The Technology Experiment Satellite (TES) was launched by ISRO on October 22, 2001 from SHAR Centre, Sriharikota, India. TES is an experimental satellite that was developed to demonstrate and validate the technologies like attitude and orbit control system, high-torque reaction wheels, new reaction control system, light-weight spacecraft structure, solid state recorder, X-band phased array antenna, improved satellite positioning system, miniaturised TTC and power systems and, two-mirror-on-axis camera optics. This mission was carried out in PSLV-C3 launch vehicle and has a mass of 1108 Kg. It aimed to test technologies in attitude and orbit control system (AOCS), high-torque reaction wheels, new-generation star sensors, digital sun sensors, and solid-state recorders. The satellite was also equipped to conduct remote sensing applications.