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#120
by
K210
on 28 Mar, 2018 07:03
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The next generation Vikas engine developed by the Liquid Propulsion Systems Centre (LPSC) is being flown for the first time. LPSC director V Narayanan told Express that the improved engine would give a significant advantage in terms of enhancing payload capability. “Usually, the chamber pressure is 58 bar, but with the use of high-thrust Vikas engine, we will achieve 62 bar, which is a 6% increase in thrust that gives us 70 kgs of additional payload gain in this mission. Right now, we are going to use the high-thrust Vikas engine only in the second stage. Basically, we are validating it. For Chandrayaan-2 mission, we will be using five such engines aiming for a payload gain of around 250 kgs,” Narayanan said.
Narayanan said this would be the best way of mission planning and optimum utilisation of propellants. “All these new things are being done keeping lunar mission in the mind and ISRO’s bigger game plan to increase GSLV payload capability. For Chandrayaan-2, we are formulating a perfect combination. The four strap-ons and second stage will be boosted with high-thrust Vikas engines; cryogenic upper stage will be loaded with enhanced propellants of 15 tonnes instead of current 12.8 tonnes and will be operated with 9.5 tonne thrust compared to the present 7.5.”
Source:
http://www.newindianexpress.com/states/tamil-nadu/2018/mar/28/with-eye-on-lunar-mission-isro-to-test-high-thrust-vikas-engine-1793608.htmlISRO confirms that GSLV F-10 will be first fully upgraded GSLV. All four L40 strapons will have high thrust vikas engines and well as the second stage. The upper stage will have propellant loading increased to 15 tons and thrust of CE-7.5 engine will be increased from present 7.5 tons to 9.5 tons.
Payload capability to GTO for GSLV has been increased by 70kg for GSLV F-08 mission to bring the GTO capability of GSLV up from 2.25 tons to 2.32 tons. With additional upgrades on GSLV F-10 mission later this year this will further boost GTO capability by 250 kg to bring GSLV GTO capability to 2.57 tons.
In short:
Current GSLV GTO capability: 2.25 tons
GSLV F-08 GTO capability: 2.32 tons
GSLV F-10 GTO capability: 2.57 tons
ISRO final goal for GSLV : 3.25 tons to GTO
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#121
by
vineethgk
on 28 Mar, 2018 11:17
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The next generation Vikas engine developed by the Liquid Propulsion Systems Centre (LPSC) is being flown for the first time. LPSC director V Narayanan told Express that the improved engine would give a significant advantage in terms of enhancing payload capability. “Usually, the chamber pressure is 58 bar, but with the use of high-thrust Vikas engine, we will achieve 62 bar, which is a 6% increase in thrust that gives us 70 kgs of additional payload gain in this mission. Right now, we are going to use the high-thrust Vikas engine only in the second stage. Basically, we are validating it. For Chandrayaan-2 mission, we will be using five such engines aiming for a payload gain of around 250 kgs,” Narayanan said.
Narayanan said this would be the best way of mission planning and optimum utilisation of propellants. “All these new things are being done keeping lunar mission in the mind and ISRO’s bigger game plan to increase GSLV payload capability. For Chandrayaan-2, we are formulating a perfect combination. The four strap-ons and second stage will be boosted with high-thrust Vikas engines; cryogenic upper stage will be loaded with enhanced propellants of 15 tonnes instead of current 12.8 tonnes and will be operated with 9.5 tonne thrust compared to the present 7.5.”
Source: http://www.newindianexpress.com/states/tamil-nadu/2018/mar/28/with-eye-on-lunar-mission-isro-to-test-high-thrust-vikas-engine-1793608.html
ISRO confirms that GSLV F-10 will be first fully upgraded GSLV. All four L40 strapons will have high thrust vikas engines and well as the second stage. The upper stage will have propellant loading increased to 15 tons and thrust of CE-7.5 engine will be increased from present 7.5 tons to 9.5 tons.
Payload capability to GTO for GSLV has been increased by 70kg for GSLV F-08 mission to bring the GTO capability of GSLV up from 2.25 tons to 2.32 tons. With additional upgrades on GSLV F-10 mission later this year this will further boost GTO capability by 250 kg to bring GSLV GTO capability to 2.57 tons.
In short:
Current GSLV GTO capability: 2.25 tons
GSLV F-08 GTO capability: 2.32 tons
GSLV F-10 GTO capability: 2.57 tons
ISRO final goal for GSLV : 3.25 tons to GTO
If the payload gain is only about 250 kg even with HTVEs in L40 and CUS upgrades in F10 flight, achieving 3.2-3.3 tonnes as they claimed earlier would appear a long shot. My guess is that either Narayanan was referring only to the effect of addition of HTVEs in L40 and GS2 when he quoted the 250kg figure, or the F10 flight wouldn't have all the major upgrades that they plan to do eventually.
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#122
by
TheVarun
on 28 Mar, 2018 18:25
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Just finished watching the televised launch of the Insat 3Dr on Gslv on Sept 8/2016. One of the Isro scientists mentioned that vehicle had an upgraded Cryogenic engine/ stage for the flight. So the C-12 has been uprated at least once. Any idea what kind of improvement was made then?
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#123
by
K210
on 31 Mar, 2018 10:18
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Just finished watching the televised launch of the Insat 3Dr on Gslv on Sept 8/2016. One of the Isro scientists mentioned that vehicle had an upgraded Cryogenic engine/ stage for the flight. So the C-12 has been uprated at least once. Any idea what kind of improvement was made then?
GSLV F05/INSAT-3DR did have a slightly improved upper stage.
Improvements were:
- C12.5 stage dry mass reduction
- Maximum thrust of CE-7.5 increased from 109% to around 112%
Changes resulted in GTO capacity rising from 2.2 ton to 2.25 ton
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#124
by
K210
on 29 Aug, 2018 12:49
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Umamaheswaran R., now Associate Scientific Secretary, ISRO, told me in October 2016 that GSLV-MkII can put 3.2 tonnes into an initial orbit of 180 km by 20,000 km.
Yes. We enhanced the GSLV-MkII with high thrust engines and so on. With the enhancement, the number is 2.7 tonnes into GTO [geostationary transfer orbit]. Now, 3.2 tonnes has become 3.8 tonnes. And 22,000 km has become 37,000 km. This combination cannot be launched by GSLV-MkII.
Source:
https://www.frontline.in/science-and-technology/article24801393.eceGSLV MK-2 now has GTO capability of 2.7 tons. That is quite a jump from previous 2.25 ton capability.
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#125
by
sanman
on 30 Aug, 2018 16:43
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#126
by
worldtimedate
on 30 Aug, 2018 21:28
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GSLV-F11 cryo engine hot test successfulThe Indian Space Research Organisation (Isro), on Thursday said it has successfully completed the hot test of cryogenic engine for the GSLV-F11, which is scheduled to launch the GSAT-7A in November this year.
A hot test is a ground test conducted to check for the safety and also whether or not all design parameters are met. Unlike a cold test where all the propellants are checked for, a hot test involves firing of the engine in test conditions.
The test, conducted at the Isro Propulsion Complex in Mahendragiri on August 27, was carried out for 200 seconds during which the engine operated in the nominal and 13% uprated thrust regimes.
"All the propulsion parameters during the test were found satisfactory and closely matched with predictions. For the first time, indigenously developed copper alloy is used in this engine," Isro said.
The cryogenic engine will now be integrated with the propellant tanks, stage structures and associated fluid lines to realise the fully integrated flight cryogenic stage.
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#127
by
worldtimedate
on 12 Sep, 2018 19:22
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Indigenisation of Copper-Chromium-Zirconium-Titanium Alloy for Cryo and Semi-Cryo engines- A Success StoryRolling Mill LayoutCopper Alloy (Cu-0.5Cr-0.05Ti-0.05Zr) is an important and vital item required for cryogenic/semi-cryogenic engines for the realisation of thrust chamber inner shell and injector face plates of Cryogenic Upper Stage (CUS) engine for GSLV Mk-II, CE20 engine for GSLV Mk-III and Semi-Cryo (SC) stage. This is also required for the Steering Engines (SE) of CUS engine, Gas generator of CUS & CE20 engines, injectors, pre-burner and pyro components of SC engine.
These projects require Copper Alloy plates, rods and forgings of various dimensions. For plates, thickness requirement range from 12 mm to 18 mm and width of 850 mm. Rods and forgings of this alloy are also required with diameters ranging from 30 mm upto 300 mm.
Vacuum Induction Melting Furnace 1000kgIndigenisation efforts were made through NFTDC, Hyderabad for CUS, CE20 and SC. Melt capacity was augmented to 1000 kg and plate rolling mill capable of 1500 mm width was established for meeting the project requirements. All required products using this alloy have been successfully realized for CUS, CE20 and Semi-Cryo projects. The hot test of the CUS engine using this copper alloy for 200 sec in the nominal and 13% uprated thrust regime was carried out at IPRC, Mahendragiri. This engine will power the cryogenic stage of GSLV Mk-II, which is scheduled to launch GSAT-7A in November this year.
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#128
by
TheVarun
on 17 Sep, 2018 23:13
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Can someone give an approximation for the number of parts in a cryogenic engine/stage like the C-12? Just approximate. Would it be in the thousands or tens of thousands? I'm asking because I want to determine the degree of difficulty a country like India( or any developing one or even developed) would experience in developing such an engine and stage. Also, what degree of indigenisation of the C-12 would have been realistically achieved until now, and what more could be reasonably expected? Again, given the presumably very high number of parts and components.
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#129
by
K210
on 18 Nov, 2023 09:58
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Going over GSLV launch history you have to wonder why ISRO keeps this launch vehicle operational. Out of 15 launches there have been 6 failures of varying degrees putting the failure rate at almost 50%. Now they have LVM3 there is no reason to keep such a unreliable launch vehicle flying.
That high failure rate is largely due to the developmental nature of the GSLV Mk1. In fact there are only 2 failures of the GSLV Mk2 to date (D3 mission in 2010 and F10 in August 2021). For those who don't know the Mk2 variant of this rocket is the operational version which has been flying since 2010.
The GSLV Mk1 as you probably know used imported Russian cryogenic upper stages which apart from not delivering the promised performance resulted in all kinds of design problems the worst of which caused the GSLV F06 RUD over the bay of bengal in December 2010.
I think if we view GSLV as more of a technology testbed of sorts we can have a more positive view of the entire GSLV program. GSLV was the first launch vehicle of ISRO to fly liquid fueled strapons, first to have a cryogenic upper stage, first to employ hot staging and of course first to achieve the Geostationary Transfer Orbit (GTO). First in something is always hard and prone to failure and hence why we should appreciate GSLV's various contributions to the Indian Launch Vehicle program.
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#130
by
Steven Pietrobon
on 19 Nov, 2023 02:13
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GSLV was the first launch vehicle of ISRO to fly liquid fueled strapons, first to have a cryogenic upper stage, first to employ hot staging and of course first to achieve the Geostationary Transfer Orbit (GTO).
The first payload sent into GTO was by PSLV, carrying METSAT 1 on 12 September 2002 (target orbit was 180x36,000 km according to the press kit). The previous GSLV Mk.I launch on 18 April 2001 had a performance shortfall and sent its payload into sub-GTO with a 32,000 km apogee.
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#131
by
zubenelgenubi
on 19 Nov, 2023 18:46
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Moderator:
I merged several GSLV MkII threads. 🚀
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#132
by
Zed_Noir
on 20 Nov, 2023 10:01
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Going over GSLV launch history you have to wonder why ISRO keeps this launch vehicle operational. Out of 15 launches there have been 6 failures of varying degrees putting the failure rate at almost 50%. Now they have LVM3 there is no reason to keep such a unreliable launch vehicle flying.
<snip>
I think if we view GSLV as more of a technology testbed of sorts we can have a more positive view of the entire GSLV program. GSLV was the first launch vehicle of ISRO to fly liquid fueled strapons, first to have a cryogenic upper stage, first to employ hot staging and of course first to achieve the Geostationary Transfer Orbit (GTO). First in something is always hard and prone to failure and hence why we should appreciate GSLV's various contributions to the Indian Launch Vehicle program.
Think it is better for ISRO to phased out the GSLV Mk2 quickly. Since even the LVM3 appears to have an end date on the horizon.
A future "LVM3" with semi-cryogenic core replacing the current hypergolic LVM3 core is a new vehicle even if ISRO stated otherwise.
Unless maintaining the 2 low volume production lines is political expediency. ISRO should consolidated their near future launches with the LVM3 to reduce production infrastructure footprint and get scale of economy with more production volume.
Interesting factoid - the strapped-on hypergolic boosters on the GSLV Mk2 have a longer burn time and higher ISP than the solid first stage.
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#133
by
K210
on 22 Nov, 2023 04:16
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GSLV was the first launch vehicle of ISRO to fly liquid fueled strapons, first to have a cryogenic upper stage, first to employ hot staging and of course first to achieve the Geostationary Transfer Orbit (GTO).
The first payload sent into GTO was by PSLV, carrying METSAT 1 on 12 September 2002 (target orbit was 180x36,000 km according to the press kit). The previous GSLV Mk.I launch on 18 April 2001 had a performance shortfall and sent its payload into sub-GTO with a 32,000 km apogee.
GSLV was the first launch vehicle of ISRO to
attempt to achieve GTO. PSLV was never designed or intended to fly to GTO orbits.
The performance shortfall in GSLV D1 was around 60 m/s or about 0.6% of the intended injection velocity which lead to a 3000-4000 km lower apogee than intended.
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#134
by
K210
on 22 Nov, 2023 04:18
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This paper goes over GSLV D1 mission in detail
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#135
by
zubenelgenubi
on 29 Nov, 2023 16:09
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My opinions:
Re: difficult GSLV MkII development
Hindsight is 20/20. 👀 👓 Congratulations. 🎊 🏅
Re: GSLV MkIII/LVM3 development
Very optimistic development schedule collided with reality, resulting in multi-year delays.
How many launches remain for GSLV? Is there an intended last launch? Or does commonality with the quite successful PSLV imply that there is no end-date yet?
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#136
by
K210
on 30 Nov, 2023 08:23
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How many launches remain for GSLV?
At least 10-12 more launches. GSLV isn't being retired anytime soon.
- 4 GSLV launches for remaining NVS satellites (NVS-2 to NVS-5)
- 1 GSLV launch for INSAT-3DS
- 3 GSLV launches for IDRSS satellites (Data relay satellites for human spaceflight mission)
- 1 GSLV launch for GISAT-2
- 1 GSLV launch for MOM-2 (TBD)
- 1 GSLV launch for Venus Orbiter Mission (TBD)
- 1 GSLV launch for NISAR
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#137
by
K210
on 31 Dec, 2023 09:47
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While GSLV's GTO payload capacity is quite low it is capable of placing more than 3 ton into 700km SSO. This is about double what the PSLV can launch into SSO in its most powerful configuration. Maybe GSLV can be used in future launches to launch heavier SSO payloads beyond what the PSLV can handle.