Rohini is a series of

sounding rockets A sounding rocket or rocketsonde, sometimes called a research rocket or a suborbital rocket, is an instrument-carrying rocket designed to take measurements and perform scientific experiments during its sub-orbital flight. The rockets are used to ...

developed by the

Indian Space Research Organisation The Indian Space Research Organisation (ISRO; ) is the national space agency of India, headquartered in Bengaluru. It operates under the Department of Space (DOS) which is directly overseen by the Prime Minister of India, while the Chairman ...

(ISRO) for

meteorological Meteorology is a branch of the atmospheric sciences (which include atmospheric chemistry and physics) with a major focus on weather forecasting. The study of meteorology dates back millennia, though significant progress in meteorology did not ...

and atmospheric study. These sounding rockets are capable of carrying

payloads Payload is the object or the entity which is being carried by an aircraft or launch vehicle. Sometimes payload also refers to the carrying capacity of an aircraft or launch vehicle, usually measured in terms of weight. Depending on the nature of ...

of between altitudes of . The ISRO currently uses RH-200, RH-300, RH-300 Mk-II, RH-560 Mk-II and RH-560 Mk-III rockets, which are launched from the Thumba Equatorial Rocket Launching (TERLS) in

Thumba Thumba is a coastal area of Thiruvananthapuram city, the capital of Kerala, India. Location and geography Thumba is a vast village bordering Menamkulam in the east, St. Dominic's Vettucaud in the north, and Kochuthura in the south; towards its ...

and the

Satish Dhawan Space Center Satish Dhawan Space Centre - SDSC (formerly Sriharikota Range - SHAR) is a rocket launch centre (spaceport) operated by Indian Space Research Organisation (ISRO). It is located in Sriharikota, Tirupati district of Andhra Pradesh. Sriharikota ...

Sriharikota Sriharikota is a Barrier island off the Bay of Bengal coast located in the Shar Project settlement of Tirupati district in Andhra Pradesh, India. It houses the Satish Dhawan Space Centre, one of the two satellite launch centres in India (the o ...

Various programs such as Equatorial ElectroJet (EEJ), Leonid Meteor Shower (LMS), Indian Middle Atmosphere Programme (IMAP), Monsoon Experiment (MONEX), Middle Atmosphere Dynamics (MIDAS), and Sooryagrahan-2010 have been conducted using the Rohini sounding rocket series. It has been the forerunners for ISRO's heavier and more complex launch vehicles, with continued usage even today for atmospheric and meteorological

Nomenclature

The rockets in the series are designated with the letters RH (for "Rohini"), followed by a number corresponding to the diameter (in millimetres) of the rocket.

Series

;RH-75 The RH-75, the first sounding rocket developed by India, was launched from TERLS on September 20, 1969. It weighed , had a diameter of and flew 15 times between November 1967 and September 1968. ;RH-125 This rocket was launched on October 9, 1971, from Sriharikota. It was a

two-stage rocket A two-stage-to-orbit (TSTO) or two-stage rocket launch vehicle is a spacecraft in which two distinct stages provide propulsion consecutively in order to achieve orbital velocity. It is intermediate between a three-stage-to-orbit launcher and a hy ...

using a

solid propellant A propellant (or propellent) is a mass that is expelled or expanded in such a way as to create a thrust or other motive force in accordance with Newton's third law of motion, and "propel" a vehicle, projectile, or fluid payload. In vehicles, the e ...

, carrying a payload to in altitude. It flew twice between January 1970 and October 1971. ;RH-200 The RH-200 is a two-stage rocket that can reach up to a maximum altitude of . Solid motors power the first and second stages of the RH-200. A polyvinyl chloride (PVC)-based propellant had previously been employed with the RH-200 rocket. In September 2020, a new propellant based on hydroxyl-terminated polybutadiene (HTPB) was successfully used flow it from the TERLS. ;RH-300 The Rh-300 is a single stage sounding rocket, derived from French Belier rocket engine technology. It has a launch altitude of 100 km (62 mi). A variant, the RH-300 Mk-II, has a maximum launch altitude of . ;RH-560 This two stage vehicle is derived from French Stromboli engine technology. Another variant, the RH-560 Mk-II, can reach a maximum launch altitude of . The RH-560 Mk-III variant's maiden flight (the flight was successful) was 12 March 2021.

Applications

The RH-200 is used for meteorological studies, the RH-300 Mk-II for Middle atmospheric studies and the RH-560 Mk-II for Upper atmospheric studies and ionospheric studies. The RH-200 was used as the rocket for the first payload launch in India made by students of VIT University in

Vellore Vellore (English: ), also spelt as Velur (), is a city and the administrative headquarters of Vellore district in the Indian state of Tamil Nadu. It is located on the banks of the Palar River in the northeastern part of Tamil Nadu and is separa ...

References

{{Use Indian English, date=January 2014 Sounding rockets of India Space programme of India