The Indian Space Research Organisation (ISRO) has unveiled plans for the development of a Two-Stage-to-Orbit (TSTO) Spaceplane Concept to assist in the development of next-generation space vehicles.
TSTO spaceplane can fulfill the near-term access-to-space goals, while greatly reducing the cost, substantially improving mission flexibility, operability, safety, and reliability, and offering significant growth potentials and multiple avenues.
TSTO-TD will take wing with its Turbo-ramjet engine that will later push the TSTO to Mach 6 speed before the Scram-jet engine takes over at 28 Km altitude that will push the speed up to Mach 9 and over 50 Km altitude after which, in second-stage, a rocket placed on the TSTO-TD will be engaged and separate from the spacecraft to propel it to 300 Km altitude to deliver a 2-ton payload at low Earth orbit (LEO), while TSTO-TD after completing stage-1 will glide down towards the earth and will engage its Turbo-ramjet engine at 15 K or lower altitude to land back at the designated airstrip.
TSTO-TD will have 133 Tons of Gross Lift-Off Mass (GLOM) that’s little over the Empty weight of Boeing C-17 Globemaster III. ISRO has not revealed when it will start to work on its development. ISRO is working on a smaller Reusable Launch Vehicle Technology Demonstrator (RLV-TD) that will reach full-scale variant only in 2030 so the TSTO-TD concept becoming reality soon is a distant dream for now.