NESC Mechanical Systems TDT: A Pillar of Support Across NASA
The NASA Engineering and Safety Center (NESC) Mechanical Systems Technical Discipline Team (TDT) serves as a crucial support system for NASA’s various mission directorates. This diverse team is composed of experts from a wide range of sub-disciplines such as bearings, gears, metrology, lubrication, tribology, mechanism design, and analysis. Additionally, they specialize in testing fastening systems, valve engineering, actuator engineering, pyrotechnics, mechatronics, and motor controls. Beyond providing technical aid, the team is responsible for the upkeep of NASA’s standard, NASA-STD-5017, which outlines the design and development requirements for space mechanisms. This document is essential in ensuring that all mechanical systems are robust, reliable, and capable of withstanding the harsh conditions of space.
Mentoring Future Engineers
The NESC Mechanical Systems TDT is not only committed to current projects but also invests heavily in nurturing the next generation of engineers. They actively engage in the Structures, Loads, & Dynamics, Materials, and Mechanical Systems (SLAMS) Early Career Forum. This initiative is geared towards mentoring young engineers at the beginning of their careers. Recently, three TDT members attended this year’s forum at the White Sands Test Facility (WSTF). The event provided an invaluable opportunity for early-career engineers to connect with peers and mentors from NESC. Participants shared insights into their work at various NASA centers and engaged in focused sessions that fostered collaborative learning and knowledge exchange.
Advancing Valve Standards for Enhanced Reliability
Valve malfunctions have posed significant challenges across NASA’s programs, often compromising mission performance and increasing risks. Many of these issues arise because the valve hardware fails to meet the environmental qualifications specified in NASA-STD-5017. To mitigate these issues, the Mechanical Systems TDT is spearheading the development of a new NASA standard for valves. By assembling a team of subject matter experts from various sectors, including propulsion, environmental control, life support systems, spacesuits, and thermal control systems, the TDT aims to create a comprehensive standard. The team is currently reviewing past experiences and best practices in valve design, with the goal of drafting a new standard by the end of 2025. This effort is expected to significantly reduce risks and enhance the reliability of NASA’s missions.
Bearing Life Testing: A Step Forward in Spacecraft Durability
In a bid to improve the performance and longevity of spacecraft components, the Mechanical Systems TDT recently completed an extensive bearing life test involving 40 motors. These motors were equipped with either pairs of all-steel bearings or hybrid bearings containing silicon nitride balls. The test revealed that hybrid bearings outperformed their all-steel counterparts, and bearings with higher conformity (54%) showed better durability than those with lower conformity (52%). Remarkably, some bearings endured over five billion revolutions and remained in excellent condition upon inspection. These findings, which are set to be published after thorough analysis, could lead to significant advancements in the design and construction of spacecraft bearings, ultimately enhancing mission success rates.
Evaluating the X-57 Electric Aircraft Design
The Aeronautics Mission Directorate recently enlisted the Mechanical Systems TDT to evaluate the design of the electric cruise motors on the X-57 aircraft. This request was part of a broader effort to ensure that the project’s timeline and objectives were met. In response, the TDT conducted an onsite visit and participated in numerous technical discussions. After a comprehensive review, the team provided valuable feedback and recommendations for higher-level risk assessments. Their insights have been instrumental in refining the design and ensuring the project’s success.
Addressing Anomalies in the CLARREO Pathfinder
The Climate Absolute Radiance and Refractivity Observatory (CLARREO) Pathfinder is tasked with taking highly accurate measurements of reflected solar radiation to improve our understanding of Earth’s climate. During functional testing, engineers detected an unexpected noise in the HySICS pointing system. Upon reviewing the design and inspection reports, TDT members discovered that the inner ring of the bearing was moving on the shaft, causing the noise. The application of lubricant to this interface resolved the issue, allowing the project to stay on track without incurring additional costs. This incident highlights the importance of thorough testing and the value of having expert teams like the TDT on hand to troubleshoot and resolve technical issues.
Extending the Longevity of the Perseverance Rover’s Drive Actuators
With changes to its mission on Mars, the Perseverance Rover is now required to travel much farther than initially planned. Originally designed to cover 20 kilometers, the rover must now traverse approximately 91 kilometers to facilitate the transfer of Mars sample tubes to the Sample Retrieval Lander. Given that the wheel drive actuators had only been tested for 40 kilometers, an extended life test was deemed necessary. The Office of the Chief Engineer (OCE) Science Mission Directorate assembled an Independent Review Team (IRT), which included members from the NESC Mechanical Systems TDT. The team provided essential feedback that improved the test plan and identified software issues affecting brake life. Thanks to these efforts, the life test has already achieved 40 kilometers out of the 137-kilometer goal, with ongoing software updates sent to the rover to further enhance brake durability.
Orion Crew Module Hydrazine Valve Challenges
When a hydrazine valve in the Orion crew module failed to close properly, the production team sought assistance from the Mechanical Systems TDT. A team member visited the valve manufacturer and discovered that the valve shared similar issues with a previously assessed 12-inch Space Launch System (SLS) prevalve. This insight prompted a comprehensive review of the valve vendor’s detailed drawings and assembly procedures. The team recommended a redesign and requalification, a suggestion that has now been escalated to high-level discussions with Lockheed Martin’s Vice President for Mission Success and Chief Engineer for Orion. This proactive approach underscores the critical role of the TDT in ensuring the safety and success of NASA’s missions.
In conclusion, the NESC Mechanical Systems TDT plays an indispensable role in supporting and advancing NASA’s diverse array of projects. Their expertise in mechanical systems not only addresses current technical challenges but also lays the groundwork for future innovations. By fostering a collaborative environment and mentoring the next generation of engineers, the TDT ensures that NASA remains at the forefront of space exploration and technological advancement. For further details, you can refer to the original source at NASA’s official website.
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