Robert Farquhar, a visionary and expert in planetary exploration, spacecraft design, and celestial navigation at NASA, the Johns Hopkins Applied Physics Laboratory (APL) in Laurel Maryland, and KinetX, Inc., in Tempe, Arizona, died from complications following a respiratory illness at his home in Burke, Virginia on Sunday, October 18. He was 83.

A 50-year veteran of deep space missions and often referred to as a genius in his field, Farquhar made pivotal contributions to deep space missions to asteroids and comets.

In 1960, he joined NASA’s Marshall Space Flight Center in Huntsville, Alabama, where he participated in the design of the Saturn V launch vehicle. From 1961-1964, he worked at the Lockheed Missiles and Space Company in California, perfecting orbital dynamics and control of satellites while also assisting in the preparation of an Interplanetary Flight Handbook for NASA.

From 1969-1990, he was employed at NASA’s Goddard Space Flight Center in Greenbelt, Maryland and NASA Headquarters in Washington. He held a number of positions that included studies of post-Apollo lunar exploration concepts, the lunar shuttle transportation system, in addition to key management positions for numerous satellite projects.

At APL from 1990-2007, he conceived, and was the flight director, for the Near Earth Asteroid Rendezvous (NEAR) mission to the asteroid named Eros. Launched in 1996, NEAR (later called NEAR-Shoemaker) was the first spacecraft to orbit and perform an in-depth investigation of an asteroid, and then safely land on it in February 2001. Thanks to Farquhar’s efforts, the mission answered many fundamental questions about the nature and origin of asteroids.

Also while at APL, he helped lead the Comet Nucleus Tour (CONTOUR) mission; the Mercury Surface, Space Environment, Geochemistry, and Ranging (MESSENGER) mission to the planet Mercury; and the New Horizons mission to the dwarf planet Pluto, and its moon, Charon.

Also among Farquhar’s career highlights was the International Sun-Earth Explorer/International Cometary Explorer (ISEE-3/ICE) mission. As the mission’s flight director, Farquhar led the crew that placed ISEE-3 in a “halo orbit” around the gravitational balancing or libration point between the sun and the Earth. He designed the quintuple lunar flyby trajectory that sent the spacecraft through the tail of the P/Giacobini-Zinner comet in September 1985. Farquhar invented this trajectory that allowed the U.S. to become the first nation to encounter a comet. Farquhar’s knowledge of halo orbits, a term that he had coined in his 1969 dissertation at Stanford University, was critical in calculating the trajectory for the successful mission.

Born in September 1932, Farquhar attended elementary and high school in Chicago. As a child, he became interested in aviation, often reading about it and building model airplanes of his own design.

Farquhar attended college briefly before joining the army in April 1951. He completed basic training at Fort Knox and jump training at Fort Benning before being deployed to Fort Bragg as part of the 82nd Airborne Division.

In late 1952 Farquhar requested to be transferred to a division which was taking part in the Korean War, being deployed to the 187th Infantry Regiment stationed in Japan. After some training in Japan, Farquhar was invited to attend clerk typist school and became the company clerk, writing reports, for some time. One day, after some North Korean prisoners were released, Farquhar’s division was moved to Kimpo airfield for one month. There, he was on the front lines until the ceasefire.

Returning to the U.S., Farquhar attended the University of Illinois Navy Pier campus before moving to the main campus at Champaign in 1957. There he decided on a career in spaceflight, finishing his bachelor’s degree in aeronautical engineering in 1959. He stayed at the University of Illinois for graduate school before applying and being accepted for a position at the University of California, Los Angeles.

During his summer after graduating Farquhar worked at the RAND Corporation in California. He completed his engineering master’s degree at the University of California and attended Stanford University for his PhD in astronautics which he obtained in 1968, working with John Breakwell to develop halo orbit and other libration point trajectory concepts and applications.

Farquhar was bestowed numerous honors and awards from the military, NASA, and a variety of space organizations and associations. Farquhar wrote the book, “Fifty Years on the Space Frontier: Halo Orbits, Comets, Asteroids, and More”, voted the best book of the year by the International Academy of Astronautics, and has written, co-written or contributed to over 200 other publications.

He is survived by his wife Irina, step-daughter Anya, and a host of relatives.