In order to prevent astronauts from losing a sense of feeling grounded, we propose an apparatus to install in the space shuttle that will simulate the feeling of gravity. When humans observe dropping objects, they too, feel like they are under the influence of gravity. Thus, our apparatus creates the visual stimulus of a dropping ball to help astronauts feel closer to their natural environment on Earth and more accustomed to life in space. This illusion not only confirms the signals that tell the body which direction is downwards but also prevents astronauts from developing Space Adaptation Syndrome.
To combat this problem of weightlessness in space, which restricts the amount of time that astronauts can conduct space exploration, we decided to create a device that would portray the feeling of being grounded to the floor, and give astronauts the physical illusion of being pulled by gravity. This device, which has its roots embedded in inspiration from Galileo’s water clock, resembles a thin, long, continuous rectangular tube, which guides the ball in a constant pathway along the four sides.
Our contraption will create a continuous dropping motion with the help of some balls and the properties of cohesion and adhesion of pure water. Water, which has great cohesion, tends to stick to itself, especially when there is no gravity. In a zero gravity environment, water molecules form water bubbles that float in air. To avoid this problem, we used tubes made of material that have great adhesion to water; the water’s adhesion to the surface of the tubes is greater than the water’s cohesion to itself. This way, the water molecules will stick to the interiors of the tubes, forming a frictionless coating of water for the semiconductor balls to slide down. To facilitate the adhesion of the water to the interior wall of the tube, the device will have small magnetic studs attached to the outer wall, so that the water will be sure to adhere to the interior in case the adhesive wall is not strong enough. Water, being a paramagnetic molecule, meaning that it can be magnetized when a magnet is placed next to it, should be able to stick to the interior of the tube.
The two balls are constructed in special composition similar to structure of a solar panel to store energy from sunlight. The two halves of each ball are constructed with extrinsic semiconductor, one with p-type semiconductor, and the other with n-type semiconductor. The two halves of the ball are isolated by the insulator in the middle to prevent the transfer of electrons between two halves of the ball. In this case, we select silicon to be our semiconductor because it is nearly an insulator with really high resistance and allowing small amount of electricity to flow through it. The p-type silicon has four valence electrons while the n-type only has three. When light shines on the p-type silicon, the photon from the light collides with one of the valence electrons of the p-type silicon, allowing it to travel to the other side of the ball, the n-type silicon.
In order for the electron to flow to the other side of the ball, it requires a mean of transmission due to the insulator in the middle separating the two halves. Therefore, the water inside the tube absorbs the energy from the transferring of electrons and directs it to two sides of the tube with the electrolytes inside composition of water. The two sides of the tube are each covered with catalysts that produce hydrogen and oxygen. In this case, we use compounds, hydrogenase and oxygenase, which produce hydrogen and oxygen when receiving energy.
The process of receiving energy from sunlight to produce hydrogen and oxygen allows us to compare this model to the light reaction of photosynthesis. In the light reaction of photosynthesis, the Photosystem II first receives sunlight, which activates the electron complex that completes photolysis of water molecules and sends electrons down to the electron transport chain. During the process of photolysis, each water molecule is split into two hydrons, two electrons, and one oxygen atom. While the electrons are being transported through the electron transport chain to Photosystem I, ATP is produced and stored for the Calvin cycle of photosynthesis. When the electrons finally arrived at Photosystem II, it excites the electron complex of Photosystem I, which leads to the production of NADPH. On the other hand, our model replaces the electron complex in both Photosystems with the semiconductor balls, which also transform sunlight into potential energy. Furthermore, we use enzymes, such as hydrogenase and oxygenase, to imitate the photolysis of water molecules, which also split up water molecules into hydron, electron, and oxygen.
In the light reaction of photosynthesis, ATP and NADPH are both molecules that carry potential energy for the Calvin Benson cycle of photosynthesis. In our model, in order to emulate these energy-carrying molecules, we connect capacitors in parallel to the tube; each capacitor is made of two conductive plates and one dielectric plate. In a circuit, the power source must consist of two ends, a positive end and a negative end. Since the dielectric plate in the middle of a capacitor has almost zero electricity flowing through it, the positive end of the power source allows one conductive plate of the capacitor to be positively charged while the negative end of the power sources gives the other conductive plate an overall negative charge.
Similar to the solar panel or the semiconductor ball, the capacitor stores potential energy and requires a mean of transmission to transfer electrons, which reduces the potential difference between two plates. In addition, the mean of transmission for electrons is the device that is powered by the capacitor. In this case, we connect a fan to the capacitor, which acts as the mean of transmission for the capacitor. The fan will then drive the ventilation system of the astronaut suit by increasing airflow within the suit.
After the spring pushes the semiconductor ball along one edge of the tube, the ball will continue in the same direction until it hits the wall of the perpendicular tube. This wall provides an impulse, sending the ball back in the direction it came from. Therefore, we designed a solution for this. Inspired by the sphincters in a human digestive system and the valves in a human heart, we implemented our own mechanical sphincters along the interior of the tubes to prevent the semiconductor ball’s backflow. Sphincters in our bodies act as sensors that open when the intended object reaches its opening, and closes after the object passes the sphincter to stop any backwards movement. Our sphincters do the same; when the ball passes the sphincter in the tube, the sphincter opens, granting access to the ball. When the ball passes the sphincter, it closes and keeps the ball moving along the tube.
An alternative solution that was initially considered was to use glass tubes, much like modern test tubes or capillary tubes that are used in scientific experiments. However, since the cohesion of the water molecules to each other is greater than the adhesion of the water molecules to the glass, it seemed improbable that the design would check out scientifically and work as intended.
When an astronaut views this device through his or her peripheral vision, the astronaut’s photoreceptor cells translate the image into signals that are passed through the optic nerve, which in turn is conducted to the brain. To prevent any confusion, the right side of the device where the semiconductor ball is recycled back up the loop, will be installed into the wall of the space shuttle, so that only the left side is visible when the ball drops downwards. Motor neurons from the cerebellum, which conduct signals from the brain to the rest of the body to control balance and movement, allow the astronaut’s muscles to react normally as they would on earth. Their actions, in return, conduct signals back to the brain through sensory neurons, and the brain processes these signals as the feeling that the body is in normal conditions. Overall, the solution we present is a system of tubes that take advantage of water’s properties to circulate semiconductor balls indefinitely, with the semiconductor balls being aided by a series of spring systems, magnets, and sphincters to make their way through the apparatus. The “dropping” movements of the semiconductor balls imitate the feeling of gravity and contribute to the reduction of Space Adaptation Syndrome for astronauts in space.