NASA almost sent a mini motorbike to the moon instead of the familiar Apollo lunar buggy, it has been revealed.

Newly released images show a series of mini motorcycles being tested by astronauts in full spacesuits.

The secretive project was developed in case the Apollo buggy was not finished it time - but never made it to orbit.

NASA investigated several different modes of transporting astronauts across the lunar surface, including this commercially available Honda CT90 minibike, which was NASA's first attempt to see if bikes could be ridden in spacesuits.

MOONBIKE SPECS Initial tests used commercially available Honda CT90 minibikes Later versions used NASA's own design Electric machine boasted a 5/8ths horsepower motor Used a 30 amp-hour battery, believed to be the same system that Boeing and GM developed for the Lunar Rover Advertisement

The project began with commercially available Honda CT90 minibikes, which were NASA's first attempt to see if bikes could be ridden in spacesuits, with engineers donning Apollo suits to try and ride.

According to the book Apollo: The Lost and Forgotten Missions, several different modes of transporting astronauts across the lunar surface were evaluated for the Apollo programme.

NASA then built its own minibike for tests aboard zero gravity flights know as the 'vomit comet' to replicate lunar gravity.

The electric machine boasted a 5/8ths horsepower motor and a 30 amp-hour battery, believed to be the same system that Boeing and GM developed for the Lunar Rover.

Test were also performed in flying the KC-135 aircraft in parabolic curves to reproduce a 1/6 gravity environment in short 20-30-second bursts - the closet the bike got the the moon.

Engineers even built a test track with a hardness device that removes 5/6 of the rider's Earth weight and that of the bike, replicating conditions on the moon

According to AmeriSpace, a prototype was under development in 1969 for use on Apollo 15, and was a backup method in case the Lunar Roving Vehicle wasn’t ready in time for the mission’s launch.

'There was some talk about the mini bikes incorporated into later Apollo missions as well, ' the site claims.

However, the closest the mini-bike ever got to space was prototype tests in a 1/6th gravity environment in 1969 in NASA’s Vomit Comet.

With no atmosphere on the moon to absorb the heat of the lunar motorbike’s motor, NASA engineers took the unusual approach of turning to beeswax, according to an article in a 1972 issue of the American Motorcycle Association's magazine.

They filled pieces of the frame with it to act as a cooling jacket that would melt and absorb heat.

Once the wax got too hot, astronauts would just stop and wait for the wax to re-harden and set off again.

A suited engineer evaluates a lunar motorbike in Building 29 at NASA's Houston MSC.

David Gordon Wilson, a mechanical engineer from MIT, even lobbied for bicycles to be used.

He claimed human power was more than adequate for lunar exploration, and in a 1979 article in Time magazine, he advocated for a two-seated quadracycle that would have astronauts pedalling in tandem across the lunar surface.