The children, aged between seven and 10, launched the camera on a weather balloon on Saturday after six months of research.

Nathan and Riley Duff, Gabriel and Jessica de Jong, Julian and Sebastien Neser, and Daniel and Alexandra Wohlfahrt did all their own marketing and secured sponsorship for their project.

"Daniel saw two magicians [on television] launch a camera into space using a balloon and he told us about it," said Gabriel.

"We were immediately fascinated by the idea and wanted to do the same."

Nathan said they wanted to get a picture of the Earth from the verge of space.

"We wanted to see if we could do it," he said.

The children, who called themselves the "Space Explorers", approached the weather service and asked it to donate two weather balloons.

They also convinced an electronics company in Brooklyn Mall, in Pretoria, to sponsor a digital camera and another compan y sponsored a GPS tracking device .

The camera was placed inside a container made of polystyrene to protect the equipment through the flight.

The Gauteng managing director of the weather service, Rudzani Malala, said: "We send two weather balloons into space daily to monitor the weather system. We have never done it with a camera attached, which is why we could not refuse the children this opportunity."

The balloon was filled with hydrogen and launched at 11.27am from the Irene weather station, east of Pretoria. It reached 11753m.

It landed on a farm near Bronkhorstspruit, about 50km away, at 1.48pm.

Daniel's father, Oscar, said that though moisture collected on the lens as the camera ascended it nevertheless captured some spectacular views.

"The camera went through clouds and moisture accumulated on the lens, which froze at higher altitudes.

"But you get to see the thin layer of the atmosphere and the darkness of outer space."

Oscar assisted the children with the maths needed to calculate the highest altitude of the balloon during the weekend.

"They are very excited and do not want to give it away. They are taking the problem to their schools so that the other pupils can work it out for themselves," he said.

The children will give a presentation explaining their experiment at their schools - Pretoria Preparatory School and Waterkloof Primary - today.

Waterkloof Primary principal Buks van Niekerk said: "They will get to see that rewards and recognition can come from applying one's mind in maths and science."