Aqua

American earth sea satellite. Aqua was also designated the EOS-PM Earth Observing System satellite, joining EOS-AM/Terra. The CERES and MODIS instruments aboard Aqua were also carried on the Terra satellite.

The satellite was built by TRW and based on the T-330/AB1200 bus. Aqua's payload consisted of a number of remote sensing instruments:

• CERES with two broadband visible-to-far-infrared radiometers which measured the energy balance of the Earth's atmosphere, as UV radiation from the Sun was absorbed and reradiated by the surface, atmosphere and clouds in the infrared. The CERES sensors measured flux in the 0.3-5 and 8-12 micron bands and overall flux in the 0.3-100 micron range.
• AIRS was an infrared (3.7-15 micron) spectrometer giving temperature and humidity vertical profiles. It had a companion 0.4-1.0 micron 4-band optical photometer.
• AMSU-A1 and AMSU-A2 were a pair of 15-channel microwave (15-90 GHz) sounders for temperature profiles.
• HSB was the Humidity Sounder for Brazil, a 4-channel microwave (150 and 183 GHz) sounder which could obtain humidity profiles even under heavy cloud.
• AMSR-E was a Japanese microwave (6.9-89 GHz) scanning radiometer which used the microwave emission scattered from raindrops to determine rainfall rates, as well as measuring sea surface winds and temperature.
• MODIS was an optical/infrared (0.4-14.5 micron) imaging spectrometer.

The Aqua science instruments were hosted by TRW's modular, standardized AB 1200 common spacecraft bus. The spacecraft was built of lightweight composite materials to allow for increased payload weight and reduce launch costs. Its inherent modularity allowed fabrication and testing in parallel to achieve schedule economies. The Earth-facing side of the spacecraft was devoted solely to the Aqua instruments, maximizing fields-of-view. All instruments were attached to the craft via simple mounting devices, allowing them to be integrated in the order received, eliminating a source of schedule bottlenecks.

Spacecraft Specification
Size:

• Stowed 8.8 ft (2.68m) x 8.2ft (2.49 m) x 21.3 ft (6.49 m)
  
• Deployed 15.8 ft (4.81 m) x 54.8 ft (16.70 m) x 26.4 ft (8.04 m)
  

Weight:

• At Launch 6,468 lb (2,934 kg)
  
• Spacecraft 3,858 lb (1,750 kg)
  
• Instruments 2,385 lb (1,082 kg)
  
• Propellant 225 lb (102 kg)
  

Electrical Power: 4,860 W end of life

Telemetry: S-band (TDRSS and Deep Space Network/ Ground Network compatible)

Data Links: X-band

Propulsion: Hydrazine blow-down system; 4 pairs of 1 lbf thrusters

Orbit: 438 mi (705 km) polar, sun synchronous

Design Life: Six years

Electric System: 4.86 average kW.