The new NASA Administrator James Frederick – 'Jim' Bridenstine – visited the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) on 5 October 2018. While at DLR's headquarters in Cologne, he took the opportunity to learn more about the pioneering projects for space exploration. The NASA Administrator was accompanied by the DLR Executive Board Members for Space Research and Technology, Hansjörg Dittus, and for the Space Administration, Walther Pelzer.
The Moon continues to be a captivating destination for space travel – even almost 50 years after the first lunar landing, and 46 since a human being last set foot on Earth's satellite. A large number of research projects are investigating how a permanent, crewed base could be built on the Moon.
Given this interest, Jim Bridenstine shared some thoughts on future collaborative projects with his German partners. The US delegation was particularly interested in current DLR projects that aim to resolve specific issues that would enable long-term space missions. "NASA and DLR already look back on a long and fruitful partnership. Spaceflight depends on international cooperation, and I am particularly pleased when we can invest our expertise in such important projects," said Professor Dittus, DLR Executive Board Member for Space Research and Technology.
"We are honoured to welcome the new NASA Administrator Jim Bridenstine here at our headquarters. This year is NASA's 60th anniversary. This organisation has been among our most important partners for many years. Our cooperation is particularly beneficial on the ISS: just recently, on 3 October, the German ESA astronaut Alexander Gerst took over the role of ISS commander from his United States colleague Drew Feustel. This is yet another indication of the increasing international respect for Germany's contributions to the aerospace sector, whose results will ultimately benefit industry and society at large.
"One of the main focuses of the discussions with Jim Bridenstine was how to open up the International Space Station for broader uses," said Walther Pelzer, DLR Executive Board Member responsible for the Space Administration.
The director of the DLR Institute of Aerospace Medicine, Jens Jordan, presented studies and applied research on how to keep astronauts healthy. Long periods of time spent in a microgravity environment cause specific reactions in the organs of the human body, such as the loss of muscle mass and bone density. Two hours of gym work per day is currently the only way for astronauts to counteract these detrimental effects. But that is laborious and expensive. This has prompted the Institute to explore new training methods, including the use of artificial gravity generated by a short-arm centrifuge.
Astronauts can experience cardiovascular problems due to their exposure to microgravity and may even suffer an increase in intracranial pressure caused by the permanent displacement of fluids towards the head. Combined with changes in the concentration of CO2 in the cabin's atmosphere, this can have negative effects on blood flow and eyesight. This is why the DLR institute is involved in specific simulation studies and is generating new findings that will also help to improve prognostics for the surgical treatment of traumatic brain injuries on Earth, as dynamic changes in intracranial pressure are often used as a prognosis criterion in the assessment of head injuries.
Sustainability in space and on Earth
The careful use of resources and recycling of products are important factors in space as well as on Earth. The optimal deployment of expensive resources transported specifically into space is a crucial factor for astronauts, and one that will determine the success of long-term missions to the Moon or even Mars. This also includes the treatment of solid and liquid waste, as well as the cultivation of food. The C.R.O.P. project is designed specifically to investigate these issues. It uses a bio-filter system to obtain a fertiliser solution from organic waste and urine that can be used directly for plant cultivation. The technology is already used in pilot projects in the agricultural sector and will be dispatched into space with the satellite mission Eu:CROPIS in late 2018. Initial tests on plant growth in a reduced gravity environment in space will yield innovative opportunities for more efficient and sustainable life support systems and food production in space or on other celestial bodies.
Sustainable construction was also the focus of the next stop on the tour of the DLR site. At the DLR Institute of Solar Research solar furnace, Jim Bridenstine learned how building blocks for a Moon base can be constructed using concentrated solar radiation and Moon dust. The Regolight project aims to develop a technology that uses concentrated sunlight and a sintering process to transform lunar dust into a kind of brick. This construction material could then be used to build a Moon base that is permanently protected from radiation and impacts, without having to transport vast quantities of building blocks from the Earth.
Protection from harmful cosmic radiation is also a vital factor in NASA’s envisaged missions to the Moon and to Mars. A cooperation already exists that will test the effectiveness of a complex radiation dosimeter developed by DLR in the shape of a humanoid torso (MATROSHKA), which will be fitted on board NASA space vehicles on their return from the Moon. There are hopes that these tests will also yield insight into occupational-medical issues and help in the development of suitable prophylactic measures.
The final topic on the agenda during the visit by the US guest was a Mars landing. Ali Gülhan, Head of Supersonic and Hypersonic Technology at DLR, presented his department's work in this field. Landing a space vehicle on a planet with an atmosphere comes with certain risks. The first is the emergence of high temperatures, caused by friction during atmospheric entry. Dust and sand particles present an additional hazard for missions to Mars, as they increase the abrasion of heat shield materials. In its research, the DLR site in Cologne uses an electric arc-heated wind tunnel – the only system in the world that is able to create a realistic simulation of the relevant conditions that prevail on entry into the Martian atmosphere.
The researchers around Gülhan have also developed instruments that allow the acquisition and wireless transmission of data during the crucial phase of entry into the atmosphere. This technology was already successfully demonstrated during the ExoMars mission back in 2016.
NASA Administrator Jim Bridenstine was thrilled by the DLR technologies and research projects and emphasised their importance for the achievement of the defined milestones in space exploration.