Two pieces of NASA mission hardware, a testing replica of the James Webb Space Telescope's Optical Telescope Element Pathfinder and a full-scale model of the Parker Solar Probe, are now on permanent display at the Smithsonian's National Air and Space Museum, Steven F. Udvar-Hazy Center in Chantilly, Virginia. The items, transferred by NASA, are located in the James S. McDonnell Space Hangar.
James Webb Space Telescope Optical Telescope Element Pathfinder
The Webb's Optical Telescope Element Pathfinder is a high-fidelity engineering model that served as the primary test article for the actual James Webb Space Telescope. Standing over 21 feet tall with a secondary mirror assembly that can extend to more than 26 feet when fully deployed, it represents the largest intact mirror support structure of its kind. This pathfinder was essential for testing the spacecraft's complex systems due to the telescope's extensive size and precision requirements.
Standing over 21 feet tall with a secondary mirror assembly that can extend to more than 26 feet when fully deployed, it represents the largest intact mirror support structure of its kind.
The actual James Webb Space Telescope, launched on December 25, 2021, is an international program led by NASA with partners ESA and CSA. It functions as a space science observatory designed to collect infrared light for studying astronomical objects such as distant galaxies, exoplanet atmospheres, and new stars, and exploring the origins of the universe. Due to its orbital distance of approximately 1 million miles from Earth, physical maintenance or updates are not feasible. Consequently, test hardware like the Pathfinder is the only material from the Webb mission available for public collections.
The test structure assisted engineers in preparing the telescope and now allows visitors to observe its scale.
Parker Solar Probe Replica
A full-scale model of NASA's Parker Solar Probe has also been added to the museum's collection. Built and operated at the Johns Hopkins Applied Physics Laboratory (APL), the actual Parker Solar Probe is designed to study solar wind, which consists of charged particles emitted from the Sun's outer atmosphere, the corona. Launched in August 2018, the probe has completed 27 close approaches to the Sun, traveling as close as 3.8 million miles from the solar surface at speeds of 430,000 mph, and continues to collect data.
It is unique for entering the corona to directly sample particles and measure the magnetic field from within the Sun's atmosphere.
The museum's replica, measuring 10 feet high, 21.5 feet long, and 8.5 feet wide, was constructed in 2024 primarily using space-grade parts and backups, including the heat shield, the WISPR camera, and the solar array cooling system. It provides insight into the technology enabling the spacecraft to operate and collect data from the Sun's extreme environment. The Parker Solar Probe is part of NASA's Living With a Star (LWS) program, managed by Goddard Space Flight Center, with Johns Hopkins APL managing, designing, building, and operating the mission.
It provides insight into the technology enabling the spacecraft to operate and collect data from the Sun's extreme environment.