India launches satellite trio aboard one PSLV rocket

Posted: October 22, 2001

An artist's concept of the TES spacecraft. Photo: ISRO
India's Polar Satellite Launch Vehicle bolted from its launch pad today, successfully hauling three technology demonstration payloads into space.

The PSLV rocket launched at 10:23 a.m. local time (0453 GMT) from India's Sriharikota complex, located on the east coast of the nation near the Bay of Bengal.

The Indian Technology Experiment Satellite (TES) and Germany's Bispectral Infrared Detector (BIRD) spacecraft were deployed in a 568 km sun-synchronous orbit. The rocket's fourth stage then performed a subsequent maneuver and released the European Project for On-Board Autonomy (PROBA) satellite in an elliptical orbit with a low point of 568 km and high point of 638 km.

The somewhat secretive Technology Experiment Satellite (TES) will be operated by the Indian Space Research Organization and will attempt to test new spacecraft bus and payload technologies, ranging from communications to remote sensing. The 1108-kg craft carries a panchromatic camera for Earth-imaging.

"Some of the technologies that are planned to be demonstrated in TES are attitude and orbit control system, high torque reaction wheels, new reaction control system with optimized thrusters and a single propellant tank, light weight spacecraft structure, solid state recorder, X-band phased array antenna, improved satellite positioning system, miniaturized TTC and power system and, two-mirror-on-axis camera optics," ISRO acknowledged.

File image of PSLV rocket lifting off. Photo: ISRO
The BIRD satellite, a 92-kg German spacecraft, is designed to evaluate new strategies and technologies in remote sensing and small satellite design.

BIRD's scientific aims include the observation of thermal events such as fires and volcanoes, clouds, surface characteristics, and vegetation. The mission's technological objectives include the evaluation of new infrared instruments and the unique use of both stereo and infrared cameras simultaneously.

During its projected two-year lifetime, the 94-kg PROBA will operate almost entirely on its own to test the validity of self-functioning space technologies. Scientific and house-keeping activities will be able to be planned by both the ground team and the satellite's on-board computer.

Functions that will be tested for autonomy possibilities include scheduling and planning of scientific experiments, data collection, communications between PROBA, scientific users, and the ground team, management of routine satellite functions, and failure detection. Most satellites currently require interaction between the ground and the spacecraft to carry out some of these activities.

In addition to its autonomy studies, PROBA also features three science payloads to be used to for both the augmentation of the satellite's demonstration mission and for independent purposes.

The three payloads will work in the fields of Earth observation, radiation monitoring, and debris impact studies.

"PROBA's multi-purpose capabilities are part of ESA's goal to promote technological missions using small spacecraft," said Frederic Teston, PROBA's Project Manager. "The micro-satellite boasts a number of technology firsts, and has the ability to observe the same spot on Earth from a number of different directions."

The Polar Satellite Launch Vehicle employs four stages and six solid-fueled strap-on boosters. This launch was the first PSLV flight since May 1999, when three satellites were launched.

Overall, the PSLV has now flown six times, with five of those having been successful.