The Nisar Earth observation satellite, a collaboration between Isro and Nasa, has achieved a significant milestone by clearing a 21-day-long test. The test was designed to assess the satellite’s performance in extreme temperatures and the vacuum of space.
The thermal vacuum test was successfully conducted at Isro’s Satellite Integration and Test Establishment (SITE) unit in Bengaluru. This test is just one in a series of tests that the satellite will undergo before its scheduled launch in 2024. The purpose of these tests is to ensure that the satellite can withstand the shaking, vibration, and jostling it will experience during launch.
During the thermal vacuum test, the Nisar satellite, which is partially covered in gold-hued thermal blanketing, endured an 80-hour “cold soak” at -10 degrees Celsius followed by a “hot soak” at 50 degrees Celsius. This was done to simulate the extreme temperature conditions the satellite will encounter in space, where it will be exposed to sunlight and darkness.
The test also evaluated the performance of the satellite’s thermal system and its two primary science instrument systems – the L-band and S-band radars. These systems will be responsible for scanning the Earth’s land and ice, monitoring movements of the Earth’s surface, and observing changes in forests, wetlands, and agricultural lands.
With the successful completion of the thermal vacuum test and the earlier antenna test, the Nisar satellite will now be fitted with solar panels and a 12-meter radar antenna reflector. This reflector, resembling a snare drum, will unfold in space at the end of a 9-meter boom extending from the spacecraft.
Further tests will be conducted before the satellite is launched into Low Earth Orbit (LEO) using a Geosynchronous Satellite Launch Vehicle (GSLV) Mark II rocket. Once in orbit, the Nisar satellite will perform its Earth observation tasks, scanning the Earth multiple times a day and providing valuable data on various natural phenomena.
Overall, the successful completion of the test brings the Nisar satellite one step closer to its mission of monitoring and studying the Earth’s surface and providing crucial data for scientific and environmental research.