Terra is the flagship satellite of NASA's Earth observing systems. Terra is the first EOS (Earth Observing System) platform and provides global data on the state of the atmosphere, land, and oceans, ... as well as their interactions with solar radiation and with one another.
Since the 1950's, it has become increasingly clear that human activities are modifying the composition of the atmosphere on a global scale. As the result of industrialization, the concentration of carbon dioxide has increased by about 20% during this period. More recently, the stratospheric concentrations of chemically-active gases containing chlorine, bromine, and fluorine have dramatically increased. These trends have created issues of global interest including global warming and declining levels of ozone (both globally and in the ozone &hole& in the Antarctic). It has become increasingly clear, however, that these processes do not occur independently of one another and can only be understood in the context of a global system. Accurate and precise measurements are needed to unravel complex and interactive relationships between chemical, radiative, and dynamical processes in the atmosphere, ocean, and on land. As a result, in 1991 NASA initiated a comprehensive program to understand the Earth's atmosphere, oceans, land, and cryosphere (ice and snow) as a single, complex, interactive system. NASA's Earth Observing System (EOS) consists of a series of spaceborne instruments to monitor crucial components of the Earth system, an advanced data handling system, and teams of scientists who will evaluate on-going climate change and predict future changes. Ultimately, EOS will produce scientifically sound recommendations for environmental policy to national and international bodies to mitigate or prepare for these changes.
Key Terra Facts:
Joint with Japan and Canada
Type: Near-polar, sun-synchronous
Equatorial Crossing: 10:30 a.m.
Altitude: 705 km
Inclination: 98.1 degrees
Period: 98.88 minutes
Repeat Cycle: 16 days
Dimensions: 2.7 m x 3.3 m x 6.8 m
Mass: 5,190 kg
Power: 2,530 W
Design Life: 6 years
[Summary provided by NASA]