First Level Design and System Design of Janus Liquid Oxygen-Liquid Methane Lander
Taking humans to space has always been a fantastic feat, but taking humans to another planet in our solar system is the new goal. Technology has come a long way and with that, so has our knowledge of space and what can be done with current technology to accomplish our goal. These technologies allow for a more efficient space system to transport future astronauts using liquid oxygen and liquid methane (LO2-LCH4) as propellants. This combination of propellants, LO2-LCH4, brings a variety of benefits. One of the main advantages is that they can be recovered or created from local resources, using in-situ resource utilization (ISRU). This will allow the production of the fuel needed to come back to earth on the surface of Mars, or the space entity being explored, making the overall mission more cost effective by enabling larger usable mass. ^ At the University of Texas at El Paso (UTEP) MIRO Center for Space Exploration Technology Research (cSETR) in partnership with the National Aeronautics and Space Administration (NASA), research and design of a lander that uses LO2-LCH4 is on the move. Janus is a robotic lander vehicle with the capability of vertical take-off and landing (VTOL) which integrates several LO2-LCH4 components such as the reaction control engine (RCE). ^ The following work describes the steps taken to accomplish the design of the first Janus prototype (J-1) which will serve as the learning platform for upcoming prototypes (J-2 and J-3) that will lead to a flight vehicle. ^ A complete description of the flight profile for the lander will be explained. For this flight profile a MATLAB script was developed to generate plots, which will be used to obtain data. The set of plots developed by the script depicts the flight profile vs time of the lander where height, rotation, velocity, angular velocity, acceleration, angular acceleration, thrust level of the CROME-X engine, thrust level of the RCEs’, and the weight of the lander throughout the mission can be seen. This information was used to determine how much propellant the lander will burn throughout the mission based on the thrust required throughout the mission. ^ The weight of the propellant required for the mission that was obtained through the script was the placed on the weight budget. The weight budget developed for Janus will be explained in this paper. This weight budget will set a limit on the weight each component has as a limit once each sub-system is complete. This weight limit on each component will ensure a smooth integration to the lander and will keep the lander under a specified weight which will ensure the landers engine (CROME-X) can handle the thrust requirements set by the flight profile. The weight budget will serve for J-2 and J-3 only since there was not weight requirements for J-1 where the testing done will be done on a static thrust stand, therefore no flight oriented equipment was required. ^ For the static testing (J-1) a set of propellant tanks stands are required to carry the tanks being manufactured. This set of stands will not only carry the tanks, but must also ensure they are safe. A requirements document has been started where a description of the tanks stands operation, interface definition, design loads, failure mode and effects analysis, design requirements and verification criteria. In this paper some of these requirements will be discusses such as the g’s of load that the tank stands must be able to withstand in case the stand is dropped or toppled in which case the tank should be unharmed. ^ A study has begun to define the landers flight configuration, where the goal is to find the best possible way that Janus can be arranged. One of the most crucial components are the tanks and placing them in a certain configuration will affect the dynamics of the lander throughout the mission. This study helps understand how the tanks placement affects and will aid in the decision making of the final orientation.^
Fernandez, Jahir, "First Level Design and System Design of Janus Liquid Oxygen-Liquid Methane Lander" (2017). ETD Collection for University of Texas, El Paso. AAI10744318.