Short answers, pulled from the story.
IBEX (also designated Explorer 91 or SMEX-10) is a NASA satellite that maps the boundary between the Solar System and interstellar space using energetic neutral atoms. It generates full-sky maps of ENA intensity every six months, imaging the heliosheath where the solar wind collides with the interstellar medium.
IBEX was launched on the 19th of October 2008 using a Pegasus XL rocket released from a Lockheed L-1011 aircraft called Stargazer over Kwajalein Atoll in the central Pacific Ocean. Launching near the equator allowed the Pegasus vehicle to carry up to 16 kilograms more mass to orbit than a launch from Kennedy Space Center would have permitted.
IBEX found a narrow ribbon of energetic neutral atoms two to three times brighter than anything else in the sky, which had not been predicted by existing models. It also discovered that the heliosphere has no bow shock, measured the Sun's speed relative to the local interstellar medium at 23.2 km/s (revising the prior Ulysses measurement of 26.3 km/s), and in July 2013 revealed a four-lobed tail on the heliosphere.
The IBEX mission is led by Dr. David J. McComas, formerly of the Southwest Research Institute and later with Princeton University. The Los Alamos National Laboratory built the IBEX-Hi sensor, Lockheed Martin Advanced Technology Center built IBEX-Lo, and Orbital Sciences Corporation manufactured the satellite bus.
IBEX-Hi detects about 500 particles per day, while IBEX-Lo detects fewer than 100. The satellite collects only a few particles per minute on average, which is why its downlink data rate of 320,000 bits per second is sufficient for the mission.
Following an orbit adjustment in June 2011 that raised its perigee to more than 30,000 kilometers, IBEX is expected to maintain a stable orbit for more than 40 years. The prime mission ended in early 2011, and the spacecraft has continued operating in an extended mission phase since then.