSLV Mk III. The stage with 120 tonnes of propellant loading and powered by a single SE2000 engine producing a thrust of 200 tonnes will enable GSLV Mk III to carry more than 5.1 tonnes of payload to GTO. Semi-cryogenic engines operate on purified Kerosene (Isrosene) and Liquid Oxygen as propellants and is a combination of high performance, cost-effectiveness, high density impulse and eco friendliness.The engine and stage development is presently at an advanced stage. Engine and stage systems/subsystems have been realised and further testing, qualification and flight stage delivery are progressing as planned.
Here We Go: #Update #Thread As #GSLVMk3 or #LVM3 prepares for its second commercial launch, @isro efforts on enhancing its weight-lifting capacity is gaining pace. I hear that the qualification tests for semi-cryo (SC120) are expected to be completed in a couple of months. 1/n
#GSLVMk3 is India’s heaviest rocket yet. Here’s some perspective: Between May 26, 1999 and Oct 22, 2022, @isro launched 345 foreign satellites, all on #PSLV, which together weigh 9,326.4kg. On Oct 23, 2022, in its first commercial mission, #LVM3 launched 5,796kg. 2/nOf course, these missions are incomparable given that most of the foreign satellites launched by PSLV were ride-sharing payloads and include tens of small, micro and nano satellites… 3/n…But there’s no doubt that the Mk3 clearly enhances India’s prospects. In fact, Isro chairman S Somanath said last week: “The GSLV-Mk3 is India’s best commercial bet.” 4/nAt present, #GSLVMk3 can carry around 4 tonnes to a GTO and at least 6 tonnes to LEO. Induction of the high propulsive SC120, along with increased propellant loading of the cryogenic upper stage (CUS) can enhance this to 6 tonnes (GTO) and 10 tonnes (LEO). 5/nIsro spokesperson Sudheer Kumar said: “GSLVMk3 prog was envisaged to eventually carry at least 10 tonnes to LEO & 6 tonnes to GTO. We’ll achieve this with an upgrade of CUS with additional propellant loading & induction of semi-cryo stage that will replace L110…” 6/n“...Work on semi-cryo engine is almost nearing completion. Qualification tests are in progress. Stage & engine devp phase is complete, and the test stand is getting ready... Sub-system level tests are going on at facilities in Mahendragiri & LPSC,” he added. 7/n#GSLVMk3 is a three-stage vehicle with two solid strap-on motors (S200), one liquid core stage (L110) and a high-thrust cryogenic upper stage (C25). While the S200 will remain the same, the SC120 will replace L110 and C25 will be upgraded. 8/n“...We are expecting qualification to be completed in a couple of months unless some anomalies are found which may call for repeated tests, which are not unusual during the evolution stage,” Kumar said. 9/nHe added that aside from increasing the payload carrying capability, the new configuration would also make the vehicle safer as it will use non-toxic elements compared to L110. 10/n“It'll use refined kerosene, which is like aviation fuel. This means stage handling will be very safe, there'll be an increased capacity, ground systems handling becomes much simpler, storage leakages & human aspect concerns get reduced while handling the stage,” Kumar said. 11/nThe #GSLVMk3 project was first approved in 2002, with a mandate of achieving the capability to launch a four-tonne class satellite to Geosynchronous orbit (GEO), which Isro achieved through three demonstration missions. 12/nThen, the phase-1 of the GSLV-Mk3 continuation programme was approved in June 2018 to build 10 launch vehicles to meet the programmatic requirements to launch communication satellites up to the year 2023. 13/nA year after this approval, the rocket, in its maiden operational flight successfully launched #Chandrayaan2 on July 22, 2019 and had its first commercial mission on October 23, 2022. It is now scheduled to launch 36 more satellites for UK-based @OneWeb in early 2023. n/n
#UPDATE #Rockets #ThreadLate yesterday, @isro said that the CE20 cryogenic engine indigenously developed for #LVM3 (#GSLVMk3) has been successfully hot-tested “at an uprated thrust level of 21.8 t for the first time”. 1/n
“This will enhance #LVM3 payload capability up to 450kg with additional propellant loading. Major modifications carried out on this test article compared to previous engines was introduction of Thrust Control Valve (TCV) for thrust control,” Isro said. 2/n
Additionally, the space agency said a 3D-printed LOX (liquid oxygen) and LH2 (liquid hydrogen) turbine exhaust casings were inducted in the engine for the first time. 3/n
“During this test, the engine operated with around 20t thrust level for the first 40 seconds, then thrust level was increased to 21.8t by moving the thrust control valve. Engine and facility performance was normal and required parameters were achieved,” Isro added. 4/n
I had reported on Oct 31 that as #LVM3 prepares for its second commercial launch, Isro’s efforts on enhancing its weight-lifting capacity is gaining pace. n/n
Successful CE20 uprated Engine Hot Test with 21.8 T vacuum thrust Home/CE20 uprated Engine Hot TestNov 09, 2022The CE20 cryogenic engine indigenously developed for LVM3 has been subjected to successful hot test at an uprated thrust level of 21.8 tonne for the first time on 9th Nov, 2022. This will enhance the LVM3 payload capability upto 450 kg with additional propellant loading.The major modifications carried out on this test article compared to previous engines was introduction of Thrust Control Valve (TCV) for thrust control. In addition to this 3D printed LOX and LH2 turbine exhaust casings were inducted in the engine for the first time. During this test the engine operated with ~20t thrust level for first 40s, then thrust level was increased to 21.8t by moving thrust control valve. During the test, engine and facility performance was normal and required parameters were achieved.
BENGLAURU: Jeff Bezos’ Blue Origin is keen on using India’s GSLV-Mk3 or LVM-3 as a crew capsule to service its Orbital Reef, a Low Earth Orbit (LEO) space station being designed for commercial space activities and tourism uses, Isro chairman S Somanth confirmed to TOI in an exclusive interview.
Somanath said: “We are exploring … In fact, we’ve already discussed it with Blue Origin and they are very keen to consider this option of LVM-3 becoming a crew capsule mission to service the Orbital Reef. It is a possibility and we are engaging through IN-SPACe (Indian National Space Promotion and Authorisation Centre).”
“...Whoever can design a docking system that matches with the US design and standard, can be used. However, we will still need to have agreements with agencies to try it out given that there are multiple interfaces — electrical, mechanical and so on. It is not just one document, we will need to work with them to develop it. We will do that.
#Update #Thread #Space #IndiaWith another flawless launch to put #Chandrayaan3 into a perfect orbit, #LVM3 has proved its reliability with seven successful launches, including 3 developmental flights. Read thread to know plans for engaging pvt players... 1/nPic: isro
Space PSU @NSIL_India, which will acquire and operate #LVM3 in the future, is now actively exploring multiple models to engage industry with the aim of increasing the production rate to at least five to six annually. 2/n
The move is in line with the Centre’s vision of enhancing private participation in the space sector and comes close on the heels of @INSPACeIND issuing an EoI to transfer the technology of @isro #SSLV, just ahead of the #Chandrayaan3 launch. 3/n
“Market analysis shows that there will be good demand for #LVM3 class of rockets. At present, we’re looking at whether the model should be a contract model similar to #PSLV, use a different risk-sharing model… 4/n
…or go the PPP [public-private partnership] way. There are a lot of modalities to be worked out and we’ll come out with a decision soon,” NSIL CMD Radhakrishnan D said. 5/n
Soon after #Chandrayaan3 launch, #LVM3 PD Mohan Kumar had said the rocket once again proved to be the most reliable heavy-lift vehicle of Isro, while VSSC director Unnikrishnan Nair said: “Launching 3 LVM3s in a year is an herculean task & team Isro has achieved that.” 6/n
Out of the seven launches LVM3 has been used in so far, three have been between October 2022 and July 2023, while its first operational flight was the launch of Chandrayaan-2 on July 22, 2019. 7/n
The frequency of launches has increased mainly on account of the opportunity Isro was presented with by OneWeb, which had to cancel its launch contract with Russia but still go ahead with putting satellites as part of its constellation within a specific timeframe… 8/n
Given the overall weight of the payload — OneWeb launched two batches of 36 satellites each with Isro — the space agency had to go with the LVM3, and both the launches were successful. n/n
