ABSTRACT
The Space Enabled Research Group at MIT is conducting a multiyear research effort to better understand the technical and logistical challenges posed by the implementation of a wax-based hybrid chemical in-space propulsion system. Paraffin and beeswax are being considered as candidate fuels. The overarching effort includes imagery analysis conducted on paraffin and beeswax centrifugal casting tests conducted onboard progressively higher-fidelity experimental platforms within transparent hardware which aids in optical investigations. Such platforms include a laboratory optical table experiment, as well as a vacuum chamber test, a parabolic trajectory microgravity aircraft (three flights to date), the Blue Origin New Shepard suborbital launch vehicle (three experiments onboard and scheduled for mid to late 2022), and potentially the Destiny laboratory module of the International Space Station. Each of these platforms allows for testing in a new environment or increasingly longer-duration microgravity. The main focus of this paper is in regards to a Suborbital flight experiment. This experimental setup had multiple limiting factors such a size, 10 cm x 10 cm x 20 cm and power of approximately 5 W. This lead to trying a new approach to the spin casting approach used previously by the team, as the method of forming the fuel grain annulus. This new approach was passive, meaning it did not require any additional power other than to melt the wax, and relied heavily on the surface tension properties of the containment chamber. The surface tension of the end caps was modified by using an oleophobic substance to repel the wax. Unfortunately, due to the Covid-19 pandemic, delays on flight caused results to not be ready before the date of publication of this paper. © 2022, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.