Aqua Earth-Observing Satellite Mission

Aqua has turned 23 on May 4, 2025! 

 


 

Aqua is currently in 'free-drift'!

What is its past, current and future altitude and equator crossing time?

Drag your cursor over the graph below to find out! 

 

Due to fuel limitations, Aqua completed the last of its drag makeup maneuvers in December 2021 and is now in a free-drift mode, slowly descending below the A-Train and drifting to later equatorial crossing times, and lower altitudes. In Fall of 2026, passivation of the aircraft will begin.

Aqua data users have expressed the need for weekly updates on Aqua’s equator crossing time (in Mean Local Time [MLT]), as well as orbital altitude. Starting this month, we’ll be adding this information to the Aqua homepage and updating it weekly using data provided by the Operations Team. Move your cursor over the chart below to view both Aqua’s Mean Local Equator Crossing Time in UTC (dark black line) and orbital altitude (grey line) for each month through 2026.

 


Latest News from the Aqua Mission

 View Past News Highlights here


May 28, 2025

'Ocean darkening' a cause for concern - scientists

A BBC news article came out today that shows that the Earth's oceans are becoming darker this was discovered using NASA Aqua and Terra MODIS data. 

Dr Thomas Davies, associate professor of Marine Conservation at the university, said: "There has been research showing how the surface of the ocean has changed colour over the last 20 years, potentially as a result of changes in plankton communities.

"But our results provide evidence that such changes cause widespread darkening that reduces the amount of ocean available for animals that rely on the sun and the moon for their survival and reproduction."

 


 

 

"Since its launch more than two decades ago, the Aqua mission has delivered observations essential to improving our understanding of global dynamics and processes occurring on the land and cryosphere, the oceans, and the atmosphere. Furthermore, the Aqua mission has addressed topics of national priority such as weather forecasting, homeland security and defense, and natural resource management [...] Aqua is one of the most highly successful Earth observing satellites ever to have orbited our planet [...] As the Aqua satellite celebrates its 20th year in space, its contributions continue to advance our knowledge of Earth's systems for the benefit of humanity.”

From the citation of the USGS Pecora 2022 Group Award to Aqua.

 

Aqua, Latin for water, is a NASA Earth Science satellite mission named for the large amount of information that the mission is collecting about the Earth's water cycle, including evaporation from the oceans, water vapor in the atmosphere, clouds,precipitation, soil moisture, sea ice, land ice, and snow cover on the land and ice. Additional variables also being measured by Aqua include radiative energy fluxes, aerosols, vegetation cover on the land, phytoplankton and dissolved organic matter in the oceans, and air, land, and water temperatures.

The Aqua mission is a part of the NASA-centered international Earth Observing System (EOS). Aqua was formerly named EOS PM, signifying its afternoon equatorial crossing time. A timeline of Aqua on-orbit progress through the initial 120 day check-out period can be found here.

Aqua was launched on May 4, 2002, and has six Earth-observing instruments on board, collecting a variety of global data sets. Aqua was originally developed for a six-year design life but has now far exceeded that original goal.

It continues collecting and transmitting high-quality data from four of its six instruments: 

Atmospheric Infrared Sounder (AIRS),

Advanced Microwave Sounding Unit (AMSU),

Clouds and the Earth’s Radiant Energy System (CERES),

Moderate Resolution Imaging Spectroradiometer (MODIS),

Advanced Microwave Scanning Radiometer for EOS (AMSR-E), suffered a major anomaly in October 2011 and ceased its high-quality data transmission at that time. Later the instrument was turned back on, and it transmitted reduced quality data important for intercalibration purposes before being powered off in March 2016. 

Humidity Sounder for Brazil (HSB), collected approximately nine months of high quality data but failed in February 2003.

 

Aqua was the first member launched of a group of satellites termed the Afternoon Constellation, or sometimes the A-Train.

 

1.) Aqua, launched in May 2002

2.) Aura, launched in July 2004

3.) PARASOL, launched in December 2004 and completed its mission and exited the A-Train in December 2013.

4. & 5.) CloudSat and CALIPSO, launched in May 2006, and

6.) GCOM-W1, launched in May 2012

7.) OCO-2, launched in July 2014

When OCO-2 was launched, it the A-Train, followed by GCOM-W1, Aqua, CALIPSO, CloudSat, and Aura. By early 2022, CloudSat, CALIPSO, and Aqua had all exited the A-Train. Due to fuel limitations, Aqua completed the last of its drag makeup maneuvers in December 2021 and is now in a free-drift mode, slowly descending below the A-Train and drifting to later equatorial crossing times. 


 

Recent Imagery Incorporating Aqua Data

Earth’s Clouds on the Move
Published on Monday June 16, 2025

Aqua Image Highlight

View the Image Highlight Archive

Aqua Status

  • Operating instruments: AIRS, AMSU, CERES, and MODIS. 
  • Current life expectancy: Aqua has a strong chance of operating successfully into September 2026.
  • Current systems issues: None.
  • Data access: The processed Aqua data are available through several NASA data centers identified on the images and data page.
  • The Aqua data are also transmitted via direct broadcast, from which they can be processed for real-time applications using technologies and algorithms available from the NASA Direct Readout Laboratory (DRL).
  • Greater detail on the status of the Aqua spacecraft, instruments, and other aspects of the mission are presented in a PDF Aqua Status file, updated monthly.
  • View past Aqua Status files here

Aqua Video Podcast Series

A series of five video podcasts (i.e., vodcasts) have been produced by NASA Goddard TV in conjunction with Aqua mission personnel.

  1. Vodcast 1, Introducing the Aqua Mission, viewable at the NASA Goddard YouTube channel and NASA Scientific Visualization Studio
  2. Vodcast 2, Aqua AIRS: Visions of Weather and Climate, viewable at the NASA Goddard YouTube channel and NASA Scientific Visualization Studio
  3. Vodcast 3, Aqua AMSR-E: Scanning Earth's Water Cycle, viewable at the NASA Goddard YouTube channel and NASA Scientific Visualization Studio
  4. Vodcast 4, Aqua MODIS: Science and Beauty, viewable at the NASA Goddard YouTube channel and NASA Scientific Visualization Studio
  5. Vodcast 5, Aqua CERES: Tracking Earth's Heat Balance, viewable at the NASA Goddard YouTube channel and NASA Scientific Visualization Studio

Aqua Science of the Month

May 2025

Darkening of the Global Ocean

Davies, T.W. and Smyth, T. (2025), Darkening of the Global Ocean. Glob Change Biol, 31: e70227. https://doi.org/10.1111/gcb.70227

 

This study used 20 years of Aqua MODIS data of the diffuse attenuation coefficient of light over the global oceans and found that it had increased across 75,341,181 km2 (21%) of the global ocean between 2003 and 2022, resulting in photic zone (areas with high productivity) depths reducing by more than 50 m across 32,449,129 km2 (9%) by area. Their results demonstrated that this darkening is not limiited to the coastal zones. This darkening of the ocean could have profound affects on the global ocean ecosystem. 

 

Details are in the caption following the image

Figure: Darkening of the Global Ocean. (A) The rate change (units per year) in the diffuse attenuation coefficient for downwelling irradiance at 490 nm [ΔKd(490)] measured from MODIS Aqua between 2003 and 2022 in 9 km resolution. Reds indicate regions where Kd(490) is increasing (oceans are getting darker), while blues indicate regions where Kd(490) is decreasing (oceans are getting lighter). White indicates regions where there was no statistically significant change in Kd(490) over the period 2003–2022. Values of ΔKd(490) were derived for each 9 km resolution pixel using quantile regression to the median performed on the fitted values of an Autoregressive Integrated Moving Average (ARIMA) model of annual averaged Kd(490) data. (B) International Hydrographic Office sea regions ranked according to the percentage of their area over which Kd(490) is increasing. Numbers inset above bars give the absolute area where Kd(490) is increasing in 10,000 km2.

 

 


 

See older science highlights here.