Subsonic cruise missile travels at a speed lesser than that of sound. American Tomahawk cruise missile is a well-known subsonic missile. Other examples are Harpoon of USA, Nirbhay of India, and Exocet of France.
The hypersonic cruise vehicle was launched by using a proven solid rocket motor, which took it to an altitude of 30 kilometres.
With the help of multiple tracking radars, electro-optical systems, and Telemetry Stations, the parameters of launch and cruise vehicle including the scramjet engine were monitored.
On 7 September, 2020, DRDO successfully flight tests Hypersonic Technology Demonstrator Vehicle (HSTDV) from Dr. APJ Abdul Kalam Launch at Wheeler Island, off the coast of Odisha.