2019.A.2.3. A Hybrid Rocket CubeSat Lunar Surface Payload Vehicle

Author(s)

MJ Rinehart (1)
Colton Smith (1)
David Evinshteyn (1)
Amanda Hipple-Bornhorn (1)
Kyle Smith (1)
Sebastian Carta (1)
Declan McCloskey (1)
Ian Beach (1)
Connor Silvia (1)
Dr. Ajmal Yousuff (1)
Colin Driscoll (2)

Drexel University, U.S.A.
a.i. solutions, Inc., U.S.A.

Session

A.2

Keywords

Hybrid Propellant, Chemical Rocket, Lunar Landing, Lunar

Abstract

Increased interest among both national and commercial organizations in launching lunar orbital missions presents a unique opportunity for researchers to deliver small-scale lunar surface payloads with looser restrictions than rideshare on lunar lander missions. We propose a low-cost 12U CubeSat lunar payload delivery mechanism, utilizing chemical propulsion rockets to deliver payloads from low lunar orbit to the Moon’s surface. Hybrid propellant motors using acrylonitrile butadiene styrene fuel (ABS) were determined to be the most optimal choice due to their low-mass structural requirements and flexible thrust control. Recent advances in additive manufacturing have allowed for the design of complex fuel grains with ABS fuel, allowing the characteristics of hybrid engines to be fine-tuned for better control and performance. Full-scale testing of CubeSat hybrid engine variants is performed at Drexel University to characterize several different fuel port profiles, collecting data for both thrust performance and propellant consumption. For constraining baseline rocket performance requirements, finite burns modeled in a high fidelity propagator (FreeFlyer) are used to optimize a lunar descent trajectory. A two burn trajectory modeled after the Apollo mission burn profiles is designed to minimize craft velocity just above the lunar surface. For ensuring safe payload delivery, a simple, yet novel, pneumatic system to eject the payload prior to touchdown is proposed. The soft-landing technique discharges excess oxidizer remaining after descent maneuvers to accelerate the payload retrograde from the descending craft, similar to the mechanism of a compressed gas cannon, avoiding the need to keep the no longer necessary components of the CubeSat intact upon landing. Performance of this system is validated by determining oxidizer pressurization after completion of rocket fire tests and sensor reading accuracy in the lunar environment. Based on these analyses, we show that a 12U CubeSat payload delivery system is able to facilitate transport of payloads with masses up to 2.8kg, and 6.8 cm x 5.9 cm x 30 cm envelopes from low lunar orbit to the Moon’s surface. By developing CubeSat-configured hybrid propellant rockets we present an opportunity to lower the barrier for researchers conducting studies on the Moon’s surface.