Fallturm Bremen

The Bremen Drop Tower is a unique scientific facility on the grounds of the University of Bremen, completed in 1990. It is operated by the Center of Applied Space Technology and Microgravity and makes it possible to conduct ground-based experiments under brief weightlessness. The structure consists of a cylindrical reinforced-concrete shaft with a conical tip, inside of which runs a 120-meter-tall evacuated drop tube. This tube is a freestanding steel structure, decoupled from the sway of the outer shell to minimize vibrations. For the experiments, 18 pumps bring the tube down to a very low residual pressure, which produces an extremely high quality of weightlessness, one that even surpasses that of crewed orbital platforms.

Inside, a capsule, whose size varies depending on the experiment, falls into a catch container filled with small expanded polystyrene beads. As a standard, the drop time is just under five seconds, with the capsule plunging into a container 8 meters deep. Since a catapult was installed in 2004, however, this time can be extended to more than nine seconds. The catapult sits in a shaft beneath the tower and uses compressed air to accelerate the capsule to a high speed before it falls back into weightlessness. To date, more than ten thousand experiments have been carried out at this facility in fields such as fluid mechanics, materials research, and biology, including the achievement of a record temperature for a Bose-Einstein condensate.

Beyond its scientific use, the tower also has cultural and social dimensions. At the top of the structure are a conference room and a panorama lounge, which can be rented for events such as weddings. The underground catapult chamber is also a place of art: its walls were painted in 1992 by the German artist A. R. Penck and his Irish colleague Felim Egan. The work, which recalls the Creation of Adam, is now accessible only to scientific staff, since the room primarily serves research. The Drop Tower thus stands not only for technological excellence, but also for the union of science, art, and public use in Bremen.