Fundamental Study into Rotor Outwash and Dust Kick-up under Mars-like Conditions

Humans have reached a limit to how much information can be collected from a purely ground-based rover exploration mission on Mars. Therefore, an airborne mission would broaden our knowledge of this planet and at the same time it would allow for a different approach to scientific research. Thus, the Mars Helicopter Scout (MHS) Project was founded. However, as this is only a technology demonstrator, its first and short-term goal is to fly in the vicinity of the Mars Rover and assess where the rover can go. This would reduce the risk of damage to the rover and allow for minimum transit times on the Martian surface. The main objective of the project is conducting small-scale hover testing of a coaxial rotor system in- and out-of-ground effect to study both rotor downwash/outwash and to examine the conditions under which dust kick-up and brownout does or does not occur under Mars-like conditions, with potential application to Mars Helicopter development. Given the exploratory nature of this project, it is limited to a proof of concept of testing techniques that may eventually be used on the full scale MHS. These future tests will help determine whether or not dust kick-up can pose a problem on the performance of the MHSs altimeter

Leveraging microgravity to investigate earth- And space-based centrifugal casting of wax

A multi-year research effort aimed at increasing understanding of the centrifugal casting process of wax fuels for hybrid chemical propulsion in multiple thermal and gravitational environments is described. As both radiative and convective heat transfer drive the casting process, the suborbital and orbital microgravity environments are critical to disentangling these contributions to heat transfer away from the fuel. The experimental effort comprises testing on multiple platforms, including the ambient atmosphere of the laboratory, as well as various mobile microgravity platforms. Testing onboard reduced-gravity aircraft facilitates increased understanding of how these types of fluids perform in the microgravity environment, while a suborbital spaceflight and orbital platform under standard atmosphere allow for longer-term observation of natural convection sans buoyancy. An orbital platform subjected to the space environment facilitates understanding of the contribution of radiation to the heat transfer away from the liquid fuel. Each progressive testing environment requires updates to the experimental setup in order to accommodate respective physical and electrical constraints which are described in detail herein. An image analysis routine was developed in order to automate post-processing and determine the solidification front speed for each test. A rotation rate actuation routine is in development which aims to improve the accuracy of the centrifuge control system by leveraging electromagnetic sensing and feeding back rotation rate measurements to the motor driver. Preliminary modeling work was conducted which aims to elucidate the fundamental physics of the centrifugal casting problem; specifically, the impact of rotation rate, material properties, and environmental conditions on the heat transfer and fluid mechanics which constitute the larger casting problem. Both paraffin wax - a solid fuel with two decades of heritage - and the more novel beeswax are considered in this study