An artist's impression of IBEX's launch and deployment. The spacecraft launched Sunday, Oct. 19, 2008. (NASA/Goddard Space Flight Center)

A spacecraft designed to map the outer edges of our solar system is in orbit high above the Earth after a successful launch Sunday, NASA said Monday.

The Interstellar Boundary Explorer, or Ibex, is the first spacecraft to focus solely on the interactions of the hot solar wind emanating from the sun and the cold vastness of outer space.

Ibex was launched aboard a Pegasus rocket on Sunday at 1:47 p.m. ET from the Kwajalein Atoll, a part of the Marshall Islands in the Pacific Ocean. During the two-year mission, the spacecraft will capture images and map the boundary of the area containing the solar wind, called the heliosphere.

The heliosphere extends far beyond the orbit of the furthest planets. The distance where the solar wind begins to slow down as it collides with cosmic rays and cooler particles of interstellar gas — called the termination shock — extends about 13.5 billion kilometres from the sun, or 90 times the distance from the sun to the Earth.

The heliosphere ends at the heliopause, the distance at which the solar wind is buffeted completely by particles from outside our solar system.

Voyager 1 and Voyager 2 crossed the termination shock in 2003 and 2007 respectively, about 30 years after the spacecraft launched from Earth, providing NASA with "in situ" observations of the far-off region of space. NASA hopes Ibex will be able to provide a "big picture" look at the region.

"The interstellar boundary regions are critical because they shield us from the vast majority of dangerous galactic cosmic rays, which otherwise would penetrate into Earth's orbit and make human space flight much more dangerous," said Ibex principal investigator David J. McComas of the Southwest Research Institute in San Antonio in a statement.

To avoid interference to its sensors from the Earth's magnetosphere, Ibex's flight path will take it far away from the Earth, reaching a distance of about 322,000 km, a process that will take about 45 days to complete. After the 45-day flight is complete, the space probe will begin its scientific observations.

The probe will still be closer to the Earth than the moon, which orbits at an average distance of about 384,000 km.