STORY WRITTEN FOR CBS NEWS \u201cSPACE PLACE\u201d & USED WITH PERMISSION<\/p>\n
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\nInternational Space Station managers Friday cleared astronauts Barry \u201cButch\u201d Wilmore and Terry Virts to proceed with a third spacewalk Sunday, as originally planned, after concluding a small amount of water in Virts\u2019 space helmet after an EVA Wednesday was an understood condition and not a threat to crew safety.<\/p>\n
The six-and-a-half-hour spacewalk is scheduled to begin around 7:10 a.m. EST Sunday when the astronauts switch their spacesuits to battery power and exit the station\u2019s airlock. The spacewalkers plan to install four antennas, laser reflectors and cabling to permit communications with approaching and departing commercial crew capsules being built by Boeing and SpaceX.<\/p>\n
\u201cWe\u2019re going to lay down over 400 feet of cable,\u201d Virts told a reporter Thursday. \u201cThese cables are going to attach to some antennas that are going to be used for the future American vehicles that are going to be docking, bringing crew to the space station starting in a few years.<\/p>\n
\u201cSo we need to put these antennas and the cables there for them, and also some reflectors so their on-board navigation systems that use lasers (to) know where the station is and what orientation it\u2019s in and will be able to dock properly. There\u2019s a lot of moving from one end to the other on the station and a lot of equipment and hardware that we\u2019re going to be bringing out there.\u201d<\/p>\n
During spacewalks last Saturday and Wednesday, Wilmore and Virts laid out some 340 feet of power and data lines needed by two new docking mechanisms what will be installed later this year and made preparations to relocate a storage module and a docking port extension. Virts also lubricated the grapple mechanisms on the end of the station\u2019s robot arm.<\/p>\n
During airlock repressurization Wednesday, Virts noticed a small blob of water floating in his helmet and reported that a water absorption pad at the back of his helmet was damp, indicating seepage through the helmet\u2019s air duct.<\/p>\n
During a spacewalk in July 2013, Italian astronaut Luca Parmitano endured a potentially catastrophic water leak that forced him to make a quick retreat to the safety of the airlock. That leak was blamed on a clogged filter inside the suit\u2019s water cooling system.<\/p>\n
But in Virts\u2019 case, the water intrusion occurred after the spacesuit had been reconnected to a station umbilical and after airlock repressurization had begun. As it turns out that same spacesuit experienced similar incidents after seven previous spacewalks, the result of condensation in the suit\u2019s cooling system after airlock repressurization.<\/p>\n
\u201cWhen you connect to the umbilical, you have a lot of cold air that\u2019s going past the cooling system of the suit and this air will often condense,\u201d Alex Kanelakos, a NASA spacewalk officer, said Friday. \u201cAnd as we repress, we have high-density gas that\u2019s flowing past this condensed water that can often move the water over the crew member\u2019s helmet.\u201d<\/p>\n
Up to 57 milliliters, or about four tablespoons, of \u201csublimator water carryover\u201d is considered acceptable, far less than what was experienced by Parmitano. In Virts\u2019 case, only about 15 milliliters \u2014 three teaspoons \u2014 of water made it into the helmet.<\/p>\n
\u201cThis spacesuit is known to have what we call carryover water,\u201d Kanelakos said. \u201cWe\u2019ve had seven other occurrences of this carryover on the spacesuit. \u2026 It\u2019s not expected every time, but it\u2019s a known feature. That\u2019s why we monitor a lot of the parameters on the ground. We\u2019re continually getting data and we\u2019re watching that to see if we\u2019re having any occurrences of this situation or the situation that Luca had. And they\u2019re very different occurrences.\u201d<\/p>\n
Speaking to a reporter Thursday, Virts said \u201cI\u2019m completely confident I\u2019m not going outside unless we\u2019re sure it\u2019s a good suit.<\/p>\n","protected":false},"excerpt":{"rendered":"
STORY WRITTEN FOR CBS NEWS \u201cSPACE PLACE\u201d & USED WITH PERMISSION International Space Station managers Friday cleared astronauts Barry \u201cButch\u201d Wilmore and Terry Virts to proceed with a third spacewalk Sunday, as originally planned, after concluding a small amount of water in Virts\u2019 space helmet after an EVA Wednesday was an understood condition and […]<\/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":[1163,4130,4123,2547,1547,4027],"class_list":["post-16521","post","type-post","status-publish","format-standard","hentry","category-news","tag-butch-wilmore","tag-eva-31","tag-expedition-42","tag-ida","tag-spacewalk","tag-terry-virts"],"acf":[],"_links":{"self":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/16521"}],"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=16521"}],"version-history":[{"count":0,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/16521\/revisions"}],"wp:attachment":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/media?parent=16521"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/categories?post=16521"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/tags?post=16521"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}