Professor Jens Jordan, Director of the Institute of Aerospace Medicine
The Institute of Aerospace Medicine at the German Aerospace Center (DLR) comprises departments in Cologne and in Hamburg with internationally unique research infrastructure. At DLR, the Institute serves as interface between sophisticated technology and biology, medicine, and psychology. The research is conducted in close collaboration with leading national and international research institutions. The long-standing experience of the Institute in selecting and caring for pilots, air traffic controllers, and astronauts in particular directly after return to Earth provides a solid foundation guiding our research efforts. Systematic ground-based studies in radiation, astro- and gravitational biology are performed in the planetary and space simulation facilities of the Institute and are complemented by successful investigations in space over many years.
From biomedical and psychological research in space and in aeronautics to applications on Earth
In space and in aeronautics, human beings are exposed to extreme environmental stresses affecting wellbeing and performance. During prolonged manned space missions, these challenges jeopardize crew health as well as the success of the mission. Fainting and fall risk which can be easily managed after return to Earth could have catastrophic consequences on another celestial body. The primary goal of our research is to elucidate the underlying mechanisms and to develop diagnostic tests predicting psychological and medical risks early on. The mechanistic insight guides our efforts to develop targeted medical and psychological countermeasures.
Many of the challenges in space and in aeronautics are highly relevant for human beings on Earth. For example, in the absence of sufficient countermeasures, space travel replicates many of the physiological changes associated with ageing including loss of musculoskeletal function, cardiopulmonary fitness, coordination, and ocular health among others. Increased radiation exposure elicits premature ageing at the cellular level. For example, radiation damage to epithelial cells maintaining ocular lens fibers promotes cataract formation, a condition observed at an older age in people on Earth. The potential for radiation exposure during spaceflight to induce tumor formation, cardiovascular disease, and damage to critical structures in the central nervous system is an area that needs to be addressed to gauge risks of long-term missions in outer space. The repair mechanisms maintaining cell integrity after radiation exposure also mitigate damage elicited through other environmental challenges, making this research relevant for people on Earth.
Both, space travel and long distance flights over several time zones perturb circadian rhythms and sleep, which in addition to affecting health may limit human performance and promote critical errors. Insufficient duration and poor quality of sleep are also recognized as an increasing health risk on Earth. Indeed, short sleep duration has been linked with increased risk for cardiovascular and metabolic disease.
Another important research area is devoted to selecting individuals for highly demanding professions, including astronauts, pilots, and air traffic controllers. The goal is to identify individuals who will be able to cope with specific technological and interpersonal tasks. Demographic changes, particularly ageing populations, coupled with shortage of skilled workers, and increasing internationalization are challenges actively investigated in aerospace psychology with applications in many other professional areas. For example, we now apply the methodologies developed in aerospace psychology for selection of medical personal.
The need for unique scientific models on Earth
Our Institute has longstanding experience conducting research under space conditions. For example we assess cardiovascular and musculoskeletal function in astronauts and in cosmonauts on the Internationals Space Station. The biological research involves experiments on the International Space Station, on compact satellites, research rockets, and parabolic flights. However, the availability of astronauts and cosmonauts for biomedical and psychological research projects is limited. Procedures that are easy to conduct on Earth, such as blood drawing, pose major issues while in space. Furthermore, research equipment for space has to be specifically developed and certified and is difficult and expensive to transport. Mechanism-oriented research is also limited in operators of aircrafts albeit to a lesser degree. Therefore, biomedical research in space and in aeronautics has to be complemented by sophisticated simulations on Earth.
Therefore, our Institute developed internationally unique expertise and research infrastructure for human studies under highly controlled environmental conditions. Opening of the :envihab – the name is derived from environment and habitat – research facility in 2013 was a great leap in that direction. The goal was to enable highly standardized simulations of environmental factors in human beings. The environmental conditions covered by our research include atmosphere composition and pressure, gravitation, noise, light, radiation, nutrition, and the microbiome.
Bedrest studies in the head-down position – one of the workhorses in space medicine – are conducted in collaboration with international space agencies. The model produces fluid shifts in the body towards the head resembling changes observed in weightlessness. Much like astronauts, participants experience reductions in muscle and bone mass and physical performance. Through the head-down bedrest model, countermeasures can be tested on Earth before they are applied during space travel.
Isolation imposes major challenges to psychological health and could conceivably endanger space missions. Therefore, isolation experiments on Earth are actively pursued to better understand the psychological traits and interpersonal risk factors affecting the response of a crew to this condition. The :envihab is equipped to conduct sophisticated isolation experiments. Perhaps, crews more or less resilient to withstand isolation can be prospectively identified. Technology might aid in relieving the negative impact of isolation on astronauts.
The :envihab also hosts ESA astronauts directly after their return from the International Space Station to Earth.
High-Fidelity Human Phenotyping
Human experiments in space and in human models on Earth are necessarily conducted in relatively small samples. In contrast, clinical studies in terrestrial medicine may include hundreds or even thousands of patients. Therefore, we developed methodologies allowing for precise and comprehensive human investigations, so called high-fidelity human phenotyping. The engineering expertise at DLR allows for development of technologies that are not available off the shelf. The modular concept of :envihab enables research on various aspects of human physiology including sleep, circadian rhythms, bone and muscle physiology, microbiological and molecular biological research under highly controlled and variable environmental conditions. The combination of advanced human physiology profiling, state-of-the-art imaging modalities, and highly standardized simulation and manipulation of environmental conditions are particular strengths of our research.
Translation from cells to humans and back to cells
Our medical research in human beings is flanked by studies at the cellular level. For example, we study cellular responses to radiation damage with the goal to derive novel preventive measures. Similarly, we developed unique methodologies to investigate cellular responses to gravity. In particular, we are interested in how mechanical forces are sensed, transduced, and integrated at the cellular level. In addition to providing insight in fundamental biology, the research is relevant for human physiology and medicine. Indeed, cellular mechanotransduction affects cardiovascular and musculoskeletal structure and function among others.
