Have you spotted a weather balloon that may have crash-landed in Kimpton?

Robert Oxford-Pope spent a year constructing a fully-functioning weather balloon and obtaining permissions to release it from Cambridge.

The 18-year-old wanted to take footage of the curvature of the Earth and stable videos of the sunrise.

Using helium and a parachute, Robert sent the balloon 29,000m up into the stratosphere on Tuesday last week, following in a car to track its trajectory.

But Robert and his dad, Steve Pope, lost track of the craft while it was descending over Letchworth.

Using a flight path simulator, Robert and Steve believe the balloon to have crashed somewhere around Kimpton.

It has a blue and gold parachute with stringed lights attached to a shoebox-sized container covered in tinfoil.

Steve said: “Basically the video is taking footage of the sunrise and the curvature of the Earth and he put a lot of work into making sure the footage was stable.

“He would be thrilled to get it back because he was terribly disappointed when we lost it.”

The balloon works by expanding as the air pressure thins, enlarging about 5m per second, before eventually bursting and parachuting down to Earth.

Robert had permission from the Civil Aviation Authority to launch the flight.

He had conducted a similar experiment last year, but found the footage to be jerky and therefore worked to stabilise the footage this time around.

“The longer it takes before it gets recovered the more likely it will have degraded,” Steve added.

Robert has been fascinated with flight and the atmosphere since he was a child, and is going to Southampton University to study Aeronautical Engineering after gap year travels to Asia.

In March last year Sandringham School in St Albans tried a similar experiment with a balloon called Hwoyee 500. However, the students miscalculated, filled it with too little helium, and lost it 2km off the coast of Felixstowe.

Anyone who finds the balloon should contact Steve on 07976602489.