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About NISAR (Satellite) Joint Project Between NASA and ISRO

NISAR (Satellite)

Source : Wikipedia

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 on an Earth observation satellite. The satellite will be the first radar imaging satellite to use dual frequencies. It will be used for remote sensing, to observe and understand natural processes on Earth. For example, its right-facing instruments will study the Antarctic cryosphere. 

With a total cost estimated at US$1.5 billion, NISAR is likely to be the world's most expensive Earth-imaging satellite.
NASA-ISRO Synthetic Aperture Radar (NISAR)
NISAR artist concept.jpg
Artist's concept of the NASA-ISRO Synthetic Aperture Radar (NISAR) satellite in orbit.
Mission typeRadar imaging
OperatorNASA · ISRO
Mission duration3 years
Spacecraft properties
Launch mass2,800 kg (6,200 lb)
Power6,500 W
Start of mission
Launch date2022
RocketGSLV Mk. II
(4 meter fairing)
Launch siteSatish Dhawan Space Center
Orbital parameters
Reference systemGeocentric
RegimeLow-Earth, Sun-synchronous
Altitude747 kilometers (464 mi)
BandKa band
The Geosynchronous Satellite Launch Vehicle (GSLV) project was initiated in 1990 with the objective of acquiring an Indian launch capability for geosynchronous satellites.

GSLV uses major components that are already proven in the Polar Satellite Launch Vehicle (PSLV) launchers in the form of the S125/S139 solid rocket booster and the liquid-fueled Vikas engine. Due to the thrust required for injecting the satellite in a GTO orbit the third stage was to be powered by a LOX/LH2 Cryogenic engine which at that time India did not possess or had the technology know-how to build one.

The first development flight of the GSLV (Mk.I configuration) was launched on 18 April 2001 was a failure as the payload failed to reach the intended orbit parameters. The launcher was declared operational after the second development flight successfully launched the GSAT-2 satellite. During the initial years from the initial launch to 2014 the launcher had a checkered history with only 2 successful launches out of 7.

Cryogenic Engine Controversy
The third stage was to be procured from Russian company Glavcosmos, including transfer of technology and design details of the engine based on an agreement signed in 1991. Russia backed out of the deal after US objected to the deal as in violation of the Missile Technology Control Regime (MTCR) May 1992. As a result, ISRO initiated the Cryogenic Upper Stage Project in April 1994 and began developing its own cryogenic engine.[11] A new agreement was signed with Russia for 7 KVD-1 cryogenic stages and 1 ground mock-up stage with no technology transfer, instead of 5 cryogenic stages along with the technology and design as per the earlier agreement. These engines were used for the initial flights and were named GSLV Mk.1.

Vehicle description

The 49 metres (161 ft) tall GSLV, with a lift-off mass of 415 metric tons (915,000 lb), is a three-stage vehicle with solid, liquid and cryogenic stages respectively. The payload fairing, which is 7.8 metres (26 ft) long and 3.4 metres (11 ft) in diameter, protects the vehicle electronics and the spacecraft during its ascent through the atmosphere. It is discarded when the vehicle reaches an altitude of about 115 km.

GSLV employs S-band telemetry and C-band transponders for enabling vehicle performance monitoring, tracking, range safety / flight safety and preliminary orbit determination. The Redundant Strap Down Inertial Navigation System/Inertial Guidance System of GSLV housed in its equipment bay guides the vehicle from lift-off to spacecraft injection. The digital auto-pilot and closed loop guidance scheme ensure the required altitude maneuver and guide injection of the spacecraft to the specified orbit.

The GSLV can place approximately 5,000 kg (11,000 lb) into an easterly Low Earth orbit or 2,500 kg (5,500 lb)(for the Mk. II version) into an 18° geostationary transfer orbit.

Liquid boosters
The first GSLV flight, GSLV-D1 used the L40 stage. Subsequent flights of the GSLV used high pressure engines in the strap-on boosters called the L40H.[15] The GSLV uses four L40H liquid strap-on boosters derived from the L37.5 second stage, which are loaded with 42.6 tons of hypergolic propellants (UDMH & N2O4). The propellants are stored in tandem in two independent tanks 2.1 metres (6 ft 11 in) diameter. The engine is pump-fed and generates 760 kilonewtons (170,000 lbf) of thrust, with a burn time of 150 seconds.

First stage
GSLV-D1 used the S125 stage which contained 125 metric tons (276,000 lb) of solid propellant and had a burn time of 100 seconds. All subsequent launches have used enhanced propellant loaded S139 stage. The S139 stage is 2.8 m in diameter and has a nominal burn time of 109 seconds. The stage generates a maximum thrust of 4700 kN.

Second stage
The GS2 stage is powered by the Vikas engine. It has a diameter of 2.8 metres (9 ft 2 in).

Third stage
The third stage of the GSLV Mk.II is propelled by the Indian CE-7.5 cryogenic rocket engine while the older defunct Mk.I is propelled using a Russian made KVD-1. It uses liquid hydrogen (LH2) and liquid oxygen (LOX) The Indian cryogenic engine was built at the Liquid Propulsion Systems Centre The engine has a default thrust of 75 kilonewtons (17,000 lbf) but is capable of a maximum thrust of 93.1 kilonewtons (20,900 lbf).

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