Former astronaut Jon McBride speaks during a remembrance ceremony Jan. 18, 2017, at NASA's Kennedy Space Center in Florida. Cernan, who flew on Gemini and Apollo missions, commanded the Apollo 17 mission and was the last person to walk on the moon.

Former astronaut Bob Cabana, director of NASA's Kennedy Space Center in Florida, speaks during a remembrance ceremony Jan. 18, 2017. Cernan, who flew on Gemini and Apollo missions, commanded the Apollo 17 mission and was the last person to walk on the moon.

A display for astronaut Gene Cernan is shown following a remembrance ceremony Jan. 18, 2017, at NASA's Kennedy Space Center in Florida. Cernan, who flew on Gemini and Apollo missions, commanded the Apollo 17 mission and was the last person to walk on the moon.

A photo of astronaut Gene Cernan is displayed alongside a memorial wreath before a remembrance ceremony Jan. 18, 2017, at NASA's Kennedy Space Center in Florida. Cernan, who flew on Gemini and Apollo missions, commanded the Apollo 17 mission and was the last person to walk on the moon.

The Astronaut Hall of Fame display for astronaut Gene Cernan is shown following a remembrance ceremony Jan. 18, 2017, at NASA's Kennedy Space Center in Florida. Cernan, who flew on Gemini and Apollo missions, commanded the Apollo 17 mission and was the last person to walk on the moon.

Therrin Protze, Chief Operating Officer, Delaware North Corporation Parks & Resorts at KSC, Inc., speaks during a remembrance ceremony Jan. 18, 2017, at NASA's Kennedy Space Center in Florida. Cernan, who flew on Gemini and Apollo missions, commanded the Apollo 17 mission and was the last person to walk on the moon.

A photo of astronaut Gene Cernan is displayed alongside a memorial wreath before a remembrance ceremony Jan. 18, 2017, at NASA's Kennedy Space Center in Florida. Cernan, who flew on Gemini and Apollo missions, commanded the Apollo 17 mission and was the last person to walk on the moon.