Joseph Schmitt, who helped develop the spacesuits worn by the nation’s first astronauts and who helped secure the straps, boots and helmets of John Glenn, Neil Armstrong and other astronauts just before their history-making flights, died Sept. 25 at a nursing home in Friendswood, Texas. He was 101.

A granddaughter, Susan Alexander, confirmed his death, but she did not know the specific cause.

Schmitt, who began his career as an airplane mechanic and instrument technician, was present at many of the momentous events in aeronautical history. He helped install and monitor the instruments of the Bell X-1 rocket plane, in which Chuck Yeager broke the sound barrier on Oct. 14, 1947.

During the 1930s, when Schmitt was in the old Army Air Corps, he had helped rig parachutes and repair flight suits. Later, when he worked for NASA’s predecessor, the National Advisory Committee for Aeronautics, that early experience prepared him for a job that had never existed before.

“They saw I had done a little work in aircraft clothing repair and asked if I wanted to work on spacesuits,” Schmitt told author Billy Watkins in the 2006 book “Apollo Moon Missions: The Unsung Heroes.” “I said sure.”

When NASA was formed in 1958, Schmitt became the agency’s chief spacesuit technician. He worked with engineers at the B.F. Goodrich tire company in Ohio to create a pressurized suit that could withstand extreme temperatures and a weightless environment.

A spacesuit would have to include devices to monitor an astronaut’s health and to allow him to breathe in an oxygen-free environment. Cool air would have to flow under the layers of aluminum-coated nylon, yet it had to allow freedom of movement.

Because even the slightest hole could have life-threatening consequences, a spacesuit had to be strong enough not to rip.

One time, Schmitt increased the pressure inside a spacesuit to five pounds per square inch.

“And the thing blew,” he said in Watkins’s book. “Sounded like a shotgun went off. We wrapped it up and sent it back to the factory.”

And, yes, Schmitt also helped invent a necessary item officially known as a urine collection device.

He accompanied the astronauts to the launchpad and was among the last people to see them before liftoff, as he secured their air hoses and buckled them into the space capsule.

He helped Alan Shepard into his spacesuit for the country’s first space flight in May 1961. Nine months later, on Feb. 20, 1962, Schmitt tightened Glenn’s helmet, gloves and boots and put the astronaut in the capsule of the Friendship 7 spacecraft in which Glenn became the first American to orbit the Earth.

In 1969, Schmitt needed an entirely new kind of suit for Armstrong and Buzz Aldrin, as they stepped out of the spacecraft to walk on the moon.

The 28-layer spacesuit, costing $100,000 apiece, had to be able to resist ultraviolet radiation and withstand a 500-degree temperature range, from minus-250 degrees Fahrenheit to 310 degrees above zero. The boots needed to be tough enough to walk on the lunar surface, yet the arms and legs of the suit had to allow enough freedom of motion for the astronauts to collect rocks and plant the American flag on the moon.

In a NASA oral history, Schmitt recalled boarding the elevator with the astronauts and riding up with them more than 320 feet, to the hatch of Apollo 11.

“My work station for ingress was just inside the spacecraft hatch just above the center seat, which means I had to get out each time the next crewman got in,” he said. “Before getting out of the spacecraft, I always made a quick check of everyone’s equipment, asking them if everything was okay and wish[ing] them good luck.”

Joseph William Schmitt was born Jan. 2, 1916, in O’Fallon, Illinois. Less than three months later, his father, a police officer, was shot and killed in the line of duty.

His mother took in laundry, and Schmitt worked shining shoes and cleaning spittoons at his brother-in-law’s barbershop.

Schmitt had a strong mechanical aptitude as a young man and took up taxidermy as a hobby. Because there were few jobs available during the Depression, he entered the Army Air Corps after high school and learned airplane mechanics.

He left the military in 1939 to join NACA, the early aeronautics research branch, and helped develop flight instrumentation for military aircraft during World War II.

After the war, Schmitt worked at the Langley Research Center in Hampton, Virginia, where early advances in the space program were made. He moved to Texas in 1963 to work at NASA’s Johnson Space Center.

Schmitt continued to refine spacesuits through the Gemini and Apollo space programs and on into the days of the space shuttle before retiring in 1983.

He appeared on an episode of the television game show “What’s My Line?” in 1963. The panel guessed that he worked in the space program but could not pin down his exact job.

His wife of 69 years, the former Elizabeth Rayfield, died in 2008. Survivors include two children, six grandchildren and nine great-grandchildren.

In 1964, Schmitt drove to artist Norman Rockwell’s studio in Stockbridge, Massachusetts, taking a couple of space suits with him.

“The reason I had to go up,” he said in the NASA oral history, “was because the Gemini spacesuits at that time were classified. So they couldn’t just put them in the mail and ship them.”

Rockwell portrayed Schmitt in two paintings, as he helped the astronauts fit into their spacesuits. When Schmitt asked why the artist included him, Rockwell replied, “Because you were always there.”