The Interstellar Boundary Explorer (IBEX) is part of NASA’s small explorer program. This mission was proposed by the Southwest Research Institute (SwRI) in San Antonio to study the region between our solar system and interstellar space. The region between the interstellar space and our solar system is called an Interstellar boundary. In November 2003, NASA selected five candidates to compete for two mission slots in NASA’s Explorer program of low cost, rapidly developed scientific spacecraft. IBEX was one of five candidates selected to participate for the two-mission slots. On January 26, 2005, IBEX was chosen by NASA for one of
the two slots.
The Interstellar Boundary Explorer satellite will launch into space on October 19th 2008. An aircraft will take off from Kwajalein Atoll in the South Pacific and will release the Pegasus rocket. The Pegasus rocket XL will launch IBEX into space. The IBEX, a small, lightweight spacecraft, will use a special solid state booster and its own onboard propulsion system to boost itself into a high altitude orbit that will reach 200 thousand miles above the Earth.
The sole and focused science objective of IBEX is to discover the global interaction between solar wind and the interstellar medium. The interstellar medium can be explained as a low-density material between the stars. The fact that this interaction has never been discovered before makes the mission more interesting. For the first time, the Interstellar Boundary Explorer will observe the global interactions between the solar wind and the interstellar medium. This will help us understand more about the sun’s interaction with the galaxy. Moreover, IBEX will also study the galactic cosmic rays that pose a threat to the health and safety of human spaceflight exploring beyond earth’s orbit. The IBEX will make all these observations from a highly elliptical orbit, ensuring there is no interference from the Earth’s magnetosphere.
The Interstellar Boundary Explorer will consist of two completely independent pixel sensors, IBEX-Hi and IBEX-Lo. These image sensors are actually energetic neutral atom (ENA) imagers, specialized to detect neutral atoms from the outer boundaries of the solar system and the galactic medium. These sensors will have a collimator which will limit the field of view. IBEX-Hi and IBEX-Lo will also have an electrostatic analyzer, a conversion surface, and a detector. The conversion surface will help to convert neutral hydrogen and oxygen into ions. The electrostatic analyzer will select ions of a specific range and suppress ultraviolet light. The detector will be able to identify particle counts and the identity of each ion.
The two single pixel sensors, IBEX-Hi and IBEX-lo, will capture the images of the interstellar boundary of the solar system by measuring the location and magnitude of charge-exchange collisions occurring in all directions. This will result in generating a map of the termination shock of the solar wind.
The payload will also include a CEU (Combined Electronics Unit), which will have a control of voltages on the collimator.
The study by IBEX will help us discover the interstellar boundary regions which protect us from the dangerous galactic cosmic rays. It will also help us to understand the sun’s interaction with the galaxy by observing the global interactions between the solar wind and interstellar medium.