In our current space exploration, all crewed missions are executed in microgravity.
We have learned that microgravity affects the human body in a debilitating physiological way. Since we are considering an interplanetary trip to Mars, our duration in space will be approximately six months to get there, with two years on the planet and six months to return.
Microgravity also provides challenges in all daily activities. One of the most common injuries during Space Flight are floating particulates that enter and damage the human eye.
Our project focuses on creating artificial gravity through rotation. Being able to have artificial gravity will allow all floating matter, such as trash, dust and lost items, to settle to and intercept a floor rather than floating about the habitat.
By turning to partial gravity, we reduce the potential risk of microbiological and toxicological contamination of crew members. Microgravity toilets can now become conventional and allow the astronaut to quickly go about their daily ablutions where sanitary bathing and grooming practices also become practical. All medical procedures such as surgeries can now be performed with less difficulty and reduced risk.
It is our aim to allow all crew to get used to the reduction of gravity found on Mars. To achieve this, we must look at the human factors needed to live and work in a 0.38 G gravity. There are optimal conditions that allow the human body to be in harmony with its surroundings.
In this abstract, we propose using two Space X starships connected by a central node with an airlock, a docking system, and a lateral tethered truss system.
Since the Starship is still developing, very little information is available concerning its technical layout for future use in space. However, we have looked closely at the documented dynamic payload dimensions, and we will be using this both for the habitation module and the necessary cargo and counterbalance.
We will require three starships with three launches. The first will have ample cargo storage capacity, comprising the connection node, which includes an airlock module, a rope, an expandable truss module, a docking module, and a dragon spaceship. This dragon capsule can be used as an emergency habitation or crew transport vehicle and will be able to dock both to the microgravity node as well as to the Starship. Once the first Starship arrives in LEO (low earth orbit), the upper part of the front fuselage will rotate open and a robotic arm similar to the Canada arm will allow all elements to be removed and placed so that the tether and trust system can be connected to the forward facing nose cone.
At this point we should have the central node with an airlock on one side and a docking node on the other to which the dragon is connected as well as a separate tether and trust node on top. Now we will wait for the second Starship to arrive and maneuver to allow the tether and trust system to connect to its nose cone so as to achieve a perfect line in which both starships face each other. At this point, a third launch will refuel both starships to full capacity. The Starship with the habitation module will be facing the direction of travel and then propel the complete system towards Mars. Once the ships have achieved the desired speed, the booster will shut off, and a 90-degree rotation maneuver will take place, allowing both space ships to proceed in a sideways trajectory keeping the same Hohmann transfer trajectory. We now have to initiate expansion and rotation to achieve artificial gravity. The collapsed truss system will start expanding at the same rate from both sides, distancing both starships from each other. The tethers will already be connected and move simultaneously with the Truss system. Once we have reached a distance of 200 meters between the two starships, we can start tightening the tethers. We will now begin to rotate both starships around the central node using lateral thrusters, gradually speeding up the rotation while the complete structure still moves forward sideways at the desired speed. As the rotation increases so does the pressure on the tethers and the trust system can compensate for the torque. In this configuration, we can allow for 1.8 rotations per minute with 200 meters of distance to generate 0.38g of artificial gravity. Lastly, we can deploy the solar arrays in each segment used to generate power and the radiators used to dissipate heat.
This mission’s complete crew comprises six members, each seated in the upper level cockpit.
Since we are achieving artificial gravity by rotation, there are several factors we have to consider. The first is the gravity gradient effect which presents a different gravity depending on the distance from the central node. Once the crew moves down to the lower levels from the cockpit, each level moving further away from the center of the spin axis will increase the gravity the astronaut feels. Other physical forces present will be the radial and tangential Coriolis force, which causes the crew to perceive a curved and sidewards winding effect when items are launched or dropped. Once the astronaut walks in the direction of the rotation, they will notice an increase in weight due to the increase in rotation speed. The opposite will happen once they walk against the rotation and feel lighter. Any transverse movement to the rotating axis will not incur any change. We should consider the non-coordination between the vestibular ear drum and the eye, which may cause motion sickness. If the astronaut moves its head in the transverse direction of the axis of rotation, an angular acceleration effect is caused.
This is often mitigated after several days, once the crew get used to their new physical condition.
It is important that astronauts have distinctive interiors which will allow them to perceive the spin axis of the spaceship. This can be achieved by changing the color scheme and using recognizable signage or variable lighting. We have also focused on the direction of staircases leading to different floors and ensuring that all activities and movements are based primarily on the paralell direction of the rotation. Changing the perception of ceiling heights between the more used daily activity areas and the more private night and rest areas allows for the most efficient space usage.