The museum is undertaking a conservation analysis of the blimp after it took to the skies above Parliament Square during protests over Mr Trump’s state visit to the UK in June 2019.
The blimp was donated to the museum in January 2021 and experts have inflated it to check if it is structurally sound, how long it holds air, and to make any small repairs.
The test was also part of a longer process for the museum’s plan of long-term preservation and any future display for the blimp.
It is hoped that it will go on show at the Museum of London’s new home in West Smithfield, which is due to open in 2026.
“It is always a challenge to preserve objects that are meant to be short-lived, like the Trump blimp,” a Museum of London representative said.
“It was made to be flown over Parliament Square during then-president Trump’s visit to London in 2019 — a quick, flexible and visible icon, as opposed to the permanent statues in Parliament Square made from much more durable materials.
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“We have worked together with scientists at University College London and the University of Ljubljana, Slovenia, to analyse the composition of the plastic.
"The blimp is made from PVC material. It is soft and flexible and very thin, much like a giant beach ball.
“Plastics age and break down in sometimes unexpected ways, so this will help us establish how we can best preserve it in the long-term as part of our collection.”
The inflation is the final test as the balloon joins other pieces in the museum’s protest collection.
They include objects relating to the suffrage movement, and banners, flags and placards from protests for more accessible public transport.