This project is solving the Deployable Greenhouse challenge.
The purpose of this project is to develop a Greenhouse prototype able to operate autonomously on the surface of Mars. With functionality in mind, we have designed sustainable and independent systems, capable of managing resources and obtaining the necessary energy without human intervention.
The following are some specifications of the greenhouse:
Dome: The modules will be made from a combination of vectran,kevlar and air as foam (to isolate the system).
The external layer will be made of Kevlar. Kevlar is a polymer of high mechanical resistance that has the advantage to be chemically stable against variable exposition conditions. Also it can withstand high and low temperatures. Kevlar is followed by a layer of Vectran
The Vectran is impact resistant, and possesses a very high protection level: it withstand radiation and UV rays, is chemically stable, among others. It also has a low coefficient of thermal expansion.
Both provide high rigidity and strength to the structure. They are both flexible and, they are able to remain bent until the time of deployment, retaining their physical, chemical and mechanical properties. Their similarity in chemical resistance and internal radiation protection are ideal for protecting the greenhouse from the Martian environment.
Energy: This process will use 5 megawatts of energy; therefore, it will be necessary to use a SP-100 reactor to accomplish it.
Temperature: The heating module will be regulated through temperature sensors, and particularly by a reactor called SP-100. These sensors will be distributed around all the greenhouse to maintain an optimum weather for the plant growth. The reactor will generate a large amount of heat (which can be cooled with cold CO2). The electric power produced by the generator will be stored in a Nickel battery of hybrid metal. This reactor will be located in the central dome, alongside of the storage shed (used to store containers, seeds and objects that can not be used at that moment).
Pressure: To be able to control or simulate the pressure for the adequate conditions for the harvest, air will be injected at one part of the module while the exit of the same will be controlled by pressure sensors or a barometer.
Ventilation: Fans will be located in the greenhouse cavities (between greenhouse walls) with the purpose of accelerating hot air fluency. Finally, at the top will be found an extraction system with a mass equivalent fluency (what goes in, goes out).
Storage tanks: storing tanks will have thick walls that allow pressures of 400kPa (the necessary to reach the separation of carbon dioxide and oxygen). The air compression process needs intermediate tanks due to the thinness of Mars’ surface, and cannot pass plenty of matter through the first extractor. The intermediate tank allows a compression process to accumulate enough air to be processed later.
Illumination: the greenhouse will be completely sealed, that is why, blue and red LEDs will be used. Their wavelength is ideal for the process of photosynthesis; arousing an even better development than with solar radiation. They can be controlled by photoresistors or light sensors.
Water: A reserve of water will be taken for the plants while it is extracted from Martian subsoil, coordinates of Buried Glaciers.
Given the location of the base, that is near the glaciers, a deep perforation in the land will be done until we reach the ice. Having done that, water will evaporate, and will be stored. This vapor will be collected and condensed to obtain liquid water.
Automatically, when the equipment lands on the Martian surface, it will deploy and start compressing atmosphere gas to be injected into the greenhouse walls. Since our greenhouse is almost entirely inflatable (except for the central module) it will be installed using Mars’ atmosphere and gas concentration.
Once the module is anchored to the ground through various drills and special anchors (to prevent Mars’ high speed winds to move or to elevate the greenhouse), and the cabin is pressurized, the filtration process will begin. It consists of compression and expansion valves to separate the condensed CO2 and to recycle it, in order to maintain an atmosphere of 99% carbon dioxide, and create the ideal environment for the plants that we want to grow. This control system regulates both ventilation and temperature.
After the greenhouse is inflated and the structure is set, the next step is to understand the mechanisms’ function in order to plant and germinate the seeds from storage. Once the seeds have grown enough to be transferred to the different columns of the aeroponic greenhouse then, a small robot located at the main cabin will move each seedling to its corresponding hole.
Subsequently, the plants placed in the columns will start nourishment through aeroponic technique, which consists in keeping the plant roots hanged in the air and supplying a vaporized solution. This technique was chosen since it is one of the most efficient in reducing energy and water consumption, as well as having a high production capacity in less time than other traditional techniques.
Later, when the time is appropriate, depending on the plant species, the automated system will release the lock that held the plants inserted in the columns, so they will fall completely (including their root) to the floor of the greenhouse. A slip system will make the vegetables fall in specific locations, where the robot will pass and collect them. Afterwards, they will be taken to a warehouse to be stored, and, in case they are not extracted by the crew of the mission for any reason, the harvest will be crushed and used as nutrients or fertilizers for the upcoming crops.
Project InformationLicense: Creative Commons BY-SA 3.0
Source Code/Project URL: https://www.dropbox.com/s/g95wfcp29wlga7v/TerraFarming.pdf
ResourcesDocument Report - https://www.dropbox.com/s/g95wfcp29wlga7v/TerraFarming.pdf
PowerPoint Presentation - https://www.dropbox.com/s/3fyfanana7i9y91/Terrafarming.pptx
Simulation Pictures of Deployment - http://www.youtube.com/watch?v=K_vA0VQB3eE
Mars landing core module simulation - http://youtu.be/jGef5Dk3e_E