NASA has authorized the John Hopkins University Applied
Physics Laboratory (APL), Laurel, Md., to proceed with the
implementation of the Geospace missions under NASA’s
existing “Living with a Star” contract with APL. The Living
with a Star (LWS) program seeks to address how the
variability in the sun affects life on Earth as well as its
affect on space weather.
LWS sets out to quantify the physics, dynamics and behavior
of the Sun-Earth system over the 11-year solar cycle and
improve understanding of solar variability and disturbances
on terrestrial climate change. It will also provide data and
scientific understanding aimed at developing a predictive
capability for space weather affects. In addition, LWS will
give scientists a detailed characterization of radiation
environments useful in the design of more reliable
electronic components for air and space transportation
systems.
The two missions assigned to the APL make-up the LWS
Geospace Project. These missions were recently identified in
a study completed by the Geospace Mission Definition Team, a
group tasked by NASA Headquarters to identify LWS Geospace
Project goals and priorities. The two missions are the
Ionosphere-Thermosphere Mapper Mission (ITM) and the
Radiation Belt Mapper Mission (RBM).
The first of these, the ITM mission, will investigate the
physical processes that modify and change the Earth’s thin
outer atmosphere, the region where the planet meets space.
The ITM will make measurements of the composition and
physical properties of the upper atmosphere between 53-620
miles altitude. Understanding this region of space above
Earth, and the sun’s effects, will help us with the
operation of the International Space Station that operates
in this region. It is also a region that modifies the
signals of navigation satellites, such as the Global
Positioning System.
The Radiation Belt Mission will use two spacecraft in a near
equatorial elliptical orbit to take measurements in the
space above the ionosphere where the Earth’s magnetic field
interacts with the magnetic field of the sun. The
interaction of these fields of wind provides an energy
source for the Earth’s magnetosphere and drives a part of
the observed variation of the Earth’s magnetic field. It is
in this region the processes of interaction of the fields of
the Earth and sun trap and energizes ions and electrons in
radiation belts. The dynamic changes of this region can have
important effects on civil and military communications
satellite systems.
The ITM and RBM are planned for launch in 2008 and 2010
respectively. The timing is such that the solar magnetic
activity cycle, operating with an 11-year period, will be at
or near a maximum during these missions. The program is
designed to use information at the extreme of this cycle to
lead to major advances in our understanding and ability to
predict space weather.
The Johns Hopkins University Applied Physics Laboratory in
Laurel, Md. is responsible for implementation of the
Geospace Project. Implementation includes the design and
development of the two spacecraft.
LWS is part of the Sun-Earth Connection theme within the
Office of Space Science at NASA Headquarters in Washington.
NASA’s Goddard Space Flight Center, Greenbelt, Md. manages
the LWS program.
More information about the LWS program is available on the
Internet at:
