AQUA
Country: United States · Also known as: 2002-022A
Live Position
Ground Track · Last 90 Minutes
Upcoming Passes · Over Your Location
About This Satellite
Aqua launched on May 4, 2002, to study Earth's water cycle. Its observations connect water vapour, clouds, precipitation, ice, and surface conditions with the planet's energy balance. The name means water, but the mission is broader than photographing oceans: it examines exchanges among several parts of the Earth system.
An afternoon observer whose orbit has evolved
Originally called EOS PM, Aqua was designed around an afternoon equator crossing. NASA reports that its last drag-makeup manoeuvre occurred in December 2021. It subsequently entered free drift, with decreasing altitude and later crossing times. This is orbital evolution, not the loss of gravity or an indication that tracking data are automatically wrong.
Six instruments launched does not mean six still working
Aqua's HSB stopped producing its science record in 2003, while AMSR-E experienced a major anomaly in 2011 and was later switched off in 2016. Historical payload lists must be read separately from current instrument availability. The original mission specification is not a live health certificate.
Mission reference: NASA: Aqua mission and free drift. Editorial review: .
How the payload divides the problem
Aqua carried AIRS, AMSU-A, HSB, AMSR-E, MODIS, and CERES. The combination brought infrared and microwave sounding, microwave radiometry, multispectral imaging, and radiation-budget measurements onto one platform. Different wavelengths and viewing methods constrain different quantities; a water-vapour profile is not the same measurement as a cloud image or a surface-temperature estimate.
Reference: NASA: Aqua spacecraft and instruments.
Why a consistent observation time was valuable
NASA's account of an Aqua orbit adjustment explains the original goal of keeping measurements at comparable local times. Similar illumination makes comparisons across days and years easier to interpret. This historical operating principle explains the sun-synchronous design; it should not be mistaken for a claim that the spacecraft still maintains that exact schedule during free drift.
Reference: NASA Earth Observatory: maintaining Aqua's original orbit.
Reading this orbital snapshot
Based on TLE epoch: 2026-09-05. Estimated altitude ranges from 685 km at perigee to 687 km at apogee, a difference of 2 km. The orbital period is about 98.5 minutes. Eccentricity 0.00018 indicates a nearly circular path. In a two-body approximation, perigee speed is 1.00 times apogee speed. These are mean-element estimates, not instantaneous measurements. Distance per orbit uses an ellipse approximation.
Saved build snapshot. If a valid TLE is retrieved, this explanation and the orbit panel update together. Otherwise this dated snapshot is retained.
Ground track is not sensor coverage
An inclination of 98.44 degrees implies approximate geocentric ground-track limits of 81.6 degrees north and south. This is a retrograde orbit, moving against the direction of Earth rotation. The plotted line marks the point beneath the object. It does not represent camera coverage, radio reception, or a guaranteed visible pass.
Accuracy and missing information
The introductory record describes the build snapshot. The orbital snapshot explanation and orbit panel share any successfully retrieved TLE; check the displayed epoch. Reentered objects retain historical data only. Mission history is not rewritten by TLE updates. TLE/SGP4 positions are predictions and can change after maneuvers or updated observations. The 14-day stale-data cutoff is a display safeguard, not an accuracy guarantee. Local passes are geometric predictions, not a visibility forecast. No verified operator or mission status means unknown, not active. Do not use this catalog for collision avoidance or operational flight decisions.
Catalog sources: CelesTrak SATCAT: NORAD 27424 · GCAT: S27424 (source update 2026 Sep 4 2345:57). Supplementary metadata: SatNOGS DB, retrieved 2026-09-05T12:57:25.375Z. Page assembled 2026-09-15. GCAT phase codes describe trajectory phases, not mission health.
Learn more: TLE data · Perigee and apogee · Ground tracks · JOT (Jewawud Live Orbital Map)