{"id":10580,"date":"2022-04-14T21:55:44","date_gmt":"2022-04-14T13:55:44","guid":{"rendered":"https:\/\/wp-productionenv-bjg9h2g2bgg5b8aa.southeastasia-01.azurewebsites.net\/news\/hydrogen-leak-halts-tanking-test-for-artemis-moon-rocket\/"},"modified":"2022-04-14T21:55:44","modified_gmt":"2022-04-14T13:55:44","slug":"hydrogen-leak-halts-tanking-test-for-artemis-moon-rocket","status":"publish","type":"post","link":"https:\/\/starpath.global\/news\/hydrogen-leak-halts-tanking-test-for-artemis-moon-rocket\/","title":{"rendered":"Hydrogen leak halts tanking test for Artemis moon rocket"},"content":{"rendered":"

EDITOR\u2019S NOTE: <\/strong>NASA officials said Friday that the earliest opportunity to re-try the Artemis 1 countdown dress rehearsal is Thursday, April 21, but that assumes technicians can find and repair the hydrogen leak.<\/p>\n

\"\"
NASA\u2019s Space Launch System on Launch Complex 39B, with gaseous oxygen vapors venting from the top of the core stage during a cryogenic tanking test Thursday. Credit: NASA\/Ben Smegelsky<\/figcaption><\/figure>\n

A hydrogen leak near the connection between NASA\u2019s Space Launch System moon rocket and its mobile launch platform foiled another attempt Thursday to pump cryogenic propellants into the towering mega-booster at the Kennedy Space Center.<\/p>\n

NASA managers called off a countdown rehearsal Thursday afternoon after hours of delays stemming from at least four technical problems. The final, and potentially most significant, issue was a hydrogen leak in the tail service mast umbilical on the mobile launch platform near the bottom of the SLS core stage.<\/p>\n

Engineers discovered the leak during operations Thursday to load liquid hydrogen into the core stage on Launch Complex 39B at NASA\u2019s Kennedy Space Center. The leak forced managers to stop the propellant loading with the core stage\u2019s liquid hydrogen tank 5% full and the liquid oxygen tank at the 49% level, according to NASA.<\/p>\n

The tail service mast umbilical routes super-cold propellants from the mobile launch platform into the rocket\u2019s 27.6-foot-wide (8.4-meter) main stage.<\/p>\n

The launch team planned to drain the propellants from the SLS core stage Thursday evening, allowing technicians to return to pad 39B to inspect the leaky umbilical connection, review data, and determine what to do next to address the problem, NASA said.<\/p>\n

\u201cHydrogen is extremely hazardous, cold, and a small molecule that is known for leaking,\u201d tweeted Jeremy Parsons, deputy manager of NASA\u2019s exploration ground systems program at Kennedy. \u201cAll of these systems have been sealed, leak checked and tested to the highest extent possible prior to wet dress rehearsal.\u201d<\/p>\n

But the leak checks between the SLS core stage and the mobile launch platform have, until recent fueling tests, all occurred at warm ambient temperatures. Liquid hydrogen fuel is chilled to minus 423 degrees Fahrenheit (minus 253 degrees Celsius), and liquid oxygen is stored at minus 297 degrees Fahrenheit (minus 183 degrees Celsius).<\/p>\n

At those temperatures, valves, seals, and gaskets can contract and change shape, revealing a leak that wasn\u2019t apparent in warmer conditions. Hydrogen can find its way through seals that would contain other molecules.<\/p>\n

\u201cUnder the unique operating conditions with the rocket, we are prepared and know leaks are a realistic possibility,\u201d Parsons tweeted Thursday. \u201cWe have amazing hazardous gas and leak detection systems that keep the rocket safe and alert us to conditions outside of normal parameters.\u201d<\/p>\n

NASA said the leak discovered Thursday is located in an area called the \u201cpurge can\u201d on the exterior of the tail service mast umbilical. The purge can is attached to the umbilical plate, which would retract into the structure\u2019s protective housing at liftoff.<\/p>\n

The purge can area is accessible to technicians while the rocket is at the launch pad, giving hope for NASA officials that the leak could be repaired without moving the Space Launch System back to the Vehicle Assembly Building.<\/p>\n

Hydrogen leaks have cropped up in other rocket programs. NASA engineers spent months tracing hydrogen leaks that kept NASA\u2019s space shuttles grounded in 1990.<\/p>\n

\u201cHaving lived through \u2018the summer of hydrogen leaks\u2019 on the shuttle I can sympathize,\u201d tweeted Wayne Hale, a former NASA flight director and former manager of the space shuttle program. \u201cAnd that was after 35 or so launches. A leak the first time is almost to be expected. But not satisfactory.\u201d<\/p>\n

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The tail service mast umbilical is located n the SLS Mobile Launcher deck, connecting to the base of the rocket\u2019s core stage. Credit: NASA \/ Spaceflight Now<\/figcaption><\/figure>\n

NASA\u2019s launch team discovered the hydrogen leak after overcoming several other issues Friday, including an outage in the gaseous nitrogen supply to pad 39B, an issue with the temperature of liquid oxygen, and a pressure surge detected when engineers initially tried loading hydrogen into the core stage.<\/p>\n

The countdown test Thursday followed two previous tries April 3 and April 4 to fully load the Space Launch System with super-cold liquid hydrogen and liquid oxygen, a key checkout known as a wet dress rehearsal. Those attempts were thwarted by problems with ground supply fans at pad 39B and a manual valve on the launch tower left in the wrong position when ground crews left the pad.<\/p>\n

NASA rolled the 322-foot-tall (98-meter) moon rocket from the Vehicle Assembly Building to pad 39B on March 17, revealing the fully stacked rocket for the first time. Once NASA manages are satisfied they have met the objectives of the wet dress rehearsal, teams will transfer the rocket back to the VAB for inspections and final outfitting for launch.<\/p>\n

NASA officials hoped to launch the moon rocket on the Artemis 1 mission as soon as early June, but that was before the countdown test encountered delays. The rocket will launch an unpiloted Orion crew capsule around the moon on a test flight before NASA puts astronauts on the second SLS\/Orion mission. The Artemis program aims to return astronauts to the moon later this decade.<\/p>\n

Going into Thursday\u2019s practice countdown, NASA managers already decided to forego loading cryogenic propellants into the upper stage of the Space Launch System. Engineers couldn\u2019t tank that element of the rocket, made by United Launch Alliance, due to a failed helium valve.<\/p>\n

The core stage, built by Boeing, contains the majority of the cryogenic propellants used by the rocket.<\/p>\n

As part of Thursday\u2019s test countdown, the NASA launch team at Kennedy flowed small amounts of cryogenic propellant up the transfer lines on the mobile launch tower to the connection with the upper stage tanks. The operation \u201cchilled down\u201d the propellant lines, allowing engineers to verify their readiness for launch day, but did not flow propellants into the upper stage tanks.<\/p>\n

Email the author.<\/i><\/b><\/p>\n

Follow Stephen Clark on Twitter: @StephenClark1.<\/strong><\/em><\/p>\n","protected":false},"excerpt":{"rendered":"

EDITOR\u2019S NOTE: NASA officials said Friday that the earliest opportunity to re-try the Artemis 1 countdown dress rehearsal is Thursday, April 21, but that assumes technicians can find and repair the hydrogen leak. NASA\u2019s Space Launch System on Launch Complex 39B, with gaseous oxygen vapors venting from the top of the core stage during a cryogenic […]<\/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":[],"class_list":["post-10580","post","type-post","status-publish","format-standard","hentry","category-news"],"acf":[],"_links":{"self":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/10580"}],"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=10580"}],"version-history":[{"count":0,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/10580\/revisions"}],"wp:attachment":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/media?parent=10580"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/categories?post=10580"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/tags?post=10580"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}