space archaeology

A bell in space

Together with my co-PI, Dr. Alice Gorman, I’ve been developing a new project: the International Space Station Archaeological Project (or ISSAP). Alice and I have actually been thinking about space archaeology for a long time — she has been working on it since 2002, and I’ve been doing it since 2009. But (with one exception), nobody has ever carried out a meaningful investigation of a human habitation site in space until now. Our friend and mentor, Prof. Beth O’Leary started the Lunar Legacy Project, which catalogued the 106 objects left behind at Tranquility Base by Neil Armstrong and Buzz Aldrin during the Apollo 11 mission in 1969. (Beth and some other colleagues just published a book about the heritage of the Apollo program — check it out!) But our project is much different in scale and time, since over 250 people have visited ISS over almost 17 years of continuous habitation. And it means we have to develop a new method, since we don’t have $75 million to pay for a ride to the space station!

Our idea is to use the millions of images that astronauts and space agencies have taken in the last 17 years showing life on board. By cataloguing and classifying the people, spaces, and objects — and the relationships between them — we can map patterns of behavior over time. Since digital photos have metadata recording the time and date when they were made, we can observe specific moments in ISS’s life. This is not so different from a stratigraphic excavation of a site on Earth. We can also identify how aspects of Earth culture have made the transition to space. How does this work? Let’s look at an example.

A photo of ISS crew in Node 2/Harmony (note the bell at upper left).

A photo of ISS crew in Node 2/Harmony in 2009 (note the bell at upper left). Photo credit: NASA, remixed and used under CC 2.0 BY-NC.

In this photo, we see the American Node 2 module (also known as Harmony), with six astronauts. As archaeologists, we focus on material culture as a means of understanding the development and maintenance of a society — even a microsociety of six people. So we might notice the uniforms worn by the crewmembers, which indicate their affiliations and identities. One of the figures, in the back on the right, is notably different in his gray jumpsuit. This is Charles Simonyi, who was a “space tourist,” a temporary visitor, rather than an astronaut selected and trained by a space agency for a specific mission (he created the programs Word and Excel for Microsoft). You can also see the array of flags and patches above the astronauts’ heads. These are the flags of the US, Japan, Russia, Canada, and the 11 European nations which participate in the ISS project. The patches are related to the specific expedition, or habitation cycle, of the ISS at this time. Note that the flags of the nations of the astronauts who were on board ISS at the time are the ones given precedence.

And then there is one other piece of material culture evident in this photo: a bell. You can see it at the upper left of the image. When we first saw this, we thought maybe it was related to the wide array of musical instruments that have been carried to ISS. But it turns out that it represents the translation of an interesting aspect of naval culture to the paradigm of space…and its location in Node 2 is no accident.

On ships at sea, a bell is often rung to announce the boarding or departure of crew from a different boat. While the Space Shuttle was still in service, Node 2 was its docking point. So when a Shuttle would arrive or leave, the bell in Node 2 would be rung in salute. As NASA astronaut Sandra Magnus, who served on STS-112 in October 2002, described it,

…we have a very nice tradition on the station where they’ll ring us off with the bell and announce that Atlantis is departing, and we knew that was officially the end of our docked stay, and home we go.

But Node 2 wasn’t launched until 2007. So the bell wasn’t located here when Magnus visited. In 2002, it was probably in the US Laboratory module (aka Destiny), adjacent to the Pressurized Mating Adapter where the Shuttle docked. Later, as the station grew, the bell was moved so that it would still be close to the entrance to the station, and so the Earth-bound naval tradition could continue. The bell shows how astronaut crews conceptualize their presence on ISS as being “on a ship,” and they recognize this by acting as though they are on a ship at sea!

You can follow ISSAP on Twitter at @ISSarchaeology or on Facebook at

Alice has written a post for Day of Archaeology here

Pale blue dot: everyday material culture on the International Space Station

The most ordinary objects sometimes end up in extraordinary contexts. Who would have thought that the humble resealable (or snap lock/ziplock/ziploc) plastic bag was a space traveler?

Image courtesy of NASA

Tom Marshburn, Roman Romanenko and Evgeny Tarelkin, Expedition 43. Image credit: NASA

In this image, taken on board the International Space Station in 2012, the astronaut and cosmonauts are looking very excited. That’s because they’ve just received a rare delivery of fresh food – carrots, capsicum, grapes, and blueberries. If the photo had been taken on Earth, you might have thought they were juggling; but juggling isn’t something you can do in a microgravity environment. The food is packaged in perfectly ordinary ziplock bags, each with a blue velcro dot attached. There seems to be three sizes represented. They’re not the kind of bags archaeologists and geologists use, with the white stripes to write labels on.

The ziplock bags mark this food immediately as different, as most astronaut food is in vacuum-sealed metallic pouches. The image raises a number of questions. Are the ziplock bags as ordinary as I presume, or are they special space bags? What happens to the bags once their contents are consumed? Do they become trash, returned to Earth, or are they recycled and used in different contexts in the space station?

If the latter, we might expect that a re-used bag might start to look cloudy over time, just as they do in our own kitchens. (There is something slightly pathetic about a worn ziplock bag). So it should be possible to monitor the condition of bags throughout the space station to work out how often their contents and use have been changed. And of course we’d have to find out how many each expedition has at their disposal. Indications are that they are abundant.

A kitchen in orbit

Below you can see astronaut Sandy Magnus cooking on Expedition 18, in 2008. Ziplock bags were her mixing bowls. The seal on the bags prevented the ingredients from floating away as she combined garlic, olives and sun-dried tomatoes. Her only equipment in this improvised space kitchen – there are galley areas on the ISS but no facilities for cooking as such – was a blunt pocket knife, the bags, and duct tape to hold the chopped ingredients down.  You can also see the duct tape on one of the bags in this image.

Sandy Magnus, Expedition 18. Image credit:NASA

To get the ingredients she needed, Sandy had to plan well in advance before she left Earth, and experiment a bit on fellow crew members to make sure her recipes and her mise-en-place worked. It was like a MasterChef challenge.

The use of the bags, usually for storage, as a mixing bowl, is an adaptation of an artefact intended for one purpose for another. Vicky Kloeris, the manager of ISS food systems during Sandy’s stint, noted that Sandy “found ways to use things beyond their original intentions”.

Perhaps these are bags recycled from the fresh food delivery. When did the practice of using the bags for cooking begin? Is this a practice initiated by the astronauts and cosmonauts themselves to add variety – and a measure of self-determination – to their restricted diet? What other options might there have been for mixing ingredients?

Cooking is an everyday activity in Earth gravity but is not a feature of orbital life. Why go to all this effort to do something that requires so much planning, with perhaps dubious results? It wasn’t about the taste or nutritional value of the food; it was more about a social concept. The feeling of home is important to people, and food is a big part of that – just as it is on Earth. As Sandy Magnus observed, “Special occasions have special food and our world revolves around eating food. Being able to have special dishes on Christmas and New Year’s made it feel more like home.”

Hang on – what was that about pocket knives? Do astronauts really use pocket knives and not some fancy sonic knife? It turns out they do. Here’s a red pocket knife lying on a galley surface, in a picture taken by Scott Kelly on Expedition 43 in 2015.

A table set for three. Image credit: NASA

Here you also see food pouches, three pairs of scissors and small snap lock bags which look like they might have pills inside them. Note that one of the pill bags is velcroed down using the blue dot. The scissors are essential flatware for space; they are used for cutting open the outer food packaging. This seems to be a table set for three. To terrestrial eyes, it looks perhaps more like a medical clinic than a dining room.

A versatile container

It’s not all about food, thought. Ziplock bags are used for a range of purposes on the ISS, such as:

Here’s a gyro repair tool kit in its official, inventoried zip lock bags. Notice the specification of the restraint – velcro – to keep each bag inside the kit from drifting away as it’s put to use. This is the blue dots again. Someone on Earth must have the job of sticking the dots onto everything.





























This one is even flame retardant! The white velcro squares are attached in the four corners of the bag, which can then be stuck onto velcro strips on the Space Station’s surfaces. Restraining objects is one of the challenges of living in microgravity. This is how astronaut Garrett Reisman described it in 2008:

One of the things about working in zero gravity is you can’t put anything down. That’s really an issue. Just think about trying to work on your car, because when we’re doing maintenance work on the Space Station it’s kind of like working on a car. Every time you unscrew a bolt, you can’t just put it down; you have to put it into a zip lock bag, or tape it somewhere, or Velcro it to a wall. If you just let go of it, or you turn your back on it, it may be gone when you turn back around again and good luck finding it because it’s hard to find things up there. So that’s a unique challenge up there. It makes it very easy to lose stuff, and it takes a long time in the beginning until you get good at managing all the parts.

The bag is an essential mechanism for recreating a feature of the Earth gravity environment that we are so used to we don’t even remark upon it. It carves up a tiny bit of the directionless space into a sort of gravity surrogate. Who knew that this flimsy piece of polyethylene could replace the relentless pull of the Earth’s mass?

The ziplock bag has a number of ‘affordances’ that enhance its usefulness in microgravity. It’s flexible, lightweight, transparent, resusable and sealable. Now that I reflect upon it, I can see that the white-label-strip bags we archaeologists often use are not the best choice for space. The strips obscure the contents for a start. And once written on, the label is not easy to remove, reducing the bag’s recyclability.

But what does this all mean?

From the pictures, you can see that there is a variety of ziplock bags in circulation aboard the ISS. Their use ranges from very particular and prescribed, to very ad hoc and informal. A question I immediately want to ask is how easily the bags move between these categories and what the behavioural constraints around them are.

Space stations have to achieve a balance between all sorts of contradictory conditions. They have to be a home where people live, but situated inside a giant scientific laboratory with little privacy; they have to use the lack of up and down to make good use of limited space, but also make astronauts comfortable and productive; they have to use technologies designed and tested on Earth to make people function in microgravity.

The ziplock bag opens up questions about how astronauts use material culture to navigate these contradictions. They’re the kind of material culture that people tend not to notice; they’re just background environment, cheap, abundant, disposable. But here we see them playing an important role in the everyday life of the crew.

It’s for this very reason that an archaeological approach to ISS material culture might bring new insights into life in space. This is why Justin Walsh and I are looking at how astronauts create their own cultures in this remote and closed world. One day there might be a space society which cannot exchange material with Earth. Then, every artefact might be the one that makes or breaks a new planetary culture.

For more information on the Archaeology of the International Space Station, you can follow us on Twitter @ISSArchaeology, on Facebook or keep up to date on our blog.  Justin St Walsh has contributed to Day of Archaeology here

Sunflower seedling, grown by Don Petit. Image credit: NASA



‘And warm with human love the chill of space’: the archaeologist in orbit

As a child growing up on a wheat and sheep farm in southern New South Wales, I was obsessed with stars. The only other lights visible at night came from inside our own house. I’d go outside and look up at the Milky Way and wonder how the universe came to be. How to attain those other worlds? Why did we not have the technology to go and visit them? I longed desperately for the future.

The Milky Way seen from the Southern Hemisphere

The Milky Way seen from the Southern Hemisphere

And yet, the past was equally fascinating. Around me, on our property, were the traces of a multi-layered occupation: Aboriginal grinding stones used as doorstops, trees with canoe scars standing in the middle of sheep pasture, abandoned wells dug by Chinese labourers, the farm machinery ‘graveyard’, the old pise (rammed earth) homestead now dissolving slowly back into the soil. Only in later years have some of the old farmers quietly mentioned to me the Aboriginal burials found in the sandhills, such well-drained soil for growing crops.

In a long, circuitous journey, these two parts of my life came back together when I decided to apply archaeological principles to the stuff that humans have sent beyond the Earth: the stuff we now call space junk.

Earth orbit is more than just far away, it’s like the land (or space) that time forgot. While on Earth we were becoming aware of the pollution caused by modern industry and the impacts of mass production and mass garbage disposal, spacefaring nations kept on merrily flinging stuff up into the sky where it would last for thousands of years.

In this cosmic rubbish heap were things that caught my imagination. I’d never really thought about what satellites looked like, or their individual histories. I suppose I’d never thought about them at all. Probably most people don’t: when they hear the term ‘space junk’, they might imagine something like a scrap yard, only floating:

A steel scrap yard in the USA

A steel scrap yard in the USA

But, you may say, why should this be archaeology and not history? Haven’t we got an abundant documentary record to tell us all about these spacecraft and their stories? Not, as it turns out. The documentary record is far from perfect, and even if it were, it doesn’t necessarily contain the answers to the questions we want to ask. Within a system of production, there are ideas and assumptions that are unquestioned and invisible: no-one writes about them, or records them, because they are the fabric of their worldview. It’s only later that we may look back and wonder why something was like that. So there may be no words or images that document a decision; there may only be the thing itself. And this is what makes it archaeology.

For the moment, I have to use documents and pictures that record the iconic early spacecraft as if they were the pottery sherds, and use them to reconstruct the rest of the story: the worldview that made a spacecraft look like THIS and not THAT. I have to think about what they meant back then, and what they mean now. And what they mean individually, and what they mean as an assemblage. For the latter, my tools are also tracking data, simulations and visualisations, like this one created by the European Space Agency.

Space junk in Earth orbit

Space junk in Earth orbit

This is, hopefully, a ‘before’ shot that we’ll look back on in 50 years in both wonder and disgust. The ‘after’ shot should look very different. Sparser. More evenly distributed, perhaps. It may include high densities at Lagrange points, places where the gravitational forces created by the Earth, Moon and Sun are equally balanced. These may be our space museums of the future, where we can park space junk safely out of the way and know that it will stay put.

The kind of spacecraft we might want to keep, for a whole range of reasons, might be one like the TRAAC satellite, launched in 1961 by the USA. The satellite collected data about the Starfish Prime Low Earth Orbit nuclear test, which detonated some 600 km below it in 1962, taking out its solar panels. TRAAC is part of the evidence of Cold War nuclear weapons testing, at a time when space was up for grabs: the UN Outer Space Treaty, which establishes space as a global commons to be used for peaceful purposes, was only accepted by the General Assembly in 1967. So TRAAC represents a vision of space very different to how we conceive it now.

Transit Research and Attitude Control (TRAAC)

Transit Research and Attitude Control (TRAAC)

The thing I really love about TRAAC is that it carried the first poem into space, inscribed on one of its instrument panels. The poem was written by Thomas G. Bergin of Yale, and is both uplifting and slightly sinister, as it views human spacecraft as weapons against the gods, who have until now had us at their mercy:

From Time’s obscure beginning, the Olympians
Have, moved by pity, anger, sometimes mirth,
Poured an abundant store of missiles down
On the resigned, defenceless sons of Earth.
Hailstones and chiding thunderclaps of Jove,
Remote directives from the constellations:
Aye, the celestials have swooped down themselves,
Grim bent on miracles or incarnations.
Earth and her offspring patiently endured,
(Having no choice) and as the years rolled by
In trial and toil prepared their counterstroke—
And now ’tis man [sic] who dares assault the sky.
Fear not, Immortals, we forgive your faults,
And as we come to claim our promised place
Aim only to repay the good you gave
And warm with human love the chill of space.

But in the last stanza, the bellicose nature of the assault weapon is turned on its head with a new vision of space. The point, for me, about this poem, is that it exists as a physical inscription, part of the fabric of the spacecraft, and its presence in space was felt to be important at the time. It’s the start of a long tradition of incorporating an element of flesh-and-blood humanity into robotic spacecraft, either as messages to those beyond us in space or to those of us who remain here on Earth.

We don’t need to destroy everything currently classed as space junk, effectively over 95% of all the stuff up there, to reduce the risks of collisions from orbital debris. We can do it in a smart way by thinking through all the heritage and environmental issues. We should stop thinking of space as a black Cartesian vacuum that is unaltered by us putting things into it, or even taking them out again. After all, we stopped thinking this way about the Earth quite some time ago. If space agencies and corporations continue to apply a 1960s approach to the space environment, it doesn’t oblige everyone else to. In the 21st century, it’s junk like TRAAC that perhaps we want to keep, for what the physical body of the spacecraft can tell us, both about nuclear war in space, and the hopes and aspirations of those who sent it up.

I’m Dr Space Junk, and on this Day of Archaeology, I’m going outside to look at the stars.