TOMS Comes to the End of Its Mission
After almost thirty years of service NASA’s Total Ozone Mapping Spectrometer (TOMS) has been decommissioned. By providing information about ozone in the upper and lower atmosphere and mapping the changes over time, the program increased awareness about the importance of the ozone layer to human health as well as the health of the planet.
The TOMS Flight Model No.1 was launched October 24, 1978 on the Nimbus-7 spacecraft. The instrument was originally designed to observe weather patterns by mapping global ozone, but scientists quickly realized the importance of the data being collected. Scientists now had a method for studying ozone in the atmosphere in a way not possible before. The immense number of available images made it possible to continuously monitor changes in the ozone levels.
Ozone in the Earth’s upper atmosphere acts as a shield from the harmful ultraviolet rays of the sun. If the upper ozone layer becomes thinner, humans are put at increased risk for developing skin cancer, cataracts and impaired immune systems, while ozone present in the lower atmosphere results in damage to lung tissue as well as plants.
The amount of ozone present in the atmosphere was determined by calculating the amount of ultraviolet light deflected back into space by the atmosphere and surface of the Earth. Because of ozone’s ability to absorb ultraviolet light, areas in which less ultraviolet light was noted were known to have higher ozone levels.
Data provided by the TOMS mission led to the discovery of the ongoing destruction of ozone over long periods of time, which led to the passage of the Montreal Protocol in 1987, an international pact limiting the production of chemicals detrimental to atmospheric ozone. The data also confirmed the annual destruction of the ozone and the resulting “ozone hole” above the South Pole.
Fourteen years after the launch of Nimbus-7, a new TOMS instrument was sent out on Russia’s Meteor-3, representing the first U.S. instrument to fly on a Russian spacecraft. It stopped working in 1994 and in July of 1996 another TOMS instrument flying on the Earth Probe spacecraft was launched into a lower altitude, providing improved resolution for observing volcanos, forest fires and other sources of pollution while making nearly 200,000 measurements daily over almost the entire planet.
The instrument’s transmitter failed late in 2006, becoming useless for returning data. With fuel and energy sources eliminated, it will continue to orbit for 37 years before reentering the atmosphere. The venerable space mission has been invaluable in helping to raise awareness about the ozone layer and its relation to humans and their environment.
This entry was posted on Tuesday, August 7th, 2007 at 7:46 pm and is filed under Public Relations, Space Agency News. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.
