HOUSTON – Dr. Robert R. Gilruth, a driving force behind U.S. human space exploration efforts died Thursday at Charlottesville, Virginia.

He was 86 and had suffered from Alzheimer’s disease for several years.

The prime crew for the first piloted Apollo mission was named at a Manned Spacecraft Center (MSC) press conference on March 21, 1966. Left to right, are Astronauts Roger B. Chaffee, Edward H. White II and Virgil Grissom. At the very end of the table is Dr. Robert R. Gilruth, Manned Spaceflight Center (MSC) Director, who made the announcement.

In 1959, he was tapped to head Project Mercury, which put the first U.S. astronauts into space in 1961.

"He was one of the greatest men I worked for and with," said Dr. Christopher C. Kraft Jr., who succeeded Gilruth as Johnson Space Center director. "He was the father of spaceflight and certainly never got the credit he deserved."

Kraft joined the Langley Laboratory in 1945, as it was known then, and became Gilruth’s special assistant during the STG’s early days.

Gilruth developed an early love of science as a boy in Nashwauk, Minnesota. His father taught high-school physics and chemistry and was later a school superintendent in Duluth, Minnesota. Gilruth's mother taught high-school math. As a youngster, Gilruth loved to build model airplanes -- but with his own designs, not those that came in the kits.

He earned Bachelor’s and Master’s degrees in aeronautical engineering from the University of Minnesota. Throughout the years, he received several honorary doctorates for his contributions to aerospace research.

Gilruth worked as an engineer at the National Advisory Committee for Aeronautics at the Langley from 1937 to 1946 before becoming chief of the pilotless aircraft research division at Wallops Island from 1946 to 1952, where he did groundbreaking research into rocket-powered aircraft.

His focus suddenly shifted to spacecraft when the Soviet Union launched the world’s first satellite, Sputnik, in 1957.

"I can recall watching the sunlight reflect off of Sputnik as it passed over my home on the Chesapeake Bay in Virginia," Gilruth said in 1972. "It put a new sense of value and urgency on things we had been doing. When one month later the dog, Laika, was placed in orbit in Sputnik 2, I was sure that the Russians were planning for man-in-space."

Gilruth got his marching orders when Project Mercury kicked off.

"I was expected to put a man in space and bring him back in good shape – and do it before the Soviets, which we didn’t do," Gilruth said during an interview for the NASA-published book Before This Decade is Out... "On the other hand, we buried the Soviets before we were through by going to the moon.

As the piloted spaceflight program began in earnest, Kraft said Gilruth was always in the middle of the action with his calm demeanor.

"He was such an interesting personality, such a beautiful man," Kraft said. "He was always around to give advice or help."

Gilruth was a pensive man of medium build who liked to smoke a pipe and can be often seen in NASA’s historical footage. His style wasn’t to seek out the limelight, but he was an omnipresent force in the piloted spaceflight program.

"A lot of people thought going to the moon was impossible," said Apollo 12 and Skylab astronaut Alan Bean. "People like Gilruth made it come true. I think of Wernher von Braun as building the rockets and Dr. Gilruth as getting the spacecraft ready."

Bean recalled that Gilruth said little during meetings, but always had the last word.

"At the end, when everyone finished, he’d then say something about the way the meeting went," Bean said. "It was not always complimentary."

He added that Gilruth’s style was to not give answers, but to help the questioner find a solution.

Former JSC Directors Robert Gilruth (left) and Christopher C. Kraft Jr. (center) at the Apollo 11 20th Anniversary Black Tie event reminiscing with keynote speaker Walter Cronkite (right).

His meticulous style of record keeping and documentation also salvaged some of the Apollo missions from not landing on the moon, or even possible disaster, Bean said. Flight controllers and astronauts could take the data and work out solutions rapidly.

"He’d learned from the early days of aeronautical research that little things are important," he said. "With the quality control and documentation, you had the history of everything and could lay your hands on it in a flash."

An avid sailor, Gilruth managed to squeeze in time to build his own boat, which he planned to sail around the world after retiring from NASA. During what spare time he had in Houston, he often sailed in Galveston Bay. Years before, he had invented an effective hydrofoil system that enabled a small boat to skim across water at high speed.

After retiring from the space agency in 1973, Gilruth and his wife Jean moved to Kilmarnock, Virginia, on the Rappahonack River. That put him closer to the sea he had enjoyed so much during his years at Langley.

The Gilruth family plans a private memorial service. Expressions of sympathy may be made to the Evans-Gilruth Foundation, 7076 Glanamman Way, Warrenton, Virginia 20187.