SYDNEY - It was like a scene from the Pixar movie "Up" except instead of a house, it was a person attached to a platform.

On Sunday (Sept 3), British-Viennese live performance artist Noemi Lakmaier suspended herself from 20,000 coloured helium balloons.

She floated for nine hours in the largest venue in the Sydney Opera House, the Concert Hall.

It was for her live installation Cherophobia, part of Antidote, a festival that celebrates ideas, art and action in society.

Cherophobia refers to a fear of happiness.

The Antidote website said the installation aimed to let everyone in the audience, whether he or she was there for the entire time or just for a short period, shares in a sense of suspense and anticipation, as they waited to see if and how she would float with the balloons.

"It's about the process, the anticipation, the wonder and unknowingness of if anything will happen," Lakmaier was quoted by ABC News as saying.

The concept originated from her own experience with disability.

"We're all supposed to want to be happy, aren't we?" said the wheelchair-bound artist.

"Being frightened of what we want seems to push and pull, and leave us in a constant Catch-22, which sounds so uncomfortable, but in so many ways resonates with the fight between my body and the balloons," she added.

According to ABC News, the performance required 6km of rope. The performance uses balloon-grade helium, a low-grade and less pure form of helium.