IMS-1 was ISRO's low-cost 83 kg imaging microsatellite, launched with Cartosat-2A in April 2008. It was first called TWSat (Third World Satellite), and its data was meant to be shared with developing countries.
No longer operational, according to the public satellite catalogue.
IMS-1 carried two cameras working in visible and near-infrared light. The multispectral camera saw at 37 m resolution over a strip 151 km wide. The hyperspectral camera split light into many narrow colours, at about 506 m resolution over 129.5 km.
The whole satellite measured about 0.6 × 1.0 × 1.1 m. Two solar panels that track the Sun gave 220 W, and a 16 Gb solid-state recorder stored images until a ground station was in view.
To point, it used a star sensor, small Sun sensors, magnetometers, gyros, miniature reaction wheels, magnetic torquers and a single 1 N hydrazine thruster. It was designed to work for two years.
PSLV-C9 launched IMS-1 from Sriharikota on 28 April 2008 along with Cartosat-2A and eight foreign nanosatellites. They went into a sun-synchronous polar orbit about 635 km high.