Aqua was launched at 2:55 a.m. PDT on May 4, 2002 on board a Boeing Delta II 7920-10L launch vehicle from Vandenberg Air Force Base, California. During launch, Aqua rose to an altitude of 680 kilometers, after which it was boosted to its final orbital altitude of 705 kilometers (438 miles). This animation shows the area surrounding the launch pad, the countdown, the rocket lift-off, and the spacecraft separation from the Delta rocket.
Shortly after achieving orbit, Aqua deployed its solar array, x-band antenna, and instruments. This time-accelerated sequence shows the following deployments: solar array, AMSR-E antenna, CERES aft, CERES fore, X-Band antenna, MODIS Earth shield, and AIRS Earth shield.
This animation shows schematically the sensing of Aqua's six Earth-observing instruments, in the following order: CERES, AIRS, AMSU, HSB, MODIS, and AMSR-E.
Credit: Jesse Allen, NASA Earth Observatory, and Claire Parkinson, NASA Goddard Space Flight Center
Aqua is positioned in a near-polar orbit around the Earth at an altitude of 705 km in synchronization with the Sun, with its path over the ground ascending across the equator at the same local time every day, approximately 1:30 p.m. Correspondingly, on the other side of its orbit, Aqua descends across the equator at approximately 1:30 a.m.
Aqua's early afternoon observation time complements the 10:30-10:45 a.m. equatorial crossing time (descending in this case) of the EOS Terra satellite, launched in December 1999. The two daytime crossing times account for why the Terra and Aqua satellites were originally named "EOS AM" and "EOS PM", respectively. The combination of morning and afternoon observations allows studies concerning the diurnal variability of many of the parameters discussed above.
Because NASA has plans to launch a substantial number of Earth-observing spacecraft over the next 15 years, it would be more efficient to operate these spacecraft in groups, as opposed to single entities. In particular, the science output from the Aqua mission will be enhanced through coordinated flying with several other satellites that will be obtaining complementary data sets. These other satellites, in order after Aqua in the lead, are CALIPSO, CloudSat, PARASOL, and Aura. Because this sequence starts with Aqua and ends with Aura, it has been termed the "A-Train."
The AIRS on Aqua is the first AIRS instrument and a major advance over earlier sounders flow in space. AIRS measures atmospheric temperatures, humidities, and a host of other products, in order to improve weather forecasting and the understanding of climate processes. This artist's concept animation shows the AIRS instrument measuring air temperatures at five levels in the atmosphere, each level indicated by a separate color.
On Aqua, AMSU is integrally coupled with the AIRS instrument. Since 1998, AMSU instruments have also flown on satellites of the National Oceanic and Atmospheric Administration. This artist concept animation shows the AMSU instrument measuring air temperatures at five levels in the atmosphere, each level indicated by a separate color.
There are two CERES instruments on Aqua, following two on the Terra satellite, launched in 1999, and one on the Tropical Rainfall Measuring Mission, launched in 1997. This artist's concept animation shows the CERES instruments (one in cross-track scan mode, the other in biaxial scan mode) measuring heat emitted (outgoing longwave radiation) to space from Earth's surface.
On Aqua, it is particularly important to obtain humidities under overcast conditions. This artist's concept animation shows the HSB instrument measuring humidities at four levels in the atmosphere, each level indicated by a separate color.
The Aqua MODIS is the second MODIS, the first having been launched in 1999 on board the Terra satellite. This artist's concept animation shows the MODIS instrument measuring clouds, land surface cover, snow cover on the land, and sea ice cover on the oceans.
This 18 minute feature begins with an overview of the mission and then highlights seven significant science accomplishments, spanning contributions from all four Aqua instrument science teams.
