stimulus-free environment of space in the absence of gravity-induced phenomena
such as sedimentation, buoyancy and convection.
Studies in microgravity opened new scientific perspectives and a new field of
experimentation. We are now able to bring an organism in a very new and unique
environment that it has not yet experienced before. What does this mean for the
organism? Does it cause stress when you take away an environmental cue that was
used for orientation? Does an organism experience less stress when a structure which
has been under tension is now relaxing or which might have sedimented on membranes will now float in the absence of gravity? What does a three-dimensional freefloating environment mean for a cell which has before been attached to a layer? What
is the effect of mechanical unloading with respect to function and differentiation?
How quickly will a biological system respond, will it adapt, what is the minimum
amount of gravitational acceleration necessary to initiate a gravity-related response?
Are there sensitive windows in development during which an organism is more
sensitive to changes of environmental parameters like gravity? In order to address
these fundamental questions which also bear—as we will see later—application
potentials, dedicated platforms for such research are needed.
Due to the presence of masses in our universe, it is impossible to achieve zero
gravity (real weightlessness). Even on the ISS circling Earth at an altitude of about
350 km, the level of gravity is only 8% less than on the Earth’s surface. It is the
velocity of the space station that creates a centrifugal force which exactly compensates the centrifugal force of the gravitational pull of the Earth that results in a freefall situation which we call microgravity (near weightlessness) due to some residual
acceleration forces in a range of 10
À2
–10
À6 g.
Limited access to space flight and high costs motivated developments to
achieve—to at least to some extent—microgravity conditions on ground. Today,
ground-based studies have great importance in gravitational space biology and
human physiology research. They increasingly contribute to our understanding of
how biological systems (from cells to humans) sense gravity and to study the
consequences when the influence of this fundamental force is lacking, to study the
impact on health and signaling cascades, but also to study adaption mechanisms to
this new environmental condition. In this chapter, we give an overview of available
ground-based microgravity simulators and platforms providing increased gravity
levels, rounded up by a comprehensive summary of platforms enabling unique
experimentation in real microgravity. We will focus on the underlying principles,
boundary conditions and the experimental possibilities.
2.2 Microgravity Simulators—Efforts to Mimic the Effects
of Weightlessness
2D, 3D, fast and slow rotating clinostats, rotating wall vessel, magnetic levitator,
Random Positioning Machine—if you are looking for devices in order to mimic the
effects of weightlessness on ground you will find a catalogue of possibilities. How
14
2 Methods for Gravitational Biology Research
such as sedimentation, buoyancy and convection.
Studies in microgravity opened new scientific perspectives and a new field of
experimentation. We are now able to bring an organism in a very new and unique
environment that it has not yet experienced before. What does this mean for the
organism? Does it cause stress when you take away an environmental cue that was
used for orientation? Does an organism experience less stress when a structure which
has been under tension is now relaxing or which might have sedimented on membranes will now float in the absence of gravity? What does a three-dimensional freefloating environment mean for a cell which has before been attached to a layer? What
is the effect of mechanical unloading with respect to function and differentiation?
How quickly will a biological system respond, will it adapt, what is the minimum
amount of gravitational acceleration necessary to initiate a gravity-related response?
Are there sensitive windows in development during which an organism is more
sensitive to changes of environmental parameters like gravity? In order to address
these fundamental questions which also bear—as we will see later—application
potentials, dedicated platforms for such research are needed.
Due to the presence of masses in our universe, it is impossible to achieve zero
gravity (real weightlessness). Even on the ISS circling Earth at an altitude of about
350 km, the level of gravity is only 8% less than on the Earth’s surface. It is the
velocity of the space station that creates a centrifugal force which exactly compensates the centrifugal force of the gravitational pull of the Earth that results in a freefall situation which we call microgravity (near weightlessness) due to some residual
acceleration forces in a range of 10
À2
–10
À6 g.
Limited access to space flight and high costs motivated developments to
achieve—to at least to some extent—microgravity conditions on ground. Today,
ground-based studies have great importance in gravitational space biology and
human physiology research. They increasingly contribute to our understanding of
how biological systems (from cells to humans) sense gravity and to study the
consequences when the influence of this fundamental force is lacking, to study the
impact on health and signaling cascades, but also to study adaption mechanisms to
this new environmental condition. In this chapter, we give an overview of available
ground-based microgravity simulators and platforms providing increased gravity
levels, rounded up by a comprehensive summary of platforms enabling unique
experimentation in real microgravity. We will focus on the underlying principles,
boundary conditions and the experimental possibilities.
2.2 Microgravity Simulators—Efforts to Mimic the Effects
of Weightlessness
2D, 3D, fast and slow rotating clinostats, rotating wall vessel, magnetic levitator,
Random Positioning Machine—if you are looking for devices in order to mimic the
effects of weightlessness on ground you will find a catalogue of possibilities. How
14
2 Methods for Gravitational Biology Research