Low Earth Orbit Vehicle Will Study X-Ray Polarization
Orbital Sciences Corporation announced Thursday that it has
been selected by the NASA to design, manufacture, integrate and
test a new low-Earth orbit (LEO) space science satellite intended
to study X-ray polarization in space. Under the $40 million
contract, Orbital will provide the spacecraft bus and conduct
mission operations for the Goddard Space Flight Center’s
(GSFC) Gravity and Extreme Magnetism (GEMS) mission. The GEMS
contract was awarded to Orbital under the space agency’s
Small Explorer (SMEX) series of cost efficient and highly
productive space science satellites. Orbital has built several
other SMEX satellites for NASA, including the in-orbit GALEX, AIM
and IBEX spacecraft, and is currently developing the NuSTAR
spacecraft that is scheduled for launch in 2011. The GEMS mission
is being led by the project’s Principal Investigator Dr. Jean
Swank and is being managed by GSFC. It is currently scheduled to
launch no later than 2015.
“Orbital is very pleased to be able to continue our
support for NASA’s SMEX program with our selection by the
Goddard Space Flight Center to build and operate the GEMS
satellite,” said Mr. Mike Miller, Orbital’s Senior Vice
President for Science and Technology satellite programs.
“With our proven capabilities to build and deploy very
reliable satellites to support the nation’s space science
research, we are looking forward to working with Dr. Swank and her
team on another important mission.”
The GEMS satellite will be the first observatory to
systematically measure X-ray polarization which encodes information
about the structure of cosmic sources, unlocking a previously
hidden astrophysical world. Previous space-based X-ray
observatories have been insensitive to polarization, which refers
to the direction of the electric field of electromagnetic waves.
Polarization measurements will allow scientists to study
scattering, magnetic fields and strong gravitational fields.
“The collaboration among the GEMS participants during the
study phase resulted in a strong team that was selected by NASA
from among several other proposed missions to go forward with its
important scientific research,” said Dr. Swank. “Over
the next several years, we look forward to completing the satellite
and flying a mission that will add important and useful new
information to the study of astrophysics.”
The purpose of the GEMS mission is to help scientists answer
fundamental questions about the universe, such as: Where is energy
released near black holes? What is the origin of X-ray emissions
from pulsars? What is the magnetic field structure in high energy
nebulae? The GEMS team will make the data from the mission readily
accessible to the astrophysics community and the general public on
NASA’s High Energy Astrophysics Science Archive Research
Center website.
The GEMS satellite will be based on Orbital’s proven
LEOStar-2 TM spacecraft bus design. GEMS will be the eighth
satellite to be based on the LEOStar-2 platform. Other
LEOStar-based satellites that Orbital has built or currently has in
development for NASA include the four SMEX satellites mentioned
above, plus the Dawn interplanetary spacecraft that was launched in
2007 and the SORCE Earth science satellite that is currently in its
seventh year of operation.
In addition to its program management role, NASA’s GSFC
will provide the X-ray polarimeter instrument and oversee the
Science Operations Center, science data processing, systems
engineering and education and public outreach. Other program
partners include NASA’s Ames Research Center, the University
of Iowa and ATK, Inc.