Rohini satellite

 Rohini was not a single satellite but it was a series of 4 satellites. Named Rohini Technology Payload( RTP), RS-1, RS-D1, RS-D2. This all satellites launched by the Indian space research organization (ISRO). This all satellites is launch by Satellite Launch vehicle(SLV). This all satellite series were mostly experimental satellites.

According to Indian astrology, Rohini is a star. So maybe that was why the satellite was named after the Star.

Rohini satellites were experimental satellites. The primary vision of ISRO to learn satellite and launch successfully into orbit rather than any specific real-life Application. 

The first Rohini satellite(RTP) only carried instruments to monitors the launch vehicle. It was not successful because the launch vehicle was failed to reach the orbit.

The Second Rohini satellite( RS-1 ) also carried only launch vehicle monitoring experiment.

Third and fourth Rohini satellites( RS-D1 and RS-D2) also carried solid-state camera for earth observation. Especially, RS-D2 took nearly 2500 images of various in infrared or visible wavelengths.

Detailed information:

1) Rohini RS-1:

• Launch Date: July 18,1980
• Weight: 35 kg
• Orbit: 300km × 900 km elliptical
• Launched by: India, SLV-3 Rocket
• Objectives: The satellites provided data on the  fourth stage performance and Ranging

Credit: ISRO 

2) Rohini satellite-D1:

• Launched date: May 30, 1981
• Weight: 35 kg
• Launched by: India, SLV-3 ( D-1) Rocket
• Orbit: 300 km × 900 km elliptical orbit
• Objectives: carried A landmark sensor payload whose solid-state camera performed to specification. This satellite re-entered the earth's atmosphere Nine days after launch on account of the launch because launch vehicle ejected the satellite into lower than expected altitude.

Read: GSAT - 02

Credit: ISRO 

3) Rohini Satellites-D2:

• Launched date: April 17, 1983
• Weight: 35 kg
• Launched by: India, SLV-3 (D-2) Rocket
• Orbit: 300 km× 900 km elliptical orbit
• Objective: The smart sensor camera was the primary payload onboard satellite. This satellite operated more than 5 months and sent more than 2500 visible infrared and visible bands photos. After completing all its mission goals, RS-D2 was closed down on sept. 24, 1984.

  

  Credit: ISRO 

 Also Read: GSAT - 17   

Mission overview:

• Launch Mass: 30-41.5 kg
• Total launched: 4
• Maiden launch: RTP,August 1979
• Last launch: Rohini RS- D2;                                        17 April 1983
• Application: Experimental                                         satellites
• Design life: 8  years
• Status: Retired