Engineering topics
Publications and source records attributed to Deans, M. C..
This is an educational briefing package for Electrified Aircraft Propulsion and Power (EAPP); this presentation will brief on NASA needs and challenges in Electrified Aircraft Propulsion and Power as well as the SBIR program and proposal guidance.
Studies of lunar polar volatile depositsare of interest for scientific purposes to understandthe nature and evolution of the volatiles, and alsofor exploration reasons as a possible in situ resource toenable long term exploration and settlement of theMoon. Both theoretical and observational studies havesuggested that significant quantities of volatiles exist inthe polar regions, although the lateral and horizontaldistribution remains unknown at the km scale and finerresolution. A lunar polar rover mission is required tofurther characterize the distribution, quantity, andcharacter of lunar polar volatile deposits at thesehigher spatial resolutions. Here we present two casestudies for NASA’s Resource Prospector (RP) missionconcept for a lunar polar rover and utilize this missionarchitecture and associated constraints to evaluatewhether a suitable landing site exists to support an RPflight mission.
While we know there are volatiles sequestered at the poles of the Moon, the detailed 3-D distribution, abundance, and physical and chemical form are largely unknown. The next giant leap, Resource Prospector (RP), will use landed assets to fully characterize the volatile composition and distribution at scales of tens to hundreds of meters. To achieve this range of scales, mobility is required. Near real-time operation of surface assets is desirable, with a concept of operations very different from that of rovers on Mars. For RP, new operational approaches are required to carry out real-time robotic exploration. The Mojave Volatiles Project (MVP) is a Moon- Mars Analog Mission Activities (MMAMA) program effort aimed at (1) determining effective approaches to operating a real-time but short-duration lunar surface robotic mission, and (2) performing prospecting science in a natural setting, as a test of these approaches. Here we describe some results from the first such test, carried out in the Mojave Desert between 16 and 24 October, 2014. The test site was an alluvial fan just E of the Soda Mountains, SW of Baker, California. This site contains desert pavements, ranging from the late Pleistocene to early-Holocene in age. These pavements are dissected by the ongoing development of washes. A principal objective was to determine the hydration state of different types of desert pavement and bare ground features. The mobility element of the test was the KREX-2 rover, designed and operated by the Intelligent Robotics Group at NASA Ames Research Center.
We know that volatiles are sequestered at the poles of the Moon. While we have evidence of water ice and a number of other compounds based on remote sensing, the detailed distribution, and physical and chemical form are largely unknown. Additional orbital studies of lunar polar volatiles may yield further insights, but the most important next step is to use landed assets to fully characterize the volatile composition and distribution at scales of tens to hundreds of meters. To achieve this range of scales, mobility is needed. Because of the proximity of the Moon, near real-time operation of the surface assets is possible, with an associated reduction in risk and cost. This concept of operations is very different from that of rovers on Mars, and new operational approaches are required to carry out such real-time robotic exploration. The Mojave Volatiles Project (MVP) was a Moon-Mars Analog Mission Activities (MMAMA) program project aimed at (1) determining effective approaches to operating a real-time but short-duration lunar surface robotic mission, and (2) performing prospecting science in a natural setting, as a test of these approaches. Here we describe some results from the first such test, carried out in the Mojave Desert between 16 and 24 October, 2014. The test site was an alluvial fan just E of the Soda Mountains, SW of Baker, California. This site contains desert pavements, ranging from the late Pleistocene to early-Holocene in age. These pavements are undergoing dissection by the ongoing development of washes. A principal objective was to determine the hydration state of different types of desert pavement and bare ground features. The mobility element of the test was provided by the KREX-2 rover, designed and operated by the Intelligent Robotics Group at NASA Ames Research Center. The rover-borne neutron spectrometer measured the neutron albedo at both thermal and epithermal energies. Assuming uniform geochemistry and material bulk density, hydrogen as either hydroxyl/water in mineral assemblages or as moisture will significantly enhance the return of thermalized neutrons. However, in the Mojave test setting there is little uniformity, especially in bulk material density. We find that lighter toned materials (immature pavements, bar and swale, and wash materials) have lower thermal neutron flux, while mature, darker pavements with the greatest desert varnish development have higher neutron fluxes. Preliminary analysis of samples from the various terrain types in the test area indicates a prevailing moisture content of 2-3 wt% H2O. However, soil mineralogy suggests that the welldeveloped Av1 soil horizon beneath the topmost dark pavement clast layer contains the highest clay content. Structural water (including hydroxyl) in these clays may explain the enhanced neutron albedo over dark pavements. On the other hand, surface and subsurface bulk density can also play a role in neutron albedo - lower density of materials found in washes, for example, can result in a reduction in neutron flux. Analysis is ongoing.