Thread by @Chethan_Dash

#Thread with details on today's #SSLV test & more:

Clearing the decks for the first flight of #SSLV, @isro today successfully carried out the ground testing of the newly developed solid booster stage (SS1) at SHAR. 1/n

The test happened at around 12.05pm. “This is the last test before the flight (developmental flight),” S Unnikrishnan Nair, director, Vikram Sarabhai Space Centre (VSSC), which is developing the SSLV, told me. 2/n

@isro will now schedule the first developmental flight which will put into orbit #EOS2 or #Microsat. While an official date for the developmental flight is yet to be arrived at, multiple scientists say it is expected to happen in the first half of this year. 3/n

A January review document from @isro reads: “The first developmental flight of the SSLV, the SSLV-D1, is scheduled to launch the EOS-2, an earth observation satellite in the first quarter of 2022.” 4/n

According to Isro, all the propulsion parameters during the test are found satisfactory and “closely matching with the predictions”. 5/n

SS1 is a 3-segmented solid propulsion stage with many new tech & innovative processes including bond-free joint between segments, high power electro mechanical actuator with digital control electronics, optimised ignitor & simultaneous propellant casting of all segments. 6/n

All these successfully validated in ground test. Monday’s success, @isro says, has given confidence to proceed with 1st developmental flight (SSLV-D1). “...The remaining stages have successfully undergone necessary ground tests & are ready for integration,” Isro. says. 7/n

Earlier, Isro had completed the SSLV Payload Fairing (SPLF) functional qualification test successfully and other testing activities are in progress. 8/n

I had reported that Isro will carry out this test this week while other crucial tests relating to the reusable launch vehicle technology demonstrator #RLVLEX and #Chandrayaan3 are also scheduled in the coming weeks. 9/n

Nair further added that once proven, each SSLV can be integrated and launched within 10 days. “That’s the beauty of an all-solid stage launch vehicle,” he said. 10/n

Designed to meet launch demand requirements in a cost-effective manner, SSLV is a three-stage all-solid vehicle with a capability to launch up to 500kg satellite mass into Low Earth Orbit (LEO). 11/n

According to VSSC, the SSLV is a three-stage launch vehicle configured with three solid propulsion stages and a liquid propulsion-based Velocity Trimming Module (VTM) as a terminal stage. 12/n

“SSLV is 2m in diameter & 34m in length with a lift off weight of around 120 tonnes. It can launch around 500kg sats in a 500km planar orbit. Key features: Low cost, low turn-around time, can accommodate multiple sats, launch on demand, min infra requirements,” VSSC adds. n/n