The Hongtu-1 (Chinese: 宏图一号), known commonly by its English-language name PIESAT-1 and infrequently as Nuwa-1, is a Chinese commercial X-band interferometric synthetic aperture radar (InSAR) satellite constellation performing Earth observation missions in Sun-synchronous orbit.

[1][2] Hongtu-1 satellites are intended to map global non-polar regions at a scale of 1:50,000 meters to produce high-precision digital surface models (DSM), likely fulfilling both commercial, scientific, and military reconnaissance tasks.

[1] Operating in a close formation, these co-orbiting satellites utilize inter-satellite communication to maintain stable and precision synchronization.

[citation needed] Hongtu-1 satellites are domestically produced by GalaxySpace, a Beijing-based private satellite developer, for PIESAT Information Technology Co. Ltd. and launched by China Great Wall Industry Corporation (CGWIC), a subsidiary of China Aerospace Science and Technology Corporation (CASC) on a Long March 2D rocket provided by CASC's Shanghai Academy of Spaceflight Technology (SAST).

[4] PIESAT has publicly announced their goal to deploy 38 satellites in the constellation, 28 of which are synthetic aperture radar (SAR) alongside 10 optical imaging satellites including panchromatic and multispectral sensors.