Providing Wired Power and Data in Lunar Permanently Shadowed Regions with a Rover-Deployed Superconducting Tether

The tethered permanently shadowed region explorer (T-REX) is an infrastructure technology pathfinder mission whose goal is to provide reliable power recharging and a communication link to other operations within PSRs of the Moon, where conventional line-of-sight radiofrequency (RF) communications and solar power generation are limited. The T-REX rover will deploy upwards of 2 km of superconducting tether in series with a 250 m conventional conductor tether connected to a commercial lunar payload services (CLPS) lander. This technology demonstration mission utilizes the cryogenic temperatures and low-noise environments within PSRs to its advantage to minimize cable mass and extend the mission lifetime of other missions in the PSRs. The initial demonstration mission (according to the competition rules, but based on CLPS provider information) would be limited in the worst case to the power and data capacities from the CLPS lander to transmit up to 8 W continuous and 40 W peak of power and 70 kb/s/kg of payload of data over a superconducting tether. The rover will store excess power from the lander to recharge other systems operating within the PSR via a HOTDOCK docking interface provided by Space Application Services. T-REX will additionally function as a repeater for local missions by connecting a wireless network the rover establishes within the PSR to the CLPS lander over VDSL2 protocol. This paper will discuss the development and testing of the T-REX rover tethered power and communications payload system. Development is done at a subsystem level initially, culminating after several iterations into integration and testing of the full system inside the dusty thermal vacuum chamber of Dr. van Susante\u27s Planetary Surface Technology Development Lab at MTU

Commissioning and Testing a New Dusty Thermal Vacuum Chamber with Inclusion of Icy Regolith

The Planetary Surface Technology Development Lab (PSTDL) purchased a new testing facility in the form of a dusty thermal vacuum chamber (DTVAC). This facility will be used to test the technology readiness level (TRL) of devices intended for extraplanetary use. Environments such as those found on the Moon and Mars will be simulated in the DTVAC via use of vacuum pumps, thermal shrouds, and simulated regolith. This paper details the commissioning and testing of systems put into place to facilitate TRL testing such as data acquisition systems, test fixtures, and baseline DTVAC performance tests. The PSTDL has purchased two insulated shipping containers that will allow for the creation and reclamation of icy regolith. Icy regolith test beds will be used in the DTVAC to test the TRL of water in situ resource utilization (ISRU) devices

Open Source 3D-Printable Planetary Roller Screw for Food Processing Applications

Historically, open source agriculture (OSA) was based on grassroots technology generally manufactured by hand tools or with manual machining. The rise of distributed digital manufacturing provides an opportunity for much more rapid lateral scaling of open source appropriate technologies for agriculture. However, the most mature distributed manufacturing area is plastic, which has limited use for many OSA applications. To overcome this limitation with design, this study reports on of a completely 3D-printable planetary roller screw linear actuator. The device is designed as a parametric script-based computer aided design (CAD) package to allow for the easy adaption for a number of applications such as food processing at different scales. The planetary roller screw is fabricated in dishwasher-safe polyethylene terephthalate glycol (PETG) on an open source machine and tested using an open source testing platform to determine if it could maintain a constant load without slipping and the maximum force. Then, this output is compared to a direct screw press using the same materials. The results found that the maximum force is more than doubled for the roller screw actuator using the same materials, making them adequate for some food processing techniques. Future work is outlined to improve the performance and ease of assembly.Peer reviewe

Testing and Development of the Tethered-Permanently Shadowed Region EXplorer: A Rover Designed to Lay Superconducting Tether into Lunar Permanently Shaded Regions

Power and communications are required for successful operations in the permanently shaded regions (PSRs) located at the lunar poles. However, due to the location of PSRs, direct solar power from the Sun and line of sight communications to Earth are limited. NASA solicited solutions from universities within the United States with the Breakthrough, Innovative, and Game-changing (BIG) Idea Challenge. The Planetary Surface Technology Development Lab (PSTDL) at Michigan Technological University (MTU) developed the Tethered-permanently shadowed Region EXplorer (T-REX) to address this problem. A conventional round tether in series with a superconducting tape tether connects to a lander at a crater rim to provide power and communications to T-REX during its descent into a PSR. This mission is enabled by the passive cooling of hardware within the naturally occurring cold environment of a PSR. T-REX was developed by using an iterative approach with testing conducted from component to system-level. System validation included testing within a sloped lunar regolith simulant chamber and component-wise testing under cryogenic temperatures. T-REX has been shown to be capable of traversing down 45° slopes and obstacles in a lunar highland terrain simulant during system mobility testing. The on-board tether deployment system was able to unspool a superconducting tether (SCT) while maintaining controlled rates of under 5 N of tension. A data transfer rate of 94 Mbps via very-high-speed Digital Subscriber Line-2 and 132.2 W of DC power transfer over the SCT when cooled to 77 K was validated through testing. Thermal analyses on the system analytically validated the performance of T-REX during the transition between shaded and illuminated regions. The T-REX rover technology was raised to Technology Readiness Level 5 over 1.5 years of research. The SCTs are high-efficiency, low mass means of providing power and data in extreme lunar environments

Testing and Development of the Tethered-Permanently Shadowed Region EXplorer: A Rover Designed to Lay Superconducting Tether into Lunar Permanently Shaded Regions

Power and communications are required for successful operations in the permanently shaded regions (PSRs) located at the lunar poles. However, due to the location of PSRs, direct solar power from the Sun and line of sight communications to Earth are limited. NASA solicited solutions from universities within the United States with the Breakthrough, Innovative, and Game-changing (BIG) Idea Challenge. The Planetary Surface Technology Development Lab (PSTDL) at Michigan Technological University (MTU) developed the Tethered-permanently shadowed Region EXplorer (T-REX) to address this problem. A conventional round tether in series with a superconducting tape tether connects to a lander at a crater rim to provide power and communications to T-REX during its descent into a PSR. This mission is enabled by the passive cooling of hardware within the naturally occurring cold environment of a PSR. T-REX was developed by using an iterative approach with testing conducted from component to system-level. System validation included testing within a sloped lunar regolith simulant chamber and component-wise testing under cryogenic temperatures. T-REX has been shown to be capable of traversing down 45° slopes and obstacles in a lunar highland terrain simulant during system mobility testing. The on-board tether deployment system was able to unspool a superconducting tether (SCT) while maintaining controlled rates of under 5 N of tension. A data transfer rate of 94 Mbps via very-high-speed Digital Subscriber Line-2 and 132.2 W of DC power transfer over the SCT when cooled to 77 K was validated through testing. Thermal analyses on the system analytically validated the performance of T-REX during the transition between shaded and illuminated regions. The T-REX rover technology was raised to Technology Readiness Level 5 over 1.5 years of research. The SCTs are high-efficiency, low mass means of providing power and data in extreme lunar environments

Can recurrences be predicted in craniopharyngiomas? β-catenin coexisting with stem cells markers and p-ATM in a clinicopathologic study of 45cases

Recurrence is a common feature of craniopharyngiomas, benign tumors that origin from squamous epithelial remnants of Rathke's pouch- arising at any segment of its whole course. There are two histotypes, showing different morphology and clinical behavior: adamantinomatous(adaCP) and papillary (papCP). An univocal strategy of management has not yet been defined, being considered the combination of surgery and radiotherapy the most effective, especially in case of incomplete resection. Therefore, the identification of factors influencing the biological and clinical behaviour is of paramount importance. β-catenin is a cell-cell adhesion protein, whose nuclear localization has been linked to the pathogenesis of adaCP: its nuclear accumulation is associated to the presence of a tumor stem cell subpopulation. The latter is made of cells capable of self-renewal, hence believed to be responsible of recurrence, metastases and resistance to therapy in all tumors. ATM is a kinase activated by autophosphorylation (p-ATM) upon DNA double-strand breaks. It is involved not only in DNA repair, but also in tumor migration and invasiveness. Its expression may have prognostic implications in many neoplastic diseases

Testing of a Bucket Ladder Excavation Mechanism for Lunar Applications

Bucket ladder excavation systems are a potential solution on the Moon for excavation of granular or lightly cemented regolith for the purpose of in situ resource utilization (ISRU), construction, and subsurface science applications. This type of mechanism can continuously excavate and transport material at high excavation rate and low power use. However, there are more potential mechanical failure points in bucket ladders mechanisms when compared to other excavation systems for the Moon. Bucket ladders are the most popular excavation mechanism for the NASA Lunabotics mining competition and all winners have used a version of the bucket ladder. Previous testing of lunar bucket ladder prototypes has shown excavation rates larger than 1,000 kg/hr at a 0.01 W/kg/hr power level in atmospheric testing, but more information is required to understand the behaviour of complex excavation mechanisms under realistic lunar environmental conditions and using lunar regolith simulants. This research effort focuses on raising the technology readiness level (TRL) of bucket ladders to TRL-5/6 for lunar applications. A bucket ladder built in the Planetary Surface Technology Development Lab (PSTDL) at Michigan Technological University (MTU) is tested in a dusty thermal vacuum chamber at MTU to assess performance during extended operations. Wear on components, excavation forces, excavation rate, and power consumption are monitored. This paper will describe the bucket ladder excavation system, test setup, and preliminary results of this ongoing project. Collected test data will provide insight to the efficacy of using bucket ladders for lunar construction and ISRU as well as explore wear and tear observations