The NASA-ISRO Synthetic Aperture Radar (NISAR) mission is a joint project between NASA and ISRO to co-develop and launch a dual frequency synthetic aperture radar satellite. The satellite will be the first radar imaging satellite to use dual frequency and it is planned to be used for remote sensing to observe and understand natural processes of the Earth.The Indian Space Research Organisation (ISRO) and the National Aeronautics and Space Administration (NASA) have collaborated to make a satellite called nisarIndia and the Unites States of America share a history of space cooperation, going back to 1963 when India launched its first U.S-manufactured sounding rocket. In the 1970’s ISRO and? NASA conducted the Satellite Instructional Television Experiment (SITE), which helped beam television programmes to more than 2400 villages across country.moreover,The NASA-ISRO Synthetic Aperture Radar satellite is likely to cost more than USD 1.5 billion and both US and India will bear the cost for the same. This could also be the world’s most expensive Earth imaging satellite NISAR is the first big collaboration between NASA and ISRO, certainly on RADAR but just in general as well. This is two frequency RADAR, it is an L-band 24 centimetre RADAR and S-band 13 centimetre. S-band is being built by ISRO and L-band by NASA.It is a major collaboration both in terms of the technical building of the satellite as well as working together across the Pacific between India and US.The launch of NISAR satellite is expected in 2021 from India aboard the Geosynchronous Satellite Launch Vehicle.