Artist rendition of IBEX spacecraft.

Launch Date Oct. 19, 2008
Launch Site Ronald Reagan Ballistic Missile Defense Test Site, Republic of the Marshall Islands
Destination Our Solar System, Beyond Our Solar System
Type Orbiter
Status Successful—Extended Mission in Progress
Nation United States
Alternate Names 2008-051A


IBEX, or Interstellar Boundary Explorer, is designed to detect the edge of our solar system. Operating from Earth orbit, the spacecraft uses neutral atom images to detect particles from the termination shock at the boundary between our solar system and interstellar space.


IBEX made the first all-sky maps of the heliosphere. One of the immediate results was a surprise: the maps are bisected by a bright, winding ribbon of unknown origin. The finding could change our understanding of the heliosphere.

Key Dates

Oct. 19, 2008: Launch


Launch Vehicle: Pegasus XL Rocket

Spacecraft Mass: 39 kilograms

Additional Resources


Southwest Research Institute: IBEX

NASA Explorers Program

Giant Ribbon Discovered at the Edge of Our Solar System

National Space Science Data Center Master Catalog: IBEX

Selected References

Siddiqi, Asif A. Deep Space Chronicle: A Chronology of Deep Space and Planetary Probes 1958-2000, NASA, 2002.

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