See the Apollo 8 “Earthrise” in a Whole New Way

Earthrise - Apollo 8
Earthrise - as seen from Apollo 8. Credit: NASA.

One of the most famous images from the history of spaceflight is the picture taken by the crew of Apollo 8 of the “Earthrise” — the first color picture of taken of Earth as it became visible as the spacecraft came from behind the farside of the Moon. The photo was taken 45 years ago on December 24, 1968. It’s been called one of the most influential environmental photographs ever taken, and is one of the most-published pictures ever. As the photographer of this photo, astronaut Bill Anders has said, “We came all this way to discover the Moon. And what we really did discover is Earth.”

The NASA Goddard Scientific Visualization Studio has now released a new video that is a re-creation of that first Earthrise. The video is based on detailed analysis of Apollo 8 photography, including vertical stereo photos that were being taken at the same time as the Earthrise photos, combined with recent topographic models from the Lunar Reconnaissance Orbiter.

“In the video,” space historian Andrew Chaikin — who narrates the new video — told Universe Today, “we see the Moon’s surface, generated from LRO data, exactly as it appeared to the astronauts through the different windows of the spacecraft. We also hear the astronauts’ voices as captured by the spacecraft’s onboard voice recorder, synchronized with the visual. The video reveals new details about this historic event and the resulting color photograph, which became an icon of the 20th century.”

Enjoy this wonderful new video, which explains how this historic image was taken. The visualization shows how Apollo 8 Commander Frank Borman and crew members Anders and James Lovell worked together to photograph the stunning scene as their spacecraft orbited the Moon in 1968. The video allows anyone to virtually ride with the astronauts and experience the awe they felt at the vista in front of them.

The “Earthrise” photo is the cover photo of TIME’s Great Images of the 20th Century, and is the central photo on the cover of LIFE’s 100 Photographs That Changed the World.

“Earthrise had a profound impact on our attitudes toward our home planet, quickly becoming an icon of the environmental movement,” said Ernie Wright, who lead the video project with the SVS.

You can read more details of how the video was put together in this NASA press release.

A computer-generated visualization of the Apollo 8 spacecraft in orbit around the moon, with Earth rising over the horizon. Image Credit:  Ernie Wright/NASA Goddard Scientific Visualization Studio
A computer-generated visualization of the Apollo 8 spacecraft in orbit around the moon, with Earth rising over the horizon.
Image Credit:
Ernie Wright/NASA Goddard Scientific Visualization Studio

This Hilarious Conversation With A Space Robot Makes Kirobo Seem Almost Human

The Kirobo talking robot on the ISS. Credit: Toyota.

Just how human-sounding is Kirobo, the first talking robot on the station? This amusing conversation, recorded on the International Space Station and broadcast on a Toyota YouTube channel, shows a pint-sized robot that not only responds to questions, but also gestures and moves around in a scary person-like way.

As Kirobo chats with Japanese astronaut Koichi Wakata — who is excellent at deadpan, by the way — the two discussed matters such as how the Earth looks from space, the Japanese robotic arm Kibo and — right at the end — the most important difference between Kirobo and his backup, Mirata.

We don’t want to spoil the joy of the conversation for you by repeating what Kirobo says, but let’s just say there’s something special about watching a Japanese space robot make a reference to the first landing on the moon, which was hailed as a huge technological achievement when it happened in 1969. 

The 13.4-inch (0.34 meter) Kirobo is sponsored by Toyota and the University of Tokyo and is supposed to be able to pick up on the facial expressions of crewmates. The robot will be working closely with Wakata during Expedition 38 and then Expedition 39, when Wakata assumes command of station.

One goal is to see how well humans and semi-autonomous robots can work together in space. To see Kirobo’s first words from station, check out our past story from September.

Book Review and Giveaway: Physics: An Illustrated History of the Foundations of Science


Book review by David L. Hamilton

Tom Jackson’s Physics: An Illustrated History of the Foundations of Science is an enjoyable read for anyone who is fascinated by the world in which we live and curious about how the world works. Reading and comprehension of the material does not require one to have a background in physics or science. Jackson takes 100 important events that occurred throughout different periods in our history and presents them in such a way that they can be understood and enjoyed by people of all ages and backgrounds. Each event covers about a page and each page has beautiful illustrations and diagrams of the various tools of the trade that the physicists used in each of the 100 breakthroughs.

The book is divided into five sections ranging from antiquity to modern physics. The first section, The Dawn of Science, covers the important figures that set the stage for scientific inquiry for the next several centuries, such as Thales, Democritus, and Aristotle.

The second section, The Scientific Revolution, introduces us to Newton and his Laws of Motionand Theories of Light, John Dalton and his investigations into the characteristics of gases, and Thomas Seebeck and his discovery of the thermoelectric effect.The third section of Jackson’s book examines the Doppler effect, Absolute Temperature, and the discovery of X-Rays, all extremely important discoveries that are still relevant in the various branches of science today, such as astronomy and medicine.

The fourth section brings the reader into the subatomic age where contributions from Titians such as Max Planck and his Constant, Albert Einstein and his Theory of Relativity, and Dane Niels Bohr who gave us Bohr’s Model of an atom.

The fifth and final section of the book covers modern physics. Jackson does a great job of explaining how Slipher, Hubble, and Georges Lemaitre used Einstein’s theory of relativity to show that our universe is not static and eternal but an expanding, changing and evolving universe that had a beginning. In this final section, the reader will also learn about Quarks, Neutrinos, Dark matter and energy, and the famous Higgs boson.

Another great feature about this book is that it includes a foldout timeline that puts the people and their discoveries into the larger contexts of World events so that the reader can see the big picture more easily.

Universe Today and Shelter Harbour Press is offering free copies to two lucky winners. In order to be entered into the giveaway drawing, just put your email address into the box at the bottom of this post (where it says “Enter the Giveaway”) before Thursday, December 26th, 2013. We’ll send you a confirmation email, so you’ll need to click that to be entered into the drawing.

David and his wife live in Conway, Arkansas. They are amateur astronomers that love spending nights stargazing and their days working in Higher Education. David graduated from the University of Arkansas at Little Rock with a Master of Education degree.

ESA’s Gaia Mission Launches to Map the Milky Way

Soyuz VS06, with Gaia space observatory, lifted off from Europe's Spaceport, French Guiana, on 19 December 2013. (ESA–S. Corvaja)

Early this morning, at 09:12 UTC, the cloudy pre-dawn sky above the coastal town of Kourou, French Guiana was brilliantly sliced by the fiery exhaust of a Soyuz VS06, which ferried ESA’s “billion-star surveyor” Gaia into space to begin its five-year mission to map the Milky Way.

Ten minutes after launch, after separation of the first three stages, the Fregat upper stage ignited, successfully delivering Gaia into a temporary parking orbit at an altitude of 175 km (108 miles). A second firing of the Fregat 11 minutes later took Gaia into its transfer orbit, followed by separation from the upper stage 42 minutes after liftoff. 46 minutes later Gaia’s sunshield was deployed, and the spacecraft is now cruising towards its target orbit around L2, a gravitationally-stable point in space located 1.5 million km (932,000 miles) away in the “shadow” of the Earth.

The launch itself was really quite beautiful, due in no small part to the large puffy clouds over the launch site. Watch the video below:

A global space astrometry mission, Gaia will make the largest, most precise three-dimensional map of our galaxy by surveying more than a billion stars over a five-year period.

“Gaia promises to build on the legacy of ESA’s first star-mapping mission, Hipparcos, launched in 1989, to reveal the history of the galaxy in which we live,” says Jean-Jacques Dordain, ESA’s Director General.

Soyuz VS06, with Gaia, lifted off from French Guiana, 19 December 2013. (ESA - S. Corvaja)
Soyuz VS06 with Gaia (ESA – S. Corvaja, 2013)

Repeatedly scanning the sky, Gaia will observe each of the billion stars an average of 70 times each over the five years. (That’s 40 million observations every day!) It will measure the position and key physical properties of each star, including its brightness, temperature and chemical composition.

By taking advantage of the slight change in perspective that occurs as Gaia orbits the Sun during a year, it will measure the stars’ distances and, by watching them patiently over the whole mission, their motions across the sky.

The motions of the stars can be put into “rewind” to learn more about where they came from and how the Milky Way was assembled over billions of years from the merging of smaller galaxies, and into “fast forward” to learn more about its ultimate fate.

“Gaia represents a dream of astronomers throughout history, right back to the pioneering observations of the ancient Greek astronomer Hipparchus, who catalogued the relative positions of around a thousand stars with only naked-eye observations and simple geometry. Over 2,000 years later, Gaia will not only produce an unrivaled stellar census, but along the way has the potential to uncover new asteroids, planets and dying stars.”

– Alvaro Giménez, ESA’s Director of Science and Robotic Exploration

Gaia will make an accurate map of the stars within the Milky Way from its location at L2 (ESA/ATG medialab; background: ESO/S. Brunier)
Gaia will make an accurate map of a billion stars within the Milky Way from its location at L2 (ESA/ATG medialab; background: ESO/S. Brunier)

Of the one billion stars Gaia will observe, 99% have never had their distances measured accurately. The mission will also study 500,000 distant quasars, search for exoplanets and brown dwarfs, and will conduct tests of Einstein’s General Theory of Relativity.

“Along with tens of thousands of other celestial and planetary objects,” said ESA’s Gaia project scientist Timo Prusti, “this vast treasure trove will give us a new view of our cosmic neighbourhood and its history, allowing us to explore the fundamental properties of our Solar System and the Milky Way, and our place in the wider Universe.”

Follow the status of Gaia on the mission blog here.

Source: ESA press release and Gaia fact sheet

Gaia's launch aboard an Arianespace-operated Soyuz on Dec. 19, 2013 from ESA's facility in French Guiana (ESA)
Gaia’s launch aboard an Arianespace-operated Soyuz on Dec. 19, 2013 from ESA’s facility in French Guiana (ESA)

Where Did Saturn’s Rings Come From?

Where Did Saturn's Rings Come From?

Dr. Kevin Grazier was a planetary scientist with the Cassini mission for over 15 years, studying Saturn and its icy rings. He was also the science advisor for Battlestar Galactica, Eureka and the movie Gravity.

Mike Brown is a professor of planetary astronomy at Caltech. He’s best known as the man who killed Pluto, thanks to his team’s discovery of Eris and other Kuiper Belt Objects.

We recently asked them about many things – here’s what they shared with us about the rings of Saturn.

Saturn’s majestic, iconic rings define the planet, but where did they come from?

Kevin Grazier: “Saturn’s rings, good question. And the answer is different depending on which ring we’re discussing.”

That’s Dr. Kevin Grazier, a planetary scientist who worked on NASA’s Cassini mission or over 15 years, studying Saturn’s rings extensively.

Mike Brown: “Saturn’s rings – the strange things about Saturn’s rings is that they shouldn’t be there, really, in the sense that they don’t last for very long. So, if they are just left over from when Saturn was formed, they’d be gone by now. They would slowly work their way into Saturn and burn up and be gone. And yet they’re there. So they are either relatively new or somehow continuously regenerated. ‘Continuously regenerated’ seems strange and ‘relatively new’ seems also kind of strange. Something broke up – a large moon broke up, or a comet broke up – something had to have happened relatively recently. And by relatively recently, that means hundreds of millions of years ago for someone like me.”

And that’s Mike Brown, professor of planetary geology at Caltech, who studies many of the icy objects in the Solar System.

Saturn and its rings, as seen from above the planet by the Cassini spacecraft. Credit: NASA/JPL/Space Science Institute. Assembled by Gordan Ugarkovic.
Saturn and its rings, as seen from above the planet by the Cassini spacecraft. Credit: NASA/JPL/Space Science Institute. Assembled by Gordan Ugarkovic.

Saturn’s rings start just 7,000 km above the surface of the planet, and extend out to an altitude of 80,000 km. But they’re gossamer thin, just 10 km across at some points.

We’ve known about Saturn’s rings since 1610, when Galileo was the first person to turn a telescope on them. The resolution was primitive, and he thought he saw “handles” attached to Saturn, or perhaps what were big moons on either side.

In 1659, using a better telescope, the Dutch astronomer Christiaan Huygens figured out that these “handles” were actually rings. And finally in the 1670s, the Italian astronomer Giovanni Cassini was able to resolve the rings in more detail, even observed the biggest gap in the rings.

The Cassini mission, named after Giovanni, has been with Saturn for almost a decade, allowing us to view the rings in incredible detail. Determining the origin and evolution of Saturn’s rings has been one of its objectives.

Saturn's rings. Credit: NASA/JPL/Space Science Institute.
Saturn’s rings. Credit: NASA/JPL/Space Science Institute.

So far, the argument continues:

Kevin Grazier: “There’s an age-old debate about whether the rings are old or new. And that goes back and forth – it’s been going back and forth for ages and it still goes back and forth. Are they old, or have they been there a long period of time? Are they new? I don’t know what to think, to be quite honest. I’m not being wishy-washy, I just don’t know what to think anymore.”

Evidence from NASA’s Voyager spacecraft indicated that the material in Saturn’s rings was young. Perhaps a comet shattered one of Saturn’s moons within the last few hundred million years, creating the rings we see today. If that was the case case, what incredible luck that we’re here to see the rings in their current form.

But when Cassini arrived, it showed evidence that Saturn’s rings are being refreshed, which could explain why they appear so young. Perhaps they are ancient after all.

Kevin Grazier: “If Saturn’s rings are old, a moon could have gotten too close to Saturn and been pulled apart by tidal stresses. There could have been a collision of moons. It could have been a pass by a nearby object, since in the early days of planetary formation, there were many objects zooming past Saturn. Saturn probably had a halo of material in it’s early days that was loosely bound to the moon.”

Enceladus, backdropped by Saturn's rings. Credit: NASA/JPL/ Space Science Institute.
Enceladus, backdropped by Saturn’s rings. Credit: NASA/JPL/ Space Science Institute.

There is one ring that we know for certain is being refreshed…

Kevin Grazier: “The E-Ring, certainly a new ring, because the E-Ring consists of roughly micron-sized ice particles. And micron-sized ice particles don’t last in space. They sputter and sublimate – they go away in very short time periods, and we knew that. And so when we went to Saturn with Cassini, we knew to look for a source of materiel because we knew that the individual components of the E-Ring don’t last, so it has to be replenished. So the E-Ring stands alone from the established system, and the E-Ring is absolutely new.”

In 2005, scientist discovered that Saturn’s E-Ring is being constantly replenished by the moon Enceladus. Cryovolcanoes spew water ice into space from a series of fissures at its south pole.

So where did Saturn’s rings come from? We don’t know. Are the new or old? We don’t know. It just another great mystery of the Solar System.

You can follow Kevin Grazier and Mike Brown at their Google+ pages!

Visions of Earth through the Yutu Rover’s Eyes

Earth eclipses the sun from Chang'e 3's location in the Sea of Rains on April 15, 2014. At the same time, we'll see a total lunar eclipse from the ground. Stellarium

Last night I used my telescope to eye-hike the volcanic plains of the Sea of Rains (Mare Imbrium) where the Yutu rover and lander sit beneath a blistering sun. With no atmosphere to speak of and days that last two weeks, noontime temperatures can hit 250 degrees Fahrenheit (122 C) . That’s hot enough that mission control at the Beijing Aerospace Command and Control Center has decided to draw the shades and give the rover a nap from science duties until December 23 when things cool down a bit.

While studying the subtle gray hues of the Imbrium lava flows I got to wondering what the sky might look like if I could don a spacesuit and visit the landing site “where the skies are not cloudy all day” (to quote a famous song). With no atmosphere to speak of, stargazing can be done both day and night on the moon though I suspect it’s better at night when there’s less glare from your surroundings. Night, defined as the time from sunset to sunrise (no twilights here), lasts about 14.5 Earth days. Days are equally long.

Lunar landscape photographed by the Chang'e 3 lander on Dec. 15, 2013. Credit: CCTV
Lunar landscape photographed by the Chang’e 3 lander on Dec. 15, 2013. Credit: CCTV

 

From Yutu’s point of view, it’s very nearly lunar noon today (Dec. 19) with the sun halfway up in the southern sky.  Looking at the map of the sky from the lander’s location, you’ll see a few familiar constellations and one very familiar planet – Earth!

Phases of the moon and Earth are complementary. When the moon is full, Earth's a crescent. This map shows the Earth in Capricornus on Dec. 20 as thin blue crescent. Stellarium
Phases of the moon and Earth are complementary. When the moon is full, Earth’s a crescent. This map shows the Earth in Capricornus on Dec. 20 as thin blue crescent. Stellarium

Today Earth appears as a very thin crescent a short distance to the left or east of the sun. Because the moon takes just as long to rotate on its axis as it does to revolve around the Earth, the same face of the moon always faces our planet. Because the two are in synchrony, astronomers call it synchronous rotation.

From the perspective of someone standing on the moon, Earth stands still in one spot of sky throughout the 29.5 day lunar day-night cycle. Well, not perfectly still. Because the moon’s orbit is inclined about 5 degrees to Earth’s orbit and its speed varies along its non-circular orbit, Earth describes a little circle in the lunar sky about 10 degrees in diameter every four weeks.

As the sun slowly moves off to the west, our blue planet remains nearly stationary from Yutu’s perspective and undergoes all the familiar phases we see the moon experience back here on Earth: an evening crescent to start followed by a first quarter Earth, Full Earth last quarter and finally, New Earth. I like the ring of that last one.

The lunar landscape at the rover's location is bathed in pale blue light on Dec. 31, 2013 during "Full Earth". Stellarium
The lunar landscape at the rover’s location is bathed in pale blue light on Dec. 31, 2013 during a Full Earth. Stellarium

Yutu and the lander will see the sun drift to the west while Earth moves east, rises higher in the lunar sky and putting on the pounds phase-wise. Today Earth’s glides across the border of Sagittarius into Capricornus. The next Full Earth happens on New Year’s Eve when the sun is directly opposite the Earth in the lunar sky.

Full Earth always happens around local midnight or about one week before sunrise during the long lunar day. On the moon the sun is up for about  two weeks and then disappears below the horizon for another two weeks before rising again.  At Full Earth time, the sun remains hidden around the lunar backside. When the nights are blackest, the bright ball of Earth spreads a welcome blue glow over the desolate landscape.

Earth covering the sun with a flash of the "diamond ring effect" just before total solar eclipse on April 15 and Oct. 8 next year. Stellarium
Simulated eclipse of the sun by the Earth just before totality on April 15 and Oct. 8 next year. On both dates, we’ll see a  total lunar eclipse from the ground.  Stellarium

Things really get interesting during lunar eclipses when the moon moves behind the Earth into the planet’s shadow. The next one’s on April 15, 2014. Here on the ground we’ll see the moon gradually munched into by Earth’s  shadow until totality, when sunlight from all the sunrises and sunsets around the rim of the planet are refracted by the atmosphere into the shadow, coloring the moon a coppery red.

Two pictures of the ring of sunset-sunrise fire around the Earth as it totally eclipsed the sun from the moon. Credit: NASA
Two pictures of the ring of sunset-sunrise fire around the Earth as it totally eclipsed the sun from the moon. Credit: NASA

Yutu will see just the opposite. Looking back toward the Earth from inside its shadow, the rover will witness a total eclipse of the sun by the Earth. If by some wonder the Chinese are able to photograph the event, we’ll see photos of the black ball of Earth rimmed in red fire from sunset and sunrise light refracted by our atmosphere. My interpretation using sky mapping software only hints at the wonder of the scene. Beijing Aerospace, if you’re reading this, please make it happen.


Earth eclipses the sun filmed by Japan’s Kaguya lunar orbiter. There are really two eclipses here – the Earth eclipsed by the limb of the moon at the video’s start followed by the solar eclipse.

On two other occasions, our robotic emissaries have photographed solar eclipses from Luna. NASA’s Surveyor 3 snapped a couple crude pictures of the April 24, 1967 eclipse from inside a crater in Mare Cognitium, the Sea that has Become Known. Japan’s orbiting Kaguya probe did the job much more eloquently on video during the February 9, 2009 penumbral lunar eclipse. In a penumbral eclipse (seen from Earth) the moon misses Earth’s dark inner shadow called the umbra, passing only through the outer penumbra, but because the Earth is three times larger than the sun (seen from the moon), it easily covered the sun completely in the complementary total solar eclipse.

And the best thing about watching eclipses from the moon? Guaranteed clear skies!

Stunning Timelapse: Stargazing in the Canadian Rockies

The night sky over Pyramid Lake in Jasper National Park in Alberta, Canada. Credit and copyright: Jack Fusco.

One of our favorite photographers, Jack Fusco, recently visited Jasper National Park in Alberta, Canada, one of the worlds largest dark sky preserves. He went there on behalf of Travel Alberta, during the annual Night Sky Festival. “I was lucky enough to have two clear nights to explore and shoot as many photos as possible to create a short timelapse while there,” Jack told us via email. “In the end, I took over 2,000 photos at locations such as Lake Annette, Athabasca Glacier, Pyramid Lake, and many others. Out of all the places I’ve traveled in search for dark skies, Jasper definitely offered some of the best views I’ve ever seen. The sky in the Columbia Icefield area was unlike any I had witnessed before.”

Jack added that it was great to be around so many people that were excited about astronomy and preserving the night sky, and he’s already looking forward to going again in 2014, and astronaut Chris Hadfield is already lined up as a guest.

If you’re rushing about for the holidays, take a few minutes to enjoy a brief respite with this lovely timelapse. You can see more images and videos at Jack’s website.

Celestial Laser Show? Nope, These Are Trails Showing Off Star Colors

Star trails above the European Space Observatory's Paranal Observatory in Chile, showing three of the four auxiliary telescopes of the Very Large Telescope Interferometer (VLTI). Credit: ESO/B. Tafreshi

There are so many colorful streaks in that image above that you’d be forgiven for thinking somebody is shooting lasers around the European Southern Observatory (ESO) in Chile. Actually, though, this demonstrates a common technique for astronomy photo-taking where you do a time lapse to watch the stars moving as the Earth makes its daily rotation.

The image of auxiliary telescopes of Very Large Telescope Interferometer is not only pretty, but does have some scientific interest as well, ESO said.

“This technique … enhances the natural colours of the stars, which gives an indication of their temperature, ranging from about 1000 degrees Celsius [1,832 Fahrenheit] for the reddest stars to a few tens of thousands of degrees Celsius [or Fahrenheit] for the hottest, which appear blue. The sky in this remote and high location in Chile is extremely clear and there is no light pollution, offering us this amazing light show,” stated the European Southern Observatory.

According to ESO, these supplementary telescopes working together allow astronomers to “see details up to 25 times finer than with the individual telescopes.” You can read more about the VLTI at this ESO link, which includes some interesting facts — such as why the interferometers are named Antu, Kueyen, Melipal and Yepun.

Source: European Southern Observatory

Chris Hadfield Launched Into Space One Year Ago Today

Chris Hadfield in the Cupola of the ISS. Credit: NASA

And we have liftoff … for a social media sensation! Canadian astronaut Chris Hadfield rocketed into orbit a year ago today (Dec. 19, 2012) accompanied by NASA astronaut Tom Marshburn and Russian cosmonaut  Roman Romanenko.

Hadfield was a part of the Expedition 34 crew, then took command of the station during Expedition 35 in early 2013. While running an extremely productive science mission, he did tons of public outreach, ranging from singing to humorous space-y how-to videos to chatting with numerous celebrities before landing in May.

The Canadian Space Agency invited folks on Twitter to share their reflections under the hashtag #hadfield1yr, which is already producing a lot of thoughtful responses (a few of which you can see below the jump). What was your favorite part of the mission? Feel free to share in the comments.

While Hadfield is retired as an astronaut, he remains very busy. He’s in the middle of a multi-country book tour and will begin teaching at the University of Waterloo in Ontario, Canada in fall 2014.

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Leaky Spacesuit Fixed For Christmas Spacewalk Blitz On Station, NASA Says

NASA astronaut Rick Mastracchio during a spacewalk on STS-118. Credit: NASA

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.

NASA astronauts Rick Mastracchio and Mike Hopkins will do spacewalks in December 2013 to swap out a cooling pump on the International Space Station. Credit: : NASA
NASA astronauts Rick Mastracchio and Mike Hopkins will do spacewalks in December 2013 to swap out a cooling pump on the International Space Station. Credit: NASA

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.

Space Station
The International Space Station in 2010. Credit: NASA

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.

Also, the agency was weighing whether to allow Orbital Sciences to fly a Cygnus cargo flight this month, and felt that they could run into a problem where the spacecraft was ready to go, but NASA needed more time to fix the problem. So that’s why the spacewalk is happening.

Here’s a diagram of the pump that Mastracchio and Hopkins plan to replace:

A view of a pump module aboard the International Space Station that is used  to maintain ammonia at the correct temperature in an external cooling loop. Credit: NASA
A view of a pump module aboard the International Space Station that is used to maintain ammonia at the correct temperature in an external cooling loop. Credit: NASA

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.

Overview of the tasks that Rick Mastracchio and Mike Hopkins will perform during three spacewalks in December 2013 to remove and replace a pump with a faulty valve inside of it. The pump is required to maintain the external cooling system at the right temperature. Credit: NASA
Overview of the tasks that Rick Mastracchio and Mike Hopkins will perform during three spacewalks in December 2013 to remove and replace a pump with a faulty valve inside of it. The pump is required to maintain the external cooling system at the right temperature. Credit: NASA