Dr Alice Gorman is an internationally recognised leader in the emerging field of space archaeology. Her research on space exploration has been featured in National Geographic, the Monocle, and Archaeology magazine. She is a faculty member of the International Space University's Southern Hemisphere Space Program in Adelaide. She has worked extensively in Indigenous heritage management, providing advice for mining industry, urban development, government departments, local councils and Native Title groups in NSW, WA, SA and Queensland. She is also a specialist in stone tool analysis, and the Aboriginal use of bottle glass after European settlement. Alice is a the Deputy Chair of the Space Industry Association of Australia, the Chair of the South Australian Chapter of the Australian Association of Consulting Archaeologists, and a Councillor of the Anthropological Society of South Australia. She tweets as @drspacejunk.

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



The death of a spacecraft

I began my Day of Archaeology preparing for a talk on space archaeology, for an audience of 70 schoolkids and their families. The talk featured some of my favourite objects and places in the solar system – the Venera landing sites on Venus, Tranquility Base on the Moon, the Telstar 1 satellite in Earth orbit, and of course, Voyager 1 and 2 – the most far-flung outposts of human activity in the universe that we can still communicate with.

I thought I should include the solar system’s most recent archaeological site too. In 2014, the European Space Agency’s Rosetta spacecraft dropped the little Philae lander on the surface of Comet 67P Churyumov-Gerasimenko. What was planned as a graceful cometfall turned into an epic bounce when the lander’s harpoon feet failed to deploy, a potential disaster with so little gravity to hold it there.

The Philae lander. Image courtesy of ESA

The Philae lander. Image courtesy of ESA

The lander came to a stop in the deep shadow of a cliff, another disaster as too little sunlight would now reach its solar panels. Nonetheless, Philae worked in fits and starts, conveying data back to the Rosetta spacecraft dancing around the comet, which then relayed it to Earth.

Among the most interesting results gained from Philae was the existence of complex molecules considered to be “prebiotic”, likely from the early phase of solar system formation. It’s hard to say exactly what this means in terms of the origins of life – but it surely means something.

The landing site. Image courtesy of ESA

The landing site. Image courtesy of ESA

It was amazing that Philae gave us so much, given its rocky start. But nothing had been heard from it since July 2015, and as the comet’s orbit took it further and further from the sun, there wasn’t going to be enough power for renewed contact. On 27 July 2016, the equipment used by Rosetta to communicate with Philae was turned off.

Of course I was following this, and was sorry to see the end of such a thrilling mission – the first time we have landed on the surface of a comet.

As I collected images and information to set the scene for describing the Philae landing site for the schoolkids, my eyes started to fill with tears.

Half an hour later I decided to go out and get a coffee, and found myself sobbing in the corridor. A passing stranger saw me and asked if I was OK. So kind of her! But what could I say? How could I explain that the silence of a robotic spacecraft, riding a comet somewhere out beyond Jupiter, was breaking my heart?

I was far from alone in mourning Philae. Across the world, space scientists and fans were feeling the same and expressing their admiration and loss in social media.

Some would say that this is a quite ridiculous result of anthropomorphising an inanimate technological object. which was what the European Space Agency’s publicity campaign around the mission invited us to do. But I think it’s something far more interesting than that. I think it speaks to how cultural significance is created.

Archaeologists are frequently also cultural heritage managers. We study places and objects, and use criteria like those in Australia’s famous Burra Charter to assess their cultural significance. The nature and degree of cultural significance helps us to decide whether a piece of cultural heritage should be preserved for future generations.

One of the categories of cultural significance is social significance. This is about community esteem, or how people feel about a place or object. You might have a site that has tremendous historical significance and scientific research potential – but if people don’t care about it, why shouldn’t we let something new take its place?

It’s often assumed that people don’t form feelings of attachment to recent technology. It’s too industrial, not ‘beautiful’ in the same way as a historic building, and it’s just there to perform a task. But in my years of research on space technology, I’ve found that this assumption is very far from true.

Something about Philae’s trials and tribulations made so many people relate to it. This remote robot was not so different to us, struggling through life doing the best we can. Perhaps if the mission had been an unmitigated success, these feelings of sympathy might not have developed in the same way.

We could say that Philae has all sorts of cultural significance. As the first human object to land on a comet, it has historic significance. We could study it as one of a suite of exploratory probes in the solar system, and look at how its technology compares with other spacecraft made for different environments – that’s scientific significance. The factors that culminated in Philae’s particular design and appearance contribute to its ‘aesthetic’ significance.

But perhaps the most important is Philae’s social significance: how it made us feel.



One thousand elephants orbiting the Earth

Could the Day of Archaeology have started in a more appropriate manner for a space archaeologist specialising in orbital debris?

Last night, while I was on my way home from a conference dinner at the National Wine Centre in Adelaide, observers in the  eastern states of Australia were mesmerised by a flaming ball that streaked through the sky. Was it a meteor? Was it a piece of space junk? (To date, no-one has suggested it was a UFO).

This morning, it was quickly established, taking into account its slow speed, re-entry path and data from US Space Surveillance, that it was a Fregat rocket body, the upper stage of Russian launch vehicle which earlier in the week had boosted a weather satellite and six other payloads into Low Earth Orbit. Now, too low to escape the drag effects of the upper atmosphere, it had fallen back to Earth.

As I faffed around making coffee, the email and phone started binging, with requests from journalists to talk about space junk.  This really was going to be an interesting day.

FRegat upper stage

This is a Fregat rocket, with the cubic satellite released. Not a traditional rocket shape!

The kinds of things that people generally want to know are: what is up there? How much of it is there? Are we in any danger from it? What about satellites and human missions in orbit? Then they often ask what the hell an archaeologist is doing working in this field. Which is a good question, really, and the short answer is that human interactions with the material world are pretty much what archaeologists study.

So let’s have a quick look at the other questions.

What: satellites, rocket bodies, fragments, flecks of paint, shrapnel, organic waste from human spaceflight missions, tools, fuel. It ranges from whole spacecraft that weigh thousands of kilogrammes, to sub-millimetre particles from eroded spacecraft surfaces.

How much of it is there? One calculation is 6000 tons, or by my reckoning, the equivalent of 1000 African elephants. (I kind of like the idea of orbiting elephants). There are over 23 000 bits over 10 cm in diameter, and millions of bits smaller than that.

Are we in any danger from it? Not really. Most of the time the re-entry goes unnoticed. For example, there have been 25 other rocket bodies that re-entered the atmosphere this year already. This one is receiving attention because so many people saw it.

What about satellites and human missions in orbit? This is a more serious question. The International Space Station, not infrequently, manoeuvres to avoid space junk, and sometimes other satellites do too. Billions of dollars and human lives are at stake. So far, while collisions have damaged satellites and there have been occasional catastrophic break-ups, there have been no fatalities or injuries. The day that happens will be a wake-up call for the whole industry.

Eventually, everything in Low Earth Orbit will get dragged out of the sky. But there’s a lot of stuff up there, and we keep launching new spacecraft. It’s a very dynamic place, where human artefacts hurtle through a matrix of cosmic particles and dust, electromagnetic currents, plasma clouds, meteors, and atomic elements. The satellites, rocket bodies and other objects decay and fragment, and the materials of Earth migrate into the gases of space.

‘Nature’ and ‘culture’ aren’t separate in Earth orbit; it’s a new kind of space which we are as much a part of as the comets and meteors. You could call it a cultural landscape, or you could look at it as part of the signature of the Anthropocene. Something I spend a lot of time thinking about is how to best characterise this diverse, decaying, high-speed population. I want to go beyond just the technology and orbital configuration and think about them less as junk and more as avatars that carry our values into space.

Lately, I’ve been thinking spacecraft as robots, and even as computronium. I suppose that’s more futurological than archaeological, but I’m OK with that. Part of the appeal of archaeology is that by imagining past worlds, we’re really opening up possibilities for the future.


‘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.