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    • By NASA
      Key adapters for the first crewed Artemis missions are manufactured at NASA’s Marshall Space Flight Center in Huntsville, Alabama. The cone-shaped payload adapter, left, will debut on the Block 1B configuration of the SLS rocket beginning with Artemis IV, while the Orion stage adapters, right, will be used for Artemis II and Artemis III. NASA/Sam Lott A test version of the SLS (Space Launch System) rocket’s payload adapter is ready for evaluation, marking a critical milestone on the journey to the hardware’s debut on NASA’s Artemis IV mission.
      Comprised of two metal rings and eight composite panels, the cone-shaped payload adapter will be part of the SLS Block 1B configuration and housed inside the universal stage adapter atop the rocket’s more powerful in-space stage, called the exploration upper stage. The payload adapter is an evolution from the Orion stage adapter used in the Block 1 configuration of the first three Artemis missions that sits at the topmost portion of the rocket and helps connect the rocket and spacecraft.
      “Like the Orion stage adapter and the launch vehicle stage adapter used for the first three SLS flights, the payload adapter for the evolved SLS Block 1B configuration is fully manufactured and tested at NASA’s Marshall Space Flight Center in Huntsville, Alabama,” said Casey Wolfe, assistant branch chief for the advanced manufacturing branch at Marshall. “Marshall’s automated fiber placement and large-scale integration facilities provide our teams the ability to build composite hardware elements for multiple Artemis missions in parallel, allowing for cost and schedule savings.”
      Teams at Marshall manufactured, prepared, and move the payload adapter test article. The payload adapter will undergo testing in the same test stand that once housed the SLS liquid oxygen tank structural test article.NASA Teams at Marshall manufactured, prepared, and move the payload adapter test article. The payload adapter will undergo testing in the same test stand that once housed the SLS liquid oxygen tank structural test article.NASA Teams at Marshall manufactured, prepared, and move the payload adapter test article. The payload adapter will undergo testing in the same test stand that once housed the SLS liquid oxygen tank structural test article.NASA Teams at Marshall manufactured, prepared, and move the payload adapter test article. The payload adapter will undergo testing in the same test stand that once housed the SLS liquid oxygen tank structural test article. NASA At about 8.5 feet tall, the payload adapter’s eight composite sandwich panels, which measure about 12 feet each in length, contain a metallic honeycomb-style structure at their thickest point but taper to a single carbon fiber layer at each end. The panels are pieced together using a high-precision process called determinant assembly, in which each component is designed to fit securely in a specific place, like puzzle pieces.
      After manufacturing, the payload adapter will also be structurally tested at Marshall, which manages the SLS Program. The first structural test series begins this spring. Test teams will use the engineering development unit – an exact replica of the flight version of the hardware – to check the structure’s strength and durability by twisting, shaking, and applying extreme pressure.
      While every Block 1B configuration of the SLS rocket will use a payload adapter, each will be customized to fit the mission’s needs. The determinant assembly method and digital tooling ensure a more efficient and uniform manufacturing process, regardless of the mission profile, to ensure hardware remains on schedule. Data from this test series will further inform design and manufacturing processes as teams begin manufacturing the qualification and flight hardware for Artemis IV.
      NASA is working to land the first woman, first person of color, and its first international partner astronaut on the Moon under Artemis. SLS is part of NASA’s backbone for deep space exploration, along with the Orion spacecraft and Gateway in orbit around the Moon and commercial human landing systems, next-generational spacesuits, and rovers on the lunar surface. SLS is the only rocket that can send Orion, astronauts, and supplies to the Moon in a single launch.
      News Media Contact
      Corinne Beckinger
      Marshall Space Flight Center, Huntsville, Ala.
      256.544.0034
      corinne.m.beckinger@nasa.gov
      View the full article
    • By NASA
      The year 2023 was productive for the Loads & Dynamics (L&D) Technical Discipline Team (TDT). New shock and modal analysis techniques were developed and mentoring the next generation of NASA discipline experts continued. Additionally, NESC Technical Bulletin No. 23-3, New Transient Finite Energy Shock Prediction Methodology, was released.

      Early Career Community Nurtures Development of NASA’s Future Discipline Leaders

      NASA has acknowledged the need for “attracting and advancing a highly skilled, competent, and diverse workforce in order to cultivate an innovative work environment…” as stated in Objective 3.1 of the 2014 NASA Strategic Plan.

      A survey conducted in 2014 by Emerge, the early-career professional group at JSC, showed that recent hires believe that “communication and collaboration amongst organizations” is a key area of improvement, while “lack of opportunities for professional growth” is the top reason why they would consider leaving the Agency. This, when coupled with NASA’s aging workforce (the average age as of 2016 was 49), stresses the importance of capturing knowledge to pass along to the next generation of NASA engineers. 

      The Structures, Loads and Dynamics, Mechanical Systems, and Materials (SLAMMS) disciplines have also been identified as critical fields for the advancement of NASA’s strategic vision, which emphasizes the importance of developing and retaining engineers in those areas. Consequently, the SLAM(M)S Steering Committee (Materials was not initially included), comprising center SLAMS Division/Branch Chiefs and NASA Technical Fellows, formed the Young Professionals Forum in 2012, which evolved into the current Early Career Forum (ECF) in 2017, and was expanded to provide year-round activities (e.g., monthly meetings, training opportunities) for the Early Career Community (ECC). 

       Over the lifetime of the ECC, the SLAMS Steering Committee was dissolved, and the stewardship of the ECC relied on the Technical Fellows, who empowered ECC leaders to take on the primary responsibility of planning and running the ECC and ECF events. 

      Today’s SLAMMS Early Career Community   

      Within the past few years, a new SLAMMS Division/Branch Chief collaboration group was formed, called the SLAMMS Leadership Working Group (LWG), and is led by James  Loughlin, GSFC Mechanical Systems Division Chief, with co-lead Elonso Rayos, JSC Structures Engineering Assistant Division Chief. The LWG is a forum focused on capability sustainment, discipline technical challenges, and workforce concerns. For example, disparate Agency technical resource access is discussed, collaboration is coordinated, and critical gaps in expertise are filled using cross-Agency cooperation. 
      The current SLAMMS ECE leadership team includes Khadijah Shariff (JSC-Structures), Dr. Matthew Chamberlain (LaRC- Loads & Dynamics), Dr. Jonathan Sauder (JPL-Mechanical Systems), and Cassie Smith (JPL-Mechanical Systems). NASA Technical Fellows supporting SLAMMS are Deneen Taylor (Structures), Dr. Dexter Johnson (Loads & Dynamics), Dr. Michael Dube (Mechanical Systems), and Dr. Bryan McEnerney (Materials).

      The SLAMMS Early Career Forum

      The ECF is the annual “face-to-face” workshop for the community. The ECF is held at a different NASA center each year and features technical presentations by early career engineers (ECE), splinter sessions with NASA Technical Fellows, mentor presentations, facility tours, networking events, design challenges, and evening social activities to advance the SLAMMS disciplines and develop NASA’s future workforce. The ECF features technical presentations given by the ECEs to their peers, senior engineers, and Technical Fellows.   
      The 12th Annual SLAMMS ECF was held at MSFC and virtually. Sixty-six ECEs, Technical Fellows, TDT mentors, and discipline managers from the SLAMMS LWG were in attendance. ECEs from 8 centers made 16 technical presentations and 18 posters, which were ranked by mentors for the top awards. Multiple splinter sessions provided ECEs with opportunities to ask career-related advice from Technical Fellows, project and systems management, and individuals experienced in design, analysis, and testing. In addition, there was a detailed discussion for each of the technical disciplines represented at the forum, and multiple site tours were provided. 

      Attendees of the 12th annual SLAMMS EFC at MSFC 2023.  The Future of the SLAMMS ECC 

      The SLAMMS ECC will continue to evolve as discussions with the ECE leadership team and Technical Fellows continue towards mapping its future. SLAMMS is igniting cross-Agency collaboration for future generations. Its current goals include communication and collaboration among organizations, professional growth of early career engineers, knowledge capturing for the next generation of NASA engineers, and developing and retaining engineers in the specific SLAMMS disciplines. It will nurture the technical, professional, and personal development of NASA’s next generation of SLAMMS discipline leaders. 
      Awards presented by Dr. Dexter Johnson. Left: “Best Presentation” (Mitchell Haglund-GSFC) Right: “Best Poster” (Tessa Fedotowsky-MSFC).
      Updating Guidance on Shock Qualification and Acceptance Test Requirements  

      The L&D TDT has completed work that will have a positive impact on shock testing of NASA flight hardware. Pyroshock is the transient response of a structure to loading induced by activation of attached or incorporated pyrotechnic devices. Typical pyrotechnic devices include frangible bolts, separation nuts, and pin pullers that are used to assemble, separate, and reconfigure spaceflight hardware during a mission. Shocks can easily propagate through structure and damage sensitive components. Thus, successful pyroshock testing is considered essential to mission success. At the request of the Gateway Program Chief Engineer, the NASA Chief Engineer initiated an inquiry to reevaluate shock testing approaches for both unit and major assembly flight hardware and requested recommendations for potential revisions to NASA-STD-7003B, Pyroshock Test Criteria, that would clarify the guidance and applicability to new programs. The work delves into topics of shock acceptance and qualification testing for unit and major assemblies, shock test tolerances, shaker shock testing, and the distinction between mechanical shock and pyroshock testing. It also provides recommendations for their inclusion in the next Agency-wide revision of NASA-STD-7003B.  

      Current NASA-STD-7003B Requirements 

      Unit and major assembly flight hardware acceptance and qualification testing are discussed in NASA-STD-7003B. It requires that all units go through shock qualification testing, with few exceptions. The purpose of a qualification test is to verify the design integrity of the flight hardware. The standard calls for pyroshock qualification testing of nonflight hardware for externally induced environments to be performed with a 3 dB margin added to the maximum predicted environment (MPE), with two shocks per each orthogonal axis. Qualification tests are performed on hardware that will not be flown but is manufactured using the same drawings, materials, tooling, processes, inspection methods, and personnel competency as used for the flight hardware. The flight hardware is not recommended to go through shock test, therefore, it lacks workmanship screening testing. The required random vibration (RV) test is considered to be a partial workmanship screening, covering only up to 2000 Hz. A full workmanship screening test for unique and sensitive hardware that may have modes above 2000 Hz needs to be evaluated on a case-by-case basis by an expert in pyroshock dynamics and approved within a program’s risk management system and/or governing board. 

      The major assembly acceptance and qualification testing are not recommended, considering that the MPE and design margin cannot be demonstrated at the system-level tests. The major assembly unmargined testing, however, may achieve three objectives. First, the functional demonstration of shock separation devices—probably the most important part of the major assembly level testing—demonstrates the source electrical and mechanical hardware functions as expected, and the interface separates without any issues. Second, the major assembly testing provides the validation of the unit shock environments.  

      Third, the major assembly testing provides transfer functions (TF) that may help to estimate the attenuation—and in some cases structural amplifications—throughout the system with all assemblies in flight configuration. NASA-STD-7003B contains discussions for the first two major assembly test objectives. However, there are no discussions on the third test objective related to the TFs. The TFs provide qualitative assessment of shock propagation paths and attenuations at joints and interfaces. The TFs may be used qualitatively as attenuation is highly dependent on the materials and joint construction and may be different if there are changes in the system configuration.  

      Suggestions for Improving NASA-STD-7003B 

      The shock tolerance specified in NASA-STD-7003B is ±6 dB from 100 Hz to 3 kHz and +9/-6 dB above 3 kHz. The constant ±6 dB tolerance bandwidths across all frequencies are possible, as many existing shock simulation systems are able to simulate shock signatures that fall within these tolerances without difficulty. These tolerances are based on practical test implementation and shock simulation equipment consideration. The tolerance tightening should be considered at the flight hardware resonant frequencies to avoid over/under testing. However, if detonator or explosive shock simulation systems are used to qualify flight hardware, the shock tolerances above 3 kHz may be kept at +9/-6 dB.  

      Measurements from many different pyro/non-pyro separation systems have been shown to have broader shock signatures and do not support the mechanical shock as being applicable to low- and mid-frequency shocks only. The standard discusses this topic and has an example of far field SRS indicating shock energy above 2 kHz. The future revision should clarify the applicability of the mechanical shocks to be broader and not to be limited to 2 kHz and below (see figure below). 
       
      An example shock response spectrum (SRS) obtained from a mechanical shock separation system, indicating a broad signature is produced by pyro devices.    The Gateway Program has benefitted from the updated guidance recommended for NASA-STD-7003B.  Even though shaker shock testing has been used in the past and is still used by some NASA organizations and contractors, there are multiple technical issues with this type of testing. The shaker-generated shock signatures in the low- and mid-frequency range (typically up to ~2 kHz) provide severe shock environments that may lead to structural failures. Most shakers are also not able to generate SRS above ~2 kHz, therefore, shaker shock test is deficient in meeting the shock requirement up to 10 kHz frequency. NASA-STD-7003B does not recommend the shaker method of shock testing due to the above limitations. This should be emphasized more in the standard. The shaker shock simulation test may be used if it is able to generate time histories that resemble signatures generated by space separation devices, and SRS levels meet the entire frequency range requirements. 

      For the next NASA-STD-7003B revision, recommendations are being made to include acceptance RV testing for partial workmanship screening testing, add the TFs to be used as qualitative information in assessing the attenuation in the structural shock paths, change the shock tolerance to ±6 dB across all frequencies, and consider mechanical shocks to be broader and not limited to low- and mid-frequency SRSs. 

      In summary, the updated guidance provides clarification to the question/uncertainty of the applicability of historical guidance to current programs, while ensuring proper applicability to future programs. This work directly benefitted the Gateway Program, and could potentially benefit the Human Lander System (HLS). 
      References: 
      Kolaini, A.R., Kinney, T., and Johnson, D.: Guidance on Shock Qualification and Acceptance Test Requirements. SCLV, June 27-29, 2023, EL Segundo, CA. Available from: https://ntrs.nasa.gov/citations/20230009008   NASA-STD-7003B, “Pyroshock Test Criteria,” June 11, 2020. 
      HLS could benefit from the updated guidance recommended for NASA-STD-7003B. Credit: Blue Origin View the full article
    • By European Space Agency
      Image: Laser light sabre View the full article
    • By NASA
      NASA/Sam Lott A test version of the universal stage adapter for NASA’s more powerful version of its SLS (Space Launch System) rocket arrived to Building 4619 at NASA’s Marshall Space Flight Center in Huntsville, Alabama, Feb. 22 from Leidos in Decatur, Alabama. The universal stage adapter will connect the rocket’s upgraded in-space propulsion stage, called the exploration upper stage, to NASA’s Orion spacecraft as part of the evolved Block 1B configuration of the SLS rocket. It will also serve as a compartment capable of accommodating large payloads, such as modules or other exploration spacecraft. The SLS Block 1B variant will debut on Artemis IV and will increase SLS’s payload capability to send more than 84,000 pounds to the Moon in a single launch.
      In Building 4619’s Load Test Annex High Bay at Marshall, the development test article will first undergo modal testing that will shake the hardware to validate dynamic models. Later, during ultimate load testing, force will be applied vertically and to the sides of the hardware. Unlike the flight hardware, the development test article has flaws intentionally included in its design, which will help engineers verify that the adapter can withstand the extreme forces it will face during launch and flight. The test article joins an already-rich history of rocket hardware that has undergone high-and-low pressure, acoustic, and extreme temperature testing in the multipurpose, high-bay test facility; it will be tested in the same location that once bent, compressed, and torqued the core stage intertank test article for SLS rocket’s Block 1 configuration. Leidos, the prime contractor for the universal stage adapter, manufactured the full-scale prototype at its Aerospace Structures Complex in Decatur.
      NASA is working to land the first woman, first person of color, and its first international partner astronaut on the Moon under Artemis. SLS is part of NASA’s backbone for deep space exploration, along with the Orion spacecraft and Gateway in orbit around the Moon and commercial human landing systems, next-generational spacesuits, and rovers on the lunar surface. SLS is the only rocket that can send Orion, astronauts, and supplies to the Moon in a single launch.
      News Media Contact
      Corinne Beckinger
      Marshall Space Flight Center, Huntsville, Ala.
      256.544.0034
      corinne.m.beckinger@nasa.gov
      View the full article
    • By NASA
      The ISRU Pilot Excavator is tested in a blacked out facility with minimal lighting that mimics the harsh, feature-less terrain of the Moon.NASA The ISRU Pilot Excavator is tested in a blacked out facility with minimal lighting that mimics the harsh, feature-less terrain of the Moon.NASA Harsh, low-angle sunlight, long and dark shadows, and a featureless terrain will make navigation difficult when NASA’s ISRU Pilot Excavator (IPEx) is sent to the Moon. Because of this, the IPEx team has begun testing various approaches to autonomously drive the excavator in a specially constructed rock yard that mimics these environmental conditions. The team plans to publish the data sets from these unique tests later this year.
      View the full article
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