DLR-NASA bed-rest study – Functional Performance Test
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DLR-NASA bed-rest study – Functional Performance Test
Object Translation Test
Three objects of varying weight – representing equipment or supplies – must be carried as quickly as possible from point A to point B and back again. A combination of strength, endurance and tactical movement is crucial for efficiently performing tasks in a habitat or when working outdoors.
In this blog series on the second campaign of NASA's sensorimotor countermeasures (SMC) bed-rest study, researchers from the DLR Institute of Aerospace Medicine present the key experiments and people behind them, showing how they develop measures to prepare humans for safe space exploration – while also advancing medical care here on Earth.
Since the beginning of May 2025, a new phase of the DLR-NASA bed-rest study has been underway at the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR). Twelve participants – eight men and four women – are taking on the challenge of spending 60 days in a 6-degree head-down position, around the clock. In this position, body fluids flow towards the head and muscle mass and bone density decrease – simulating the experience of astronauts in space. The aim is to record the physiological changes that occur in microgravity conditions and to test effective countermeasures. For scientists and researchers in space medicine, this model provides reliable data on long-term changes in the human body.
How does physical performance change as a result of bed rest?
The current study focuses on two questions: How well can astronauts move after a prolonged stay in microgravity, when arriving on foreign planets or upon their return to Earth? And, what problems, particularly in terms of balance and coordination, need to be anticipated and addressed? This is exactly where the 'Functional Performance Test' comes in – a course of movements completed by the participants before and immediately after the 60-day bed-rest period. This provides a targeted assessment of how physical performance has changed as a result of bed rest and whether the training and therapy approaches tested are effective in counteracting its negative effects. The Functional Performance Test consists of four standardised tasks that simulate the real-life demands placed on astronauts after long space flights:
Obstacle Course Test
The obstacle course includes various coordinated movements to test basic mobility and coordination.
The Obstacle Course Test: Participants complete a course including various forms of coordinated movement. These include slalom running, rapid changes of direction, climbing over and crawling under obstacles and walking sideways. This test assesses basic mobility and coordination under conditions similar to those encountered when passing through narrow module structures in a spacecraft or space station, or when navigating the rough terrain of a planet's surface. Next, it's the …
Jump Down Test
From a standing position, participants jump from a small platform and must land as quietly and stably as possible. This movement places high demands on muscle strength, balance and neuromuscular control – skills that can be severely impaired after a prolonged period without gravity.
Jump Down Test: From a standing position, participants jump from a small platform and must land as quietly and stably as possible. This movement places high demands on muscle strength, balance and neuromuscular control – skills that can be severely impaired after a prolonged period without gravity.
Object Translation Test: Here, three objects of varying weight, representing equipment or supplies, must be carried as quickly as possible from point A to point B and back again. A combination of strength, endurance and tactical movement is crucial for efficiently performing tasks in a habitat or when working outdoors.
Recovery from Fall Test
This test assesses the ability to regain a stable position independently after a fall – an essential safety requirement for any space mission.
Recovery From Fall Test: Participants begin the test lying on their stomachs and, after two minutes in this position, must get up as quickly as possible. They must then stand as still as possible for 30 seconds. This test assesses the ability to regain a stable position independently after a fall – an essential safety requirement for any mission.
These four tasks assess at a functional level whether astronauts would be able to continue their work safely and efficiently after spaceflight – or, in this case, after a spaceflight simulated by 60 days of bed rest. Comparing the test results before and after bed rest shows whether the countermeasures taken can sufficiently mitigate muscle loss, loss of coordination or circulatory problems.
DLR researchers and international colleagues will use these findings to better prepare for future space missions. This is no longer just about returning to Earth after a mission in space, but increasingly about long-term stays on the Moon or Mars.
