In our age, we’ve grown accustomed to pictures of astronauts inside the International Space Station, as they float in zero-G and tend their science experiments. We’re even getting used to images of spacewalking astronauts. But this is something new.
An image of two astronauts on a spacewalk, taken from the ground.
Living and working in space for extended periods of time is hard work. Not only do the effects of weightless take a physical toll, but conducting spacewalks is a challenge in itself. During a spacewalk, astronauts can become disoriented, confused and nauseous, which makes getting home difficult. And while spacewalks have been conducted for decades, they are particularly important aboard the International Space Station (ISS).
Hence why the Charles Stark Draper Laboratory (aka. Draper Inc.), a Massachusetts-based non-profit research and development company, is designing a new spacesuit with support from NASA. In addition to gyroscopes, autonomous systems and other cutting-edge technology, this next-generation spacesuit will feature a “Take Me Home” button that will remove a lot of the confusion and guesswork from spacewalks.
Spacewalks, otherwise known as “Extra-Vehicular Activity” (EVA), are an integral part of space travel and space exploration. Aboard the ISS, spacewalks usually last between five and eight hours, depending on the nature of the work being performed. During a spacewalk, astronauts use tethers to remain fixed to the station and keep their tools from floating away.
Another safety feature that comes into play is the Simplified Aid for EVA Rescue (SAFER), a device that is worn by astronauts like a backpack. This device relies on jet thrusters that are controlled by a small joystick to allow astronauts to move around in space in the event that they become untethered and float away. This device was used extensively during the construction of the ISS, which involved over 150 spacewalks.
However, even with a SAFER on, it is not difficult for an astronaut to become disoriented during and EVA and lose their bearings. Or as Draper engineer Kevin Duda indicated in a Draper press statement, “Without a fail-proof way to return to the spacecraft, an astronaut is at risk of the worst-case scenario: lost in space.” As a space systems engineer, Duda has studied astronauts and their habitat on board the International Space Station for some time.
He and his colleagues recently filed a patent for the technology, which they refer to as an “assisted extravehicular activity self-return” system. As they described the concept in the patent:
“The system estimates a crewmember’s navigation state relative to a fixed location, for example on an accompanying orbiting spacecraft, and computes a guidance trajectory for returning the crewmember to that fixed location. The system may account for safety and clearance requirements while computing the guidance trajectory.”
In one configuration, the system will control the crew member’s SAFER pack and follow a prescribed trajectory back to a location designated as “home”. In another, the system will provide directions in the form of visual, auditory or tactile cues to direct the crew member back to their starting point. The crew member will be able to activate the system themselves, but a remote operator will also be able to turn it on if need be.
According to Séamus Tuohy, Draper’s director of space systems, this type of return-home technology is an advance in spacesuit technology that is long overdue. “The current spacesuit features no automatic navigation solution—it is purely manual—and that could present a challenge to our astronauts if they are in an emergency,” he said.
Such a system presents multiple challenges, not the least of which has to do with Global Positioning Systems (GPS), which are simply not available in space. The system also has to compute an optimal return trajectory that accounts for time, oxygen consumption, safety and clearance requirements. Lastly, it has to be able to guide a disoriented (or even unconscious astronaut) effectively back to their airlock. As Duda explained:
“Giving astronauts a sense of direction and orientation in space is a challenge because there is no gravity and no easy way to determine which way is up and down. Our technology improves mission success in space by keeping the crew safe.”
The solutions, as far as Duda and his colleagues are concerned, is to equip future spacesuits with sensors that can monitor the wearer’s movement, acceleration, and relative position to a fixed object. According to the patent, this would likely be an accompanying orbiting spacecraft. The navigation, guidance and control modules will also be programmed to accommodate various scenarios, ranging from GPS to vision-aided navigation or star tracking.
Draper has also developed proprietary software for the system that fuses data from vision-based and inertial navigation systems. The system will further benefit from the company’s extensive work in wearable technology, which also has extensive commercial applications. By developing spacesuits that allow the wearer to obtain more data from their surroundings, they are effectively bringing augmented reality technology into space.
Beyond space exploration, the company also foresees applications for their navigation system here at home. These include first responders and firefighters who have to navigate through smoke-filled rooms, skydivers falling towards the Earth, and scuba divers who might become disoriented in deep water. Literally any situation where life and death may depend on not getting lost could benefit from this technology.
In the space of just 3 days, a pair of NASA astronauts conducted an unplanned and rapidly executed contingency space walk on the exterior of the space station on Tuesday, May 23 in order to replace a critical computer unit that failed over the weekend.
The spacewalk was conducted by Expedition 51 Commander Peggy Whitson – NASA’s most experienced astronaut – and Flight Engineer Jack Fischer aboard the International Space Station (ISS).
This marked the 10th spacewalk for Whitson – who already has the most cumulative spacewalk time by a female and the most time in space by a NASA astronaut. This was Fischer’s second spacewalk.
Furthermore Whitson now moves into third place all-time for cumulative spacewalking time totaling 60 hours, 21 minutes. Only Russia’s Anatoly Solovyev and NASA’s Michael Lopez-Alegria have more spacewalking time to their credit.
NASA managers ordered the spacewalk over the weekend when a computer unit known as multiplexer-demultiplexer-1 (MDM-1) unexpectedly failed Saturday morning, May 20 at 1:13 p.m. Central time.
The cause of the MDM failure is not known, says NASA. Multiple attempts by NASA flight controllers to restore power to the MDM-1 relay box were not successful.
The US dynamic duo successfully changed out the MDM computer relay box with a spare unit on board the station. They also installed a pair of antennas on the station on the U.S. Destiny Laboratory module to enhance wireless communication for future spacewalks.
The MDM functions as a data relay box and is located on the S0 truss on the exterior of the US segment of the ISS, thereby necessitating a spacewalk by astronaut crew members.
After NASA engineers thoroughly assessed the situation and reviewed spacewalk procedures on Sunday, May 21, they gave the go ahead for Whitson and Fischer to carry out the hurriedly arranged extravehicular activity (EVA) spacewalk on Tuesday.
Meanwhile, Whitson worked on Sunday to prepare the spare data relay box and test its components to ensure it was ready for Tuesdays swap out of the failed unit.
“The relay box, known as a multiplexer-demultiplexer (MDM), is one of two units that regulate the operation of radiators, solar arrays and cooling loops.” says NASA.
“Because each MDM is capable of performing the critical station functions, the crew on the station was never in danger and station operations have not been affected.”
The two MDM’s housed in the truss are fully redundant systems.
“The other MDM in the truss is functioning perfectly, providing uninterrupted telemetry routing to the station’s systems.”
The spacewalk began Tuesday morning, May 23 at 7:20 a.m. EDT when the two NASA astronauts switched their spacesuits to battery power.
While Whitson focused on the MDM swap, Fischer worked on the antenna installation.
The unplanned spacewalk marks the second this month by Whitson and Fischer. The first was on May 12 and the 200th overall. The Destiny module antenna installation was deferred from the May 12 spacewalk.
The relatively short EVA lasted a total of two hours and 46 minutes. It concluded at 10:06 a.m. EDT.
Overall this was the 201st spacewalk in support of the space station assembly, maintenance and upgrade. Spacewalkers have now spent a total of 1,250 hours and 41 minutes working outside the orbiting lab complex since its inception.
Spacewalk 201 was also the sixth spacewalk conducted from the Quest airlock in 2017 aboard the ISS.
Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.
This past week (on Thurs. March 30th), two crew members of Expedition 50 conducted an important spacewalk on the exterior of the International Space Station. During the seven hours in which they conducted this extravehicular activity (EVA), the astronauts reconnected cables and electrical connections on a new Pressurized Mating Adapter (PMA-3) and installed four new thermal protection shields on the Tranquility module.
These shields were required to cover the port that was left exposed when (earlier in the week) the PMA-3 was removed and installed robotically on the Harmony module. In the course of the EVA, the two astronauts – Commander Shane Kimbrough and Flight Engineer Peggy Whitson – were forced to perform an impromptu patch up job when one of the shield unexpectedly came loose.
While things flying off into space is not entirely unusual, on this occasion, there were concerns given the size and weight of the object. This shield measures about 1.5 meters by 0.6 meters (5 feet by 2 feet) and is 5 centimeters (2 inches) thick. It also weighs a little over 8 kg (18 lbs), which would make it a serious impact hazard given the relative velocity of orbital debris (28,000 km/h).
After coming loose, the bundled-up shield quickly floated away and became visible in the distance as a white dot. In response, a team from the Mission Control Center at NASA’s Johnson Space Center began monitoring the shield as it drifted. At the same time, they began working on a contingency plan to substitute the shielding, and advised the astronauts to finish covering the port with the PMA-3 cover Whitson removed earlier that day.
The plan worked, and the cover was successfully installed, providing thermal, micrometeoroid and orbital debris protection for the port. Kimbrough and Whitson finished their EVA at 2:33 pm EDT, having successfully installed the remaining shields on the berthing mechanism port. A few hours after it came loose, Mission Control also determined that the shield posed no risk to the ISS and will eventually burn up in Earth’s atmosphere.
Before concluding their spacewalk, Kimbrough and Whitson also installed what has been nicknamed a “cummerbund” around the base of the PMA-3 adapter. This cloth shield – which also provides micrometeorite protection – is so-named because it fits around the adapter in a way that is similar to how a tuxedo’s cummerbund fits around a person’s waist.
Another highlight of this spacewalk was the fact that Peggy Whitson set two new records with this latest EVA. In addition to setting the record for the most spacewalks by a female astronaut (eight), she also set the record for most accumulated time spent spacewalking – just over 53 hours – by a female astronaut. The 57-year old astronaut now ranks fifth on the list of all-time spacewalking by any astronaut.
On top of all that, Expedition 50 is Whitson’s third mission to the ISS, and she has spent a total of 500 days in space – also a record for any female astronaut. She arrived aboard the ISS aboard the Soyuz MS-03 – along with ESA flight engineer Thomas Pesquet and Roscosmos flight engineer Oleg Novitskiy – and is scheduled to return to Earth in June (though she may remain there until September).
The top spot for most accumulated time in spacewalking is currently held by Russian cosmonaut Anatoly Solovyev, who has participated in 16 spacewalks for a grand total of 82 hours spent in EVA. And in total, spacewalkers have now spent a total of 1,243 hours and 42 minutes performing 199 spacewalks in support of the assembly and maintenance of the ISS.
When it comes to being an astronaut, one of the most important requirements is flexibility – the ability to adapt to unexpected situations and come up with solutions on the fly. Crew 50 and Mission Control certainly demonstrated that this week, maintaining a tradition that brought the Apollo 13 astronauts safely back to Earth and has kept the ISS running for almost two decades.
It’s been a while since I read the NASA manual on space helmet operation, but if I recall correctly, they really just have one major rule. When you go to space, keep your space helmet on.
I don’t care what haunting music those beguiling space sirens are playing. It doesn’t matter if you’ve got a serious case of space madness, and you’re hallucinating that you’re back on your Iowa farm, surrounded by your loved ones. Even if you just turned on an ancient terraforming machine and you’re stumbling around the surface of Mars like an idiot. You keep your helmet on.
Not convinced? Well then, allow me to explain what happens if you decide to break that rule. Without a helmet, and your own personal Earth-like atmosphere surrounding you, you’ll be exposed to the hard vacuum of space.
Within a moment, all the air will rush out of your lungs, and then you’ll fall unconscious in about 45 seconds. Starved for oxygen, you’ll die of suffocation in just a couple of minutes. Then you’ll freeze solid and float about forever. Just another meat asteroid in the Solar System.
That’s the official stance on space helmet operation, but just between you and me, there might be a little wiggle room. A few other places in the Solar System where you can take your helmet off for just a moment, and maybe not die instantaneously.
Earth is obviously safe. If you’re down here on the planet, and you’re still wearing your helmet, you’re missing the whole point of why you need a helmet in the first place. That space helmet rule only applies to space, silly, you can take it off down here.
In order to survive, the human body needs a few things. First, we need pressure surrounding our body, and helping to keep our lungs inflated. The Earth’s atmosphere provides that service, stacking a huge column of air down on top of you.
Without enough pressure, the air will blast out of your lungs and you’ll suffocate. Too much pressure and your lungs will crush and your heart will give out.
You’re going to want atmospheric pressure somewhere between .5 to 5 times the atmosphere of Earth.
If you can’t find air, then some other gas or even water will do in a pinch. You can’t breathe it, but it can provide the pressure you’re looking for.
If you’ve got the pressure right, then your next priority will be the temperature. You know what it’s like to be too cold on Earth, and too hot, so use your judgement here. It’s too cold if you’re starting to die of hypothermia, and too hot if you’re above 60 C for a few minutes.
If you really want to thrive, find air you can breathe. Ideally a nice mixture of nitrogen and oxygen. Again, here on Earth, that column of air pushing down on you also allows you to breathe. If you swapped air for carbon dioxide or water, you’re going to need to hold your breath.
So what are some other places in the Solar System that you could take your helmet off for a few brief moments?
Your best bet is the planet Venus. Not down at the surface, where the temperature is hot enough to melt lead, and it’s 90 atmospheres pressure.
But up in the cloud tops, it’s a whole different story. At 52.5 kilometers altitude, the temperature is about 37 C. A little stifling, but not too bad. And the air pressure is about 65% Earth’s air pressure.
The problem is that this region is right in the middle of Venus’ sulphuric acid cloud layer, so you might inhale a mist of toxic acid if you tried to breathe. Not to mention the fact that Venus’ atmosphere is carbon dioxide, which means you’ll asphyxiate if you tried to breathe it.
But assuming you had some kind of air supply to breathe, and a suit to protect you from the sulphuric acid, you could hang around, without a helmet as long as you liked.
Take that! Overly draconian NASA helmet rules.
Out on the surface of Titan? Good news! The surface pressure on Titan is 1.45 times that of Earth. You won’t need a pressure helmet at all, ever. You will need a warming helmet, however, since the temperature on Titan is -179 C. You might be able to take that helmet off for a brief moment, before your face freezes, but don’t take a breath, otherwise you’ll freeze your lungs.
Want another location? No problem. Astronomers are pretty sure there are vast reservoirs of water under the surface of many moons and large objects in the Solar System, from Europa to Charon.
They’re heated up through tidal interactions, and could be dozens of kilometers thick. Drill down through the ice sheet, and then just dive into the icy waters without a helmet. It’ll be really cold, and you won’t be able to breathe, but you can stay alive as long as you can hold your breath.
Did you jump out of your spacecraft and now you’re falling to your death into one of the Solar System’s gas giants? That’s bad news and it won’t end well. However, there’s a tiny silver lining. As you fall through the atmosphere of Jupiter, for example, there’ll be a moment when the temperature and pressure roughly match what your body can handle.
Go ahead and take your helmet off and enjoy that sweet spot before you plunge into the swirling hydrogen gas. Once again, though, don’t breathe. Hold your breath, the moment will last longer before you go unconscious.
And listen, if you really really need to take off your helmet in the cold vacuum of space, you can do it. Make sure you completely exhale so you don’t wreck your lungs. Then you’ve got about 45 seconds before you go unconscious.
That’s enough time to jump across to an open airlock, or kick that nasty xenomorph holding onto your leg into deep space.
Even though the NASA space helmet manual has one rule – keep your helmet on – you can see there are a few times and places where you can bend those rules without instantly dying. Use your judgement.
I’d like to thank Mechadense for posting a comment on an earlier Guide to Space YouTube video, which became the inspiration for this episode. Thanks for doing the math Mechadense and bringing the science.
UPDATE, 11:42 a.m. EDT: Rick Mastracchio and Steve Swanson finished their spacewalk in just 1 hour and 36 minutes, nearly an hour faster than what NASA budgeted for. Early tests show the replacement computer is working well, providing backup once again for the robotics, solar arrays and other systems on station.
Can two astronauts fix a broken computer quickly on the International Space Station, preventing possible problems with the solar arrays and robotics? Watch live (above) to find out.
The NASA spacewalk involving Rick Mastracchio and Steve Swanson is scheduled to start today (April 23) at 9:20 a.m. EDT (1:20 p.m. UTC), with coverage starting around 8:30 a.m. EDT (12:30 p.m. UTC). The spacewalk is scheduled to last 2.5 hours. Bear in mind that the times could change as circumstances arise.
The computer, also called a multiplexer/demultiplexer (MDM), failed for unknown reasons a couple of weeks ago. While the primary computer is working perfectly and the crew is in no danger, things get more risky if the primary computer also breaks. That’s why NASA worked to get the spacewalkers outside as quickly as possible. You can see a full briefing of the rationale here.
As a note, all non-urgent spacewalks have been suspended because NASA is still working on addressing the recommendations given after a life-threatening water leak took place in a NASA spacesuit last summer. Urgent spacewalks can still go ahead because the agency has implemented safety measures such as snorkels and helmet absorption pads in case of another leak.
Legs — yes, legs — are on the manifest for the next SpaceX Dragon flight. The commercial spacecraft is expected to blast off March 16 with appendenges for Robonaut 2 on board, allowing the humanoid to move freely around station. After some initial tests in June will come R2’s first step, marking a new era in human spaceflight.
What’s exciting about R2 is not only its ability to take over simple tasks for the astronauts in station, but in the long run, to head “outside” to do spacewalks. This would greatly reduce risk to the astronauts, as extravehicular activity is one of the most dangerous things you can do outside (as a spacesuit leak recently reminded us.)
When installed, Robonaut will have a “fully extended leg span” of nine feet (wouldn’t we love to see the splits with that). Instead of a foot, each seven-jointed leg will have an “end effector” that is a sort of clamp that can grab on to things for a grip. It’s similar to the technology used on the Canadarm robotic arm, and also like Canadarm, there will be a vision system so that controllers know where to grasp.
The robot first arrived on station in February 2011 and (mostly while tied down) has done a roster of activities, such as shake hands with astronaut Dan Burbank in 2012 (a humanoid-human first in space), say hello to the world with sign language, and do functions such as turn knobs and flip switches. During Expedition 34/35 in 2012-13, astronaut Tom Marshburn even made Robonaut 2 catch a free-floating object through teleoperation.
Eventually NASA expects to use the robot outside the station, but more upgrades to Robonaut 2’s upper body will be needed first. The robot could then be used as a supplement to spacewalks, which are one of the most dangerous activities that humans do in space.
Closer to Earth, NASA says the technology has applications for items such as exoskeletons being developed to help people with physical disabilities.
UPDATE: As of Tuesday morning (Eastern time), UrtheCast announced that telemetry was successfully received, “contrary to the online broadcast of the installation.” CEO Scott Larson added that his company “can now focus on the routine commissioning of the cameras in preparation for the unveiling of our Ultra HD, color video of Earth.” Below is the report from Monday.
A second crack at installing the UrtheCast cameras on the International Space Station also ran into data trouble, according to a press release from NASA, although the company involved with the cameras says it is still waiting for more information about the telemetry.
“The duo translated to the Zvezda service module and installed a high-resolution camera and a medium-resolution camera to capture Earth imagery. However, the medium resolution camera again experienced telemetry issues,” NASA stated.
On Twitter, however, UrtheCast stated that it is still awaiting confirmation on the status of the telemetry. We’ll keep you posted when they issue an update.
Kotov and Ryazanskiy spent six hours, eight minutes outside performing this and other routine tasks, marking the fourth spacewalk in about a month for Expedition 38. Besides the other Russian spacewalk in late December, two American astronauts ventured out close to Christmas to make a contingency swap on a faulty ammonia pump.
When NASA astronaut Mike Hopkins steps into space for the first time this week, he will wear a spacesuit that previously sprung a water leak and forced Italian astronaut Luca Parmitano back to station in July, NASA officials said Wednesday (Dec. 18).
While at first glance this sounds like an extra bit of drama as Hopkins and Rick Mastracchio make contingency spacewalks Dec. 21, 23 and 25 to kickstart a shut-down cooling loop, NASA officials say the suit is ready to go for another trip outside because astronauts (under NASA’s direction) have made a bunch of changes to the unit.
Repurposing spacesuit parts, a new pad will be added to the back of all NASA spacesuit helmets to soak up water, should one leak again. Astronauts also velcroed a pipe into each suit — a sort of snorkel — that in the worst case, would give an astronaut with a water leak an alternate route for drawing in air.
Also, the Expedition 38 crew swapped out a fan pump separator that likely malfunctioned and caused the spacesuit leak. The cause is still under investigation, but NASA believes that a problem in the water chemistry caused contamination that plugged a tiny hole inside the water separation part of the unit. This allowed the water to escape, enter the air loop and get into the helmet.
Finally, there are new procedures in place for the astronauts themselves. They will monitor the helmet pad for fluid. NASA additionally plotted out its spacewalk procedures — which include the use of a Canadian robotic arm on station — to make sure the astronauts are always within reasonable reach of an airlock.
So here’s why the spacewalks are happening: a week ago (Dec. 11), a flow control valve inside of a pump — the pump is located outside of the station — stopped regulating ammonia temperatures inside of an external cooling loop. The loop is required to, as the name implies, cool down space station electronics. The loop got too cold, it shut down automatically, and NASA took science experiments and redundant systems offline to deal with the problem. (The main problem is NASA can’t run a heat exchanger on Node 2, which affects experiments in the U.S. Columbus laboratory and Japanese Experiment Module. No completed research has been lost to date, however.)
After figuring out that it couldn’t control the valve again, NASA shifted its attention to an isolation valve upstream. That valve is only designed to be in two positions — opened or closed — but the hardware vendor said it could be used at spots in between to regulate the ammonia flow. So software engineers created a patch to make this happen, and uploaded it to station.
Throw in another element, however: the station is about to enter what’s called an annual “high beta” period, when orbital dynamics mean the sun will be shining on it for longer periods of time than usual. (Read more technical details here.) When the angle exceeds 60 degrees, for safety reasons NASA suspends all cargo flights to station as well as spacewalks. This year, it will happen between about Dec. 30, 2013 and Jan. 9, 2014.
So if NASA spent time playing with the valve and found out it couldn’t work in the long run, a couple of problems could happen. First, it would be harder to do a spacewalk to fix it.
Here’s a diagram of the pump that Mastracchio and Hopkins plan to replace:
The “nominal” plan is for three spacewalks, but it could range anywhere from two to four depending on how things go. To put things simply, here’s how the spacewalks would go:
EVA 1: The pump with the broken valve would be disconnected and a spare pump (which is some distance away, but reachable using Canadarm2) would be prepped for the swap.
EVA 2: The pump with the broken valve would be removed and set aside while the spare pump is partially installed (meaning, only the bolts and electrical connections would be put in.)
EVA 3: The spare pump’s installation would be finished, and the pump with the broken valve would be stowed more permanently outside. NASA thinks that eventually, it could use that first pump again if astronauts installed a new valve on it, but that isn’t a need for the time being.
Flying Canadarm2 would be Japanese astronaut Koichi Wakata, who has operated every type of robotics currently in orbit. Mastracchio has six spacewalks under his belt already, while Hopkins will be on his first go.
If all goes to plan, NASA will not only swap out the pump, but also preserve the option for the Russians to proceed with a planned Dec. 27 spacewalk that is less urgent. In that case, the cosmonauts plan to swap out experiments, put in a foot restraint and install some cameras.
We’ll cover the spacewalks as they happen. They’re scheduled for Dec. 21, 23 and 25 at 7:10 a.m. EST (12:10 p.m. UTC) and should run about 6.5 hours each. Broadcasts will run live on NASA Television.
By the way, the pump with the problem is just three years old — astronauts had to make three spacewalks in 2010 to install it after a more severe failure. NASA characterized this situation as a more unusual failure and said this is not a symptom of an aging station at all.