Moffett Field's "Hangar One" (built during the Depression era for the USS Macon) and the row of World War II blimp hangars are still some of the largest unsupported structures in the country.
The airship hangar is constructed on a network of steel girders sheathed with galvanized steel.
It rests firmly upon a reinforced pad anchored to concrete pilings.
The floor covers eight acres (32,000 m²) and can accommodate Six (6) (360 feet x 160 feet) football fields.
The airship hangar itself, measures 1,133 feet (345 m) long and 308 feet (94 m) wide.
The building has aerodynamic architecture.
Its walls curve upward and inward, to form an elongated dome 198 feet (60 m) high.
The clam-shell doors were designed to reduce turbulence when the Macon moved in and out on windy days.
The "orange peel" doors, weighing 500 tons (511.88 tonnes) each, are moved by their own 150 horsepower motors operated via an electrical control panel.

The airship hangar's interior is so large that fog sometimes forms near the ceiling.
A person unaccustomed to its vastness is susceptible to optical disorientation.
Looking across its deck, planes and tractors look like toys.
Along its length maintenance shops, inspection laboratories and offices help keep the hangar busy.
Looking up, a network of catwalks for access to all parts of the structure can be seen.
Two elevators meet near the top, allowing maintenance personnel to get to the top quickly and easily.

Narrow gauge tracks run through the length of the hangar.
During the period of lighter-than-air dirigibles and non-rigid aircraft, the rails extended across the apron and into the fields at each end of the hangar.
This tramway facilitated the transportation of an airship on the mooring mast to the airship hangar interior or to the flight position.
During the brief period that the Macon was based at Moffett, Hangar One accommodated not only the giant airship but several smaller non-rigid lighter-than-air craft simultaneously.

In 2003 plans to convert Hangar One to a space and science center were put on hold with the discovery that the structure was leaking toxic chemicals into the sediment in wetlands bordering San Francisco Bay.
The chemicals originated in the lead paint and toxic materials, including polychlorinated biphenyls (PCBs), used to coat the hangar.
Options under debate included tearing down the hangar and reusing the land, and cleaning the toxic waste from the site and refurbishing the hangar for future preservation.

The US Navy evaluated options for remediating the PCBs, lead and asbestos, and NASA evaluated options for reuse of the hangar.
Some historic and nonprofit groups wanted the hangar preserved as a historic landmark, as the hangar is a major Bay Area landmark and historic site.

In 2006, an offer to clean the hangar and coat its outsides with solar panels to recoup the costs of cleaning was floated by a private company, but the plan never saw fruition because it was too costly.

In August 2008, the Navy proposed simply stripping the toxic coating from the hangar and leaving the skeleton after spraying it with a preservative.
The Navy claimed that to reclad the structure would cost another $15 million and that this was NASA's responsibility.
This was regarded as a partial victory by campaigners.

In September 2008, NASA indicated that it was still urging the Navy to restore the hangar, but that it was willing to help save the structure; in particular, NASA was in favor of re-covering the structure at the same time that it was stripped.

 In April 2011, the exterior panels began coming down, starting at the top.
Moffett Field's "Hangar One" (built during the Depression era for the USS Macon) and the row of World War II blimp hangars are still some of the largest unsupported structures in the country. The airship hangar is constructed on a network of steel girders sheathed with galvanized steel. It rests firmly upon a reinforced pad anchored to concrete pilings. The floor covers eight acres (32,000 m²) and can accommodate Six (6) (360 feet x 160 feet) football fields. The airship hangar itself, measures 1,133 feet (345 m) long and 308 feet (94 m) wide. The building has aerodynamic architecture. Its walls curve upward and inward, to form an elongated dome 198 feet (60 m) high. The clam-shell doors were designed to reduce turbulence when the Macon moved in and out on windy days. The "orange peel" doors, weighing 500 tons (511.88 tonnes) each, are moved by their own 150 horsepower motors operated via an electrical control panel.
The airship hangar's interior is so large that fog sometimes forms near the ceiling. A person unaccustomed to its vastness is susceptible to optical disorientation. Looking across its deck, planes and tractors look like toys. Along its length maintenance shops, inspection laboratories and offices help keep the hangar busy. Looking up, a network of catwalks for access to all parts of the structure can be seen. Two elevators meet near the top, allowing maintenance personnel to get to the top quickly and easily.
Narrow gauge tracks run through the length of the hangar. During the period of lighter-than-air dirigibles and non-rigid aircraft, the rails extended across the apron and into the fields at each end of the hangar. This tramway facilitated the transportation of an airship on the mooring mast to the airship hangar interior or to the flight position. During the brief period that the Macon was based at Moffett, Hangar One accommodated not only the giant airship but several smaller non-rigid lighter-than-air craft simultaneously.
In 2003 plans to convert Hangar One to a space and science center were put on hold with the discovery that the structure was leaking toxic chemicals into the sediment in wetlands bordering San Francisco Bay. The chemicals originated in the lead paint and toxic materials, including polychlorinated biphenyls (PCBs), used to coat the hangar. Options under debate included tearing down the hangar and reusing the land, and cleaning the toxic waste from the site and refurbishing the hangar for future preservation.
The US Navy evaluated options for remediating the PCBs, lead and asbestos, and NASA evaluated options for reuse of the hangar. Some historic and nonprofit groups wanted the hangar preserved as a historic landmark, as the hangar is a major Bay Area landmark and historic site.
In 2006, an offer to clean the hangar and coat its outsides with solar panels to recoup the costs of cleaning was floated by a private company, but the plan never saw fruition because it was too costly.
In August 2008, the Navy proposed simply stripping the toxic coating from the hangar and leaving the skeleton after spraying it with a preservative. The Navy claimed that to reclad the structure would cost another $15 million and that this was NASA's responsibility. This was regarded as a partial victory by campaigners.
In September 2008, NASA indicated that it was still urging the Navy to restore the hangar, but that it was willing to help save the structure; in particular, NASA was in favor of re-covering the structure at the same time that it was stripped.
 In April 2011, the exterior panels began coming down, starting at the top.
Moffett Federal Airfield