Interstellar Boundary Explorer
From Wikipedia, the free encyclopedia
The Interstellar Boundary Explorer (IBEX) is a NASA satellite that will make the first map of the boundary between the Solar System and interstellar space. It is part of NASA's Small Explorer program. The Interstellar Boundary Explorer (IBEX) mission is scheduled to be launched in June 2008. The nominal mission baseline duration will be two years to image the entire solar system boundary.
The mission is being led by the Southwest Research Institute, with Los Alamos National Laboratory and Lockheed Martin Advanced Technology Center serving as Co-Investigator institutions responsible for the IBEX-Hi and IBEX-Lo sensors respectively. Orbital Sciences Corporation will provide the spacecraft bus and will be the location for spacecraft environmental testing.
[edit] Mission Parameters
The satellite will be a sun-oriented spinner in a highly-eccentric elliptical Earth orbit, ranging from 5000 km at perigee to 40-50 Earth radii (roughly 250,000 - 300,000 km or three-quarters the distance to the moon) at apogee and allowing it to move out of the Earth's magnetosphere when performing science operations. This is critical due to the large degree of interference that would occur while imaging within the magnetosphere. When within the magnetosphere of the Earth (10-12 Earth radii or 70,000 km), the satellite will perform housekeeping operations such as downlink. The spacecraft will require a Solid Rocket Motor as a final boost stage to achieve this type of orbit, and will be launched via a Pegasus rocket which will be fired from an aircraft that will take off from Kwajalein Atoll.
[edit] Payload
The heliospheric boundary of the solar system will be imaged by measuring the location and magnitude of charge-exchange collisions occurring in all directions that will ultimately yield a map of the termination shock of the solar wind. The satellite's payload will consist of two energetic neutral atom (ENA) imagers, IBEX-Hi and IBEX-Lo. Each of these sensors will consist of a collimator that will limit field of view, a conversion surface to convert neutral hydrogen and oxygen into ions, an electrostatic analyzer to supress ultraviolet light and select ions of a specific energy range, and a detector to identify particle counts and the identity of each ion. IBEX-Hi will record particle counts at a higher energy band than -Lo. The payload will also include a Combined Electronics Unit (CEU) that will control the voltages on the collimator and ESA and will read and record data from the particle detectors of each sensor.