— Pathfinder is back in his “space” three and a half years after his “landing” on Earth.
Pathfinder, an early replica of NASA’s now-retired winged orbiters, was returned to its place on the propulsion stack of a space shuttle at the U.S. Space & Rocket Center in Huntsville, Alabama, on Wednesday morning (Aug. 28), signaling the imminent completion of a multimillion-dollar restoration effort.
“Pathfinder’s return to the shuttle stack after an extensive restoration process is an important milestone for us,” said Kimberly Robinson, CEO and executive director of the Space & Rocket Center, in a statement to collectSPACE. “We are so happy to have this emblem of a program that helped launch telescopes and satellites and build the International Space Station over 30 years and 135 flights.”
Workers used two heavy-lift cranes to lift Pathfinder — stripped of its wings and main engines — 80 feet (24 meters) above the ground onto its pedestal, which rests on an external fuel tank and two solid rocket boosters. The horizontal display, which is angled 10 degrees to make it look like Pathfinder is rising into the sky, is one of only two such full-stack displays in the world (the other, at the California Science Center in Los Angeles, features the space shuttle Endeavour).
Pathfinder’s wings are scheduled to be installed on Thursday, and the engines on Friday, weather permitting. In total, the cranes will have lifted more than 143 tons to reassemble the orbiter on its stack.
Originally built in 1977 to test whether NASA’s ground equipment was ready to receive the flight-capable spacecraft, Pathfinder consisted of a steel fuselage clad in wood panels, but lacked the details and markings that would later make the flown vehicles iconic.
After its use by NASA, Pathfinder was modified by the American-Japanese Society to look more like the orbiters that were later launched into space. Pathfinder was exhibited at the Great Space Shuttle Exposition in Tokyo from 1983 to 1984 before finding a permanent home at the US Space & Rocket Center, site of US Space Camp, in May 1988.
Pathfinder was equipped with the first propulsion test object for the shuttle’s external tank and two prototype solid rocket boosters. It was also equipped with engine nozzles, two of which were part of the flight hardware. Nozzle 2005 flew on the first five flights of Space Shuttle Columbia, and Nozzle 2020 was used on the fifth through ninth Challenger launches. (The third nozzle was a development unit.)
In February 2021, the rocket center began restoring Pathfinder and its Shuttle Plaza exhibit, funded in part by a $500,000 grant from Save America’s Treasures. The orbiter was lowered to the ground and stripped down to its original red fuselage while work began to repair and repaint the tank and boosters.
Pathfinder was restored to its original length – 37 metres from nose to tip of the vertical stabilizer – after being shortened for its display in Japan. Its frame was reinforced with cold-formed steel to accommodate 516 3D-printed panels, which in turn were painted to add the vehicle’s external detailing.
“It’s the perfect representation of our rich history,” Robinson said. “The 3D printed panels that now cover the orbiter combine that history with the technologies of today, creating a story we are proud to tell.”
Pathfinder was reattached to its external tank using eight 0.625 in (1.6 cm) bolts and nuts at the front and two 2.5 in (6.3 cm) bolts, nuts and washers at the rear. Teflon bearings were used at the rear mounts to facilitate movement. Thirty-two fasteners are required for each wing, while 80 are required for each of the engine nozzles.
Pathfinder’s lift was the last remaining piece needed to restore the rocket center’s “spaceline” after work was completed to repair, repaint and reposition the historic boosters in the center’s rocket park. Several months of work are still needed before Shuttle Plaza can reopen, with a grand opening tentatively planned for this fall.
