Thread by @Chethan_Dash

Here we go. #Thread #space #update

2 key missions of spl test vehicle developed as part of #Gaganyaan are most likely in Aug & Dec. As I’d reported earlier, @isro is working towards 2 tests to establish crew abort & escape systems before the first uncrewed mission. 1/n

We are looking to schedule the 1st abort mission in Aug & the 2nd in Dec: Somnath. @isro to intentionally cause an anomaly & allow crew module to come out of it, do tumbling manoeuvres, deploy parachutes, & land in a designated spot on the sea before being recovered. 2/n

Aside from this — which is only one type of abort test — there are different events such as maximum dynamic pressure condition, maximum acceleration condition, some transient condition etc, in which abort will become critical in flight... 3/n

In all, Isro has realised four such special test vehicles, two missions of which will happen this year. 4/n

Work on the 2,275-kg data relay sats — Indian Data Relay Satellite System or #IDRSS — is ongoing. On Apr 4, @isro received satellite structure from @HALHQBLR (see pic), but a lot of work is still pending. “...The relay satellites have not been scheduled this year,” Somnath. 5/n

Its importance: At any given point — during #Gaganyaan launch and orbiting — at least 1 ground station needs to be able to see it. But with current network (@isro is working on securing at least 40 ground stations) that won’t be possible, bringing #IDRSS into play. 6/n

Further, the #PSLV mission scheduled to launch earth observation satellite-6 (EOS-6) or #Oceansat3 will now only happen in August-September. 7/n

“This is a more complex satellite and unlike the earlier ones in the family where the optics (sensors) were imported this will have indigenous ones. There are several challenges that are being addressed,” Somanath said. 8/n

However, the space agency is looking at another #PSLV mission in May involving a commercial satellite, which will be done through Space PSU @NSIL_India. 9/n

On the proposed landing experiment or #LEX of the re-usable launch vehicle technology demonstrator or #RLVTD, Somnath said: “If wind conditions are favourable, we should be able to do it this month. This work is progressing.” 10/n

Sources in VSSC said that the vehicle has returned from Challakere where it underwent some captive tests last month. “The data is being studied and we are preparing for #LEX,” one of them said. 11/n

The much-awaited first developmental flight of SSLV is scheduled for May, Isro will conduct two more this year. “After one in May, we’re looking to schedule one in August and one in December. All three are developmental flights,” Somanath said. 12/n

And, #AdityaL1 is expected to make the Sept-Oct window, missing which would push the mission to 2023. While the team is confident, headquarters is yet to take a final call on launch dates. “In all likelihood, it could happen this year,” one source said. 13/n

However, #Chandrayaan3 is expected to be pushed to 2023 even as testing of various systems continues. “The list of tests is long & we don't want to compromise on anything. It's unlikely that we launch this year given that we have specific windows to do it,” Somanath said. n/n