{"id":23585,"date":"2026-02-18T19:48:15","date_gmt":"2026-02-18T11:48:15","guid":{"rendered":"https:\/\/wp-productionenv-bjg9h2g2bgg5b8aa.southeastasia-01.azurewebsites.net\/news\/second-sls-wdr-appears-to-go-as-planned-march-6-target\/"},"modified":"2026-02-18T19:48:15","modified_gmt":"2026-02-18T11:48:15","slug":"second-sls-wdr-appears-to-go-as-planned-march-6-target","status":"publish","type":"post","link":"https:\/\/starpath.global\/news\/second-sls-wdr-appears-to-go-as-planned-march-6-target\/","title":{"rendered":"Second SLS WDR appears to go as planned \u2013 March 6 target"},"content":{"rendered":"<p>NASA worked through a second Wet Dress Rehearsal for Artemis II, after the SLS vehicle experienced hydrogen leaks around propellant loading during the first test.<\/p>\n<p>Work on the Tail Service Mast Umbilical (TSMU) took place while the vehicle remained on Pad 39B, avoiding a rollback and a potential delay to the retargeted launch opportunities in March. That is now a possibility after what appeared to be a smooth and successful second test on Thursday, with NASA now feeling confident about setting March 6 as the target.\n<\/p>\n<\/p>\n<p><iframe title=\"NASA conducts Second Wet Dress Rehearsal on SLS ahead of Artemis II\" src=\"https:\/\/www.youtube.com\/embed\/pOAOV9I6zEA?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen=\"\" name=\"fitvid0\" data-gtm-yt-inspected-14=\"true\" data-gtm-yt-inspected-21=\"true\"><\/iframe><\/p>\n<p>NASA teams gave a \u201cGO to proceed into tanking at 9:27 am and entered chilldown operations. No issues have been reported at this time, and NASA is now providing engineering cams for this test.<\/p>\n<p>Slow fill tanking began a few minutes ahead of schedule. However, fast fill on the LH2 side was delayed due to a ground communication issue.<\/p>\n<p>That was resolved in under an hour, allowing LH2 fast fill to begin.<\/p>\n<p>Loading of the vehicle continued without issue, with the Core Stage at 100 percent of LH2 without any holds to the loading flow. All tanks, both on the Core Stage and ICPS (Interim Cryogenic Propulsion Stage), have since filled to 100 percent.<\/p>\n<p>The closeout crew then closed the hatch to Orion.<\/p>\n<p>Space Technology<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>Spaceflight history books<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>NASA educational resources<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>&nbsp;<\/p>\n<p><img fetchpriority=\"high\" decoding=\"async\" class=\"alignnone size-full wp-image-112124\" src=\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2026\/02\/NSF-2026-02-19-22-37-00-403.jpg\" alt=\"\" width=\"1251\" height=\"701\" srcset=\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2026\/02\/NSF-2026-02-19-22-37-00-403.jpg 1251w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2026\/02\/NSF-2026-02-19-22-37-00-403-350x196.jpg 350w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2026\/02\/NSF-2026-02-19-22-37-00-403-625x350.jpg 625w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2026\/02\/NSF-2026-02-19-22-37-00-403-768x430.jpg 768w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2026\/02\/NSF-2026-02-19-22-37-00-403-1170x656.jpg 1170w\" sizes=\"(max-width: 1251px) 100vw, 1251px\"><\/p>\n<p>The team then proceeded through the count, and despite a slightly extended hold at T-10 minutes, the objectives were completed at the T-90 seconds and T-33 seconds marks, except for a voltage issue.<\/p>\n<p>This all occurred as SpaceX launched a Falcon 9 out of the neighboring SLC-40.<\/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=2024662082709533165&amp;lang=en&amp;origin=https%3A%2F%2Fwww.nasaspaceflight.com%2F2026%2F02%2Fartemis-ii-wdr-resolutions-march-target%2F&amp;sessionId=f94dc67397017e33b5cf699e2b946fcd29a24724&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=\"2024662082709533165\"><\/iframe><\/p>\n<blockquote class=\"twitter-tweet\" data-width=\"550\" data-dnt=\"true\" data-twitter-extracted-i1783492504995446457=\"true\">\n<p lang=\"en\" dir=\"ltr\">Artemis II WDR 2: HOLD as planned at T-33 seconds. Next is to recycle to T-10 mins as part of the WDR. So far this has gone very well indeed! https:\/\/t.co\/3enwjkgl1s pic.twitter.com\/1MHAxgaf4O<\/p>\n<p>\u2014 NSF \u2013 NASASpaceflight.com (@NASASpaceflight) February 20, 2026<\/p>\n<\/blockquote>\n<p>The count then returned to T-10 minutes and holding as planned. Another terminal count took place an hour later.<\/p>\n<p>That count ran all the way down to T-29 seconds, as planned, concluding the test. NASA provided information on the test on Friday.<\/p>\n<p><iframe id=\"twitter-widget-2\" 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-2&amp;features=eyJ0ZndfdGltZWxpbmVfbGlzdCI6eyJidWNrZXQiOltdLCJ2ZXJzaW9uIjpudWxsfSwidGZ3X2ZvbGxvd2VyX2NvdW50X3N1bnNldCI6eyJidWNrZXQiOnRydWUsInZlcnNpb24iOm51bGx9LCJ0ZndfdHdlZXRfZWRpdF9iYWNrZW5kIjp7ImJ1Y2tldCI6Im9uIiwidmVyc2lvbiI6bnVsbH0sInRmd19yZWZzcmNfc2Vzc2lvbiI6eyJidWNrZXQiOiJvbiIsInZlcnNpb24iOm51bGx9LCJ0ZndfZm9zbnJfc29mdF9pbnRlcnZlbnRpb25zX2VuYWJsZWQiOnsiYnVja2V0Ijoib24iLCJ2ZXJzaW9uIjpudWxsfSwidGZ3X21peGVkX21lZGlhXzE1ODk3Ijp7ImJ1Y2tldCI6InRyZWF0bWVudCIsInZlcnNpb24iOm51bGx9LCJ0ZndfZXhwZXJpbWVudHNfY29va2llX2V4cGlyYXRpb24iOnsiYnVja2V0IjoxMjA5NjAwLCJ2ZXJzaW9uIjpudWxsfSwidGZ3X3Nob3dfYmlyZHdhdGNoX3Bpdm90c19lbmFibGVkIjp7ImJ1Y2tldCI6Im9uIiwidmVyc2lvbiI6bnVsbH0sInRmd19kdXBsaWNhdGVfc2NyaWJlc190b19zZXR0aW5ncyI6eyJidWNrZXQiOiJvbiIsInZlcnNpb24iOm51bGx9LCJ0ZndfdXNlX3Byb2ZpbGVfaW1hZ2Vfc2hhcGVfZW5hYmxlZCI6eyJidWNrZXQiOiJvbiIsInZlcnNpb24iOm51bGx9LCJ0ZndfdmlkZW9faGxzX2R5bmFtaWNfbWFuaWZlc3RzXzE1MDgyIjp7ImJ1Y2tldCI6InRydWVfYml0cmF0ZSIsInZlcnNpb24iOm51bGx9LCJ0ZndfbGVnYWN5X3RpbWVsaW5lX3N1bnNldCI6eyJidWNrZXQiOnRydWUsInZlcnNpb24iOm51bGx9LCJ0ZndfdHdlZXRfZWRpdF9mcm9udGVuZCI6eyJidWNrZXQiOiJvbiIsInZlcnNpb24iOm51bGx9fQ%3D%3D&amp;frame=false&amp;hideCard=false&amp;hideThread=false&amp;id=2024709398686240969&amp;lang=en&amp;origin=https%3A%2F%2Fwww.nasaspaceflight.com%2F2026%2F02%2Fartemis-ii-wdr-resolutions-march-target%2F&amp;sessionId=f94dc67397017e33b5cf699e2b946fcd29a24724&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=\"2024709398686240969\"><\/iframe><\/p>\n<blockquote class=\"twitter-tweet\" data-width=\"550\" data-dnt=\"true\" data-twitter-extracted-i1783492504995446457=\"true\">\n<p lang=\"en\" dir=\"ltr\">NASA provided a brief update following today&#8217;s Wet Dress Rehearsal:<br \/>\u2013 The Artemis II crew observed part of the test in the Launch Control Center (LCC).<br \/>\u2013 Hydrogen concentration remained below the 16% threshold throughout the countdown.<br \/>\u2013 During the early part of the countdown,\u2026 pic.twitter.com\/HkKabEWcoz<\/p>\n<p>\u2014 Jay Keegan (@_jaykeegan_) February 20, 2026<\/p>\n<\/blockquote>\n<p>At the press conference, officials took the unusual step of proclaiming March 6 as the launch date, before adding caveats that this is pending outstanding work and the Flight Readiness Review (FRR). Traditionally, NASA makes a point of saying no launch date is ever set before the conclusion of the FRR.<\/p>\n<p>The decision to double down on the launch date mention was based on confidence in the WDR 2\u2019s results, not least with the leak issue on the TSMU now resolved, and a wish for the media to drive interest in the launch.<\/p>\n<p>WDR 1:<\/p>\n<p>Freezing temperatures and winds at Kennedy Space Center had already delayed the start of the WDR by 48 hours before approval from the Mission Management Team (MMT) was given to enter fueling operations on Monday.<\/p>\n<p>An issue observed was a persistent leak at the TSMU interface during the initial stage of core stage fueling, but it was deemed within limits to proceed.<\/p>\n<p>Before proceeding further, the closeout team encountered extended work requirements, including an inadvertently vented valve, which contributed to an extended hold during the countdown and delayed overall progress.<\/p>\n<p>Once the closeout team left the pad, controllers had one final opportunity to attempt the terminal count. With the clock running down from T-10 minutes, the Crew Access Arm (CAA) retracted, visually showing the countdown was running through the same steps as it would ahead of launch.<\/p>\n<p><iframe id=\"twitter-widget-3\" 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-3&amp;features=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%3D%3D&amp;frame=false&amp;hideCard=false&amp;hideThread=false&amp;id=2018553005243789652&amp;lang=en&amp;origin=https%3A%2F%2Fwww.nasaspaceflight.com%2F2026%2F02%2Fartemis-ii-wdr-resolutions-march-target%2F&amp;sessionId=f94dc67397017e33b5cf699e2b946fcd29a24724&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=\"2018553005243789652\"><\/iframe><\/p>\n<blockquote class=\"twitter-tweet\" data-width=\"550\" data-dnt=\"true\" data-twitter-extracted-i1783492504995446457=\"true\">\n<p lang=\"en\" dir=\"ltr\">CAA retract. pic.twitter.com\/tlnyPQyn8l<\/p>\n<p>\u2014 NSF \u2013 NASASpaceflight.com (@NASASpaceflight) February 3, 2026<\/p>\n<\/blockquote>\n<p>However, the countdown clock then showed before a hold was called at T-5:15 minutes, again for a hydrogen leak, ultimately leading to a scrub.<\/p>\n<p>\u201cWe successfully loaded cryogenic propellants into the SLS core stage and interim cryogenic propulsion stage, performed Orion closeout procedures, and safely offloaded the propellants,\u201d noted Amit Kshatriya, NASA Associate Administrator.<\/p>\n<h4 class=\"widget-title penci-border-arrow\">See Also<\/h4>\n<ul>\n<li>Artemis Section<\/li>\n<li>L2 Artemis<\/li>\n<li>Click here to Join L2<\/li>\n<\/ul>\n<p>\u201cHowever, we encountered several challenges, including a recurring liquid hydrogen leak at the tail service mast umbilical interface. This led to an early termination at T-5:15 during the countdown.<\/p>\n<p>\u201cDespite these issues, we met many of our planned objectives, such as propellant loading and countdown milestones. To allow our teams to fully review the data, implement fixes, and potentially conduct a second wet dress rehearsal, we\u2019re moving off the February launch window and targeting March as the earliest possible opportunity for Artemis II.\u201d<\/p>\n<p>This was the first time the Artemis II vehicle had entered fueling operations, unlike the Artemis I SLS, which underwent two Green Run tests at NASA Stennis before being shipped and fully stacked at KSC.<\/p>\n<p>\u201cTo me, the big takeaway was we got a chance for the rocket to talk to us, and it did just that. The test gave us exactly what we needed,\u201d added John Honeycutt, chair of the Artemis II Mission Management Team.<\/p>\n<p>\u201cIt was an opportunity for us to wring out the system as a team before we asked our crew to go fly. We pushed through cold weather delays and the hydrogen issues, but the data we gathered is invaluable.\u201d<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-111868\" class=\"wp-image-111868 size-full\" src=\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2026\/02\/NSF-2026-02-04-13-01-50-365-wmarked.jpg\" alt=\"\" width=\"1538\" height=\"955\" srcset=\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2026\/02\/NSF-2026-02-04-13-01-50-365-wmarked.jpg 1538w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2026\/02\/NSF-2026-02-04-13-01-50-365-wmarked-350x217.jpg 350w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2026\/02\/NSF-2026-02-04-13-01-50-365-wmarked-564x350.jpg 564w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2026\/02\/NSF-2026-02-04-13-01-50-365-wmarked-768x477.jpg 768w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2026\/02\/NSF-2026-02-04-13-01-50-365-wmarked-1170x726.jpg 1170w\" sizes=\"(max-width: 1538px) 100vw, 1538px\"><\/p>\n<p id=\"caption-attachment-111868\" class=\"wp-caption-text\">TSMU work ahead of Artemis I via NSF<\/p>\n<p>WDR 2:<\/p>\n<p>Resolution work took place while the vehicle was still at the pad, with workers installing a platform to provide access to the interfaces on the LH2 TSMU, with a specific focus on the bleed lines and using the experience from a similar issue seen during Artemis I.<\/p>\n<p>The TSMU serves as the interface between the launch pad\u2019s ground systems and the SLS core stage\u2019s aft (rear) section, facilitating the transfer of cryogenic propellants along with electrical power and data cables.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-111869\" class=\"wp-image-111869 size-full\" src=\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2026\/02\/NSF-2026-02-04-13-03-54-548.jpg\" alt=\"\" width=\"2077\" height=\"1174\" srcset=\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2026\/02\/NSF-2026-02-04-13-03-54-548.jpg 2077w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2026\/02\/NSF-2026-02-04-13-03-54-548-350x198.jpg 350w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2026\/02\/NSF-2026-02-04-13-03-54-548-619x350.jpg 619w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2026\/02\/NSF-2026-02-04-13-03-54-548-768x434.jpg 768w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2026\/02\/NSF-2026-02-04-13-03-54-548-1920x1085.jpg 1920w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2026\/02\/NSF-2026-02-04-13-03-54-548-1170x661.jpg 1170w\" sizes=\"(max-width: 2077px) 100vw, 2077px\"><\/p>\n<p id=\"caption-attachment-111869\" class=\"wp-caption-text\">TSMU via ML-1 umbilical video overview via L2<\/p>\n<p>The TSMU is engineered with pressure-assisted seals to ensure a secure fit during loading, but it can be sensitive to factors like flow rates, pressures, and temperature changes, which have led to challenges such as hydrogen leaks in past tests.<\/p>\n<p>It also has propellant transfer lines, connected between the TSMU and core stage via quick-disconnect (QD) fittings with pressure-assisted seals at the umbilical plate interface.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-111870\" class=\"wp-image-111870 size-full\" src=\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2026\/02\/NSF-2026-02-04-13-05-45-387.jpg\" alt=\"\" width=\"1554\" height=\"935\" srcset=\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2026\/02\/NSF-2026-02-04-13-05-45-387.jpg 1554w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2026\/02\/NSF-2026-02-04-13-05-45-387-350x211.jpg 350w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2026\/02\/NSF-2026-02-04-13-05-45-387-582x350.jpg 582w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2026\/02\/NSF-2026-02-04-13-05-45-387-768x462.jpg 768w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2026\/02\/NSF-2026-02-04-13-05-45-387-1170x704.jpg 1170w\" sizes=\"(max-width: 1554px) 100vw, 1554px\"><\/p>\n<p id=\"caption-attachment-111870\" class=\"wp-caption-text\">TSMUs inside the VAB, via NASA<\/p>\n<p>These include the larger 8-inch diameter fill-and-drain line for primary propellant transfer into\/out of the core stage tank, and a smaller 4-inch diameter bleed line positioned below it for the redirection\/venting function.<\/p>\n<p>\u201cWhat we have learned during the Artemis tanking campaign is that this interface is sensitive to flow rates and pressures. We learned that during Artemis I, and we saw the same thing,\u201d noted Charlie Blackwell-Thompson, Artemis II launch director.<\/p>\n<p>\u201cIt was when we went to fast fill. We were in slow fill (and) were within our limits and within our bands. It was when we transitioned to fast fill that we began to see the limits creeping up and the concentrations within the cavity creeping up.\u201d<\/p>\n<p>Some specifics on the level of the leak were provided, with a range of 12 percent creeping up to 16 percent, at which point the limits were tripped. Attempts to slow the leak, based on procedures from Artemis I, were employed.<\/p>\n<p>\u201cThat\u2019s when we did stop flow and revert and decided to invoke our procedure for letting that interface warm up and then retrying it again. During Artemis 1, we found that sometimes that was very successful. I mean, that\u2019s a pressure-assisted seal. So, sometimes letting it warm up and then putting some more pressure across it, you\u2019ll see the seal improve.\u201d<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-111871\" class=\"size-full wp-image-111871\" src=\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2026\/02\/NSF-2026-02-04-13-08-51-524.jpg\" alt=\"\" width=\"1740\" height=\"1086\" srcset=\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2026\/02\/NSF-2026-02-04-13-08-51-524.jpg 1740w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2026\/02\/NSF-2026-02-04-13-08-51-524-350x218.jpg 350w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2026\/02\/NSF-2026-02-04-13-08-51-524-561x350.jpg 561w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2026\/02\/NSF-2026-02-04-13-08-51-524-768x479.jpg 768w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2026\/02\/NSF-2026-02-04-13-08-51-524-1170x730.jpg 1170w\" sizes=\"(max-width: 1740px) 100vw, 1740px\"><\/p>\n<p id=\"caption-attachment-111871\" class=\"wp-caption-text\">The NASA presser discussing the WDR, via Max Evans for NSF<\/p>\n<p>The test was aborted when the leak spiked during terminal count during the pressurization of the core stage. It is not yet known which bleed line on the TSMU interface was the culprit.<\/p>\n<p>\u201cIn terms of when we saw the spike in the leak, it was in terminal count, as we began to pressurize the tank. And whether that came through the eight-inch or the four-inch bleed, we really need to get into the plate and take a look.<\/p>\n<p>\u201cBut right now, I\u2019d tell you that based on the timing, it looked like in real time that it was likely through the eight-inch, could have been the four though, so we\u2019ll take a look at all that and see what was going on there. But it did go up, and it went up very quickly, and so we knew that we had something there we didn\u2019t understand. That\u2019s why the operator immediately gave a cut off, and we got into safing.\u201d<\/p>\n<p>It is understood that testing on the removed seals did not show any issues, but they were replaced as a matter of course. WDR 2 will see if that aids the path to a successful loading of the vehicle on Thursday.<\/p>\n<p><em>Lead photo: Artemis II on the pad, via Sawyer Rosenstein.<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"<p>NASA worked through a second Wet Dress Rehearsal for Artemis II, after the SLS vehicle experienced hydrogen leaks around propellant loading during the first test. Work on the Tail Service Mast Umbilical (TSMU) took place while the vehicle remained on Pad 39B, avoiding a rollback and a potential delay to the retargeted launch opportunities in [&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":[7871,5942,624,7894],"class_list":["post-23585","post","type-post","status-publish","format-standard","hentry","category-news","tag-39b","tag-artemis-ii","tag-sls","tag-tsmu"],"acf":[],"_links":{"self":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/23585"}],"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=23585"}],"version-history":[{"count":0,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/23585\/revisions"}],"wp:attachment":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/media?parent=23585"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/categories?post=23585"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/tags?post=23585"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}