NISAR data, featuring high-resolution L-band and S-band radar, is archived and distributed by the Alaska Satellite Facility (ASF) DAAC as of early 2026. Users can access Level 0-3 products—covering Earth's surface, ice, and ecosystems—via Vertex Data Search, Earthdata Search, and direct S3 access. 

https://search.asf.alaska.edu/ (search for dataset "NISAR")