{"id":38098,"date":"2019-03-13T17:32:13","date_gmt":"2019-03-13T09:32:13","guid":{"rendered":"https:\/\/wp-productionenv-bjg9h2g2bgg5b8aa.southeastasia-01.azurewebsites.net\/news\/despite-political-drama-nasa-boeing-press-on-with-sls-core-stage-structural-loads-tests-at-marshall\/"},"modified":"2019-03-13T17:32:13","modified_gmt":"2019-03-13T09:32:13","slug":"despite-political-drama-nasa-boeing-press-on-with-sls-core-stage-structural-loads-tests-at-marshall","status":"publish","type":"post","link":"https:\/\/starpath.global\/news\/despite-political-drama-nasa-boeing-press-on-with-sls-core-stage-structural-loads-tests-at-marshall\/","title":{"rendered":"Despite political drama, NASA, Boeing press on with SLS Core Stage structural loads tests at Marshall"},"content":{"rendered":"<p>NASA and Space Launch System (SLS) Core Stage prime contractor Boeing are in the middle of a busy period of testing structural test articles (STA) at the Marshall Space Flight Center in Huntsville, Alabama.\n<\/p>\n<p>One team is busy running test cases on the intertank STA in a large, indoor test facility while another is preparing the liquid hydrogen (LH2) tank STA for its test runs in another large, but outdoor stand down the road.<\/p>\n<p>The continued testing shows a program that has not been impacted by the uncertainty created by comments made by NASA administrator&nbsp;Jim Bridenstine over recent days, pointing to evaluations that dampen SLS\u2019 viability for missions it had already been tasked with.<\/p>\n<p>The latest potential change of plan was noted on Wednesday morning, per options to launch Exploration Mission -1 (EM-1) on two commercial Heavy Lift rockets.<\/p>\n<p><iframe id=\"twitter-widget-1\" scrolling=\"no\" frameborder=\"0\" allowtransparency=\"true\" allowfullscreen=\"true\" class=\"\" style=\"position: static; visibility: visible; width: 0px; height: 0px; display: block; flex-grow: 1;\" title=\"X Post\" src=\"https:\/\/platform.twitter.com\/embed\/Tweet.html?creatorScreenName=NASASpaceflight&amp;dnt=true&amp;embedId=twitter-widget-1&amp;features=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%3D%3D&amp;frame=false&amp;hideCard=false&amp;hideThread=false&amp;id=1105859576023445506&amp;lang=en&amp;origin=https%3A%2F%2Fwww.nasaspaceflight.com%2F2019%2F03%2Fnasa-boeing-sls-core-stage-structural-tests-marshall%2F&amp;sessionId=8fec1d3d2f126e2533a59249abce65e2a207d73c&amp;siteScreenName=NASASpaceflight&amp;theme=light&amp;widgetsVersion=6a3ad42b224df%3A1778106238597&amp;width=550px\" data-gtm-yt-inspected-14=\"true\" data-gtm-yt-inspected-21=\"true\" data-tweet-id=\"1105859576023445506\"><\/iframe><\/p>\n<blockquote class=\"twitter-tweet\" data-width=\"550\" data-dnt=\"true\" data-twitter-extracted-i1783498940583332687=\"true\">\n<p lang=\"en\" dir=\"ltr\">We need to consider all options to meet the Exploration Mission-1 target launch date of June 2020, including launching on commercial rockets. pic.twitter.com\/fR5b2NzPtg<\/p>\n<p>\u2014 Jim Bridenstine (@JimBridenstine) March 13, 2019<\/p>\n<\/blockquote>\n<p>However, that remains just an evaluation, set to be concluded in April and not an official change of plan. As such, and as&nbsp;expected, SLS is continuing to press through its test cycle unabated.<\/p>\n<p>Per the latest milestones, the test articles are being squeezed, stretched, twisted, and bent after several hours of freezing to simulate the forces and environment that flight structures are expected to see during launch and ascent into space. The test cases will help qualify the structures for first flight and validate the fidelity of computer models that can continue to be used for future analysis of virtual cases.<\/p>\n<p>The team is also testing the structures to verify they are designed with the required factor of safety above and beyond expected launch conditions, and is planning on taking advantage of the structures to evaluate how much additional margin there is above the required safety level.<\/p>\n<p>NASA mission patches<path d=\"M7.59009 18.59L9.00009 20L17.0001 12L9.00009 4L7.59009 5.41L14.1701 12\" style=\"animation: initial !important; background: initial !important; border: 0px !important; box-shadow: none !important; color: inherit !important; cursor: inherit !important; direction: inherit !important; display: inline !important; fill: currentcolor !important; filter: initial !important; float: none !important; margin: 0px !important; opacity: initial !important; outline: 0px !important; overflow: initial !important; padding: 0px !important; stroke: initial !important; transform: initial !important; vertical-align: initial !important; visibility: inherit !important;\"><\/path>Space Shuttle models<path d=\"M7.59009 18.59L9.00009 20L17.0001 12L9.00009 4L7.59009 5.41L14.1701 12\" style=\"animation: initial !important; background: initial !important; border: 0px !important; box-shadow: none !important; color: inherit !important; cursor: inherit !important; direction: inherit !important; display: inline !important; fill: currentcolor !important; filter: initial !important; float: none !important; margin: 0px !important; opacity: initial !important; outline: 0px !important; overflow: initial !important; padding: 0px !important; stroke: initial !important; transform: initial !important; vertical-align: initial !important; visibility: inherit !important;\"><\/path>Aerospace &amp; Defense<path d=\"M7.59009 18.59L9.00009 20L17.0001 12L9.00009 4L7.59009 5.41L14.1701 12\" style=\"animation: initial !important; background: initial !important; border: 0px !important; box-shadow: none !important; color: inherit !important; cursor: inherit !important; direction: inherit !important; display: inline !important; fill: currentcolor !important; filter: initial !important; float: none !important; margin: 0px !important; opacity: initial !important; outline: 0px !important; overflow: initial !important; padding: 0px !important; stroke: initial !important; transform: initial !important; vertical-align: initial !important; visibility: inherit !important;\"><\/path>\n<p>     (adsbygoogle = window.adsbygoogle || []).push({});<\/p>\n<p>Current plans are for the last article, the liquid oxygen (LOX) tank STA, to be delivered to Marshall and set up for testing somewhere in the middle of the year while LH2 tank STA test runs are being executed.<\/p>\n<p>Halfway through Intertank STA test cases<\/p>\n<p>The team running the structural qualification test cases on the intertank STA was about halfway through them in early March. \u201cWe\u2019re about halfway through,\u201d Matt Cash, NASA Test Conductor for the SLS Intertank Structural Qualification Test, said in a March 4 interview. \u201cWe have gone past the influence load cases, where you\u2019re really working on model correlation and systems checkouts and we\u2019re into the flight-like or flight-level load cases.\u201d<\/p>\n<p>The structural loads tests run on the SLS Core Stage structural test articles are grouped into three sets, beginning with influence load cases. \u201cInfluence are half of the flight magnitude, so they are fifty-percent of the flight load and they are typically unidirectional,\u201d Cash explained. \u201cSo we\u2019ll torque clockwise, we\u2019ll torque counterclockwise, we\u2019ll apply uniform compression, we\u2019ll apply uniform bending.\u201d<\/p>\n<p><img fetchpriority=\"high\" decoding=\"async\" aria-describedby=\"caption-attachment-60607\" class=\"wp-image-60607 size-full\" src=\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/P1120887.35pct.jpg\" alt=\"\" width=\"1714\" height=\"1286\" srcset=\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/P1120887.35pct.jpg 1714w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/P1120887.35pct-350x263.jpg 350w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/P1120887.35pct-466x350.jpg 466w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/P1120887.35pct-768x576.jpg 768w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/P1120887.35pct-1170x878.jpg 1170w\" sizes=\"(max-width: 1714px) 100vw, 1714px\"><\/p>\n<p id=\"caption-attachment-60607\" class=\"wp-caption-text\">Intertank STA in the test stand at the Building 4619 load test annex at Marshall. Credit: Philip Sloss for NSF\/L2.<\/p>\n<p>\u201cAt the SRBs (attach points), you\u2019ll go uniform compression, uniform tension, pinch. You\u2019ll run through a pinch case. So you\u2019re not combining axial moment, shear, bending, torque,\u201d he continued.<\/p>\n<h4 class=\"widget-title penci-border-arrow\">See Also<\/h4>\n<ul>\n<li>SLS Forum Section<\/li>\n<li>L2 SLS Section<\/li>\n<li>L2 SRB Section<\/li>\n<li>Click here to Join L2<\/li>\n<\/ul>\n<p>\u201cYou want to do those first so you see that [the article] is going to react the way you think before you really add in some loads,\u201d Heather Haney, Dry Structures Test Lead for NASA\u2019s SLS Stages Office, added.<\/p>\n<p>After the influence cases, then dynamic cases using limit loads and finally ultimate loads are run with combinations of different types of loads. For the intertank, a total of forty-one tests are planned currently. Twenty-one influence cases were completed last year, they are in the middle of eighteen limit load cases, with two ultimate load cases at the end.<\/p>\n<p>Limit loads are one-hundred percent of expected flight loads and ultimate loads are one-hundred forty percent to test that the structure meets the requirement of having a factor of safety of 1.4.<\/p>\n<p>\u201cWe\u2019ve done twenty-nine cases so far,\u201d Cash noted. \u201cRight now I think we\u2019re looking at the first of April to be done with that qual testing part,\u201d Haney added. They are typically running tests twice a week.<\/p>\n<p>The STA arrived at Marshall in March, 2018, and after being configured in the test stand the influence load cases were run in July. Moving into limit testing was then delayed.<\/p>\n<p>\u201cWe took a break. We had some technical challenges that we had to work out,\u201d Cash explained. \u201cYou want to make sure you\u2019re meeting all your requirements so we took time to do that, so that\u2019s why you\u2019re seeing a lull between influence end and the limit start,\u201d Haney added.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-60608\" class=\"wp-image-60608 size-full\" src=\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/P1120886.35pct.jpg\" alt=\"\" width=\"1714\" height=\"1286\" srcset=\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/P1120886.35pct.jpg 1714w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/P1120886.35pct-350x263.jpg 350w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/P1120886.35pct-466x350.jpg 466w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/P1120886.35pct-768x576.jpg 768w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/P1120886.35pct-1170x878.jpg 1170w\" sizes=\"(max-width: 1714px) 100vw, 1714px\"><\/p>\n<p id=\"caption-attachment-60608\" class=\"wp-caption-text\">A wide shot of the intertank STA and test stand in the central high bay of the 4619 load test annex at Marshall. Credit: Philip Sloss for NSF\/L2.<\/p>\n<p>And then the government shutdown for five weeks, which forced the live test system normally maintained in a ready state to be powered off and safed. \u201cWe safed all of our systems,\u201d Cash said.<\/p>\n<p>\u201cThe load plates will actually move, you\u2019ll get drift in all of these cylinders so mechanical stops are installed, you turn off purges, you shut down systems.\u201d After returning from furlough, it took an additional week or so get back to a test-ready state.<\/p>\n<p>\u201cEvery time you turn very, very expensive data systems off something doesn\u2019t come back on,\u201d he added. We had some of those challenges in there, we had some hardware failure to go work out, but we fixed them relatively quickly.<\/p>\n<p>The test article is set up in its test stand inside the Central High Bay in the Building 4619 load test annex (LTA) at Marshall. \u201cWe can test articles up to sixty feet in diameter and up to thirty million pounds of compressive loads, they are very few facilities on the planet with this capability,\u201d Cash noted.<\/p>\n<p>The test article is comprised of an intertank qualification article, which is structurally identical to a flight intertank article, with a simulator attached on each end. It is oriented upside down in the stand, with each simulator attached to a load ring.<\/p>\n<p>\u201cThe original drop of intertank loads we got exceeded the crosshead capacity, so we inverted the test article,\u201d Cash explained. \u201cI think on our highest loaded case, we\u2019re at thirteen million pounds of compressive load. We\u2019re going to do 4.8 [million pounds] on the crosshead and about 4.2 [million pounds] on each SRB load plate.\u201d<\/p>\n<p>Loads are applied to the article through hydraulic load cylinders attached at locations around the test article. \u201cWe\u2019ve got a hundred different actuators we\u2019re using to apply various load combinations to the intertank,\u201d Cash noted. \u201cThere\u2019s forty-eight hydraulic actuators that bolt to the crosshead. Those will do the engine loads, compression and bending and tension.\u201d<\/p>\n<p>\u201cAnd then you see these two orange plates on the east and west, those are Solid Rocket Booster attach points that you can see that are attached to the plates,\u201d he continued. \u201cActually the hat, the round piece. That is actually a simulator that bolts to our load plates, the actual thrust fitting is inside that hat. Twenty actuators on each side attach to a plate that will apply loads to a single point.\u201d<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-60606\" class=\"wp-image-60606 size-full\" src=\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/P1080246.35pct.jpg\" alt=\"\" width=\"1714\" height=\"1286\" srcset=\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/P1080246.35pct.jpg 1714w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/P1080246.35pct-350x263.jpg 350w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/P1080246.35pct-466x350.jpg 466w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/P1080246.35pct-768x576.jpg 768w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/P1080246.35pct-1170x878.jpg 1170w\" sizes=\"(max-width: 1714px) 100vw, 1714px\"><\/p>\n<p id=\"caption-attachment-60606\" class=\"wp-caption-text\">One of the \u201ctop hats\u201d (middle left center) seen covering the SRB attach fittings on either side of the thrust beam that runs through the intertank. The covers facilitate applying the desired loads to the attach fittings and the thrust beam. Credit: Philip Sloss for NSF\/L2.<\/p>\n<p>\u201cOne of the real challenges for this test is you\u2019ve got to apply loads into the actual thrust beam, which is basically a ball joint,\u201d he explained. We\u2019ve got twenty actuators that attach to a load plate that goes into a ball joint so it can swivel about all three axes. So we have taken painstaking care to make sure that we get that four million pound load at the perfect angle.\u201d<\/p>\n<p>Additional actuators are connected at the top of the inverted test article. \u201cEight actuators attach to those orange weldments, so we can do pure torsion, too, \u201d Cash added. \u201cWe can do shear in any clocking and pure torsion, both clockwise and counterclockwise.\u201d<\/p>\n<p>For the limit and ultimate load test cases, the mechanical interfaces at the intertank qualification article\u2019s flanges are also chilled down with cryogenic liquid nitrogen to more accurately simulate flight conditions. In addition to being bolted to ends of the stage\u2019s cryogenic tanks, most of the volume on the inside of the intertank is taken up by the aft dome of the liquid oxygen tank and the forward dome of the liquid hydrogen tank.<\/p>\n<p>\u201cJust one of the influence cases had cryo and it was independent from mechanical loads, that way you\u2019re understanding each joint,\u201d Cash said. \u201cWhen you take joints to minus three-hundred and twenty degrees materials behave differently and joint geometries actually change.\u201d<\/p>\n<p>Test days now start with flowing LH2 through ducting at both flanges. \u201cWe bring in first shift at 3:30, 4 am,\u201d he said.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-60610\" class=\"wp-image-60610 size-full\" src=\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/MSFC-1800342_large.jpg\" alt=\"\" width=\"1920\" height=\"1277\" srcset=\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/MSFC-1800342_large.jpg 1920w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/MSFC-1800342_large-350x233.jpg 350w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/MSFC-1800342_large-526x350.jpg 526w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/MSFC-1800342_large-768x511.jpg 768w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/MSFC-1800342_large-1170x778.jpg 1170w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/MSFC-1800342_large-585x390.jpg 585w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/MSFC-1800342_large-263x175.jpg 263w\" sizes=\"(max-width: 1920px) 100vw, 1920px\"><\/p>\n<p id=\"caption-attachment-60610\" class=\"wp-caption-text\">The intertank STA is moved into the test stand in late March, 2018. This view provides a clearer view of the some relative locations of the hydraulic loading equipment at the top and on the sides. Credit: NASA\/Emmett Given.<\/p>\n<p>\u201cI\u2019ll bring in a skeleton crew to get the article cold and then we\u2019ll bring in the rest of the test team at 7 or 8. It takes six hours to get thermally stable.\u201d<\/p>\n<p>Over two-thousand channels of data are being recorded during the current tests, with additional instrumentation added after the influence cases were completed bringing the total data channels up over 2800.<\/p>\n<p>\u201cPrimarily strain gauges, but we\u2019ve also got thermocouples,\u201d Cash noted. \u201cSo when you\u2019re making things cold, you\u2019ve got to thermally correct the strain so there are hundreds of thermocouples, there are twenty or thirty CLTSs (Cryogenic Linear Temperature Sensors), we\u2019ve got over a hundred deflection measurement points that we\u2019re doing with an optical [system].\u201d<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-58466\" src=\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2018\/10\/L2-banner@2x.jpg\" alt=\"\" width=\"4500\" height=\"2532\"><\/p>\n<p>\u201cFirst test I\u2019ve ever worked where we\u2019re completely reliant on an optical deflection measurement system, that\u2019s Boeing proprietary PhotoG system. We\u2019ve got a control room adjacent to the high bay where we\u2019ve got all our load control operators, cryo control operators, PhotoG operators, the data system operator. Obviously we record video and audio live for all of this.\u201d<\/p>\n<p>\u201cWe brought in two and a half million pounds of steel in addition to the facility and all of that is bolted together with over 25000 fasteners,\u201d he added. \u201cSo we\u2019ve got accelerometers located strategically to help us determine if any of our bolted joints slipped. We want to understand if we\u2019re seeing test article related stuff or test equipment related stuff.\u201d<\/p>\n<p>Structural qualification test cases also calibrate, update analytical models<\/p>\n<p>In addition to qualification of the different Core Stage structures, the loads tests also help to \u201canchor\u201d Boeing\u2019s analytical models that predict how the structures will respond them. The structural loads tests on live hardware are much more limited in the number of cases than virtual models that can analyze how the structures should behave in a broader set of conditions.<\/p>\n<p>\u201cAn analyst when he\u2019s designing or doing the analysis on say the intertank, they\u2019re looking at eight-hundred or a thousand load cases,\u201d Cash said. \u201cWe can\u2019t physically do a thousand test cases because we\u2019d damage the hardware, so what they do is they pare those cases down.\u201d<\/p>\n<p>\u201cSay for rollout, for instance \u2014 rolling out from the VAB (Vehicle Assembly Building) to the pad \u2014 they will look at all of the high-strain states at different conditions and will combine those into a test case. So we will have a limit case that is a combination of different rollout environments to hit all of the peak stress.\u201d<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-60612\" class=\"wp-image-60612 size-full\" src=\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/nac_march_2018_hill_-_smith_3-23-2018_final.Core-Stage-Intertank-STA.Slide-13.png\" alt=\"\" width=\"1290\" height=\"968\" srcset=\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/nac_march_2018_hill_-_smith_3-23-2018_final.Core-Stage-Intertank-STA.Slide-13.png 1290w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/nac_march_2018_hill_-_smith_3-23-2018_final.Core-Stage-Intertank-STA.Slide-13-350x263.png 350w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/nac_march_2018_hill_-_smith_3-23-2018_final.Core-Stage-Intertank-STA.Slide-13-466x350.png 466w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/nac_march_2018_hill_-_smith_3-23-2018_final.Core-Stage-Intertank-STA.Slide-13-768x576.png 768w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/nac_march_2018_hill_-_smith_3-23-2018_final.Core-Stage-Intertank-STA.Slide-13-1170x878.png 1170w\" sizes=\"(max-width: 1290px) 100vw, 1290px\"><\/p>\n<p id=\"caption-attachment-60612\" class=\"wp-caption-text\">A slide from a March, 2018, NASA presentation to the NASA Advisory Council showing the intertank test configuration and statistics about the facility. Credit: NASA.<\/p>\n<p>\u201cSome cases you don\u2019t have to test because they don\u2019t overstress the article, some do and you combine a subset of those flight cases,\u201d he added. \u201cBut we\u2019re really looking for a strain state in the article.\u201d<\/p>\n<p>The limit and ultimate load cases that are being tested on the different STAs should qualify the Core Stage structure to fly both in current Block 1 and future Block 1B configurations.<\/p>\n<p>\u201c[Boeing] took the worst cases from Block 1 and the worst cases from Block 1B and they combined them into a combined load set,\u201d Cash explained. Believe it or not, even though Block 1 is a different vehicle configuration as your trajectories change and your flight path changes and your payloads changes there are actually loads from Block 1 that are driving design and there are Block 1B loads that are driving design.\u201d<\/p>\n<p>\u201cBoeing\u2019s intent was to take a combined load set, an enveloping load set from both packages and qualify the intertank for that, so it\u2019s supposed to meet Block 1 and Block 1B [requirements]. It wasn\u2019t truly as simple as saying \u2018we\u2019re going to go qualify to Block 1B and ignore Block 1\u2019, because it\u2019s not that simple.\u201d<\/p>\n<p>The bigger, higher-performance SLS Block 1B configuration employs the Exploration Upper Stage (EUS), both still in design. The Trump Administration recently proposed cancellation of Block 1B, EUS, and related Exploration projects, but they remain funded for the current fiscal year.<\/p>\n<p>If EUS and Block 1B survive current and future cancellation attempts, then the new upper stage and associated structures would go through structural qualification testing \u2014 the four Core Stage structures going through qualification testing now would not need to be retested.<\/p>\n<p class=\"post-nav-links\">Pages: 1 2<\/p>\n","protected":false},"excerpt":{"rendered":"<p>NASA and Space Launch System (SLS) Core Stage prime contractor Boeing are in the middle of a busy period of testing structural test articles (STA) at the Marshall Space Flight Center in Huntsville, Alabama. One team is busy running test cases on the intertank STA in a large, indoor test facility while another is preparing [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":"","_links_to":"","_links_to_target":""},"categories":[2],"tags":[624],"class_list":["post-38098","post","type-post","status-publish","format-standard","hentry","category-news","tag-sls"],"acf":[],"_links":{"self":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/38098"}],"collection":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/comments?post=38098"}],"version-history":[{"count":0,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/38098\/revisions"}],"wp:attachment":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/media?parent=38098"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/categories?post=38098"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/tags?post=38098"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}