First pic from US’s secret space plane - as its TRUE purpose remains mystery

New photo shows the Earth hanging in space like a blue marble, snapped whilst the craft orbited hundreds of miles out in the black.

Camera was trained on our planet, so the picture reveals very little of the spacecraft itself.

X-37B is the smallest and lightest orbital spaceplane ever.

It is boosted into space by a rocket launch vehicle before detaching and landing on earth .