During three weeks in a thermal vacuum chamber in Bengaluru, India, the joint NISAR, the trailblazing Earth-observing radar satellite being developed by the United States and Indian space agencies, passed a major milestone on November 13, emerging from a 21-day test aimed at evaluating its ability to function in the extreme temperatures and the vacuum of space.
NISAR’s Mission and Capabilities
Short for NASA-ISRO Synthetic Aperture Radar, NISAR is the first space hardware collaboration between NASA and the Indian Space Research Organisation, or ISRO, on an Earth-observing mission. Scheduled to launch in early 2024, the satellite will scan nearly all the planet’s land and ice twice every 12 days, monitoring the motion of those surfaces down to fractions of an inch. It will be able to observe movements from earthquakes, landslides, and volcanic activity and track dynamic changes in forests, wetlands, and agricultural lands.
Rigorous Testing Procedures
The thermal vacuum test occurred at ISRO’s Satellite Integration and Test Establishment in the southern Indian city of Bengaluru. It’s one of a battery of tests the satellite will face leading to launch. Other tests will ensure it can withstand the shaking, vibration, and jostling that it will encounter during launch.
NISAR, partially covered in gold-hued thermal blanketing, entered the vacuum chamber on October 19. Over the following week, engineers and technicians lowered the pressure to an infinitesimal fraction of the normal pressure at sea level. They also subjected the satellite to an 80-hour “cold soak” at 14 degrees
Collaborative Efforts and Future Plans
ISRO and the L-band and S-band radars – under the most extreme temperature conditions they will experience in space.
This latest round of testing followed 20 days of testing in September in which engineers used ISRO’s compact antenna test facility to evaluate whether the radio signals from the two radar systems’ antennas passed requirements. Blue foam spikes lining the facility’s walls, floor, and ceiling prevent radio waves from bouncing around the room and interfering with measurement.
With thermal vacuum and compact antenna tests successfully done, NISAR will soon be fitted with its solar panels and its nearly 40-foot (12-meter) radar antenna reflector, which resembles a snare drum and will unfold in space at the end of a 30-foot (9-meter) boom extending from the spacecraft.
The satellite will undergo additional tests before being packed up and transported about 220 miles (350 kilometers) eastward to Satish Dhawan Space Centre, where it will be mounted atop ISRO’s Geosynchronous Satellite Launch Vehicle Mark II rocket and sent into low Earth orbit.
More About the Mission
NISAR is an equal collaboration between NASA and ISRO and marks the first time the two agencies have cooperated on hardware development for an Earth-observing mission. NASA’s Jet Propulsion Laboratory, which is managed for the agency by Caltech in Pasadena, California, leads the U.S. component of the project and is providing the mission’s L-band SAR. NASA is also providing the radar reflector antenna, the deployable boom, a high-rate communication subsystem for science data, (function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(d.getElementById(id))return;js=d.createElement(s);js.id=id;js.src="https://connect.facebook.net/en_US/sdk.js#xfbml=1&version=v2.6";fjs.parentNode.insertBefore(js,fjs);}(document,'script','facebook-jssdk'));