Introduction
The Aqua Earth Observing System is a satellite designed to help understand global environmental changes. It is part of NASA's Earth Science Enterprise, which aims to study the planet's processes through remote sensing spacecraft and international research collaborations.

Specifications
The Aqua satellite measures 8.8 ft x 8.1 ft x 21.3 ft when stowed and 15.7 ft x 55.9 ft x 21.9 ft when deployed. It weighs 6,662 lb, with 4,277 lb for the spacecraft and 2,385 lb for the instruments. It operates with an electrical power of 4,740 W and uses S-band telemetry compatible with TDRSS and the Deep Space Network. Aqua orbits at 438 mi in a polar, sun-synchronous path.

Mission and Capabilities
Launched in 2002, Aqua collects climate-related data using sensors that measure various environmental parameters such as clouds, precipitation, atmospheric temperature, moisture content, terrestrial snow, sea ice, and sea surface temperature. Its low-earth orbit allows it to pass over the same location each afternoon, facilitating comprehensive long-term change assessments.

Development and Design
Northrop Grumman Space Technology built the Aqua platform, integrating NASA-provided instruments. The spacecraft is based on the T330 bus design, which is modular and scalable, allowing for payload adjustments without affecting the overall design or schedule.

Instruments and Developers
- AIRS: Atmospheric Infrared Sounder by NASA JPL / Lockheed Martin
- AMSR/E: Advanced Microwave Scanning Radiometer-EOS by NASDA / Mitsubishi
- AMSU-A1, A2: Advanced Microwave Sounding Unit by NASA GSFC / Aerojet
- CERES: Clouds and the Earth’s Radiant Energy System by NASA LaRC / Northrop Grumman Space Technology
- HSB: Humidity Sounder for Brazil by Brazil / Matra Marconi
- MODIS: Moderate Resolution Imaging Spectroradiometer by NASA GSFC / Santa Barbara Remote Sensing

Conclusion
The Aqua satellite plays a crucial role in providing data to understand and predict global environmental changes, supporting efforts to prepare for and mitigate these changes.