Nasa, Isro jointly working on synthetic aperture radar mission

Indian Space Research Organisation (Isro) and its US counterpart National Aeronautics and Space Administration (Nasa) are jointly working to co-develop the Nasa-Isro Synthetic Aperture Radar (NISAR), a dual frequency synthetic aperture radar satellite.

Artist concept of the NASA-ISRO Synthetic Aperture Radar (NISAR) satellite in orbit

Nasa-Isro Synthetic Aperture Radar (NISAR) mission is a dual frequency (L&S Band) Radar Imaging Satellite. In this joint mission, Nasa's Jet Propulsion laboratory will be responsible for design and development of L-band SAR, 12m unfurlable antenna, GPS system and data recorder.

Isro will be responsible for design and development of S-band SAR, spacecraft bus, data transmission system, spacecraft integration and testing, launch using GSLV and on-orbit operations.

The NISAR mission aims to design, develop and launch a dual frequency (LandS band) radar imaging satellite. It will explore newer application areas using L and S band microwave data, especially in natural resources mapping and monitoring, estimating agricultural biomass over full duration of crop cycle, assessing soil moisture, monitoring of floods and oil slicks, coastal erosion, coastline changes and variation of winds in coastal waters, besides assessment of mangroves and surface deformation studies due to seismic activities.

The two agencies have already signed an implementation arrangement (IA), defining the roles and responsibilities of Isro and Nasa in September 2014.

Isro has completed the baseline design reviews of spacecraft and S-band SAR payload while JPL has successfully completed the mission concept and key decision point reviews.

The first joint steering group (JSG) meeting of NISAR was held on 21 July 2015. NISAR satellite is expected to be launched during the year 2021.

The cost of the project comprises the) cost of Isro's work share, which is estimated to be Rs788.00 crore and cost of JPL's work share, which is expected to be around $808 million, minister of state (independent charge) for development of north-eastern region (DoNER), PMO, personnel, public grievances and pensions, atomic energy and space, Jitendra Singh informed the Rajya Sabha during question hour today.

Reusable satellite launch vehicle.

Isro is in the process of developing reusable launch vehicles, which is a technical challenge and involves the development of many cutting edge technologies.

The first test flight (HEX-01) of the reusable launch vehicle – technology demonstrator (RLV-TD) would demonstrate the hypersonic aerodynamics characteristics, avionics system, thermal protection system, control system and mission management. Based on the test flight results, further flights would be required to demonstrate reusability of the winged body.

Reusable launch vehicles are aimed at cutting down the cost of satellite launches. However, the magnitude of cost reduction depends on the development and realisation of fully reusable launch vehicle and its degree of reusability.

At present, operational launch vehicles in India are expendable, which are designed to be used only once and their stages are not recovered for reuse.

The launch vehicle typically consists of several rocket stages and the stages are jettisoned one by one during various phases of the mission as the launch vehicle gains desired altitude and speed, Jitendra Singh stated in the Rajya Sabha.

Besides, he said, Isro has taken up the development of a new generation launch vehicle named GSLV Mk III, with capability to launch up to four tonne class of satellites to GTO.

As a part of development, an experimental flight of GSLV Mk III with passive cryogenic stage was successfully launched on 18 December 2014 to validate the critical atmospheric regime of the flight.

The endurance hot test of high thrust indigenous cryogenic engine of GSLV Mk III has been successfully conducted for duration of 800 seconds on 16 July 2015.

After the successful qualification of the integrated cryogenic engine and stage, the first developmental flight of GSLV Mk III is planned, the minister added.