CHAPS is a next-generation hyperspectral imaging spectrometer currently being matured for spaceflight under NASA’s Earth Science Technology Office Instrument Incubator Program. CHAPS is designed to address emerging requirements for high–spatial resolution atmospheric composition measurements from low Earth orbit, providing observations of trace gases such as nitrogen dioxide (NO₂) at spatial scales down to 1 × 1 km². CHAPS represents a new sensor and small-satellite payload design concept that combines hyperspectral sensing (300–500 nm, 0.6-nm spectral resolution) with advanced enabling technologies, including freeform optics, topology optimization, and additive manufacturing. These innovative optical and structural technologies significantly reduce instrument mass, volume, and complexity while maintaining science-grade performance, enabling deployment on small satellites, hosted payloads, and future satellite constellations. The instrument’s focal plane assembly is currently being upgraded with a space-qualified detector, along with space-ready electronics and onboard processing systems, to ready the instrument for planned space flight. The project builds upon the CHAPS-D precursor system, which served as both a laboratory testbed and airborne simulator. Laboratory characterization, calibration activities, and flight campaigns have demonstrated the performance of the sensor architecture and form the basis of space-qualification efforts. The instrument employs established differential optical absorption spectroscopy (DOAS) retrieval techniques and supports future integration with atmospheric models and in situ observations for improved emissions quantification. Beyond air quality applications, the CHAPS architecture is scalable across ultraviolet, visible, and shortwave infrared wavelengths (270–2400 nm), providing a flexible foundation for future hyperspectral Earth observation missions. The combination of compact sensor design, innovative optical technologies, advanced calibration approaches, and constellation-enabled observing strategies offers a pathway toward next-generation remote sensing systems. This paper presents a summary of ground and airborne testing to date and ongoing development for a potential space demonstration.