29. March 2018
Less than a week after arriving at the International Space Station in Soyuz MS-08 for a five-month stay, two astronauts carried spacesuits to head outside the complex. Six-hour extravehicular activity (EVA)
Expedition 55 Flight Engineers Drew Feustel and Ricky Arnold of NASA conducted the fourth spacewalk of 2018 for the ISS program. The primary tasks included the installation of antennas for wireless communication in the module Tranquility and the replacement of a camera system at Port Truss, according to to the US Space Agency. While US EVA-49 was limited to approximately six hours in its carbon dioxide scrubber suits due to a limited consumable the duo was still able to meet all of its primary goals and perform on-the-fly tasks.
Between Feustel and Arnold, the two have about 55 hours of spacewalk with the former head of six previous field trips – three during the STS-125 Hubble mission in 2009 and three during the STS-134 ISS rally mission in 2011 – and the latter conducted two – both during the STS-119 ISS rally mission.
For this spacewalk, the two began their day with the final preparations for the EVA and dressing. They were supported by the two Expedition 55 astronauts Scott Tingle of NASA and Norishige Kanai of the Japan Aerospace Exploration Agency.
During these final checks, Feustel's suit failed three leak controls. As a result, he had to remove his helmet and gloves to clean the seals before trying again, which seemed like the suit had passed the fourth tightness test.
Because of the delay due to the leakage controls the spacewalk schedule was behind the timeline by about 90 minutes. Eventually, after infiltrating the Quest airlock and depressurizing it, the crew was able to launch the EVA. The official start time was EDT at 13:33 GMT on March 29, 2018, when the duo switched their suits to battery power.
As soon as they were outside, the two parted their first tasks. Feustel, who wore the suit with red stripes and was labeled EV-1, went to Tranquility to begin installing the wireless communication antennas, while Arnold, who wore the suit without stripes, and EV-2 was called, gathered a footrest and went to the waiting robot Canadarm2 to drive on to the P1 carrier.
At Canadarm2's control were Tingle and Kanai, who were in the outpost of the Robotics workstation in the Cupola module. They brought it together with Arnold to a construction site in a heat sink with heat dissipation system on the P1 truss segment. There he worked on removing several hoses attached to one of six radiator jet valve modules ( RBVM ) that were believed to be leaking.
The hoses were identified as potentially leaking in 2016 after the data began to show a decline in this general area and after the European space astronaut Thomas Pesquet inspected the hoses in a spacewalk in 2017 . Afterwards, Mission Control in Houston worked to remotely route the station's cooling water and vent the lines.
Now, the hoses are being returned to Earth for inspection so NASA engineers can better understand why they are leaking and improving future systems.
While Arnold worked on it, Feustel continued his installation of Antennas on Tranquility . In particular, he attached two handrails to the module to which the WiFi antennas were attached before power and data lines were connected to the device.
Around this time, about three hours after the spacewalk, Mission Control noted that the duo's suit carbon dioxide scrubbers would be a limiting factor in how long they could stay out. To make the most of your time, the task of replacing Camera, Light and Pan / Tilt Assembly (CLPA) has been changed.
Instead of removing a high-definition camera before installing a replacement CLPA and then reinstalling the camera, Arnold was told (while he was attached to the robotic arm) to remove the entire CLPA (camera and everything), install the replacement and the old Feustel (which was now completed with its antenna task) pass the airlock. The crew would later remove the camera at the outpost.
As soon as Feustel arrived at the airlock assembly, about four hours on the spacewalk, it was found that there was enough time to install the high-definition camera. So he removed the camera from the CLPA and transferred it back to the P1 truss segment to hand over to Arnold. After all primary tasks were completed, NASA commissioned Arnold to clear its work area on Canadarm2 and return to the airlock. However, Feustel was given the preparation task of breaking the torque on four bolts on a replacement ammonia pump module for a future spacewalk to install.
After all, three were back to Quest to finish their first expedition 55 expedition. The official end of the spacewalk was at 3:43 pm EDT (19:43 GMT) to bring the total time spent for US EVA-49 to six hours, 10 minutes.
Feustel's seven career hikes bring him to 48 hours, 28 minutes, while Arnold's three bring him to 18 hours, 44 minutes. Several more spacewalks are planned for Spring 2018, but NASA has not officially planned them.
This was the 209th Spacewalk to support the installation and maintenance of space stations, the first in 1998. Astronauts and cosmonauts now have a total of 54 days, 10 hours working outside the ISS, according to NASA.
Derek Richardson holds a degree in mass media specializing in contemporary journalism from Washburn University in Topeka, Kansas. While at Washburn he was editor-in-chief of the student newspaper Washburn Review. He also has a blog about the International Space Station called Orbital Velocity. He met with members of the Space Flight Insider team during the flight of a United Launch Alliance Atlas V 551 with the satellite MUOS-4. Richardson joined our team shortly thereafter.
His passion for space caught fire as he watched Space Shuttle Discovery launch into space on October 29, 1998. Today, this excitement has accelerated towards orbit and shows no sign of slowing down. After trying his hand at math and engineering classes at college, he soon realized that his true vocation was to communicate with others through space. Since joining SpaceFlight Insider in 2015, Richardson has been working to improve the quality of our content and ultimately become our editor-in-chief. @TheSpaceWriter