30 July 2004

NASA launches Aura

Amateur scientists and students can use simple instruments to validate measurements of haze and water vapor made from space by NASA satellites. For example, Lans Martin, a junior at Seguin High School in Seguin, Texas, has used the Radio Shack Sun and Sky Monitoring Station to successfully validate haze measurements made by the MODIS instrument on NASA's Terra satellite.

The latest satellite that amateur scientists can validate is Aura, which was successfully launched from Vandenburg Air Force Base, California, at 3:01:59 a.m. PDT on 15 July 2004. The launch vehicle was a Boeing Delta II rocket (see nearby image).

Aura is in a Sun-synchronous orbit about 705 km (438 miles) above Earth. Its suite of four instruments will provide new capabilities to monitor ozone and air pollution. The instruments include the High Resolution Dynamics Limb Sounder (HIRDLS); the Microwave Limb Sounder (MLS); the Ozone Monitoring Instrument (OMI); and the Tropospheric Emission Spectrometer (TES).

According to the NASA media release, HIRDLS was built by the United Kingdom and the United States. OMI was built by the Netherlands and Finland in collaboration with NASA. NASA's Jet Propulsion Laboratory in Pasadena, California., constructed TES and MLS.

The Aura mission will be managed by scientists at NASA's Goddard Space Flight Center in Greenbelt, Maryland, who are elated by the successful launch. Aura's OMI ozone monitoring instrument is badly needed to replace the aging Total Ozone Mapping Spectrometer (TOMS) aboard the EarthProbe satellite. Other instruments will provide entirely new ways to analyze the troposphere and the stratosphere.

Aura will measure aerosol optical thickness (AOT) in a column through the atmosphere at various wavelengths. This method of measuring haze provides important data about earth's radiative balance.

The Society for Amateur Scientists has acquired the remaining inventory of Radio Shack's Sun and Sky Stations, which come with a 64-page manual containing detailed instructions about making AOT measurements from the ground. When properly calibrated, this instrument can also measure photosynthetic radiation and the total column abundance of water vapor. Sun and Sky Stations include a 3.5-digit readout and four light sensitive detectors installed behind a diffusing panel. For more information, click here.

Forrest M. Mims III