High-Level Project Summary
The Dandelion Mission provides a practical solution for energy generation and storage on Venus. We use radioisotope heaters to generate more heat so thermoelectric generators (thermophotovoltaic cells) can turn it into electricity. The electricity is then stored using an Ambri Battery (which withstands 500°C ) ready for use.
Link to Final Project
Link to Project "Demo"
Detailed Project Description
The Dandelion Mission utilizes the conversion of heat into electricity to power the rover. If you want to last 60 days on Venus it will take a lot. Instead of 1 rover we will use multiple smaller rovers that require less electricity each. Venus is smaller than earth, so it’s gravity is a fraction of earths gravity. However Venus has a very thick atmosphere, 92x thicker than earth. If we want rovers to last, we cannot use wheels. The wheels would burn quickly or be solid metal and very inefficient. So we will take advantage of the atmosphere and gravity, and power propellers instead. With more atmosphere taking off would be easier as there is more air to lift off and less gravity to pull you down.
Moving on, the energy system will consist of a battery and a generator. The battery will be like an ambri battery. It works by using calcium alloy, antimony, and molten sodium electrolytes. the battery will have separated calcium alloy and antimony that will be liquid because of the heat of Venus. Due to the potential difference between calcium and antimony, the calcium will become calcium ions that will work as a circuit. As the battery is used, the calcium will mix with the antimony creating calcium/antimony alloy. At this point it will no longer produce ions. In order to separate the alloy, we have to run electrons through the alloy, which is what our generator is used for. The electricity it produces separates the alloy. Once separated, that battery can be reused again
The generator that refuels the battery will be a contraption of coolants, radioisotope heaters, and thermal electrical generators that from now on will be referred to as TEGs. A TEG works by having a hot and cold side. By using the Seebeck effect, it creates electricity. The Seebeck effect is where two different temperatures cause different voltages. Positive and negatively charged electrons flow towards the cooler side. If there are two different materials, one positive, and the other negative. It can be combined to create voltage. Our power source will rely on a radioisotope heater with TEGs to power a cooling system. A radioisotope heater has a core that will slowly decay. This decaying process releases heat in which we will use thermoelectric generators to get the energy. The flaps on the side are heat sinks so the core doesn't get too hot. Using the generator, we will power a cooling system that will be used by more TEGs. we can cool the walls between each TEG. Each teg will have a wall and an open area next to them. By putting them in the open, we can have a hot side and by using coolants we can have a cold side creating a good difference in temperature. With that we can create electricity. And With this electricity we can power the battery.
The body of the chamber will be made of inconel 600. An alloy that will not melt until 2000 celsius. The battery is designed to withstand 500 celsius so it will survive on venus
Our 3d models were made in Solidworks and Pro Bot Beta. The real life models were made of cardboard, tin foil, duck tape, and skewers.
We hope to be able to help explore extreme environment planets, and in doing so we might just unlock another secret in the universe.
Website: https://dandelionmission.multiscreensite.com/
Space Agency Data
We used NASA's database of solar system temperatures to figure out which way of generating electricity was the best and how to build it. We also looked at "energy storage technologies for future planetary science missions" as a jumping-off point to figure out what batteries we should use and which ones we shouldn't. Other sources of inspiration from NASA include the technology of Perseverance, which inspired the radioisotope idea. As well as the Venus Rover Challenge Winner that used a fully mechanical concept of a rover, which lead us to the mechanical opening of the carrier.
Hackathon Journey
On the first day, the team met with and assigned the roles. Ashley, Ryan, and Oliver are in charge of batteries and energy storage, while Lynna, Matthew, and Lucas are in charge of building and engineering the rover. In the morning, Lynna worked out the mini rover that would fit inside the rover, while Matthew built the main carrier for the rovers. There were two models for the mini robots: one with only one propeller and another with two. The variation with two propellers proved to be better as it increased the power and made flying around easier. The propeller works by pulling air behind itself, which then results in the mini robot being pushed forward from the pressure difference. These mini robots will fly out to take pictures of the surface of Venus. On the main robot, there are 6 mini robots and 3 batteries. After landing, the robot will slowly unfold itself and allow the mini robots to start flying around.
References
https://www.reachelectrical.com/product/fiberglass-insulated-resistance-wire-
500c/#:~:text=This%20high%20temperature%2C%20heat%20%26%20flame,temperatures%20of%20500%C2%B0C.
https://news.mit.edu/2022/thermal-heat-engine-0413
https://isorepublic.com/photo/dandelion-flowers/
https://pubs.acs.org/doi/10.1021/acsenergylett.2c01075
https://arc.aiaa.org/doi/abs/10.2514/6.2020-2935
https://gizmodo.com/mit-heat-engine-thermophotovoltaic-cell-1848825594