A White House panel of independent space experts have concluded that another NASA trip to the Moon isn't realistic.

The problem, apparently, is money. The panel estimates that another Moon landing would cost about $3bn a year beyond NASA's current budget, according to the Associated Press.

A plan to revisit the Moon before 2020 was proposed by then-President George W. Bush, five years ago. At the time, savings from retiring the space shuttles was the intended source of income.

But now, President Barack Obama's expert panel say any plans to go beyond low-Earth orbit are "not viable" with current spending, according to a summary report posted online yesterday.

NASA already has spent $7.7 billion on the reportedly abandoned Moon plan, including the design and construction of new rockets.

This will be good news for investors in NASA space memorabilia from the Apollo Moon landings - with collectors' items gaining more value through their uniqueness, rarity and historical significance.