IRNSS 1B: Civil Services Mentor Magazine - July 2014

IRNSS 1B

Introduction (Free Available)
IRNSS Satellites (Free Available)
IRNSS-1A (Free Available)
IRNSS-1B (Free Available)
Recent Developments (Only for Online Coaching Members)
Future of IRNSS Project (Only for Online Coaching Members)

Introduction

In the 67 years of India's independence, there has been a significant development in the field of Science and Technology. In this context, India has always tried to create an indigenous platform for its space and satellite mission. While there has been a dependence on the advanced nations, in terms of the scientific know-how, India has always made ingenious efforts towards capacity building.

It is in this context that the development of the Indian indigenous Navigation system was made a priority. As of now, there is a dependence on the American system of Global Positioning System (GPS) for navigation and communication. In order to become self-sufficient in this technology, it is an urgent task before the Indian scientists to develop the Indian satellite system, to provide for an indigenous navigation technology.

The vision of the Indian navigation system has been materialized in the form of the Indian Regional Navigation Satellite System (IRNSS) Programme, which seek to develop the capacity, which is at par with the US GPS.
After years of efforts and research, Indian scientists have been able to make remarkable progress in the field.

IRNSS Satellites

The IRNSS project was approved in 2006.

Each IRNSS satellite has two payloads: a navigation payload and CDMA ranging payload, in addition with a laser retro-reflector. The design of the payload makes the IRNSS system inter-operable and compatible with the GPS and Galileo. The satellite is powered by two solar arrays, which generate power upto 1,660 watts, and has a life-time of a decade.

The IRNSS constellation of satellites is currently under construction and will consist of 7 spacecraft in Geostationary and Geosynchronous Orbits when complete. Once operational, the IRNSS will give India an independent access to navigation data without relying on foreign programmes, like- GPS or Glonass.

After the launch of the first satellite (IRNSS-1A) of the seven IRNSS, India launched the IRNSS-1B. The IRNSS constellation of satellites is slated to be launched to provide navigational services to the region. The IRNSS-1B was successfully placed in the geosynchronous orbit on April 4, 2014.

IRNSS-1B is expected to help augmenting the satellite based navigation system of India, which is currently under development. The proposed navigation system would target the South Asian region. It has been designed to provide navigation, tracking and mapping services.

IRNSS-1A

IRNSS-1A was launched on July 1, 2013, from Satish Dhawan Space Center, Sriharikota. It is the first navigational satellite in the Indian Regional Navigational Satellite System (IRNSS) series of satellite. It has already been placed in the geosynchronous orbit. The development of the satellite itself was an ambitious project, that cost around Rs. 125 crore.

Scientists from the German Aerospace Center (DLR)'s Institute of Communication and Navigation have successfully received signals from IRNSS-1A.

IRNSS-1A will provide IRNSS services to the Indian public, which would be similar to the GPS, but only for India and the region around.

IRNSS-1B

IRNSS-1B was launched on April 4, 2014, aboard the PSLV-C24 rocket from the Satish Dhawan Space Center, Sriharikota. It weights around 1,432 Kg.

IRNSS-1B carries two payloads:

A navigation payload- to transmit navigation signals to the users. It also contains the laser retro-reflector. The satellite also features a highly accurate Rubidium atomic clock, as a part of its navigation payload; and,
CDMA ranging payload. It consists of a C-Band transponder which facilitates accurate determination of the range of the satellite. IRNSS-1B also features Corner Cube Retro Reflectors for laser ranging.
The payload generates navigation signals at L5 and S-band. The design of the payload makes the IRNSS system interoperable and compatible with Global Positioning System (GPS) and Galileo.

The Satellite is powered by two solar arrays, which generate power upto 1,660 watts, and has a life-time of ten years.

It's configuration is similar to that of the IRNSS-1A. The satellite was realized in less than 7 months, after the launch of its predecessor, which is a significant achievement in itself.

The IRNSS-1B satellite has been designed and developed by the Indian Space Research Organization (ISRO). It is based on the I-1K Satellite Bus. The Spacecraft Bus is 1.58 x 1.5 d 1.5 meters in size with a dry mass of 614 Kg.

The main propulsion system for large orbit adjustments and apogee maneuvers consists of a Liquid Apogee Motor (LAM). It provides a thrust of 440 Newtons and uses Mixed Oxides of Nitrogen as fuel and Unsymmetrical Dimethylhydrazine as oxidizer. The engine operates at a mixture ratio (O/F) of 1.65 and has a nozzle ratio of 160. The engine's injector is a co-axial swirl element made of titanium while the thrust chamber is constructed of Columbium alloy that is radiatively cooled. The engine is certified for long firings of up to 3,000 seconds. The Propellants are stored in spherical tanks that are pressurized with Helium.

The Spacecraft will support Standard Positioning Service that is open to all users as well as Restrictive Service, with high accuracy that is only provided to authorized users. The system will provide an accuracy of 10 to 20 meters.

After its launch, the satellite control was taken over by the Mission Control Facility (MCF) at Hassan in Karnataka. The MCF will manage the satellite's orbit infrastructure for controlling, tracking and other facilities.