NASA plans to launch a $1.3 billion satellite next month that scientists say will, for the first time, give them the tools to comprehensively study the Earth as a system, including the delicate interplay of its lands, oceans and atmosphere.
The Terra satellite is scheduled to be launched December 16 from Vandenberg Air Force Base, California aboard an Atlas 2-AS rocket. The launch has been delayed nine months because of the failure last spring of a rocket engine identical to that used on the Atlas.
The satellite will enter a 100-minute, polar orbit 437 miles (705 kilometers) above the Earth for its five-year mission, flying in close formation with Landsat 7, which was launched in April.
The school bus-sized satellite carries five instruments, two of which are supplied by Canada and Japan. As the flagship of NASAs Earth Sciences Enterprise, and its most expensive mission ever, Terra will begin compiling what scientists hope will become an 18-year data set that could revolutionize how they model the Earths climate.
"If we want to understand this complex system, if we want to predict how that might change because of natural or human processes, we need to have an orbiting monitoring system," said Yoram Kaufman, Terras project scientist, speaking at a briefing held Tuesday at NASA headquarters. "This is to provide a deserved and necessary checkup of the Earth system."
Terra, originally known as EOS AM 1, will pass the equator each orbit at 10:30 a.m., when cloud cover is minimal over the globes landmasses. It will later be joined by a complementary satellite, EOS PM -- or Aqua -- that will hit the equator each orbit at a later time.
Ghassem Asrar, NASAs associate administrator for Earth science, said the satellite would allow for the interdisciplinary study of global climate, including the creation of forecast models that can peer months, even seasons, ahead.
"Our focus in Earth sciences is to take advantage of the technology NASA is putting in place and look into the future," Asrar said.
Terras five instruments will focus on climate and global changes. They will monitor Earths radiation balance, including the effect of heavier cloud cover on the amounts of solar radiation absorbed by the planet. Sea surface temperatures and levels of greenhouse gases will be gauged. Also measured will be changes in land cover use, including those attributable to human activity; ice sheet volume; chemistry of the mid- to upper atmosphere and the effects of volcanic activity on the atmosphere.
"[It will create] a data set that is unprecedented in the history of remote sensing," said Kevin Grady, Terras project manager.
Within 100 days of launch, Terra is expected begin returning as much as 1 terabyte of data a day.
advertisement
