Search NASA⌕ Search

SEARCH · Search NASA

Results for “sub meter”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

398 records · Page 23

Lunar Wormbot: Design and Development of a Ground Base Robotic Tunneling Worm for Operation in Harsh Environments

From 1969 to 1972, the National Aeronautics and Space Administration (NASA) sent Apollo missions to the moon to conduct various exploration experiment. A few of the missions were directed to the study and sampling of moon soil, otherwise known as lunar regolith. The extent of the sample acquisition was limited due to the astronauts' limited ability to penetrate the moon's surface to a depth greater than three meters. However. the samples obtained were sufficient enough to provide key information pertaining to lunar regolith material properties that would further assist in future exploration endeavors. Analysis of the collected samples showed that the properties of lunar regolith may lead to knowledge of processed materials that will be beneficial for future human exploration or colonization. However, almost 40 years after the last Apollo mission, limited infonnation is known about regions underneath the moon's surface. Future lunar missions will require hardware that possesses the ability to burrow to greater depths in order to collect samples for subsequent analysis. During the summer of 2010, a team (Dr. Jessica Gaskin, Michael Kuhlman. Blaze Sanders, and Lafe Zabowski) from the NASA Robotics Academy at Marshall Space Flight Center (MSFC) was given the task of designing a robot to function as a soil collection and analysis device. Working with the National Space Science and Technology Center (NSSTC), the team was able to propose an initial design, build a prototype, and test the various subsystems of the prototype to be known as the "Lunar Wormbot" (LW). The NASA/NSSTC team then transferred the project to a University of Alabama in Huntsville (UAH) Mechanical and Aerospace Engineering (MAE) senior design class for further development. The UAH team was to utilize the NASA Systems Engineering Engine Design Process in the continuance of the Lunar Wormbot project. This process was implemented in order to coordinate the efforts of the team and guide the design of the project to ensure a high quality product that met requirements within the academic year timeframe. When the transition from the NASA NSSTC team to the UAH team occurred in August 2010, the scope and requirements were provided to the UAH team. The main objective for the UAH team was to design and fabricate a robotic burrowing prototype using peristaltic or earthworm-like motion with the purpose of collecting soil samples. The team was tasked with the design of a sub-system of the LW called the locomotive, or active, segment. Through the design process, the team extensively reviewed the requirements and functions to be performed of the LW, which led to the proposal of a final design. The present paper provides the details of the development of the design up to and including the Critical Design Review (CDR) of the Lunar Wormbot. This document briefly describes thc overall system and its function but primarily focuses on the design and implementation of the locomotive segment. Content presented includes: general design and system functionality, technical drawings, system analysis, manufacturing methods, and general project costs.

Boyles, Charles↗

OPEN2018 (continuation of GENSETS effort)

This project has demonstrated the key components and engineering principles to support a residential scale (1 to 2 kWe) recuperated Brayton cycle generator based upon a screw compressor and screw expander. This technical work is a continuation of the previously awarded ‘GENSETS’ program. The product goal has been to achieve a 40% fuel-to-electric LHV efficiency, an 80% overall CHP efficiency, emissions qualified to the California Air Resources Board standards, and at noise levels of 55 dB or less at 1 meter. Further, the product must operate with 8,000 hour service intervals and achieve a mean-time to overhaul of 90,000 hours. Lastly, and possibly most importantly, the product must meet demanding cost targets, exhibiting a factory cost well below $1,500/kWe. After extensive aerodynamic studies under the ‘GENSETS’ program, Brayton concluded that miniature turbomachinery could not achieve an efficiency consistent with the product’s system performance goal. Given compressor and turbine efficiency targets in the range of 78 to 81%, Brayton turned to the rotary screw machines. While the justification for a screw compressor over a conventional centrifugal compressor is well supported by industry experience, the high temperature expander represented the core technology advancement. To meet the extremely high efficiency goals, an all-ceramic rotary screw expander hot section was developed and has now been tested in the laboratory. This first-of-its-kind ceramic screw expander prototype was able to demonstrate aerodynamic efficiency in line with predictions. The test article was successfully run to full stress conditions so has also validated the mechanical design of such a unit. This has opened new avenues for the commercialization of high efficiency, small scale power generation. Interest in the technology has sparked several requests for alternate uses, an invitation to present at a screw machine conference, and continued interest from parties looking to develop a product in the spirit of the original ‘GENSETS’ goals.

42 ENGINEERING↗