Edwin “Buzz” Aldrin, the Apollo 11 astronaut who became the second person to set foot on the moon during a mission that captivated the world in the summer of 1969, will be a featured speaker at the San Diego Air and Space Museum on July 20.

Aldrin, 94, is scheduled to participate in a question-and-answer session during a gala that will be held on the 55th anniversary of the moon landing, which was broadcast to an estimated 650 million people on Earth.

Astronaut Neil Armstrong left the lunar module Eagle first and famously said, “That’s one small step for man, one giant leap for mankind,” as he touched the surface.

He was followed roughly 20 minutes later by Aldrin, who described what he saw as “magnificent desolation.” They explored the surface while their colleague, astronaut Michael Collins, orbited the moon in the command module.

The museum gala also will feature Charlie Duke, who walked on the moon in 1972 as a member of the Apollo 16 crew. Tickets for the July 20 event are available at sandiegoairandspace.org.