The Indian Space Research Organisation (ISRO) successfully carried out the third hot test of its semi-cryogenic engine Power Head Test Article (PHTA) on 28 May 2025 at the ISRO Propulsion Complex (IPRC), Mahendragiri. The test is part of a series of performance evaluations aimed at validating key subsystems of the 2000 kN-class SE2000 engine that will eventually power the SC120 propulsion stage intended to replace the existing L110 liquid core stage of the LVM3 launch vehicle. ISRO began this series of performance evaluations in March 2025, focusing on critical components such as low- and high-pressure turbo-pumps, the pre-burner, the start-up system, and various control mechanisms.

The three-phased trials

According to the official ISRO press release, the PHTA has undergone two hot tests earlier, which included all systems except the thrust chamber. The first test on 28.03.2025 demonstrated the smooth ignition & bootstrap operation over a short duration of 2.5 seconds. The second hot test on 24.04.2025 demonstrated the start transient build-up and tested the start-up sequence by carrying out a hot-firing for a duration of 3.5 seconds. The third test was carried out for a duration of 3 seconds to fine-tune further & finalize the start-up sequence.

The SE2000 employs an oxidizer-rich staged combustion cycle using liquid oxygen and kerosene. It is able to deliver a chamber pressure of 180 bar and a specific impulse of 335 seconds—an upgrade over the L110 stage’s hydrazine-based propulsion.

Future Integration and Impact on Indian Launch Capability

With the subsystem validations complete, ISRO will now begin integrated engine-level trials, moving toward full operational readiness. The SC120 stage powered by SE2000 is expected to increase LVM3’s payload capacity from 4 to 5 tonnes to Geostationary Transfer Orbit (GTO) and from 8 to 10 tonnes to Low Earth Orbit (LEO).