Recently, NASA released some pretty spectacular footage captured by an astronaut wearing a GoPro camera while spacewalking around the International Space Station. In the videos, Earth slowly rotates below the space station while astronauts fiddle with cables, install antennae, and work on the robotic arm.
You can see both videos here (and we’ve included some screen grabs in the gallery above).
The astronaut wearing the camera is Terry Virts, and his fellow spacewalker is Barry “Butch” Wilmore. The team had stepped outside to reconfigure parts of the space station so future crewed spacecraft can dock. You can see some of the work they do in each of the two videos, which last for around an hour apiece. But the two extravehicular activities sent Virts and Wilmore into space for longer than six hours.
After sifting through the spacescapes, we were curious about a few things. For example, what’s the source of the sound in the videos? Sound waves can’t travel in a vacuum, but there’s a persistent humming and clanking accompanying both spacewalks. NASA’s spacewalk teams say they believe that is the sound of the spacesuit’s fan, which circulates air and also drives the water pump and water separator. “The camera was mounted to the mini-workstation which is mounted to the suit. So, the vibrations just carried through the system,” NASA spokesperson Dan Huot relayed.
We had some more questions about these videos, so we caught up with Huot, who’s based at NASA’s Johnson Space Center in Houston, Texas, and got a brief glimpse behind the scenes.
NG: First, what’s going on in each of the two videos?
Dan Huot: The first spacewalk, EVA 30, was on February 25th. It was the second in a series of three that the pair of them — Terry Virts and Butch Wilmore – did. Terry had the camera in both. They finished routing a bunch of cables, a little over 360 feet of cabling, and got it tied down and connected. Those cables provide power and data to one of the new docking adapters that’s going to make its way up there. Terry Virts had to apply some grease to a couple of parts inside the robotic arm, and that’s what a lot of the first video shows.
EVA 31, on March 1, was the same two guys. They installed two new metal antennae booms. They routed over 400 feet of cable to plug it all in. Those are for the new communication system those commercial vehicles are going to use to communicate with the station, get range data, help get their final rendezvous and docking information.
NG: What is that little spinning satellite dish in the first spacewalk doing?
Huot: That’s a device called RapidScat. It’s a scatterometer that measures wind speed and direction over the ocean, using radar pulses that are reflected from the ocean surface. It’s used for things like weather forecasting, monitoring hurricanes, and large-scale climate changes. It’s doing that all the time, and is a fairly recent addition, too – it just flew up there in the fall of 2014.
NG: What other fun instruments can we see?
Huot: In EVA 30, Terry Virts actually spends quite a bit of time looking at a big circle that’s basically the business end of the space station’s robotic arm. It’s called Canadarm 2 and it basically built the space station. It’s used for moving around modules and moving around people – they can lock their feet to the end of it and ride it around during spacewalks. He had to go in and apply a bunch of grease to some of the internal components because they were starting to show some wear.
NG: How often do astronauts go on spacewalks?
Huot: It’s pretty varied. They do them whenever there’s an emergency reason – every once in a while, stuff breaks and they have to go out and replace a part or fix something. That’s happened quite a few times in the last couple of years.
This year, they had the three planned walks at the end of February and beginning of March. There are four more planned throughout the rest of the year. The number varies a lot year-to-year because we’re not really building the station anymore. When we were building the station, we would have dozens in a given year.
In history, there’s been 187 spacewalks in total – both U.S. and Russian spacewalks.
NG: What will happen during the other spacewalks this year?
Huot: They’re actually going to be continuing the work from the walks these videos were taken from. We’re preparing the station for some new additions – like new docking adapters, two of them in the next year or so. The first will fly up this summer. So we have to do a spacewalk shortly after to get that installed.
These new docking adapters are for the new commercial crew vehicles.
NG: Can you tell me some more about those vehicles?
Huot: NASA contracted with two commercial companies, SpaceX and Boeing, to build crew vehicles. Since the shuttle program ended, we haven’t had a U.S. vehicle to bring men and women to the ISS. We’ve been relying on our Russian partners and their vehicles. At the end of last year, Boeing and SpaceX were each awarded a contract to develop a crewed vehicle, and they’re supposed to be flying to the space station with humans aboard in 2017. So we need to get these adaptors installed and make sure the station is ready.
NG: How long do spacewalks normally last?
Huot: Normally, between six and eight hours. That’s between six and eight hours, nonstop, for these guys. It’s actually one of the most exhausting things an astronaut can do. I think each of these spacewalks was right around the 6.5 hour mark.
NG: Who decides who gets to spacewalk?
Huot: Crew members are chosen based on proficiencies and the tasks they’ve trained for, how much spacewalking experience they already have. Like anything we do, there’s a lot of metrics that go into it. It’s not the astronauts pulling straws, saying well, “He went last time, I’m going to go this time.” The two guys who did these walks had trained for them on the ground a whole bunch of times.
NG: What kind of training had they done?
Huot: We have a facility called the Neutral Buoyancy Laboratory, and it’s this massive indoor pool about 40 feet deep and 200 feet long. We have a full-scale replica of the space station inside. All the astronauts will go there and they’ll train for these spacewalks. They’re able to choreograph and go through all these tasks down on the ground, so by the time they’re in space and it’s show time, they’ve already done it five or six times.
NG: How long are the training sessions?
Huot: They’re long, about eight hours plus prep time. They’ll simulate the entire spacewalk, and do it five or six times for each scenario.
NG: Why use the GoPros now?
Huot: The cameras are actually from our Russian colleagues; we don’t have any GoPros. So, they let us borrow them and take ‘em out. We don’t have any other capability yet to take an HD camera outside. The astronauts always have helmet cams, but they’re low-def, about 20 years old.
NG: Are there any plans to get GoPros and start sending them out in space?
Huot: I don’t know if it would be a GoPro or not, but we’ve been looking at it for a while, trying to get some type of high-def camera up there. Not only because it looks cool, but you can get engineering analysis video – there are a lot of advantages to getting higher-def video. And the rest of it is really cool-looking.