NASA's nearly identical twin STEREO spacecraft, designed
and built by the Applied
Physics Laboratory, arrived in Florida last week for
final prelaunch testing and preparations. Once in orbit,
the observatories will capture the first-ever 3-D "stereo"
views of the sun and solar wind.
APL also will operate the twin observatories for NASA
during the mission.
The observatories arrived May 3 by truck at the Astrotech
Spacecraft Processing Facility — just outside NASA's
Kennedy Space Center — where they will be placed
inside a clean room. They're scheduled for launch no
earlier than July 22 aboard a single Delta II rocket from
Cape Canaveral Air Force Station's Launch Complex 17, Pad
STEREO, which stands for Solar TErrestrial RElations
Observatory, recently completed five months of
space-environment tests at NASA Goddard Space Flight
Center, in Greenbelt, Md., and at APL. These tests
simulated conditions the observatories will undergo during
launch and their two-year space-based operations.
Throughout the next few months, the observatories will
undergo final checks of their systems and instruments
before being loaded onto the launch vehicle. Mission
operations personnel and engineers will rehearse the launch
countdown and participate in mission simulations of
STEREO's two-week launch window opens at 3:11 p.m. on July
22 and extends through Aug. 6, with two opportunities a day
for launch during that time frame. Mission operations
personnel at APL will begin the final countdown 12 hours
During the two-year mission, the observatories will explore
the origin, evolution and interplanetary consequences of
coronal mass ejections. These powerful solar eruptions are
a major source of the magnetic disruptions on Earth and a
key component of space weather, which can greatly affect
satellite operations, communications, power systems and the
lives of humans in space.