Astronauts Christina Koch and Andrew Morgan floated out of doorways the Global Home Predicament Sunday and carried out a 7-hour, 1-minute spacewalk to open changing batteries on the far left side of the research outpost’s solar array truss, the main of as much as six excursions scheduled sooner than the pause of October.
Koch and Morgan reliable up for Sunday’s spacewalk within the region space’s Quest airlock module. Once in their spacesuits, they entered Quest’s crew lock and began depressurizing the airlock compartment. The astronauts switched their spacesuits to battery energy at 7:39 a.m. EDT (1139 GMT) to officially label the initiating of the spacewalk.
After exiting the Quest airlock, Koch and Morgan gathered instruments and moved to the gap’s far port-side truss section, or P6, to open the battery replacement work.
Six unique lithium-ion batteries maintain been introduced to the gap Sept. 28 by Japan’s eighth HTV cargo freighter to interchange rising outdated nickel-hydrogen batteries on the P6 truss.
The region space’s energy system contains eight electrical channels, two on each of the research lab’s solar array modules with wings extending 240 feet (73 meters) tip-to-tip. The P6 truss powers the gap’s 2B and 4B electrical channels.
Sunday’s spacewalk became as soon as the 2d within the careers of every Koch and Morgan, and the 219th spacewalk in strengthen of region space assembly and maintenance since 1998.
Every of the four solar array truss segments firstly operated with 12 nickel-hydrogen batteries. Doubtless the most elevated-skill lithium-ion batteries carry the gap of two nickel-hydrogen units. By the pause of the month, astronauts on 5 spacewalks would possibly well well maintain eliminated the 12 nickel-hydrogen batteries and effect in six upgraded batteries, along with unique adapter plates, in their space on the P6 truss.
Sooner than Sunday’s spacewalk, the region space’s robotic arm pulled a cargo pallet from the Jap HTV provide ship and moved it to a degree advance the P6 work residing. However the P6 truss is out of doorways the attain of the robotic arm, so spacewalkers must manually shuttle the humble and unique batteries between the pallet and the P6 truss work residing.
Koch and Morgan labored thru the battery responsibilities more instant than anticipated Sunday, and mission support a watch on in Houston gave the spacewalkers the ride-forward to entire further responsibilities, doing away with and and installing batteries that maintain been firstly scheduled for work at some stage in a spacewalk Friday, Oct. Eleven
“It became as soon as a fully passable (spacewalk) and more lately, as they maintain been in a position to entire all their main responsibilities and loads of gain-forward responsibilities, the truth is getting some batteries swapped out that weren’t presupposed to carry space until the 2d spacewalk,” stated Dan Huot, the NASA TV commentator for Sunday’s spacewalk.
For Sunday’s spacewalk, Koch became as soon as designated EV-1 and wore a spacesuit with pink stripes. Morgan, designated EV-2, wore a spacesuit and not using a markings. Both astronauts wore helmet cameras to wait on mission support a watch on apply along with their progress, with Koch wearing digicam No. Eleven, and Morgan digicam No. 18.
Twelve unique lithium-ion batteries maintain been linked on two of the gap’s solar array modules over the last few years after deliveries on two previous HTV missions, however the robotic arm became as soon as in a position to attain the work net sites for the installation of these batteries on the solar array truss segments nearer to the gap’s pressurized modules.
“The inboard solar arrays are accessible by the arm, so as that allowed the robotic arm to rep out heaps of the battery changeout,” stated Keith Johnson, NASA’s spacewalk officer. “However they couldn’t hook up the electrical connectors, so we needed to send out EVA crew contributors to ride carry out that. With the outboard batteries, these that we’re going to rep out here on the port side, the robotic arm can’t attain.
“So it will get as far as it’ll ride with the uncovered pallet, which holds the batteries and the adapter plates,” Johnson stated.
“It’s a prolonged system available, it’s a prolonged translation path. However then the crew contributors maintain to ride backward and forward between this palette and the integrated equipment assembly to rep out this changeout.”
On Sunday’s spacewalk, the astronauts eliminated one in every of the humble nickel-hydrogen batteries and transferred it to the HTV cargo pallet mounted on the gap truss. Then they retrieved a novel lithium-ion battery and effect in it on the P6 truss’s integrated equipment assembly, adopted by the elimination of one more nickel-hydrogen battery for mounting on the HTV pallet, which will at final re-enter the atmosphere and dissipate.
“The choreography that the crew contributors maintain backward and forward is considerable because they’re going to be transferring a box that’s about 428 pounds (194 kilograms), and taking it off of the pallet and transferring it out to the integrated equipment assembly (on the P6 truss),” Johnson stated in a press briefing sooner than Sunday’s spacewalk. “After which they’ll carry off an ancient battery, which weighs about 365 pounds (165 kilograms), and carry that lend a hand all over again.”
The battery boxes haven’t got any weight in microgravity, but they’re aloof huge and beefy.
“If you focus in your kitchen fridge, and you sever your fridge in half, that’s about the dimensions of these batteries,” stated TJ Creamer, a NASA flight director and aged astronaut. “It’s a runt of a volumetric difficulty.”
“So it takes two crew contributors, they form out it between the 2 of them, and so that they ride very slowly,” Johnson stated. “It’s what we call shepherding. They’ll maintain a hand on it, and one crew member will transfer a runt bit farther along and gain in space, after which the next crew member will push the battery forward and hand it over to them. And so it’s form of a prance backward and forward,” Johnson stated. “It’s it’s form of attention-grabbing going lend a hand and forth, and it takes about an EVA to rep out a pair of batteries. And so as that’s why you’ll survey us doing this over a budge of 5 days because we gain some carried out, and we hope to ride away it in a correct reveal at the pause of every of at the 2d. And then we come out the subsequent EVA and rep up the put we left off.”
The spacewalkers fastidiously maneuvered the batteries along the truss from the HTV cargo pallet to the P6 integrated equipment assembly.
“I the truth is maintain the battery,” Morgan radioed at some stage in 1 in all the battery hand-offs as they astronauts inchwormed along the truss.
“I survey that. You would possibly well well even maintain the battery,” Koch replied.
Koch and Morgan carried out the fashioned responsibilities for Sunday’s spacewalk with time to spare, so that they proceeded with the elimination of a third nickel-hydrogen battery and the installation of a 2d lithium-ion unit on the P6 truss. As deliberate, they linked one in every of the lithium-ion batteries to the region space’s electrical community.
The astronauts wrapped up their work and headed lend a hand to the Quest airlock to entire the spacewalk. After closing the hatch to the airlock, pressurization of the Quest crew lock began at 2:40 p.m. EDT (1840 GMT) to label the legit pause of the excursion at 7 hours, 1 minute.
“On behalf of the P6 battery EVA ground team, we’d admire to thank you to your good work lately,” radioed astronaut Stephanie Wilson from mission support a watch on in Houston. “We now maintain made huge progress in upgrading the batteries on the (channel) 2B side. High-quality job.”
NASA is planning four more spacewalks with Koch, Morgan, flight engineer Jessica Meir and space commander Luca Parmitano on Oct. Eleven, Oct. sixteen, Oct. 21, and Oct. 25 to entire the battery changeouts.
Koch and Morgan are all over again assigned to the subsequent spacewalk on Oct. Eleven.
A Russian spacewalk is scheduled for Oct. 31 to carry the total October EVA tally to six at the region space.
Once the battery responsibilities are entire, NASA plans one more 5 spacewalks in November and December to repair the region space’s Alpha Magnetic Spectrometer particle physics experiment. The agenda makes the subsequent two months the busiest for spacewalks at the region space since 2011, when NASA retired the region shuttle and declared the gap’s assembly entire.
A closing reveal of six unique lithium-ion batteries can be delivered on Japan’s next HTV resupply mission in Would possibly perhaps well well merely 2020, adopted by a a linked collection of spacewalks to install them.
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