Charles Elachi, the director of the Jet Propulsion Laboratory since 2001, has announced that he is retiring at the end of June 2016. He will become professor emeritus at the California Institute of Technology, where he currently serves as a vice president and professor of Electrical Engineering and Planetary Science.

Elachi began his career at JPL in 1970. Over the span of 45 years, he has been an active researcher and science investigator on a number of space exploration missions and projects. He has authored more than 230 publications in the fields of active microwave remote sensing and electromagnetic theory, and he holds several patents in those fields. He taught "The Physics of Remote Sensing" at Caltech from 1982 to 2001.

In 1988, the Los Angeles Times selected Elachi as one of "Southern California's rising stars who will make a difference in L.A." His accomplishments in the space program span the solar system and beyond.

In an email to employees Wednesday, Elachi reflected on his past 15 years as director.

"I marvel at what we have accomplished together," Elachi said. "An array of missions to Mars - Mars Reconnaissance Orbiter, the lander Phoenix and the rovers Spirit, Opportunity and Curiosity - have provided exquisite detail of that planet.

Cassini has explored majestic Saturn and its fascinating moons. Cloudsat, Jason 1, Jason 2, Aquarius, OCO-2, GRACE, SMAP and a host of science instruments have provided vital information about the state of our planet. Deep Impact's intentional collision with a comet provided an unusual Fourth of July fireworks display and new science, and Stardust brought us samples from a comet."

Also under Elachi's leadership, the GRAIL mission mapped the moon's gravity, Genesis returned samples of our star, and Dawn has studied two bodies in the asteroid belt including dwarf planet Ceres. Juno, currently on its way to Jupiter, will provide new knowledge about our solar system's largest planet.

The Galaxy Evolution Explorer, the Spitzer Space Telescope, Kepler, WISE, and NuStar revolutionized our understanding of our place in the universe. The Voyager 1 spacecraft, launched in 1977, became the first man-made object to reach interstellar space.

"Looking ahead, I see an array of exciting projects that will keep the Lab busy and challenged for years to come," Elachi said. "Flagship missions such as Mars 2020 and the Europa mission, plus the Asteroid Redirect Mission, additional Earth missions including Jason 3 and the GRACE follow-on and a number of smaller missions are examples of the tremendous opportunities we have to continue our tradition of exploration and discovery."

Elachi assured employees he is not giving up his passion for space exploration in retirement. His position as professor emeritus will allow him to pursue research interests while he continues to participate as a science investigator on a number of space missions His plans include being a proactive advocate for a strong space science and exploration program.

Originally from Lebanon, Elachi attended university in France. In the late 1960s, he moved to California to continue his graduate studies at Caltech. He holds several degrees in science, engineering and management. In 2006, he was selected as one of America's Best Leaders by U.S. News and World Report and the Center for Public Leadership at Harvard University's Kennedy School of Government.