Overall view of the center unit and the "extender tube" (including a
low-fidelity Mercury spacecraft mockup).
The Redstones manufactured specifically for the Mercury-Redstone program had
propellant tanks which were lengthened about 6 feet and had modified aft units.
When at the Michigan Space & Science
Center, the Redstone was displayed as a Mercury-Redstone. Since
the display started out as a standard Redstone missile and was displayed
without the tactical missile's aft unit, it was necessary to add an "extender
tube" to extend the missile's length to that of a Mercury-Redstone booster.