The Space Shuttle Enterprise was dedicated to the fallen crews of the US space flight programme.
Back on 27 April 2012, the Enterprise retired to the Intrepid Sea, Air & Space Museum in New York City. Three years later, the family members of crews of the Apollo 1, Challenger and Columbia gathered at the Intrepid in New York to unveil a new plaque in memory of the missions' crews.
"It's an honour to be here to recognize the crews of Apollo 1, Challenger and Columbia as we dedicate the Space Shuttle Enterprise in their honour. I thank all of you, the families of our fallen heroes, for joining us today. Know that we will never, we will never forget your loved ones," said Nasa Administrator Charles Bolden, Jr.
The Space Shuttle Enterprise was Nasa's first orbiter. It was a prototype that conducted tests within the Earth's atmosphere in 1977. These tests paved the way for Nasa's later space shuttle flights to outer space.
June Scobee Rodgers, was married to Francis "Dick" Scobee when he commanded the doomed mission of the Space Shuttle Challenger on 28 January 1986.
The Challenger's seven member crew was killed when the space shuttle exploded shortly after launch. The explosion was caused by low-temperature impairment of an O-ring, a mission critical seal. Scobee Rodgers said both the Challenger and the Enterprise were especially important to her late husband.
"My husband Dick Scobee was the commander of Challenger, but he was also the commander as a test pilot on the 747 that tested the Enterprise that flew around the world. So that's especially meaningful to us," she said.
Scobee Rodgers added, "It's also terrific to be here with all these people that we've bonded with when our grief became so public. It helped us to have each other to bond together and support one another."
Also attending the dedication ceremony was Lowell Grissom. He is the brother of Virgil I. "Gus" Grissom, Apollo 1's Command Pilot.
The three-person crew of Apollo 1 was killed on January 27, 1967 when a fire broke out inside the spacecraft during a pre-launch test. As a result of the deadly fire, major design and engineering changes were made to the Apollo to make it safer.
"I'm just so pleased and honoured that the Intrepid has decided to honour these heroes that we have. They contributed so much to the advancement of the space program and to be here and to see the shuttle and to be with the other families, it's just quite an honour for me," said Grissom.
By the time Nasa's space shuttle program came to an end in 2011, its space shuttle fleet had flown 135 missions.