When NASA's Glory satellite plummeted into the Pacific Ocean last year shortly after launch, it took with it a University of Colorado instrument that was designed to measure the sun's energy, continuing a record of "solar irradiance" data that stretches back to 1978.
The loss of the Total Irradiance Monitor, riding on Glory, caused scientists to fear that a gap would be created in the record.
Today, data on solar irradiance is gathered by a TIM instrument onboard the Solar Radiation and Climate Experiment satellite, which was designed and built by CU's Laboratory for Atmospheric and Space Physics. But the instrument, designed to last five years and launched in 2003, may not last much longer.
The loss of Glory sent CU scientists scrambling to get another TIM into space before the current instrument sputters out. This week, CU announced that a new TIM would hitch a ride into space on a satellite built by Boulder-based Ball Aerospace and set to launch in 2013.
If all goes well, the new TIM and the old TIM will both send back data over a period of time.
"Overlap between the (two) TIMs helps account for possible calibration differences between the two instruments so that we can be assured they are both accurately measuring the same solar irradiance values," said LASP scientist Greg Kopp, principal investigator for the TIM instrument set to be launched in 2013.
Kopp said continuing the measurement record is critical to understanding the sun's impact on the Earth.
"The solar irradiance record is important as it provides an extremely accurate measurement of the entire amount of energy from the sun," Kopp said in an email. "This energy is what drives the Earth's climate system, providing over 2,500 times the combined amount of all other energy sources, such as radioactive decay and geothermal in the Earth's interior."
But preparing an instrument for launch at the last minute is no easy task. Building a new TIM in time for a launch in 2013 -- as well as calibrating it, testing its performance in a space-like environment and integrating it with a spacecraft -- wasn't feasible. So CU researchers turned to a ground-based TIM that the team built alongside the instrument that is now sending back data from the Solar Radiation and Climate Experiment Satellite.
"Even preparing an existing instrument for space flight on this compressed time scale is challenging, though," said Kopp, who noted that his team is working long hours to get the TIM ready. "What is really impressive about this program and this team, though, is the enthusiasm the members have for getting this ambitious goal accomplished. People see progress and the results of their work quickly on this fast-paced project, and that provides good motivation for the long hours they are happily and cheerfully dedicating."
Finding a satellite for the new TIM to ride on required the cooperation of a handful of organizations. The agreement to put the new TIM on the STPSat-3 spacecraft was the result of a collaboration among NASA, the National Oceanic and Atmospheric Administration, the U.S. Air Force, LASP and Ball Aerospace.
STPSat-3 was able to accommodate the late addition thanks to its flexible design, according to Ball. The instrument is part of a series built by Ball with the goal of creating a standard spacecraft design that can be used multiple times by the U.S. Air Force for different missions. Having a standard spacecraft body cuts down on the cost and time it takes to build a new satellite. The ability of the design to accommodate multiple types of instruments allowed the TIM to secure a ride late in the development process.
"The STPSat-3 was built in only 47 days, and demonstrated the outstanding flexibility of its standardized interface approach by accommodating additional payloads after the spacecraft was completed," said David Taylor, Ball president and CEO, in a statement.
The responsibilities of the TIM onboard STPSat-3 will eventually be overtaken by the next-generation solar irradiance monitor, which is expected to launch in 2016 onboard the Joint Polar Satellite System satellite, also being built by Ball.
Contact Camera Staff Writer Laura Snider at 303-473-1327 or email@example.com.