NASA NTRS · 20240007549
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David Hamilton. 2024-06-28. David Hamilton Experience. https://ntrs.nasa.gov/citations/20240007549
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NASA is developing an expendable heavy lift launch vehicle capability, the Space Launch System, to support lunar and deep space exploration. To support this capability, an updated ground infrastructure is required including modifying an existing Mobile Launcher system. The Mobile Launcher is a very large heavy beam/truss steel structure designed to support the Space Launch System during its buildup and integration in the Vehicle Assembly Building, transportation between the Vehicle Assembly Building and launch pad 39B by the Crawler Transporter, and provides the launch platform at the launch pad. As part of the Verification and Validation of the Mobile Launcher and Crawler Transporter, two rollouts of the Mobile Launcher transported by the Crawler Transporter, Integrated System Verification and Validation (ISVV) 005 and 010, have been performed to demonstrate the Crawler Transporter’s ability to transport the Mobile Launcher. ISVV-005 occurred in September 2018 and ISVV-010 occurred in late June 2019. ISVV-005 and ISVV-010 also provided the opportunity to gather data that can be used identify the Mobile Launcher on the Crawler Transporter rollout modal characteristics and refine the estimates of the Artemis I integrated launch vehicle rollout forcing functions. While the rollout environment has historically produced relatively small launch vehicle structural loads for the Saturn/Apollo and Space Shuttle programs in comparison to launch and ascent loads, these relatively small structural loads are inputs to structural fatigue analyses. The same holds true for the Space Launch System. Because the rollout forces acting on the Mobile Launcher and the Crawler Transporter are not directly measurable, Operational Modal Analysis techniques, instead of traditional Experimental Modal Analysis techniques, provide an empirical means to identify the Mobile Launcher on the Crawler Transporter rollout modal characteristics. The ISVV-010 rollout modal characteristics provide important supplemental modal information, which along with the Mobile Launcher modal test that was performed in June 2019 immediately prior to ISVV-010 rollout, combine to reduce uncertainty in the test correlated Mobile Launcher on the Crawler Transporter finite element model. A well test correlated finite element model will play a key role in the Building Block approach the Space Launch System program has implemented as part of its certification process for the Artemis I flight and in refining the Artemis I rollout forcing functions. At the time of the ISVV-005 rollout in September 2018, the Mobile Launcher was still undergoing construction, and therefore its modal characteristics are not directly comparable to those of the Mobile Launcher during the June 2019 Mobile Launcher modal test and subsequent ISVV-010 rollout. Hence the ISVV-005 rollout modal characteristics will not be looked at in this paper. This paper will briefly describe the Mobile Launcher and Crawler Transporter physical characteristics, ISVV-010 rollout data collection, the challenges in implementing Operational Modal Analysis techniques due in part to the Crawler Transporter harmonics, and how these challenges were overcome to obtain the ISVV-010 Mobile Launcher on the Crawler Transporter rollout modal characteristics.
This presentation is a review of the timeline for Apollo's approach to Planetary Protection, then known as Planetary Quarantine. Return of samples from Apollo 11, 12 and 14 represented NASA's first attempts into conducting what is now known as Restricted Earth Return, where return of samples is undertaken by the Agency with the utmost care for the impact that the samples may have on Earth's environment due to the potential presence of microbial or other life forms that originate from the parent body (in this case, Earth's Moon).
A fortuitous arrangement of a west-facing solar cell and a bracket on the Apollo 12 ALSEP (Apollo Lunar Surface Experiments Package) has allowed us to precisely determine the relative position of the Sun near sunset relative to the Apollo 12 central station over a period of nearly 8 years. The small bracket, mounted on the central station due west of the cell, casts a shadow on the cell near sunset, decreasing the output of the cell proportional to the area of shadow covering the cell. The pattern of shadowing by the bracket gives good agreement with the known change of solar azimuth on a yearly timescale, but the pattern gradually but constantly changed from year-to-year, in a manner inconsistent with the known and changing position of the Sun.