Isro hot-tests cryo engine, ups LVM3/GSLV-Mk3 payload capacity

BENGALURU: The Indian Space Research Organisation (Isro) late on Wednesday said that the CE20 cryogenic engine indigenously developed for LVM3 (GSLV-Mk3) has been successfully hot-tested “at an uprated thrust level of 21.8 t for the first time”.
“This will enhance the LVM3 payload capability up to 450 kg with additional propellant loading. The major modifications carried out on this test article compared to previous engines was introduction of Thrust Control Valve (TCV) for thrust control,” Isro said.
Additionally, the space agency said a 3D-printed LOX (liquid oxygen) and LH2 (liquid hydrogen) turbine exhaust casings were inducted in the engine for the first time.

“During this test, the engine operated with around 20t thrust level for the first 40 seconds, then thrust level was increased to 21.8t by moving the thrust control valve. Engine and facility performance was normal and required parameters were achieved,” Isro added.
The TOI had reported on October 31 that as the LVM3 prepares for its second commercial launch, expected in early 2023, Isro’s efforts on enhancing its weight-lifting capacity is gaining pace with the space agency expected to complete qualification tests for the semi-cryogenic stage (SC120) in a couple of months.
Isro spokesperson Sudheer Kumar had then told TOI: “The (LVM3) programme was envisaged to eventually carry at least 10 tonnes to LEO and six tonnes to GTO orbits. We’ll achieve this with an upgrade of the cryo stage with additional propellant loading and induction of the semi-cryo stage that will replace the L110…”
Semi-Cryo
Work on the semi-cryo engine is almost nearing completion and qualification tests are in progress. Stage and engine development phase is complete and the test stand is getting ready for carrying out tests.
“At present sub-system level tests are going on at testing facilities in Mahendragiri and LPSC (Liquid propulsion systems centre),” Kumar had said.
GSLV-Mk3 is a three-stage vehicle with two solid strap-on motors (S200), one liquid core stage (L110) and a high-thrust cryogenic upper stage (C25). While the S200 will remain the same, the SC120 will replace L110 and C25 will be upgraded. The qualification of SC120 is expected to be completed in a few months unless anomalies are found.