On November 13, NISAR, the groundbreaking Earth observation radar satellite being developed by the United States and the Indian Space Agency, passed an important milestone test. The test lasted for 21 days and was designed to evaluate the satellite's ability to operate in extreme temperatures and the vacuum environment of space. For three weeks in a thermal vacuum chamber in Bangalore, India, the joint NASA and Indian Space Research Organization satellite demonstrated its endurance in the harsh space environment.
After launch in early 2024, NISAR will scan nearly all of Earth's land and ice twice every 12 days. In orbit, the satellite will extend solar panels and a nearly 40-foot-long (12-meter) radar antenna reflector, which resembles a small drum and will be deployed at the end of a 30-foot (9-meter) boom extending from the spacecraft. Image credit: NASA-JPL/Caltech
NISAR mission and capabilities
NISAR is the abbreviation of NASA-ISRO Synthetic Aperture Radar (NASA-ISRO Synthetic Aperture Radar). It is the first space hardware cooperation between NASA and the Indian Space Research Organization (ISRO) on Earth observation missions. The satellite, scheduled to launch in early 2024, will scan nearly all of Earth's land and ice twice every 12 days, monitoring the movement of those surfaces down to fractions of an inch. It will be able to observe movements caused by earthquakes, landslides and volcanic activity, and track the dynamics of forests, wetlands and farmland.
On October 19, the NISAR satellite entered the thermal vacuum chamber of the Indian Space Research Organization facility in Bengaluru. After three weeks, the satellite met all performance requirements in extreme temperatures and a space-like vacuum. Source: Indian Space Research Organization
Rigorous testing procedures
The thermal vacuum testing was conducted at ISRO's Satellite Integration and Test Facility in the southern Indian city of Bangalore. This is one of a series of tests the satellite will face before launch. Other tests will ensure the satellite can withstand the shakes, vibrations and turbulence of launch.
On October 19, NISAR, partially covered with a golden thermal blanket, entered the vacuum chamber. Over the next week, engineers and technicians reduced the pressure to a tiny fraction of the normal pressure at sea level. They also subjected the satellite to a "cold soak" of 14 degrees Fahrenheit (minus 10 degrees Celsius) for 80 hours, followed by an equally long "heat soak" of 122 degrees Fahrenheit (50 degrees Celsius). This simulates the temperature fluctuations a spacecraft would experience when exposed to sunlight and darkness in orbit.
The NISAR satellite stayed at the ISRO antenna test facility for 20 days in September while engineers evaluated the performance of its L-band and S-band radar antennas. Foam spikes lining the walls, floors and ceilings prevent radio waves from bouncing around the room and interfering with measurements. Source: Indian Space Research Organization
Collaborative efforts and future plans
For three weeks, ISRO and JPL teams worked around the clock to test the performance of the satellite's thermal system and its two main science instrument systems (L-band and S-band radars) in the most extreme temperature conditions it will experience in space.
Prior to the latest round of testing, engineers conducted 20 days of testing in September using ISRO's Compact Antenna Test Facility to evaluate whether radio signals from the two radar system antennas met requirements. The facility's walls, floors and ceilings are lined with blue foam spikes to prevent radio waves from bouncing around the room and interfering with measurements.
With the thermal vacuum and compact antenna testing successfully completed, NISAR will soon be equipped with solar panels and a nearly 40-foot-long (12-meter) radar antenna reflector.
The satellite will undergo more testing before being packed and transported about 220 miles (350 kilometers) east to the Satish Dhawan Space Center, where it will be mounted on an Indian Space Research Organization's Geostationary Satellite Launch Vehicle Mark II rocket and placed into low Earth orbit.
More information about tasks
NISAR is an equal collaboration between NASA and the Indian Space Research Organization (ISRO), marking the first time the two agencies have collaborated to develop hardware for an Earth observation mission. NASA's Jet Propulsion Laboratory, managed on behalf of the California Institute of Technology in Pasadena, California, is the U.S. portion of the project and is responsible for providing the mission's L-band synthetic aperture radar. NASA also provides radar reflector antennas, deployable booms, science data high-speed communications subsystems, GPS receivers, solid-state recorders and payload data subsystems. The URRao Satellite Center (URSC) in Bengaluru leads ISRO's missions and provides spacecraft buses, launch vehicles and related launch services and satellite mission operations. ISRO's Space Applications Center in Ahmedabad provides S-band synthetic aperture radar electronics.