Glitch with GSLV's third stage caused ISRO to lose its Earth observation satellite

ISRO saw a smooth 26-hour countdown that began yesterday with the rocket being moved to the launchpad and then being filled with propellant. The final countdown and launch went off without a hitch, but five minutes in, the rocket started "pitching downrange" according to Karthik Naren, an avid space enthusiast and blogger.According to a report by PTI, after the mission director gave the go-ahead for the launch, the GSLV-F10 blasted off.Mission control said the performance of the first and second stages of the rocket was normal.[caption id="attachment_9888281" align="alignnone" width="1280"] Screengrab of ISRO's mission control during the EOS-03 launch mission. Image credit: ISRO/YouTube/Karthik Naren[/caption]Naren told Firstpost, "Around five minutes into the launch, the rocket kept losing attitude and velocity of the upper stage and eventually fell - you can see the slope on the graphic at the end.""The fairing had already separated, and the satellite was exposed to the vacuum of space at 130 km altitude."Scientists were seen holding discussions, after which Range Operations Director announced the "mission could not be accomplished fully" due to a "performance anomaly".[caption id="attachment_9888261" align="alignnone" width="1024"] About the EOS-03. Image credit: Karthik Naren[/caption]Later, ISRO Chairman K Sivan announced, "(The mission) could not be fully accomplished mainly because there is a technical anomaly observed in the cryogenic stage. This I wanted to tell all my friends.""The satellite didn't reach orbit since the indigenous Cryogenic upper stage or CUS-15 had to burn for another few minutes to reach orbital speed. It needed to reach a targeted Geo Synchronous Transfer orbital velocity of more than 7.9 kmps, for 170 × 36297 at an inclination of 19.4°, but it could only reach 4.7 kmps during the tumbling of stage, which is why it was an anomaly", Naren explains.According to data provided by ISRO, the CUS-15 has to burn for a total of 13 minutes (from T+5 minutes to T+18 minutes and 29 seconds), but it started having issues after the ignition at the six-minute mark.[caption id="attachment_9888291" align="alignnone" width="1280"] Screengrab from the EOS-03 mission launch showing GSLV-F10's third stage pitching downwards. Image credit: ISRO/YouTube/Karthik Naren[/caption]So where is the satellite? Naren opines it may have splashed into the Bay of Bengal, and the stage splashed down between the Andaman Islands and Thailand, in the region of Gulf of Martaban.Hindustan Times reports the GSLV rockets are not as successful as ISRO's workhorse PSLV. Three of 14 GSLV missions have failed as compared to two of the 53 PSLV missions. The GSLV rocket was used to launch the Chandrayaan-2 mission, which also was a partial failure as the lander-rover module crashed on the moon's surface, while the orbiter continues its science mission. The GSLV will also be the one to take Indian astronauts into space for the first time if all goes to plan."ISRO really need to master the usage of Cryogenics for their future launch vehicles. They have already worked on Cryogenics, but these type of failures now will create another opportunity to review their cryogenic stages, especially before the Gaganyaan mission and their upcoming Heavy Launch Vehicle projects," adds Naren.

In conversation with PTI, veteran space scientist and former ISRO chief G Madhavan Nair was shocked at the unsuccessful GSLV-F10 launch. However, he also said he is confident ISRO will bounce back and not lose heart, as this is not unusual."It's a shock for all of us. But we will recover from this shock soon and we will be back on track. The ISRO community is resilient enough to face such difficulties," Nair said."This is a very complex mission. Normally, the Cryogenic stage is the most difficult one compared to all other rocket propulsions," he added.From 2003-2009, Nair was the ISRO chief and oversaw 25 successful missions.ISRO has mastered cryogenic technology over the years and has a good track record, he said. It is not as bad as compared to Russia or some European countries, where cryogenic stage failure was estimated to be around 20 percent."This is the eighth launch of cryogenic stage. The first one was a problem (unsuccessful). Subsequently, all other launches turned in textbook performance. There is a finite possibility of failure with any such complex system. We need not be disappointed.""But at the same time, we should go to the root cause (of the failure) and fix it so that we don't repeat."Jitendra Singh, Union Minister of State (Independent Charge) Science & Technology; Minister of State (Independent Charge) Earth Sciences; MoS PMO, Personnel, Public Grievances, Pensions, Atomic Energy and Space, said that he has spoken to Sivan about the failure."Spoke to Isro chairman Dr K Sivan and discussed in detail. The first two stages went off fine, only after that, there was a difficulty in the cryogenic upper stage ignition. The mission can be re-scheduled some time again", said Singh in a tweet.After ISRO announced this mission didn't go as planned, many people online showed their support towards the national space agency. Words of encouragement and pride poured out from fans and well-wishers, along with some unsolicited advice.