About Aura

This image is an animated version of the Aura satellite in orbit. The satellite, seen centered in the image, is made up of silver and gold box-like shapes and instruments. Spanning out to the right of the satellite is a long sheet of solar panels. In the background of the image at the bottom is a portion of Earth seen with clouds and a blue haze surrounding it. The top of the background is the deep black of space, with a cluster of green colored stars to the left.

The Aura spacecraft was launched on July 15, 2004, aboard a Delta II 7920-10L, a two-stage expendable rocket, from the Vandenberg Western Test Range.

Aura has a sun-synchronous, near polar (98.2-degree inclination) orbit. It orbits 705 km (438 miles) above the Earth with a sixteen-day repeat cycle and 233 revolutions per cycle. The ascending node is in daylight and crosses the equator at approximately 1:45 PM. The Aura spacecraft is flying in formation with other Earth observing satellites called the A-Train.   

Aura's instruments measure trace gases in the atmosphere by detecting their unique spectral signatures. Microwave Limb Sounder (MLS) observes the faint microwave emissions from rotating and vibrating molecules. High Resolution Dynamics Limb Sounder (HIRDLS) and Tropospheric Emission Spectrometer (TES) observe the infrared thermal emissions also due to molecular vibrations and rotations. Ozone Monitoring Instrument (OMI) detects the molecular absorption of backscattered sunlight in the visible and ultraviolet wavelengths.

The Environmental Protection Agency (EPA) monitors six criteria pollutants to make their air quality forecasts. The Aura spacecraft monitors five of the six pollutants: ozone (O3), carbon monoxide (CO), aerosols, nitrogen dioxide (NO2), and sulfur dioxide (SO2). Scientists use Aura data to monitor the production and transportation of these pollutants across the globe.

Ground Operations

Aura’s control and data acquisition is the responsibility of the Goddard Space Flight Center (GSFC) Flight Operations Team, while the GSFC EOS Data and Operations System is responsible for data acquisition and data processing. Science data products are produced by each instrument principal investigator.

The Operations Team tracks and controls Aura to keep it in its designated orbit and monitor health and safety of the spacecraft and its instruments. The team commands and controls the instruments on the spacecraft to meet the data acquisition requirements of the ground stations. The team also coordinates observations from multiple instruments, provides mission timelines, and develops and implements contingency plans.

Aura is tracked through a network of ground stations and satellites known as TDRSS (Tracking and Data Relay Satellite System). Data are downlinked to polar ground stations in Norway and Alaska. The Flight Operations Team also interacts with NASA 's international partners' instrument control centers for exchange of planning and command and control information.

Aura data validation is performed by comparing measurements collected during the same period with instruments whose performance is well known. These correlative measurements are taken in nearly the same air mass in space and time that Aura instruments are measuring.   [Visit the Validation Center]

Correlative measurements are made with a variety of instruments from the ground, aircraft, or high-altitude balloons. These measurements could either be in-situ where the local air is sampled directly for content or remotely sensed using instruments like those flying on Aura.

Sky viewing ground-based radiometers and spectrometers can make column measurements like those flying on Aura. Lidars can measure temperature and some trace gas constituent profiles. Airborne measurement campaigns deploy instruments on aircraft and balloons. Aircraft such as the DC-8 (medium altitude) and the WB-57 (high altitude) carry airborne spectrometers, radiometers, and air samplers to measure upper atmospheric constituents.