THIRUVANANTHAPURAM: Indian Space Research Organisation is planning the technology demonstration of its Reusable Launch Vehicle, expected to make space missions economically viable, by mid May.The flight integration of the Reusable Launch Vehicle-Technology Demonstrator (RLV-TD) is almost complete at the Vikram Sarabhai Space Centre (VSSC) here and it will be shifted to Bengaluru for further tests next week, VSSC Director K Sivan said today."RLV-TD is almost integrated and tests are progressing. It will be shifted to Bengaluru next week for an acoustic test and then to Satish Dhawan Space Centre, Sriharikota (SHAR) for final preparations before the launch," he told reporters here."We want clear weather conditions for the launch. We hope it will happen by first half of May," he said.RLV-TD is a series of technology demonstration missions that have been considered as a first step towards realising a Two Stage To Orbit (TSTO) fully re-usable vehicle.Under the preliminary mission, which is planned as a suborbital one, a double-delta winged vehicle, which more or less resembles an aircraft, will be launched from the SHAR.The 6.5 meter-long vehicle, having a mass of 1.75 tonne, will go up to around 70 km after which it is expected to descend at a particular point on the sea.Sivan said the proposed mission would be just a "baby step" in terms of the RLV technology and no way near to the real Reusable Launch Vehicle."What we do now is only a demonstration. It is no way near to the real RLV. It is like a drop test to bring back a launched vehicle to some point. It is just a baby step towards the giant leap," he said.Flush air-data system, slow burning propellant and composite movable fin are among the significant features of the RLV-TD.The total cost of the mission is estimated to be around Rs 95 crore, the VSSC Director said adding the launch would give major inputs for the designing of the full scale RLV in future.