OPEN ZARM: The Bremen Drop Tower Opens its Doors to the Public

An impressive 10,000 experiments in weightlessness have been carried out at the Bremen Drop Tower. To celebrate this achievement, the Center of Applied Space Technology and Microgravity (ZARM) at the University of Bremen is hosting an Open Day on February 11, 2024.

At OPEN ZARM, everyone is invited to explore not only the Drop Tower, but also the GraviTower Bremen Pro, the new laboratory for research in weightlessness. ZARM scientists will present their research and explain, among other things, what a house on Mars might look like, how it would be supplied with oxygen, and why it is so difficult to create a gas station in space. Admission is free.

For the first time, the public will have access to more than just the Drop Tower’s hall: In the main building, the microgravity laboratories and the control center will be presented and the setup of individual experiments in the drop capsules will be explained. In the second part of the building, visitors can admire a scale model of a research laboratory on Mars and learn how satellites are maneuvered in space. If you want to finally understand what makes black holes so special, this is the place to be. There is also a children's program with the opportunity to take an astronaut training course. For students and young space enthusiasts in particular, information about degrees and outreach programs will be provided. Finally, for those who want to book a tour of the Drop Tower or even get married at the top: we will be ready to answer all of your questions.

The World's Most Used Microgravity Laboratory

10,000 successful experiments prove that ZARM has been creating highly professional conditions for research in microgravity for more than 30 years. ZARM director Professor Marc Avila points out: “With the 10,000th experiment, we have reached a milestone that we are very happy about. This success is not only the result of outstanding technology, but also reflects the commitment and expertise of our team.” The Drop Tower allows scientists from around the world to conduct research in microgravity without the costly and time-consuming use of rockets or satellites. “We are proud to make our laboratories accessible to the international scientific community, enabling groundbreaking discoveries and helping to shape the future of space exploration," explains Avila.

The 10,000th experiment in the Drop Tower is an artificial photosynthesis experiment by ZARM scientist Dr. Katharina Brinkert, whose research project is funded by the German Aerospace Center (DLR). The experiment examines how magnetism can be used to separate oxygen bubbles from water in weightlessness. Brinkert is one of many scientists who regularly use the Bremen Drop Tower for their research. In 2016, she conducted her first experiment in the Drop Tower as part of a research stay at the European Space Agency. In 2021 she joined ZARM, where she is working on a device that is superior in many ways to existing life-support systems, implementing artificial photosynthesis. “How can oxygen, hydrogen, and other chemicals be produced sustainably in microgravity, and how can we benefit from this here on Earth? These are key questions to us,” says Brinkert.

Oxygen for Survival in Space

The challenges of a long-duration space mission are numerous, and not just in terms of building a high-performance spacecraft. A significant part of exploration research is working on the development of reliable, efficient, and sustainable life support systems. Space lacks almost everything that humans need to survive and take for granted on Earth. One could try to bring enough oxygen, energy, and food, which is needed for survival from Earth, but the energy and transportation costs increase significantly with every ounce that has to be carried.

Current systems, such as the one on the ISS, produce oxygen using a water electrolyzer that is powered by electricity generated by solar panels. This consumes about a third of the total energy used by the life-support and control systems. These devices are very large, heavy, and prone to failure. ZARM is now investigating photoelectrochemical (PEC) devices that can produce oxygen through artificial photosynthesis using direct sunlight. This saves energy. The devices are also smaller and lighter, and their design takes into account the fact that components can be produced locally in an emergency, for example from Martian soil. In addition to oxygen, they can produce hydrogen, fuels, fertilizers, medicines, and other chemicals – ideal for use in space.

Sustainable Hydrogen Production on Earth

Although Brinkert's team is developing PEC devices primarily for space missions, they can also be used on Earth for the new green energy transition – and even more easily than in microgravity. “It is clear that preparations for space missions and the green energy transition on Earth face similar challenges: we need to produce fuels more sustainably and use them more efficiently,” states Brinkert.

The conditions under which the devices must operate vary greatly depending on where they are used. On the Moon, solar radiation is much stronger due to its proximity to the Sun. On Mars, additional devices are needed to concentrate the solar radiation in order to operate the PEC systems efficiently. In a current Nature Communications article, Brinkert's team presents the first-ever framework for evaluating the efficiency of PEC devices at different locations in space.