Extreme conditions

The suits only spent a few days on the moon, where temperatures oscillate between -150°C and 120°C.

But they have spent the rest of the four decades in some of the nation's most humid places, like Houston, Texas, home to the Johnson Space Center; Florida, where the Kennedy Space Center is located; or the museum in Washington, known for its sticky summers.

Lewis said that to preserve this part of history it is unlikely that the whole suits — topped with a helmet with its visor blackened by a layer of gold to protect it from ultra-violet light — will continue to be displayed.

"We won't display them as a suit any more, but we hope to have the component on display in five years" such as gloves or boots if technicians manage to halt the decay she said.

It depends on the funding, she added.

The lunar lander is also undergoing a make-over.

The four-footed module, which is seven meters high, is one of 12 constructed by NASA for the Apollo program which ended in 1972.

The one on display never went into space but is identical to the others which were left on the moon when the astronauts returned to Earth.

Along with the astronauts' footprints still imprinted on the lunar surface, the museum curators are anxious to conserve the site of the original moon landings, especially as NASA gears up for a return by 2020.

"This is an actual artifact," said Needell of the landing site at the moon's Sea of Tranquility.

"Let's hope the next ones won't put footprint over the old footprint at Tranquility Bay. I hope they will leave it alone," he said, worried that future generations of moonwalkers may try to remove pieces of history and sell them on eBay.

"It's not abandoned property, it belongs to NASA," he stressed.