Smithsonian’s National Air & Space Museum Udvar-Hazy Center in Chantilly, Virginia, offers the unique sight of a complete Mercury spacecraft. Many of these spacecraft are available for viewing all over the United States, but this one is special because it did not fly.

     During the course of a Mercury flight, several parts of the spacecraft are jettisoned and not recovered, including the retro package. This piece of equipment is visible here in my photos as the striped metal object strapped to the bottom of the heat shield. This small cluster of solid rocket motors was responsible for the safe return of the astronaut from space, making just enough thrust to change the shape of the orbit so that it would meet the atmosphere and use aerobraking for a ballistic reentry.

     If this package had not fired properly, the astronaut would be faced with the dire situation of being stuck in orbit. Fortunately, this never happened in real life, but it was captured in the fanciful novel “Marooned” by Martin Cardin, in which a NASA astronaut was stranded on orbit after his retro rockets failed. When the book was released in 1964, it was so influential that it actually changed procedures for Mercury’s follow on program Project Gemini, adding more redundancy to the spacecraft’s reentry flight profile.

     Alan Shepard, the first American in space and later Apollo 14 moonwalker, didn’t fail to notice that there was a leftover spacecraft at the end of the Mercury program. He lobbied for a second Mercury flight in this ship, speaking personally to both NASA Administrator James Webb and President John Kennedy about this flight. He told them his idea of an “open ended” mission in which they would keep him in orbit indefinitely until there was a malfunction or consumables began to run out. Webb stated (and Kennedy agreed) that it was more important to shelve the Mercury spacecraft in order to jump start the more capable Gemini Program. Thus, we now have this whole Mercury on display for future generations to appreciate.