Volume Optimization for Food Product During Deep Space Exploration
Group Members: Tyler Ballard, Tyler Robins, Holden Covington, Jack Satterfield, Michael Foley, Steven Reece, & Harold Brooks
23 September 2019
Project Description
Astronauts prefer some fresh food in space. There have been previous space gardening systems that allowed astronauts to take care of plants and grow food themselves. However, this takes a lot of time out of their busy schedule. For a future deep space mission to send humans to Mars which will take over six months, the XHAB Space Food System will automatically grow plants such as lettuce and radishes. With a seedling to harvest cycle of approximately forty days, this will allow multiple generations of plants to be grown on the trip.
The system will grow plants by constantly monitoring their health through a variety of sensors. General environmental conditions will be monitored such as temperature, relative humidity, and photosynthetically active radiation (PAR) to optimize plant growth needs. When one of these conditions is not being met, the system will change the environment as necessary. For individual plants, the humidity will be monitored to detect when the plant needs to be watered. These readings can also be used to detect when the plant has stopped accepting water. A thermal camera will be attached to a robotic arm to monitor plant health by detecting when the seedlings have grown too big for their environment and moving them to a larger grow area. The thermal camera readings combined with the individual humidity sensors should be able to determine when plants are starting to die.
The electrical team’s responsibility is to handle sensors, data management, and power management. As the needs for the agriculture and mechanical teams change, the electrical system will change to adapt to their needs.
Technical Approach
For the project, three main standards are going to be targeted. The first standard regards IEEE 1233, System Requirements Specification (SRS), which is a structured collection of information that embodies the requirements of a system.[1] This will be used to keep the data collected from the sensors in an organized manner while also allowing us to maintain constant analysis of the plant moisture and health of the plants/seedlings. Another standard that will be used is I2C which focuses on communication between the sensors and the Arduino. Lastly, standard IEEE 1801, Unified Power Format (UPF), will be implemented. UPF is intended to ease the job of specifying, simulating and verifying designs that have several power states applied to them.[2] This will allow for easier tracking of power supplies and voltages that go into the sensors.
Along with the standards are constraints that should be monitored throughout the project. One constraint will be health and safety: focusing more on the health of the plants as they are enclosed in their cubicle. A second constraint will be sustainability: trying to figure out how to make a product that will be reliable to the astronauts while this system accompanies them on their space travel. A third constraint explored will be economic: what is the cheapest design that can be made in order to save money while provided the goal of the project. The last constraint deals with social aspect of the design: how will this be viewed in society, and if its benefits space travel, what other methods could this same design apply to.
Management Approach/Facilities to be used
We expect most of the students to meet in a common room at the same time, at least once per week. Mechanisms for sharing documents will be established e.g. GroupMe, Slack, etc. Much of the student work will be accomplished in the dedicated greenhouse and the Mechanical Engineering Project Room which contains machine and power tools, and an assembly and test area.
Mechanical Engineering students could be designing the pots, shelves, and selecting or designing a robot arm with gripper.
ECE students will be responsible for integration of electrical components, programming and ground station development. Eventually fabricated and assembled subsystems will be transported to the greenhouse for further subsystem verification testing and integration, after which the completed system will be tested and worked toward validation of the mission objective and concept of operations.
Agricultural student will be working in the greenhouse from the onset of the project, during which time they will study best substrates to grow the plants, select the crops more appropriate to grow for long space trips, and study combinations of nutrients to more adequately grow the plants. In addition, they will assist engineering students in the design of the automation.
Budget
NASA has provided funds of $10,000 for each group. A single university account will be set up to charge all costs. Faculty purchasing cards will be used to order all materials. Faculty must approve all charges. One student will be selected to serve as project manager, who will schedule reviews, meeting locations, develop a Work Breakdown Structure or Gantt Chart, and keep track of all purchases and Bill of Materials.
Timeline (NASA Organized)
| DATE | ACTION |
| Early August, 2019 | Faculty, technicians meet and plan |
| August 16 – August 30 | Classes begin, projects announced, teams formed, first team meeting take place, student training on Systems Engineering, plant basics, team communication strategies and software. Corporate greenhouse visits by all participants, e.g. Agronomics. Planting decision, begin first planting cycles (1-2 months for leafy vegetables, 2-4 months for fruited plants, plant growth and multiple cycles continued throughout the schedule) |
| August 30 – October 8 | Kickoff Meeting begin formulating mission objective, system level requirements, tradeoffs, feasible architectures etc. for SDR. |
| October 8 | System Definition Review and Report |
| October 8 – Nov. 11 | Review NASA feedback, complete a preliminary design, PDR hardware and software, top level requirements, feedback on plant growth and testing |
| Nov. 11 | Preliminary Design Review and Report |
| Nov. 11 – Jan. 21 | Complete detailed design of all drawings, BOM, interfaces, software, electrical, mechanical systems. Begin fabrication |
| January 21 | Critical Design Review and Report |
| Jan. 21 – March 11 | Fabrication, assembly, verification and integration of subsystems, begin or have begun last planting cycle for system testing |
| March 11 | Progress Checkpoint Review |
| March 11 – May 6 | Complete assembly, testing, and validation |
| May 6, 2020 | Project Completion and Report to NASA |
Disposition Agreement
At the conclusion of this project, all final products, reports, data, etc. will be reported and sent to NASA in hopes that the finalized design is worth being used for real-life usage on NASA space travels.
PowerPoint Presentation of proposal presented in class.
[1] Inflectra: What are System Requirements Specifications/Software (SRS)
[2] Tech Design Forum: Unified Power Format (UPF)
Space Food 