I didn't have the chance to view the PSLV-42 launch video. So, I am not aware of what the ISRO officials said regarding the GSLV MK-III D2 launch. But in December, GSAT-11 is scheduled to launch. Who knows, the media may have mixed up GSAT-11 with GSAT-29 ? Then there is the GSAT-7A launch on the cards as well in November. But as far as defence and space related news is concerned, the Hindu's reporting is very credible. And if Dr. Sivan's words are to be believed quoted by the Hindu, then GSLV MK-III launch in on track.Quote"Right now with the status of the rocket, the GSLV Mk-3 M1, and the present status of the satellite, we are not expecting any more delay. At the same time tests are going on. If unexpected things happen, that may have some impact. But right now, we are not anticipating any delay."At the moment, GSLV-MK-III D2 launch and its getting operationalized as early as possible is more desirable to me than the launch of any other PSLV missions. ISRO has to extricate itself from the dependence on ESA for launching heavy communication satellites by operationalizing GSLV MK-III. Moreover, GSLV MK-III has to undergo 10 launches including the two unmanned mission before the launch of India’s manned mission. I don't think it would be wise of ISRO to launch Chandrayaan-2 in January, next year without launching the GSLV-MK-III D2. But in the launch business, though the delay in launching a mission is frowned upon, yet it is unavoidable.
"Right now with the status of the rocket, the GSLV Mk-3 M1, and the present status of the satellite, we are not expecting any more delay. At the same time tests are going on. If unexpected things happen, that may have some impact. But right now, we are not anticipating any delay."
Post launch speech isro chairmen k.sivan clearly said next launch would be PSLC C43, Then after GSLV MK 3 D2 launch,In the next month
This is just speculation but i think there are problems with GSAT-29 AND the MK3 D2 vehicle. The GSAT-29 is highly experimental in nature and contains technology that isro has no prior experience with so that might be causing some problems on the payload side. On the vehicle side the MK3 will undergo several upgrades through this D2 mission. Not only will high thrust vikas engines be used on L110 core stage for first time the C25 upper stage will stretched to C30 and burn time will go up from 640 seconds to around 800 seconds so that also brings in a lot of complexities. ISRO has given itself quite a challenge with a mission like this.
Attached news article makes mention of all upcoming missions of isro except D2 mission. Could the silence be interpreted as something has gone wrong? News Article: http://www.andhrabhoomi.net/content/nation-8122
Quote from: K210 on 10/24/2018 04:14 amThis is just speculation but i think there are problems with GSAT-29 AND the MK3 D2 vehicle. The GSAT-29 is highly experimental in nature and contains technology that isro has no prior experience with so that might be causing some problems on the payload side. On the vehicle side the MK3 will undergo several upgrades through this D2 mission. Not only will high thrust vikas engines be used on L110 core stage for first time the C25 upper stage will stretched to C30 and burn time will go up from 640 seconds to around 800 seconds so that also brings in a lot of complexities. ISRO has given itself quite a challenge with a mission like this.I'd read GSAT-29 can do upto 100Gbps through 104 different beams to countries across Southeast Asia -- so that's the "multi-beam". What exactly is this "optical communications" - is it laser communication?Never knew that C25 has been extended to C30. Will it gradually be extended further on future missions, to gradually morph into ULV?
800 seconds? That’s more than 13 minutes... most launch vehicles burn time of all stages combined is less than 10 minutes. Can that be right?
Stating that prior to stage development hot tests, three CE20 engines were realised and two engines were subjected to qualification tests in sea level conditions, ISRO said, this included 800 seconds duration hot test and the third engine identified for flight was tested in high altitude conditions for a duration of 25 seconds.
The space agency described the C25 stage as the "most powerful" upper stage developed by ISRO which uses Liquid Oxygen (LOX) and Liquid Hydrogen (LH2) propellant combination.It said the stage carries 27.8 tonnes of propellants loaded in two independent tanks.
The CE-20 was ignited and tested for 800 seconds from 5 p.m. to study the performance of the engine though the actual required duration was only 635 seconds.During the actual flight of the GSLV, the engine will be ignited for only 635 seconds.
Quote from: Lars-J on 10/30/2018 02:02 am800 seconds? That’s more than 13 minutes... most launch vehicles burn time of all stages combined is less than 10 minutes. Can that be right?Yes, the burn time is right. Even though C25 will normally burn for 640 secons, yet ISRO tested it to burn for 800 seconds with an increase of over 25% normal burn time. GSLV MK-III's core stage L110 burns for only 203 seconds with the loading of hypergolic propellant for first stage in a two stage launch vehicle. After that C25 upper stage propelled by 1 CE-20 cryogenic engine takes over to compensate for the less efficent core stage's performance.
Quote from: Lars-J on 10/30/2018 02:02 am800 seconds? That’s more than 13 minutes... most launch vehicles burn time of all stages combined is less than 10 minutes. Can that be right?It's actually in the ballpark of most LH2 upper stage of today (Centaur, Ariane 5 2nd stage etc.)