Aqua (EOS PM-1) is a
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...
scientific research
satellite
A satellite or an artificial satellite is an object, typically a spacecraft, placed into orbit around a celestial body. They have a variety of uses, including communication relay, weather forecasting, navigation ( GPS), broadcasting, scient ...
in
orbit
In celestial mechanics, an orbit (also known as orbital revolution) is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an ...
around the
Earth
Earth is the third planet from the Sun and the only astronomical object known to Planetary habitability, harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all ...
, studying the
precipitation
In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls from clouds due to gravitational pull. The main forms of precipitation include drizzle, rain, rain and snow mixed ("sleet" in Commonwe ...
,
evaporation
Evaporation is a type of vaporization that occurs on the Interface (chemistry), surface of a liquid as it changes into the gas phase. A high concentration of the evaporating substance in the surrounding gas significantly slows down evapora ...
, and
cycling
Cycling, also known as bicycling or biking, is the activity of riding a bicycle or other types of pedal-driven human-powered vehicles such as balance bikes, unicycles, tricycles, and quadricycles. Cycling is practised around the world fo ...
of
water
Water is an inorganic compound with the chemical formula . It is a transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance. It is the main constituent of Earth's hydrosphere and the fluids of all known liv ...
. It is the second major component of the
Earth Observing System
The Earth Observing System (EOS) is a program of NASA comprising a series of artificial satellite missions and scientific instruments in Earth orbit designed for long-term global observations of the land surface, biosphere, earth's atmosphere, at ...
(EOS) preceded by
Terra
Terra may often refer to:
* Terra (mythology), primeval Roman goddess
* An alternate name for planet Earth, as well as the Latin name for the planet
Terra may also refer to: Geography Astronomy
* Terra (satellite), a multi-national NASA scient ...
(launched 1999) and followed by
Aura (launched 2004).
The name "Aqua" comes from the
Latin
Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...
word for water. The satellite was launched from
Vandenberg Air Force Base
Vandenberg may refer to:
* Vandenberg (surname), including a list of people with the name
* USNS ''General Hoyt S. Vandenberg'' (T-AGM-10), transport ship in the United States Navy, sank as an artificial reef in Key West, Florida
* Vandenberg S ...
on May 4, 2002, aboard a
Delta II
Delta II was an expendable launch system, originally designed and built by McDonnell Douglas, and sometimes known as the Thorad Delta 1. Delta II was part of the Delta rocket family, derived directly from the Delta 3000, and entered service in ...
rocket
A rocket (from , and so named for its shape) is a vehicle that uses jet propulsion to accelerate without using any surrounding air. A rocket engine produces thrust by reaction to exhaust expelled at high speed. Rocket engines work entirely ...
. Aqua operated in a
Sun-synchronous orbit
A Sun-synchronous orbit (SSO), also called a heliosynchronous orbit, is a nearly polar orbit around a planet, in which the satellite passes over any given point of the planet's surface at the same local mean solar time. More technically, it is ...
as the third in the satellite formation called the "
A Train" with several other satellites (
OCO-2
Orbiting Carbon Observatory-2 (OCO-2) is an American environmental science satellite which launched on 2 July 2014. A NASA mission, it is a replacement for the Orbiting Carbon Observatory which was lost in a launch failure in 2009. It is the seco ...
, the Japanese
GCOM W1,
PARASOL
An umbrella or parasol is a folding canopy (building), canopy supported by wooden or metal ribs that is mounted on a wooden, metal, or plastic pole. It is usually designed to protect a person against rain. The term ''umbrella'' is traditionall ...
,
CALIPSO,
CloudSat, and
Aura) for most of its first 20 years; but in January 2022 Aqua left the A-Train (as Cloud Sat, CALIPSO and PARASOL had already done) when, due to its fuel limitations, it transitioned to a free-drift mode, wherein its equatorial crossing time is slowly drifting to later times, from its tightly controlled orbit.
Mission
Aqua is one of NASA's missions for
Earth science
Earth science or geoscience includes all fields of natural science related to the planet Earth. This is a branch of science dealing with the physical, chemical, and biological complex constitutions and synergistic linkages of Earth's four spheres ...
operating in the A-Train constellation. It has demonstrated a very high level of precision in making the primary long-term measurements of the mission. These highly calibrated climate quality measurements of radiance, reflectance, and backscatter have been used to cross-calibrate past and present sensors launched by NASA, as well as a variety of sensors launched from other agencies and the international community. Thousands of scientists and operational users from around the world have made use of the Aqua data to address NASA's 6 interdisciplinary Earth science focus areas: Atmospheric Composition, Weather, Carbon Cycle and Ecosystems, Water and Energy Cycle, Climate Variability and Change, and Earth Surface and Interior.
Aqua has experienced some minor, non-mission ending anomalies.
Because of a 2007 anomaly with the Solid State Recorder (SSR) it can only hold two orbits worth of data. A series of solar array and array regulator electronics anomalies starting in 2010 has led to the loss of 23 strings of solar cells out of a total of 132 strings.
A 2005 short circuit within a battery cell led to a partial loss of cell capacity. In 2009, a solar panel
thermistor
A thermistor is a semiconductor type of resistor in which the resistance is strongly dependent on temperature. The word ''thermistor'' is a portmanteau of ''thermal'' and ''resistor''. The varying resistance with temperature allows these devices ...
failed and an error in the Solar Array offset was detected. The offset issue has been corrected periodically since then. On September 8, 2007, the Dual Thruster Module (DTM-2) Heater experienced an anomaly.
On August 16, 2020, The Formatter Multiplexer Unit (FMU) experienced an anomaly, corrupting some data in the SSR and stopping all data streams until it was recovered on September 2, 2020.
Aqua completed the last of its drag makeup maneuvers, mandated by fuel limitations, in December 2021 and entered a free-drift mode, slowly descending below the A-Train and drifting to later equatorial crossing times, and lower altitudes. For a time Aqua was a candidate for a life-extending re-fueling mission, but that was never attempted. The current end of mission plan is to begin passivation of the spacecraft in the fall of 2026. A worst-case scenario would result in a re-entry by 2046.
File:Orbit path - Aqua ascending - day.png, Aqua's ascending orbital path as of 2021
File:Orbit path - Aqua descending - night.png, Aqua's descending orbital path as of 2021
Instruments
Aqua carries six instruments for studies of water on the Earth's
surface
A surface, as the term is most generally used, is the outermost or uppermost layer of a physical object or space. It is the portion or region of the object that can first be perceived by an observer using the senses of sight and touch, and is ...
and in the
atmosphere
An atmosphere () is a layer of gases that envelop an astronomical object, held in place by the gravity of the object. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A stellar atmosph ...
, of which four are still operating:
*Advanced
Microwave
Microwave is a form of electromagnetic radiation with wavelengths shorter than other radio waves but longer than infrared waves. Its wavelength ranges from about one meter to one millimeter, corresponding to frequency, frequencies between 300&n ...
Scanning Radiometer-EOS (AMSR-E) — measures
cloud
In meteorology, a cloud is an aerosol consisting of a visible mass of miniature liquid droplets, frozen crystals, or other particles, suspended in the atmosphere of a planetary body or similar space. Water or various other chemicals may ...
properties,
sea surface temperature
Sea surface temperature (or ocean surface temperature) is the ocean temperature, temperature of ocean water close to the surface. The exact meaning of ''surface'' varies in the literature and in practice. It is usually between and below the sea ...
, near-surface
wind speed
In meteorology, wind speed, or wind flow speed, is a fundamental atmospheric quantity caused by air moving from high to low pressure, usually due to changes in temperature. Wind speed is now commonly measured with an anemometer.
Wind spe ...
,
radiative energy flux, surface water,
ice
Ice is water that is frozen into a solid state, typically forming at or below temperatures of 0 ° C, 32 ° F, or 273.15 K. It occurs naturally on Earth, on other planets, in Oort cloud objects, and as interstellar ice. As a naturally oc ...
and
snow
Snow consists of individual ice crystals that grow while suspended in the atmosphere—usually within clouds—and then fall, accumulating on the ground where they undergo further changes.
It consists of frozen crystalline water througho ...
. Furnished by the
National Space Development Agency of Japan. The AMSR-E instrument had over 480 pounds of spinning mass, and the lubricant in the bearing assembly gradually deteriorated over the course of the mission. By 2007, there was a noticeable increase in motor current. This led to the development of new contingency procedures in case of high current or torque, which were put in place in 2011. In October 2011, the instrument began to cause yaw vibrations in the spacecraft that exceeded torque limits and on October 4, 2011, was automatically slowed to 4 rpm from the normal 40 rpm and then, because it could not maintain 4 rpm, was slowed to a stop. A recovery procedure was developed and tested through 2012, culminating with a December 4, 2012 successful acceleration to 2.0767 rpm to allow for cross-calibration with the AMSR-2 instrument launched in 2012 aboard the
GCOM-W1
GCOM (Global Change Observation Mission), is a JAXA project of long-term observation of Earth environmental changes. As a part of Japan's contributions to GEOSS (Global Earth Observation System of Systems), GCOM will be continued for 10 to 15 yea ...
satellite. On December 4, 2015, AMSR-E was slowed to a stop and then on March 3, 2016, it was turned off.
*
Moderate Resolution Imaging Spectroradiometer (MODIS) — also measures cloud properties and radiative energy flux, also
aerosol
An aerosol is a suspension (chemistry), suspension of fine solid particles or liquid Drop (liquid), droplets in air or another gas. Aerosols can be generated from natural or Human impact on the environment, human causes. The term ''aerosol'' co ...
properties; land cover and
land use change
Land use is an umbrella term to describe what happens on a parcel of land. It concerns the benefits derived from using the land, and also the land management actions that humans carry out there. The following categories are used for land use: for ...
, fires and
volcano
A volcano is commonly defined as a vent or fissure in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface.
On Earth, volcanoes are most oft ...
es. An identical MODIS instrument is also aboard
Terra
Terra may often refer to:
* Terra (mythology), primeval Roman goddess
* An alternate name for planet Earth, as well as the Latin name for the planet
Terra may also refer to: Geography Astronomy
* Terra (satellite), a multi-national NASA scient ...
. As of 2017, some degradation of channels in the MODIS short wave visible bands has been observed by the Ocean Biology Processing Group (OBPG).
*
Advanced Microwave Sounding Unit
The advanced microwave sounding unit (AMSU) is a multi-channel microwave radiometer installed on meteorological satellites. The instrument examines several bands of microwave radiation from the atmosphere to perform atmospheric sounding of tempe ...
(AMSU-A) — measures atmospheric
temperature
Temperature is a physical quantity that quantitatively expresses the attribute of hotness or coldness. Temperature is measurement, measured with a thermometer. It reflects the average kinetic energy of the vibrating and colliding atoms making ...
and
humidity
Humidity is the concentration of water vapor present in the air. Water vapor, the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation (meteorology), precipitation, dew, or fog t ...
. Since launch, AMSU has lost 5 of 15 channels.
Power to the AMSU-A2 microwave instrument was lost at 19:47 UT September 24, 2016. This caused the loss of Channels 1 and 2. All recovery attempts were unsuccessful and no further recovery attempts are planned.
*
Atmospheric Infrared Sounder (AIRS) — measures atmospheric temperature and humidity, land and sea surface temperatures. Cooler A telemetry became frozen on March 24, 2014, but this had no impact on science gathering.
On September 25, 2016, Cooler-A experienced a shut down anomaly. Anomaly recovery occurred two days later and also cleared a condition that had disabled Cooler-A telemetry since the 2014 Cooler-A anomaly.
*
Humidity Sounder for Brazil (HSB) —
VHF band equipment measuring atmospheric humidity. Furnished by
Instituto Nacional de Pesquisas Espaciais of Brazil. The HSB instrument has been in survival mode, and thus non-operational, since February 5, 2003, when the scan mirror motor failed.
*
Clouds and the Earth's Radiant Energy System (CERES) — Flying Modules 3 and 4, measure broadband radiative energy flux. CERES' shortwave channel on module 4 failed on March 30, 2005, but its two other channels remain operational.
The Aqua spacecraft has a mass of about , plus propellant of about at launch. Stowed for launch, the satellite fit in a volume of 2.68 m x 2.49 m x 6.49 m. Deployed, Aqua is 4.81 m x 16.70 m x 8.04 m.
File:Aqua instruments.jpg, Aqua instruments
File:Aqua satellite simulation.jpg, Aqua satellite
File:2007 Arctic Sea Ice.jpg, Image of Arctic shrinkage
Sea ice in the Arctic region has declined in recent decades in area and volume due to climate change. It has been melting more in summer than it refreezes in winter. Global warming, caused by greenhouse gas forcing is responsible for the decline ...
from Aqua observations
See also
*
Terra
Terra may often refer to:
* Terra (mythology), primeval Roman goddess
* An alternate name for planet Earth, as well as the Latin name for the planet
Terra may also refer to: Geography Astronomy
* Terra (satellite), a multi-national NASA scient ...
*
Aura
*
Fire Information for Resource Management System (FIRMS) – provides information on active fire locations as part of NASA's Earth Science Data Systems program
References
External links
NASA Aqua siteAqua Mission Profileb
NASA's Solar System ExplorationMission Control Tunes Up Aqua's Orbit August 20, 2009
{{Orbital launches in 2002
Earth observation satellites of the United States
Spacecraft launched in 2002
Spacecraft launched by Delta II rockets
NASA satellites
NASA satellites orbiting Earth