Technology Experiment Satellite (TES) is an experimental satellite to demonstrate and validate, in orbit, technologies that could be used in the future satellites of Indian Space Research Organisation (ISRO). TES weighs 1108 kg and was successfully placed in 568 km sun synchronous orbit on October 22, 2001 using the PSLV-C3 version of Polar Satellite Launch Vehicle. PSLV-C3 also injected two more satellites: PROBA, a Belgian satellite and BIRD, a German satellite.
The technologies demonstrated in TES are attitude and orbit control system, high torque reaction wheels, new reaction control system with optimised thrusters and a single propellant tank, light weight spacecraft structure, solid state recorder, X-band phased array antenna, improved satellite positioning system, miniaturised TTC and power system and, two-mirror-on-axis camera optics.
TES has a pan chromatic camera for remote sensing. The camera is which is capable of producing images of 1 metre resolution. 1 m resolution means the camera is able to distinguish between two objects which are separated at least a metre.
The launch of TES made India the second country in the world after the United States that can commercially offer images with one metre resolution. It is used for remote sensing of civilian areas, mapping industry and geographical information services.
TES, which was launched in 2001, helped the US army with high-resolution images during the 9/11 counter-terrorism offensive against the Taliban.