Legendary astronaut Alan Bean, — the fourth person to walk on the moon — has died at the age of 86 Saturday, a NASA statement says.

RIP Alan Bean, 4th human being to walk on the Moon, Skylab astronaut and accomplished artist. https://t.co/FKPJ9VpiKX pic.twitter.com/Bj76dZeu0H — NASA Solar System (@NASASolarSystem) May 26, 2018

Bean, who passed away at Houston Methodist after battling a short illness, was a lunar module pilot on Apollo 12 in 1969, the second manned flight to land on the moon.

In 1973, Bean was spacecraft commander of the second manned mission to Skylab, the first U.S. space station.

The astronaut spent a total of 1,671 hours and 45 minutes in space.

Astronaut Scott Kelly mourned Bean on Twitter, calling him a “spaceflight pioneer.”

“Sad day. Not only did we lose a spaceflight pioneer, 4th man to walk on the moon, but also an exceptional artist that brought his experience back to Earth to share with the world. Fair winds and following seas, Captain,” Kelly tweeted.

Sad day. Not only did we lose a spaceflight pioneer, 4th man to walk on the moon, but also an exceptional artist that brought his experience back to Earth to share with the world. Fair winds and following seas, Captain. #RIP #AlanBean pic.twitter.com/85dJjdA86A — Scott Kelly (@StationCDRKelly) May 26, 2018

“Alan was the strongest and kindest man I ever knew. He was the love of my life and I miss him dearly,” said Leslie Bean, the moonwalker’s wife of 40 years, said in a statement.

“A native Texan, Alan died peacefully in Houston surrounded by those who loved him.”

We remember Apollo 12 astronaut Alan Bean, who walked on the Moon in 1969, commanded the second Skylab crew in 1973 and went on in retirement to paint the remarkable worlds and sights he had seen like no other artist. Learn more about his life at https://t.co/h6HUiwbVFX. pic.twitter.com/xgGuCwBmEd — NASA (@NASA) May 26, 2018

“Alan and I have been best friends for 55 years — ever since the day we became astronauts,” said Walt Cunningham, a Lunar Module Pilot on the Apollo 7 mission.

“When I became head of the Skylab Branch of the Astronaut Office, we worked together and Alan eventually commanded the second Skylab mission.”

“We have never lived more than a couple of miles apart, even after we left NASA. And for years, Alan and I never missed a month where we did not have a cheeseburger together at Miller’s Café in Houston. We are accustomed to losing friends in our business but this is a tough one,” the astronaut added.