IBEX began its ride to space in 2008, when it launched from Kwajalein Island, Marshall Islands. An airplane called an L-1011 took a Pegasus rocket to high altitude. Then, the Pegasus rocket fired its own rockets to propel it, and the IBEX spacecraft, into space. The IBEX satellite climbed into an orbit that goes 5/6 of the way to the Moon. This orbit is very high, which allows the satellite to spend much of the time out of the Earth's magnetosphere, which can interfere with its observations. Even though this orbit is high, it is still very far from the Solar System boundary that it is measuring.
As part of a nationwide contest held just prior to launch in 2008, IBEX's own Pegasus rocket received a special name: Mercator (pronounced mer-KAY-tur). The name Mercator was chosen in honor of Gerardus Mercator, the famous 16th century Dutch mapmaker. In addition to the many maps that he made, he also invented a way to create terrestrial (Earth) and celestial (sky) globes out of paper mache, allowing for quicker production of larger numbers of globes than the wooden or brass globes that were previously carved by hand. Because the data from the IBEX spacecraft is used to make the first maps of our Solar System boundary ever produced, the IBEX team thought Mercator was a perfect choice!