In June 2015 , the Smithsonian made public a report which documented the need for extensive renovations to the Air and Space Museum . Many of the building 's mechanical and environmental systems were redesigned during its construction from 1972 to 1976 , which left them inadequate to handle the environmental , visitor , and other stresses placed on the building and its exhibits . Subsequently , these systems are in serious disrepair and exhibits are being harmed . The report noted that the HVAC system is close to failure , and the roof has been compromised so badly that it must be replaced . The Tennessee marble façade has cracked and become warped , and in some areas is so damaged it could fall off the building . The museum 's glass curtain walls ( among those elements of the 1976 structure whose design was altered for cost reasons ) are too permeable to ultraviolet radiation . Several exhibits ( such as the spacesuit worn by John Young during the Gemini 10 mission , and the coating on the '' Spirit of St. Louis '' aircraft ) have been damaged by this radiation . Additionally , the Smithsonian 's report noted that cutbacks in building design prior to and during construction left the museum with too few amenities , main entrances which are partially obscured , and exhibit space which does not meet current ADA accessibility standards . New security measures , required after the September 11 attacks in 2001 , have created extensive queues which extend outside the building . Exposed , lengthy queues are both a security hazard and often cause visitors to wait in inclement weather
September 11 attacks
September 11 attacks
National Air and Space Museum