Two NASA astronauts, Victor Glover and Mike Hopkins, are conducting a deliberate 6.5 hour Extravehicular Exercise (EVA, or spacewalk) to perform a number of duties deferred from a collection of spacewalks carried out thus far this 12 months.
The duo started U.S. EVA-73 at 08:14 EST/13:14 UTC after they took their spacesuits to battery energy earlier than exiting the Quest Airlock.
For the spacewalk, EV1 shall be Victor Glover, sporting the red-striped swimsuit, and EV2 shall be Mike Hopkins, sporting the plain white swimsuit.
The primary activity, after translating out to the P6 truss, shall be to vent the Early Ammonia Servicer (EAS) jumpers of ammonia to allow them to be safely stowed with out danger of rupturing as a consequence of thermal growth.
These jumpers have been used throughout troubleshooting efforts to find an ammonia leak on the P6 truss, throughout which a spare Photograph Voltaic Radiator (PVR) was deployed to isolate the leak; nonetheless, the leak was finally discovered to be inside the Pump Circulate Management Subassembly, so the PVR was re-stowed.
As soon as Glover and Hopkins have vented the ammonia from the jumpers, one jumper shall be stowed on the P6 truss whereas the opposite is positioned exterior the Quest airlock so it may be simply accessed if ever wanted on the Starboard facet of the Station.
The spacewalking pair will then translate to the European House Company’s Columbus module the place they may troubleshoot the P1 and P2 PAPOS (Payload Parking Place Interface) energy connectors on the brand new Bartolomeo exterior platform.
Crews have been unable to correctly mate the connectors on a earlier EVA, so Glover and Hopkins will try additional steps to mate them — which entails inserting a pen-like device to unfold aside the pins within the connectors, that are believed to be too tight.
While on the Columbus worksite, the spacewalkers can even exchange a cable for a failed Beginner Radio on ISS (ARISS) antenna.
A special failed Wi-fi Exterior Transceiver Meeting (WETA) at Digital camera Port 12 (CP12) on Node 1 — which is an exterior wi-fi video information relay — can even get replaced.
The duo will then route two ethernet cables alongside the aft facet of the P1 truss to Digital camera Port 9 (CP9), in preparation for future wi-fi entry level and Excessive Definition exterior video digicam installations.
Moreover, Glover and Hopkins will set up a stiffener ring onto the hatch thermal cowl on the Quest airlock that can guarantee the material cowl correctly seals across the hatch with none gaps and isn’t pushed apart when the airlock’s hatch is opened firstly of an EVA, throughout which the final remnants of air contained in the airlock rush out into area.
The pair will then head again contained in the airlock to conclude the EVA.
Nearly all of work on this EVA was deferred from U.S. EVA-72 on Friday, 5 March.
Throughout that outing, NASA astronaut Kate Rubins and Japan Aerospace Exploration Company (JAXA) astronaut Soichi Noguchi accomplished all deliberate and deferred duties referring to the set up of recent modification kits to the 2B and 4B Mast Canister Assemblies on the P6 truss.
The Mast Canisters held the Station’s authentic/present set of photo voltaic arrays throughout launch, and the brand new mod kits will function mounting factors for a brand new set of arrays that can start launching later this 12 months.
The ISS is provided with eight Photo voltaic Array Wings (SAWs), every of which have been designed to supply round 30 kilowatts (kW) of energy, for a complete of about 250kW throughout all eight arrays.
On account of degradation — which was anticipated — the power-generating arrays now solely produce round 160kW of energy. On the similar time, the Station’s customers, together with the just lately added Nanoracks Bishop airlock and European Bartolomeo exterior platform, are requiring extra energy than was initially envisioned on the time of the outpost’s design.
While the Station’s photo voltaic arrays have been initially designed to be utterly eliminated and changed by way of the House Shuttle, the retirement of that car pressured the ISS program to provide you with an modern answer to extend the quantity of accessible energy.
As a result, the ISS Power Augmentation (IPA) program was born. The plan calls for adding six additional solar arrays to the ISS to augment its power generation and restore it back to original levels.
Particularly, six new ISS Roll Out Photo voltaic Arrays (IROSA) shall be added. The IROSAs are a brand new sort of array know-how, which differs from the Station’s authentic arrays which have been folded up and deployed in an accordion-like method.
The IROSAs shall be put in into the brand new mod kits.
Nonetheless, work to construct these first two mod kits took longer than anticipated throughout each U.S. EVA-71 and -72. That, coupled with a spacewalk-limiting battery stage on one of many spacesuits on EVA-72 meant that a big portion of its deliberate duties wanted to attend for a future spacewalk.
A small, pinpoint gap found in one among Kate Rubins’ gloves in the course of the -72 spacewalk, whereas monitored, was not a priority and was not the rationale for concluding the EVA.
(Lead picture: NASA astronaut Drew Feustel throughout a spacewalk in 2018. Credit score: NASA)