View astronauts in a work-a-day world above the world. As ever-more complex activities continue aboard ISS the following article details the progress underway. While they continue preparations and fittings for the next spacewalk, they are also preparing for the next Cygnus cargo ship arrival.
The Expedition 55 crew on board the International Space Station has been working hard to prepare for Wednesday’s spacewalk, and they’ll still have a lot of difficult work ahead of them when Flight Engineers Ricky Arnold and Drew Feustel head outside the airlock. If you’ve ever wondered what makes spacewalks such a big deal, check out chapter 17 of the new NASA ebook, The International Space Station: Operating an Outpost in the New Frontier. The book, which was written by space station flight directors, is now available to download for free at… https://go.usa.gov/xQbvH.
Chapter 17: Extravehicular Activities – Building a Space Station
Planning and Training Extravehicular Activity Tasks
On paper, the tasks needed for International Space Station assembly—e.g., driving a bolt, carrying something from one place to another, taking off a cover, plugging in an electrical cord—might not seem too complex. However, conducting such tasks while wearing a spacesuit with pressurized gloves (possibly with one’s feet planted on the end of a long robotic arm), working in microgravity, maneuvering around huge structures while moving massive objects, having time constraints based on spacesuit consumables, and using specialized equipment and tools made these tasks and EVAs challenging.
Tasks such as working with cables or fluid hoses are hand-intensive work—fingers and forearms get quite a workout in pressurized gloves that feel like stiff balloons and resemble oversized garden gloves. Added to these complexities, space “walking” is mostly done with the hands. The astronaut grasps handholds and maneuvers the combination of the Extravehicular Mobility Unity, Simplified Aid for EVA Rescue, tools, and himself or herself around the structure.
The team on the ground has to come up with a choreography and order of events for the EVA, in advance. The flight control team creates the EVA timelines based on a high-level prioritized list of tasks determined by ISS management (e.g., move a specific antenna, install a particular avionics box). The flight controllers start with the top ISS priority task and assesses the other tasks that can fit into the EVA based on multiple factors such as how long the tasks will take based on past experiences, whether both crew members need to work together, task location on the ISS, how much equipment will fit into the airlock, the tools required, crew experience level, and the level of crew effort to complete the task. A task that might fit (but only if the team is efficient) is put on the list as a “get-ahead” task.
Real-time discussions in Mission Control of EVA time remaining, crew fatigue, and suit consumables could allow the get-ahead task to be accomplished in addition to the planned tasks. Some tasks are performed on a “clock”; i.e., if power is removed from an item, it might get cold and need heater power in a matter of hours or sometimes within minutes to prevent damage. While a timeline is still in a draft version, the team conducts testing as required to prove out the operations. The team then trains the crew and refines and/or changes the timeline, sometimes up to the day of the EVA.
Earlier in the day:
Two NASA astronauts are finalizing their preparations with a view ahead of Wednesday morning’s spacewalk to swap thermal control gear outside the International Space Station. The Expedition 55 crew also worked on biomedical operations, radiation checks and Cygnus communications gear.
Flight Engineers Ricky Arnold and Drew Feustel checked their tools and reviewed their procedures one last time today before tomorrow’s spacewalk. The pair will work for about 6.5 hours swapping a pair of thermal control devices, known as Pump Flow Control Subassemblies, which control the circulation of ammonia keeping external station systems cool.
The veteran spacewalkers will set their spacesuit batteries to internal power Wednesday at about 8:10 a.m. EDT signaling the official start of the 210th spacewalk in space station history. NASA TV will begin its live broadcast of the activities beginning at 6:30 a.m.
Science and maintenance are always ongoing aboard the orbital lab even despite the spacewalk and cargo mission readiness activities. Feustel and Japanese astronaut Norishige Kanai collected their biological samples this morning and stowed them in a science freezer for later analysis. Cosmonaut Oleg Artemyev explored cardiac bioelectric activity at rest. Commander Anton Shkaplerov collected radiation measurements from dosimeters he retrieved from the orbital lab’s U.S. segment.
Orbital ATK is getting its Cygnus space freighter ready for launch Sunday at 5:04 a.m. to deliver science, supplies and hardware to the Expedition 55 crew. Astronaut Scott Tingle checked out command and communications gear that will be used when Cygnus arrives four days later on Thursday for capture at 5:20 a.m.
And even earlier, we view the activity with Scott Tingle’s view of ISS in his ‘Captain’s Log’:
Week three. The time is flying by. The SpaceX Dragon cargo craft is 80% loaded. This has been a big effort for the crew as well as our specialists on the ground. Tracking a large matrix of storage locations, special requirements and loading locations is a nightmare, but our team on the ground made it look easy. Our crew is becoming more versatile and now flexes between operations and science tasking with what is seemingly just a flick of a switch. I had the opportunity to set up our Microgravity Science Glovebox for the Trans-Alloy experiment. Unfortunately, the team had to abort the science run due to high temperatures in the glovebox. Tomorrow morning, we will remove the science hardware, remove the cooling plugs, and set it all back up again. Reworks like this don’t bother me, and I am happy to do what is needed to reach success. We are on, and sometimes beyond, the frontline of science where lines between science, engineering and operations become very blurry and complex. We have to be flexible! The International Space Station (ISS) has now entered its 20th year of operations. What an engineering marvel. As with any aging program, we have accumulated an expanse of experience operating in space. As an engineering community, we are much smarter about operating in space than we were 30 years ago when we designed ISS. I will be very encouraged to see our community apply lessons learned as we create new systems to require less training, less maintenance and less logistics.
I’ve managed to take a few moments over the last week to take some pictures of Earth. Sunrises are the most beautiful part of the day. Out of total darkness, a thin blue ring begins to form that highlights the Earth’s circumference. At this moment, you can really see how thin our atmosphere is. Within a few minutes, the sun rises on station and highlights the docked vehicles while Earth just below is still in night’s shadow. A few minutes later, ISS is over brightly-lighted ground and water, providing a fresh view of the features below. The promise of a new day is real!
The crew managed to have a movie night last night, which provided some good fun and camaraderie. This was a welcome break from the busy routine we endure. Unfortunately, today, I woke to hear that astronaut and moonwalker John Young had passed away. And I also learned that a good friend from the Navy had passed away after a challenging battle with cancer. When he learned he had cancer two years ago, he decided to ignite the afterburners and live every day like there was no tomorrow…he was just as successful in his final days as he was in his previous 50 years. To two remarkable American heroes, thank you for all you have sacrificed and thank you for a lifetime of inspiration. Fair winds and following seas.
Written By: Mark Garcia NASA
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