Space Skyroot Aerospace test fires 3D printed cryogenic engine Skyroot Aerospace test fires 3D printed cryogenic engine Skyroot Aerospace, a private rocket builder, achieved a major milestone by successfully test-firing an advanced fully 3D-printed cryogenic engine for a record 200 seconds. The endurance test of 'Dhawan-II' was carried out at Solar Industries propulsion test facility in Nagpur, Maharashtra, using indigenously developed mobile cryogenic engine test pad. This achievement follows the November 2022 launch of Vikram-S, which made the firm the first Indian private company to send a rocket into space.