NISAR Passes Thermal Vacuum Test in Indian Spacecraft Facility

The NISAR satellite, partially covered in gold-hued thermal blanketing, enters the thermal vacuum chamber at the Indian Space Research Organisation's Satellite Integration and Test Establishment (ISITE) in Bengaluru, India, on Oct. 19, 2023. Short for NASA-ISRO Synthetic Aperture Radar, NISAR was bound for a 21-day trial aimed at evaluating its ability to function in the extreme temperatures and the vacuum of space. The satellite emerged from the chamber on Nov. 13, having met all requirements of the test.

Teams from ISRO and NASA's Jet Propulsion Laboratory worked around the clock, evaluating the performance of the satellite's thermal systems and its two primary science instrument systems – the L-band and S-band radars – under the most extreme temperature conditions they will experience in space.

During the three-week period, engineers and technicians lowered the pressure inside the chamber 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 Fahrenheit (minus 10 degrees Celsius), followed by an equally lengthy "hot soak" at up to 122 F (50 C). This simulates the temperature swings the spacecraft will experience as it is exposed to sunlight and darkness in orbit.

After further tests, the satellite will be transported about 220 miles (350 kilometers) eastward to Satish Dhawan Space Centre, where it will be inserted into its launch faring, mounted atop ISRO's Geosynchronous Satellite Launch Vehicle Mark II rocket, and sent into low-Earth orbit.

NISAR is the first space-hardware collaboration between NASA and ISRO on an Earth-observing mission. Scheduled to launch in early 2024, the satellite will scan nearly all of the planet's land and ice twice every 12 days, monitoring the motion of those surfaces down to fractions of an inch. It will also track other processes, including the dynamics of forests, wetlands, and agricultural lands.

JPL, which is managed for NASA by Caltech in Pasadena, leads the U.S. component of the project.