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.
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 at this direct link.
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.