NASA's Upper Atmosphere Research Satellite (UARS) was launched on September
12, 1991, from the Space Shuttle Discovery (STS-48). It was released three
days later into a 585 km altitude orbit, inclined 57 degrees to the equator.
UARS will study the physical and chemical processes of the Earth's stratosphere,
mesosphere, and lower thermosphere.
Four instruments (CLAES, ISAMS, MLS, HALOE) measure atmospheric composition
and temperature, two instruments (HRDI, WINDII) observe atmospheric winds,
and three other instruments (SOLSTICE, SUSIM, PEM) measure the energy inputs
from solar radiation and charged particles. A tenth instrument (ACRIM II)
will take advantage of a flight of opportunity to continue NASA's solar
constant measurements.
Collection Environment
Data are collected from a near circular Earth orbit of about 585 km
altitude and 57 degree inclination
Platform Mission Objectives
It is the UARS mission to study the coupled energy inputs, chemistry
and dynamics of the upper atmosphere, improve the understanding of natural
and man-made perturbations to the upper atmosphere, and to learn more about
long term climate effects. The mission objectives also include the study
of energy input and loss, photochemistry, and dynamics in the upper atmosphere,
coupling among these processes, and coupling between the upper and lower
atmosphere. The near complete latitude coverage is achieved by performing
a yaw maneuver approximately every 36 days, whereby the spacecraft is rotated
180 degrees to view in the opposite hemisphere along the trajectory path.
Thus, coverage is increased from a range of 34S - 80N to a range of 80S
- 80N.