Navigation satellite IRNSS-1D launch postponed due to technical glitches

Test flight of Reusable Launch Vehicle to be conducted by second quarter of 2015, says Ministry

The Indian Space Research Organisation (Isro) has postponed launch of fourth navigation satellite IRNSS-1D onboard PSLV-C27,  following an anomaly identified in on of the telemetry transmitters of the satellite.

The satellite was originally scheduled for launch on March 9, 2015, from Satish Dhawan Space Centre, Sriharikota.

Isro, in an announcement, said, “During the integrated electrical checks of launch vehicle along with satellite after the closure of heat shield on March 3, 2015, an anomaly was observed in one of the telemetry transmitters of the satellite.”

“In order to resolve the technical anomaly through further test, simulation and analysis, the launch of PSLV-C27 with IRNSS-1D has been postponed,” it added.

It is one of the seven satellites under the Indian Regional Navigation Satellite System (IRNSS), an independent Indian Satellite based positioning system for critical national applications. The main objective of the constellation of satellites is to provide reliable position, navigation and timing services over India and its neighbourhood, to provide positioning services over Indian region with an absolute position accuracy of better than 20 metres.

Space segment consists of seven satellites, three satellites in geo-stationary (GEO) orbit and four satellites in geo-synchronous orbit (GSO) orbit with inclination of 29 degree to the equatorial plane.

All the satellites will be visible at all times in the Indian region.

The first satellite was launched in 2013 and the total seven satellite constellation is scheduled to be in place by 2016, according to Isro website. Out of the seven satellites required in the constellation, three satellites namely, IRNSS-1A, 1B and 1C have already been successfully placed in the orbit.

The work on remaining three satellites is in progress. The associated ground segment for maintaining the satellites in orbit, monitoring the constellation status, correction of the orbital parameters and navigation data uploading is in place, said Jitendra Singh, minister of state in the Prime Minister’s Office and minister of state in the ministry of Personnel, PG & Pensions in a reply in the Parliament on Wednesday.

<B>Test flight of re-usable launch vehicle this year</B>
Isro will carry out a test flight of Reusable Launch Vehicle – Technology Demonstrator (RLV-TD) by second quarter of 2015, said Jitendra Singh in the Parliament on March 4.

The technology demonstrator winged body vehicle weighing 1.5 tonne will be lifted to a height of 70 km using solid booster, attaining five times the speed of sound. Thereafter, it will descend by gliding and splashing down into the sea.

This test flight would demonstrate the hypersonic aerodynamics characteristics, avionics system, thermal protection system, control system and mission management, said the minister.

He added the development of reusable launch vehicles was a technical challenge and it involved development of many cutting edge technologies and the magnitude of cost reduction depends on development and realisation of fully reusable launch vehicle and its degree of re-usability.

Isro has taken steps to develop next generation launch vehicle GSLV Mk III, capable of launching four tonne class communication satellites to geo-synchronous transfer orbit, which would bring down the cost of satellite launches, added Singh.