BALTIMORE — Robert Kraemer, former director of planetary exploration for NASA who was also an expert in rocket engines, died Aug. 20 at Brightview Assisted Living in Catonsville of complications from a fall. He was 84.

The son of a citrus rancher and a homemaker, Robert Samuel Kraemer was born in Fullerton, Calif., and raised in Placentia, Calif. He was a 1946 graduate of Fullerton High School and earned a bachelor’s degree in 1950 in aeronautical engineering from the University of Notre Dame.

After earning a master’s degree in aeronautics and rocket propulsion from the California Institute of Technology in 1951, he went to work for North American Aviation’s Rocketdyne Division in Canoga Park, Calif., working on rocket propulsion for a secret intercontinental cruise missile called Navaho.

“By 1961, he was head of all advanced projects for the NAA rocket team, also called Rocketdyne. His work with high-performance launch engines during this time led him to determine they had all the rocket technology the U.S. would use for the next two decades,” Brian Compere, assistant managing editor of The Diamondback campus newspaper at the University of Maryland, wrote in a profile of his grandfather.

He then took a job as chief engineer for space systems at Ford Aeronautical in Newport Beach, Calif., where he worked until he joined NASA in 1967. He managed the deployment of the Voyager Mars Surface Laboratory at NASA’s headquarters in Washington.

After the project was canceled because of congressional concerns, Kraemer was appointed manager of advanced planetary programs and technology and in 1970 was named director of planetary programs.

“In this position he oversaw the successful completion of 12 missions to launch spacecraft into the solar system to study its planets, moons and more,” wrote Compere. “He faced political, financial and technical challenges in managing an unprecedented burst of planetary exploration” that produced groundbreaking results.

Kraemer was associated with the missions Mariner 9 and 10, Pioneer 10 and 11, Helios 1 and 2, Viking 1 and 2, Voyager 1 and 2, and Venus 1 and 2.

Noel Hinners, who was associate administrator for space science at NASA’s headquarters, worked with Kraemer.

“Overall and first of all, Bob was very technically competent and a very good engineer, and he was very good at picking the right people for the right job,” said Hinners, who retired from NASA in 1979 and now lives in Littleton, Colo.

“He had an excellent staff to work all the details. He had a real good team who knew what the goal was and worked toward it. He could solve most of the problems that came up in the division, and sometimes he came to me. Viking was a major challenge at the time,” he said.

Kraemer wrote several books, including “Rocketdyne: Powering Humans into Space” and “Beyond the Moon: A Golden Age of Planetary Exploration 1971-1981.” He received the Distinguished Service Medal, which is NASA’s highest honor.

Kraemer retired in 1990.

Kraemer lived in Rockville from 1967 to 1981, when he moved to Annapolis. Since 2007, he had been a resident of the Charlestown Retirement Community in Catonsville.

In addition to his grandson, survivors include his wife of 59 years, the former Anne LaVerne Park; three sons, David Kraemer of Catonsville, Timothy Kraemer of Germantown and Stephen Kraemer of Athens, Ga.; three daughters, Kathryn McCoy of Kensington, Joan Compere of Ellicott City and Anita Kraemer of Catonsville; and 10 other grandchildren.