Wednesday, November 17, 2010

The sky is falling: How Skylab became an Australian icon

A couple of months back Ursula Frederick asked me if I'd be interested in contributing to a volume of the Journal of Australian Studies, guest edited by her and Kylie Message (both of ANU), on the theme of Media and Materiality.  To cut a long story short, the theme is about how studies of material culture intersect with cultural studies.  It's a teensy bit postmodern for me (sorry, Urs!), but Dr Space Junk is nothing if not versatile, or so I like to think.

Ursula thought I might like to write about Skylab, and she was right.  I have quietly been filing away bits and pieces about it with the intention of doing something with them, so here is the spur.  Despite this, coming up with a coherent abstract to fit the theme of the volume was harder than I thought.  Here it is as sent to Ursula; as usual the actual paper will probably evolve a bit as I get into the research and writing of it.

The sky is falling:  how Skylab became an Australian icon.
In 1979, the US orbital space station Skylab made a spectacular re-entry that was widely anticipated across the world.  As it disintegrated, debris from the spacecraft fell around the town of Esperance in Western Australia and were scattered over the arid inland.  Like the de-orbiting of Mir in 2001, Skylab’s re-entry caused a media frenzy.

Skylab is perhaps remembered more for this than for its actual mission, which was far less dramatic than the preceding Apollo program.  It was not even the first space station, as the USSR’s first Salyut had been launched two years before Skylab in 1971.  Skylab’s main purpose was to investigate physiological, social and practical aspects of how humans could survive in space.  For the first time, thought was given to the comforts of astronauts and the spacecraft was designed to be a home.  

This faraway house could only be seen by those who made the effort to look up when it was passing; like all orbital material, it was largely invisible, its presence felt only through media reports.  In its reentry, however, the disembodied spacecraft became tangible, visible, and collectable, in the form of its scattered, and charred remains, in a way it had never been before.  These pieces were collected, curated, displayed and marvelled over in small and large museums and in private collections.  Anyone could own a piece of space if they were lucky; the debris was both space junk and precious artefact.  

When the Shire of Esperance, tongue-in-cheek, fined the US Government for littering, Australia had made a statement about the relationship between spacefaring and non-spacefaring states, and the nature of space industry:  being in space did not remove more terrestrial responsibilities. Through these local and personal interventions after its decay, the social significance of this house in the sky came to outweigh its historic significance.  In this paper I consider how the parts of Sklylab became more than the sum of its whole.

Thoughts, leads, information, all welcome!

Friday, November 12, 2010

Doing orbital archaeology from space

I know I wrote a while ago that I was over remote sensing, but looking at a wonderful picture by CNES this morning of the Tango satellite as seen from the Mango satellite (if I remember the details correctly) I think I may have been too hasty.  It would be possible to do an archaeological survey of orbital space remotely from another spacecraft in orbit. Or many spacecraft in orbit.  Sampling would be critical to get across, as the distances are just so vast, but that's a minor problem, I think.

Terrestrial tracking could be recast as a kind of archaeological survey - they're just not aware that that is what they're doing yet!  Anyway this is more of a note to myself to remind me to come back to this idea. I have ten minutes before I leave for work, and this morning's task of delivering a masterclass to the graduates on conference networking. This afternoon the graduates are doing presentations on their industry work placements, there will be drinks, and if I don't imprison this thought in words now I might forget it in the awful rush of end-of-semester stuff.

Wouldn't some wealthy aerospace company like to give me job researching this kind of thing? It would make me so happy.

OK. Going to catch the bus now, in the rain.

Tuesday, November 09, 2010

Space food: recreating an authentic space experience on Earth. A review of The Astronaut's Cookbook.

I've had an ongoing interest in Space Food Sticks, which have quietly vanished from Australian supermarket shelves in the last few years, despite the fact that they seemed to have a healthy export market in the US. So when I learnt of Springer's recently launched The Astronaut's Cookbook:  Tales, Recipes, and More, by Charles T. Bourland and Gregory L. Vogt, I was curious to see what it might have to say about them.

The space food stick was created by Pillsbury in a form that could be inserted into a helmet port - but of course that was never going to work with the pressure differential.  Despite this, the originally caramel-flavoured sticks were part of the Apollo menu. Bourland and Vogt imply that sales of the Pillsbury space food stick were disappointing and the product never took off, so to speak (Bourland and Vogt 2010:32).

This is interesting as they certainly took off in Australia!  They were manufactured by White Wings, a company owned by Uncle Ben's (I think). I remember them as being chocolate, not caramel, although there was a caramel version available.  In later years the box featured a picture of a BMX bike rather than a spacecraft.  Perhaps there was a subtle safety message in this:  "astronauts wear helmets, so it's cool to wear a bike helmet".  Assuming that the callow youth thought astronauts were cool, of course.

When I held a symposium about the history and heritage of Woomera a few years ago, I bought many boxes and put an individually wrapped stick in each delegate's bag of symposium stuff.  A year or so later, I wanted to buy some to take to the Centre Spatial Guyanais, and was unable to find them anywhere.  (Perhaps, in retrospect, the intended recipients in French Guiana may have reason to be grateful for that).

USA peanut butter flavoured space food stick box.
Image courtesy of Mojowski 77

Australian chocolate space food sticks.  Author's image.

While Bourland and Vogt don't have much more to say about space food sticks, they do offer a recipe for Bacon Bars (2010:35):

Bacon Bars
1 lb cooked bacon

1. Fry the bacon until golden brown
2.  Place the warm bacon into a hamburger press
3.  Exert 3000 lbs of pressure for 10 seconds
4.  Remove the compressed bacon and let cool.
Yield:  more than you would want.
After samping the bar - so that you can say that you tried it - give the rest to the family dog. One nibble, and Fido will prance around the house barking [Translation:  "It's BACON!").

While I don't own a hamburger press, or have a dog, I confess I am very tempted to try making some version of this. Hell - it's BACON!

I was also amused by this recipe:

Breakfast cereal
1 cup of your favourite cold cereal*
1/3 cup of powdered milk
2 tsp of sugar or 1 packet artificial sweetener
1/2 cup cold water
1 resealable plastic sandwich bag
*Frosted cereals stay crisper longer than unfrosted cereals.

1.  Put all the ingredients in the bag.
2. When ready to eat, add water and reseal the bag.
3.  Shake the bag to dissolve the milk and sugar.
4. Open the bag and eat immediately with a spoon.
5.  Write a note to yourself to never do that again unless you become an astronaut.
Yield:  1 serving.

I think this recipe may reflect the US palate, much sweeter than the Australian, as I can't imagine any adult would actually add sugar to an already frosted cereal, let alone 2 teaspoons.  But perhaps things have to be sweeter in space.  (Hmmm.  This might not be too bad with Froot Loops ......).  If you want to try this one, I think the first step should read "Put all the ingredients in the bag EXCEPT the water".  There is an art to writing recipes that is often overlooked.  Or perhaps I mean a logic.

So you can see this is a very quirky and entertaining book, and may even have some recipes worth trying at home in it, as well as the historical and scientific background to space cuisine. (They include Russian space food as well).  I like the idea that we can be space tourists at home by recreating space experiences, in the same way that space food attempts to replicate the tastes and experience of being at home on Earth. The snippets offered here are from the promotional download, available at the Springer website,

I don't yet have my own copy.  And Christmas is not far away ...........

Saturday, November 06, 2010

Voyage to Venus: an archaeological survey of the Venusian surface

Introductory note
This was written as part of a book chapter, but as it developed Venus became increasingly irrelevant, so I took it out. I've been meaning to do something with it ever since. Posting it here might remind me!

Our tropical twin sister
Although Venus is a close neighbour, and had been the subject of speculation and study since ancient times, very little was known about it in the late 1950s due to the impenetrable cloud layers above the surface (Burgess 1985:8-9). Exploring Venus would be a scientific first as it was considered to be critical in understanding the evolution of the Earth (Dorfman and Meredith 1980:773). Our “twin sister” (Marchal 1983:269) had similar mass, gravity and volume.  Before the first missions, Venus also held the promise of life ….

Speculations ranged from a warm, swampy world that resembled Palaeozoic Earth, dry dusty mountains, oceans of carbonic acid, a surface covered in hot oil or puddles of molten metals (Burgess 1985:13, 131). C. S. Lewis (1943) created a lyrical sensorium of fragrant floating islands, a new Eden; Isaac Asimov (1954) imagined telepathic frogs swimming Venus’ warm oceans.  But when the first missions returned data, the dream of Venusian life was dashed.

Sapphires, diamonds and Daleks
The earliest missions were flybys. Venera 1 (USSR), launched 1961, failed to return data and entered a heliocentric orbit. In 1962, the US Mariner 2 flyby of Venus discovered that the surface temperature was likely around 430° C (Burgess 1985:2).  Venera 2, launched in 1965, also failed.

Venera 3 was a landing mission: the spacecraft crashed on the surface but also did not return data (Burgess 1985:22; Figure 1).  Venera 4, which reached Venus in 1967, was the largest interplanetary spacecraft yet launched at 1100 kg (Burgess 1985:22).  It had a more sophisticated heat shield, developed from experience with re-entry studies on ICBM warheads (Burgess 1985:38).  Venera 5 and Venera 6 (1969; Figure 5) were even heavier, and designed to resist up to 27 atmospheres (atm): but it seemed that the Soviet designers were reluctant to accept the estimation of a surface pressure of around 100 atm.  Both spacecraft were crushed before they reached the ground (Burgess 1985:40).

Venera 7, in 1970, was the first to land intact and return data from the surface (Basilevsky et al 2007:2097).  This time the landing capsule was designed to resist 180 atm, had stronger insulation and a titanium pressure sphere core (Pauken et al 2006:2).  Finally, the surface temperature and pressure were confirmed, and Venera 8, launched 1972, was designed to withstand only 105 atm (Burgess 1985:43).

Veneras 9 and 10, in 1975, were redesigned with a circular ring shock absorber.  They returned the first pictures of the surface.  In these extraordinary images, we see a field of flat rocks, with curve of the shock absorber visible on the lower edge.  The perspective, as if a person is looking down on their feet, gives the photographs a personal feeling.  The Veneras, in appearance, are not unlike the cyborg Daleks:  they almost seem as if they could start moving of their own volition, uttering some staccato imperative (Figure 2).  The images give a sense of the spacecraft orphaned on a strange planet.
Figure 1:  Venera 3 spacecraft.  Image courtesy of NASA

Figure 2:  Venera 9 spacecraft.  Image courtesy of NASA
In 1978, both the US and USSR sent missions to Venus.  Veneras 11 and 12 weighed in at 5000 kg each (Burgess 1985:48).

Figure 3:  Landing sites on Venus. Image courtesy of Philip Stooke
Pioneer Venus has been the only US program to place material on the surface of Venus.  Arriving at Venus in 1978, a bus delivered one large (called Large), and three small probes to the surface:  the engagingly named North, Day and Night for their proposed destinations.  The large probe was 1.5 m in diameter; the three small ones were 0.8 m.  Each had a payload of scientific instruments.

The spacecraft were designed and developed by the Hughes Aircraft Company.  The large probe was a pressure vessel module 73 cm in diameter and a deceleration module weighing 317 kg.  The heat shield was carbon phenolic with aluminium and fibreglass fittings. The pressure module containing the instrumentation was a titanium shell with ports and four sapphire and one diamond window for the instruments.  Internal shelves were made of beryllium (Dorfman and Meredith 1980).  The small probes were also titanium pressure modules with carbon phenolic heat shields, internal beryllium shelves and two diamond windows each.  The Large probe jettisoned its heat shield on the way down to the surface; the small probes retained theirs (Burgess 1985:82).

The last human artefacts to land on Venus were the Vega 1 and Vega 2 probes, released by rockets on their way to a rendezvous with Halley’s Comet.  They were essentially developments on the basic Venera lander type. Launched in 1984, both Vegas successfully landed on Venus in 1985 and returned data.  All subsequent missions have been flybys or orbiters.  Table 1 shows the all the Venus missions which have left material on the surface of Venus.

Date    Nationality    Mission    Components on surface
1965    USSR    Venera 3    Hard lander
1967    USSR    Venera 4    Hard lander
1969    USSR    Venera 5    Hard lander
1969    USSR    Venera 6    Hard lander
1970    USSR    Venera 7    Soft lander
1972    USSR    Venera 8    Soft lander
1975    USSR    Venera 9    Soft lander
1975    USSR    Venera 10    Soft lander
1978    USA    Pioneer Venus    4 probes
1978    USSR    Venera 11    Soft lander
1978    USSR    Venera 12    Soft lander
1981    USSR    Venera 13    Soft lander
1981    USSR    Venera 14    Soft lander
1984    USSR    Vega 1    Soft lander
1984    USSR    Vega 2    Soft lander

Table 1:  Missions with surface components on Venus

Archaeological sites of the future
The data returned by the Venera, Pioneer Venus and other missions revealed a fierce environment with the most corrosive upper atmosphere in the solar system: Venus’ yellow clouds are concentrated sulphuric acid (Reddy and Walz-Chojnacki 2002:36-37). On the surface, pressure from the predominantly CO2 atmosphere is 90 times that on Earth; Veneras 3-6 were crushed as they descended through the atmosphere.  The surface temperature is 430° C (740 K), above the melting points of lead, tin and zinc.  In such conditions, is it possible that the landers and probes have survived?

There is no evidence of plate tectonics and only “modest” evidence of geological activity on Venus (Jones 2007:169).  Erosion processes are slow, as there is no water, and surface winds move at human walking pace (Saunders 1999:100, 108, Jones 2007:343).  While the winds can move sand and dust, “the slow speed makes the particles ineffective as cutting tools and agents of erosion (Saunders 1999:108), so much so that craters a few million years in age appear fresh (Jones 2007: 275, Saunders 1999:100).  There is also little danger from the upper atmosphere.  The cloud layers start at around 45 km from the surface.  Droplets of sulphuric acid do leak downwards, but evaporate as the temperature rises towards the surface – they do not survive below about 25 km (Jones 2007:342).  Being on the surface would be like immersion in a hot dry ocean with slow currents of air (Burgess 1985:132).  There is no reason why archaeologists of the future should not find the Veneras, the Vegas, and the Large, North, Day and Night probes exactly where they landed, the diamond and sapphire eyes gazing sightlessly at the dull brown terrain (Figure 3).

The Venera and Vega spacecraft can be seen as representing the Cold War battle to imprint space with ideology (Gorman and O’Leary 2007).  Burgess even conceptualised the Veneras as “Red flags on Venus”, and each Venera mission carried Soviet emblems to commemorate the landing (Burgess 1985:35-36).  But they are much more than that.

The spacecraft also represent an evolution and adaptation to increasingly more accurate information about the nature of the “errant twin”:  each set of returned data enabled the design of spacecraft more suited to surviving Venusian conditions.  Like the early Cold War launch sites, and the cloud of orbital debris surrounding the Earth, they have made Venus a cultural landscape where the interaction of the environment and human material culture have formed a new entity.

Asimov, Isaac  1954  Lucky Starr and the Oceans of Venus.  Doubleday and Company
Basilevsky, A.T., M.A. Ivanov, J.W. Head, M. Aittola and J. Raitala  2007  Landing on Venus:  past and future.  Planetary and Space Sciences 55:2097-2112
Burgess, Eric  1985  Venus:  an errant twin.  Columbia University Press, New York
Dorfman, Steven D. and Clarence M. Meredith  1980  The Pioneer Venus Spacecraft Program.  Acta Astronautica 7:773-795
Gorman, A.C. and Beth Laura O’Leary  2007  An ideological vacuum:  the Cold War in space.  In John Schofield and Wayne Cocroft (eds) A fearsome heritage:  diverse legacies of the Cold War.  Left Coast Press, Walnut Creek, California
Jones, Barrie W.  2007  Discovering the solar system.  Second Edition, John Wiley and Sons Ltd, Chichester UK
Lewis, C.S.  1943  Perelandra.  John Lane, London
Marchal, C.  1983  The Venus-New-World Project.  Acta Astronautica 10(5-6):269-275
Pauken, Michael, Kolawa, Elizabeth, Manvi, Ram, Sokolowski, Witold and Joseph Lewis  2006  Pressure vessel technology developments.  4th International Planetary Probe Workshop, 27 June – 30 June 2006, Pasadena, California.  Available at  Viewed 15 September 2008
Reddy, Francis and Greg Walz-Chojnacki  2002  Celestial delights:  the best astronomical events through 2010.  Celestial Arts
Saunders, R. Stephen  1999  Venus. In J. Kelly Beatty, Carolyn Collins Peterson and Andrew Chaikin (eds).  The New Solar System.  Fourth Editions, Sky Publishing Corporation and Cambridge University Press, Cambridge pp 97-110

Sunday, October 31, 2010

Mormon space sites - fundamentalism and high technology

I've long been fascinated by Mormons. It's not that they're necessarily weirder than any other Christian sects or denominations, but they are relatively recent, and New World, and their origins have been played out in the full glare of media such as newspapers and telegraphs (not something your other major prophets have had to deal with). There is also a rich tradition of Mormon archaeology (by serious archaeologists like Mark Leone [for example, 1973, 1977, 1979], not just people trying to prove the Book of Mormon, although they exist too).

But the fundamental polygamist sects are freaky (for a whole range of reasons that are not relevant here). The reason I am contemplating this at all is because on a recent train journey I took Jon Krakauer's fine book Under the Banner of Heaven, an analysis of fundamental polygamist Mormon sects and the nature of belief, to read on the way. Would you be surprised to learn that there was a space connection? And as I read those pages with excitement, little pieces of paper fell out of the book, indicating that I had bookmarked them on an earlier reading.  This is why:
At the moment, DeLoy is driving his thirdhand Chevy van on a dirt road on the outskirts of town.  One of his two wives and eight of his seventeen children are riding in the back.  Suddenly he hits the brakes, and the van lurches to a stop on the shoulder.  "Now there's an interesting sight", DeLoy declares, sizing up the wreckage of a television satellite dish behind some sagebrush off the side of the road.  "Looks like someone had to get rid of their television.  Hauled it out of town and dumped it".
Members of the religion, he explains, are forbidden to watch television or read magazines or newspapers.  The temptations of the outside world loom large, however, and some members of the faith inevitably succumb.  "As soon as you ban something", DeLoy observes, "you make it incredibly attractive.  People will sneak into St George or Cedar City and buy themselves the dish, put it up where it can't easily be seen, and secretly watch TV during every free moment.  Then one Sunday Uncle Rulon will give one of his sermons about the evils of television. He'll announce he knows exactly who has one, and warn that everyone who does is putting their eternal souls in serious jeopardy.
Every time he does that, a bunch of satellite dishes immediately get dumped in the desert, like this one here.  For two or three years afterward there won't be any televisions in town, but then, gradually, the dishes start secretly going up again, until the next crackdown. People try to do the right thing, but they're only human". (Krakauer 2003:11)

What interests me about this is firstly the satellite dishes, which I have argued (Gorman 2009) are as much space archaeology as anything else, and second of all the domination/resistance theme. So we have accumulations of satellite dishes out in the desert, deposited periodically, representing the impact of telecommunications technology. They are archaeological sites of the space age on Earth.  With a turnover of three years or so, this landscape would make a nice study in change in satellite design .....

Domination and resistance have been studied extensively by historical archaeologists, in terms of the ways that people find to assert their identities using material culture and space in controlled situations such as plantations, prisons, asylums, utopias etc.  In this case, the discarded satellite dish observed by DeLoy Bateman and Jon Krakauer is visible from the road out of town - on the outskirts - so despite the secrecy involved in accessing satellite television in Colorado City, its disposal is barely concealed. That in itself speaks volumes about the efficacy of, and responses to, strict control of behaviour in the fundamental communities of the city. 

And all this makes me think of similar social pressures in places like Woomera - of a very different kind, such as keeping out the contagion of communism, and of course a completely different relationship to technology - but both are desert enclaves where information must be tightly controlled. Apparently the desert outside the township of Woomera bears the evidence of social activities unacceptable in the family atmosphere of the town.

This isn't quite where I thought I was going when I started writing this, but now I'm here, I don't mind it.  Perhaps I shall have to explore this similarity a little further.  Permeable boundaries of technology and the role of space material culture in mediating identity?  Something like that.

Gorman, A.C.  2009  Beyond the Space Race:  the significance of space sites in a new global context.  In Angela Piccini and Cornelius Holtorf (eds)  Contemporary Archaeologies:  Excavating Now.  pp 161 - 180  Bern:  Peter Lang
Krakauer, Jon  2003  Under the banner of heaven.  A story of violent faith. London:  Doubleday
Leone, Mark P. 1977 The New Mormon Temple in Washington, D. C. In Historical Archaeology and the Importance of Material Things. Historical Archaeology. Special Publication Series 2:43-61.
Leone, Mark P. 1973 Archaeology as the Science of Technology: Mormon Town Plans and Fences. In Charles L. Redman (ed) Research and Theory in Current Archaeology, pp 125–150. John Wiley and Sons.
Leone, Mark P.  1979  Roots of Modern Mormonism. Cambridge, Massachusetts: Harvard University Press

Wednesday, October 27, 2010

A space debris-tracking satellite

 WASHINGTON — NASA’s Marshall Space Flight Center is gathering information for the possible development of a demonstration satellite to track pieces of orbital debris that are too small to be seen by current systems but still pose a threat to operating spacecraft. Spurred by the new U.S. National Space Policy that emphasizes tracking and mitigating orbital debris, Huntsville, Ala.-based Marshall may partner with industry and academia to field a low Earth orbiting satellite as soon as 2014, said Bruce Wiegmann, an engineer in Marshall’s Advanced Concepts Office (full story at

This is an interesting concept, as, in my opinion, there isn't enough of this going on at the moment.  Debris in GEO is not as well modeled as lower orbits because of the difficulties of tracking stuff that far away; but there are only a few satellites being used to obtain data on GEO (at least as I understand the situation).

This demo satellite is aimed at tracking debris from 1-10 cm in diameter, what's known as the medium-sized class.  The stuff above 10 cm is well tracked from Earth. The problem with the medium debris size class is that collision with a piece can cause a lot of damage to a functioning spacecraft, and even mission failure. And there's far more of it than the big stuff, so collision is far more likely.

I will have to keep an eye on this development to see if there are implications for space heritage.

Monday, October 18, 2010

Vostok space beer: from prehistory to space tourism. An interview with Dr Jason Held.

You might wonder why Dr Space Junk is interested in space beer? (A. She's an archaeologist.  Beer comes with the territory).  But seriously, what has beer got to do with space archaeology?

My interest in this was piqued for a number of reasons.  Firstly, nationalist symbols, and the achievement and claiming of "firsts" has been a major feature of space exploration from the start.  Australia did quite well in this sphere once, being the fourth nation to launch a satellite (WRESAT 1).  Since then our space industry has languished, although we may be heading for a renaissance, fingers crossed!  Producing the first space beer reflects the national obsession with this beverage, and so has some symbolic overtones, I believe. Secondly, as you will see,  Held contextualises the beer in a trajectory of social culture that I think is quite interesting as I am thinking along the same lines myself.

I think it also raises questions about the future complexion of existence in space.  What kinds of artefacts will distinguish the era of space tourism from the era of exploration?  I am reminded of a site I saw at Maralinga in outback South Australia, where legendary surveyor Len Beadell and his team left behind a scatter of beer cans (as they were in those days) with tins of spam and tobacco as evidence of their survey in the desert.  I don't think we are going to see beer bottles littering orbital space, as they won't be in glass, which is too heavy for a start.  (Damn!  I forgot to ask Jason how it would be packaged).  But I wonder how the material culture will differ, and how the terrestrial accoutrements of tourism will be transformed in the space context.

Anyway, here is Jason to tell the story.

DrSJ: Where did the inspiration for the project to develop a space beer come from?

JH:  Several of us are avid homebrewers at Saber Astronautics, both in the US and in Australia, so this is also a chance for us to combine two arenas we love very much.  But the original idea for space beer came out of an internal discussion on space logistics needs for tourism.  Tourism by its nature is geared towards commerce and entertainment, rather than exploration, so the demands emerge from the people who go up, rather than decided top-down by a government body.  

For the beer itself, the usual approach was to study brewing in space, with the goal of bringing beer down to Earth, but logistically this isn't cost effective.  At least, not if you wish to be mass market.  It makes more sense to brew on Earth, and send the beer up, as the largest market is here.  Since there are physical issues with drinking beer in space (carbonation, flavor, etc), we realized that there was an opportunity not just to support the space tourism industry, but fellow beer lovers as well.  Consider the history of the India Pale Ale, the thought of making the world's first space beer is really exciting for us-- it's a real contribution to making people happy for a long long time.

DrSJ: Cosmonauts are already known to have consumed vodka in space.  Why do you think future space tourists will demand beer? Is this worth pursuing, given the difficulties in dealing with carbonation and taste?

JH: Vodka certainly makes sense as a space alcohol-- with a few tweaks it's usable as a rocket fuel, so there's some fun thought experiments there.  But at the end of the day, people on Earth love beer, therefore people in space will also want beer.  Also we felt that beer is a bit safer, less flammable, less toxic to the astronauts/cosmonauts/tourists who simply may wish for a bit of taste of home.  

DrSJ: You were quoted as saying "Wherever humanity goes, beer is sure to follow".  Did you do much research into the history of beer as part of this project, and if so, what was the most relevant fact you discovered?  Are there past methods of beer manufacture that can inform this project?

JH: We did run into academic debates over the effects that alcohol has had on human society.  Some argue that beer is one of the key causes of human society, but I feel it's more of a correlation.  There's some evidence that we've evolved with beer as well, especially considering the genetic differences between people in metabolizing alcohol.  

Initially we took inspiration from the history of the India Pale Ale, but the quote comes from a personal desire to try beer recipes from ancient Egyptian and Sumerian cultures.  Unfortunately, my homebrewing skills aren't quite up to snuff there, but I'm hoping to convince our friends at the 4-Pines to give it a go.  

The 4-Pines Brewing Company follows German purity laws, and that's as far back in history as we're willing to go with the actual manufacturing.  Old brewers had very different problems to solve than we do-- astronauts can take vitamin supplements instead of drinking beer to help stave off scurvy. Beer might be good to help morale in long duration trips (i.e., Mars).  But for the recipe we're really looking at a unique class of problems which have no historical baseline. 

DrSJ: The new beer is called Vostok.  Why choose a Russian name for an Australian beer? Were there other names that you considered?

JH: This was in honor of Yuri Gagarin as the first person in space onboard the Vostok 1.  It's a name everyone in humanity should know.

DrSJ: What are the possible physiological risks of consuming beer in space, as opposed to other alcoholic drinks?

JH: Aside from issues of carbonation, I doubt there's much difference.  Formal studies in alcohol absorption in microgravity and other possible effects have not been done.  There are known issues of cabin pressure effects on alcohol absorption which we account for in the study.  There also may be interaction effects between medications and alcohol.  Part of the point of this study is to learn as much as we can before people start flying to space in larger numbers in 2012.

One difference might be in long duration storage.  Since beer contains live organisms ("yeast samples in solution"), there may be changes in shelf life in microgravity. 

DrSJ:  You've already done some tests on the beer in the Queensland University of Technology drop tower, which creates microgravity for a few seconds.  What were the results?  Would you have been able to initiate the project without the drop tower, which was only completed recently? 

JH: I'll be able to answer more about the QUT Drop Tower in a week or two.

DrSJ: In the recent media coverage, was there anything omitted that you would like to talk about now?

JH: We often think of astronauts/cosmonauts as being examples of human perfection, and are quick to judge at the suggestion of them having a tipple.  After all - think of what these fine people had to do just to get in to a space program in the first place...  They are subjected to harsh conditions and workloads and still must meet the expectations we place on them.  What we have to realize is that they are at a base level very human, and having a beer is very much a part of that.  

And here's the point - NASA is right to be conservative, since alcohol can be abused, and the body's limits in space are not known.  So this research is not just to make a beer to enjoy, but also to learn how people's drinking limits change in microgravity.  Knowing these limits is the only responsible way to allow explorers to drink under any condition.  Because if anyone deserves a good beer, it's them.

DrSJ: When you have mastered the principles of gaseous drinks in space, is there any chance you will move on to champagne? 

JH:  Champagne is a tough one because everybody wants those big, distinctive bubbles.  Beer has a bit more "wiggle-room" on the recipe.  

You don't have to be a space tourist;  Vostok beer (it's a stout) is already available on Earth!  Many thanks to Jason for his insightful answers.

Dr Space Junk's Heritage Tour of the Solar System

A  lovely poster for my recent seminar, created by the talented Lisa Bennett (Flinders University).

Saturday, October 02, 2010

Australia contributes beer to international space culture

Australia doesn't even have a space program but a partnership between space engineers and a Sydney brewery aims to make damn sure we won't be beaten to the first space-certified beer (Moses 2010).

Now it's not quite true that we don't have a space programme - we had a ripper one some time ago, and with the new Space Policy Unit, and funding for space research in Australia, we might be able to do something in this line again.  Still, point taken.  Now for the beer.

I have heard, and I believe there are some studies which show this, that altitude affects the sense of taste.  This is why airline food is always so uniformly awful.  A problem, you might imagine, exacerbated a thousandfold in space.  Fine for astronauts who are trained for space conditions, but not so much for your affluent space tourist expecting a bit of luxury.  Or even something a bit normal.

So Saber Astronautics Australia and the Manly-based 4 Pines Brewing Company have formed a joint venture, Vostok, to develop a microgravity beer.

"Humanity has had beer longer than we've had writing so, wherever humanity goes, beer is going to follow," Saber director Jason Held said.  "So if we're to go into space we need to understand how the human body responds to alcohol. It's very difficult to drink beer in zero gravity because you have a reduced sense of flavour and anything carbonated is going to have a hard time because gases respond differently in space than they do on Earth." (Quoted in Moses 2010)

He's right about the antiquity of beer.  It's not really my area, but I do know that beer was consumed like water by the ancient Egyptians, and also by the Tudors.  This was extremely weak beer, and there are some arguments that it prevented people from catching diseases from contaminated water.  However, apart from the ostensible goal of producing a microgravity beer which tastes nice, there may be many other spinoffs in terms of understanding physiology and food in space that could be quite interesting.  If only they weren't starting with a stout - not my favourite at the best of times.

Moses, Asher  2010  Beam me up Shhhcotty ..... the Aussie space beer with zero gravity.  Sydney Morning Herald October 1  Viewed October 1 2010

Sunday, September 26, 2010

Interpreting space technology: Honeysuckle Creek

Going through some of my photographs to help a friend who is putting together a book about field archaeology.  He is very interested in sunny Australian pics as opposed to grey rainy European ones!  Came across this one, taken at the former Honeysuckle Creek NASA Tracking Station in the ACT.  This stela is located where one of the footings of the 26m antenna would once have been.

People are critical of the design and the way the interpretation has been done, but I rather like the contrast of the rusting iron, reminiscent of the decaying site and perhaps the decay of Australia as a space player, and the bright blue.  I like the retro font too.

Saturday, September 25, 2010

Extra-terrestrial mining: issues in environmental and heritage management

Today I am trawling through data from the Australian Bureau of Statistics, to get a handle on the state of the mining industry in Australia.  This is for a couple of reasons:  firstly, many of our graduates from the Department of Archaeology at Flinders University will end up working in heritage management for the resource extraction industry; and I have been having some interesting conversations recently with Dr John Kinahan, an archaeologist and heritage consultant from Namibia, about common experiences working with mining companies in our respective countries. We are thinking of writing something about it.

I was thinking to myself, as I looked at the trends in OPBT (Operating Profit Before Tax, as I now know) that there is not much space relevance in my task for this morning.

But wait!  Not so, I have realised.  One of the big space industries on the horizon, predicted for many many decades, is mining.  The Moon, asteroids, probably other celestial bodies too.  One supposes that extra-terrestrial mining will work in much the same way as it does on Earth:  exploration, pre-feasibility studies, feasilibity studies, planning, construction, operation, decommissioning and rehabilitation.

There will of course be environmental issues, particularly with rehabilitation.  How exactly do you rehabilitate a lifeless site? There is no vegetation to grow back, or animal communities to reestablish.  Will extra-terrestrial mining companies pay for rehabilitation at all?  How will environmental groups and those concerned with the ethics of our exploitation of space approach this issue?  Do we even want to erase the evidence of our activities?  Perhaps it is better to make it obvious that a mining site is not natural.  All this depends on what we think the values of space environments are, and as I have often opined in various writings, space industry barely conceives of space as an environment to begin with, so it's a bit of a leap to get them to think about its values.

Heritage issues may come in if mining operations of whatever kind take place on or near historic landing sites.  There may also be things to think about in the heritage values of the mining infrastructure - heritage as it happens, in the now.  We have to consider the human values of the use of space too.

Now that I think of these things I am intrigued by the possibilities.  How would one write an Environmental Management Plan (EMP) or a Cultural Heritage Management Plan (CHMP) for an extraterrestrial mining site?  How would they be similar or different to terrestrial mining sites?  Will the Outer Space Treaty be of any relevance?  (Actually there is some interesting literature on how the OST might work in the context of national resource extraction industries).

Well, I'd better focus on terrestrial mining for the moment, it would be too easy to get distracted at this point when I have other things to do!  I'll make another coffee, I think, before I get back to the stats.

Monday, September 20, 2010

Dr Space Junk is now on Twitter

Certain friends in the blogosphere have been urging this for some time, but it was the revelation from aeronaut Dr Brett Holman that drspacejunk was not yet taken that precipitated the establishment of a Twitter account late last night after my esteemed colleague Dr Lynley Wallis had plied me with Moscato.

I don't really know what I'm doing though ..... I'm following a number of space agencies, wondering where I draw the line between personal/professional (I love Lady Gaga, but does Dr Space Junk?). I'm guessing that the smart thing is to link blog/facebook/twitter/ (lordy!  How many of these things can one person do?), but maybe it's not the smart thing.  So advice is appreciated.

Friday, September 03, 2010

Dismantling space infrastructure: thoughts on the shuttle launch pad.

It's the fate of industrial heritage: when no longer useful, it is dismantled, demolished, sold off for scrap.  This is what happened at Woomera after the end of ELDO and Apollo, and it's about to take place at the US Space Shuttle launch pad, 39B, at the Kennedy Space Centre.  The launch pad is quite historic. It was first used by the Saturn V for the Apollo 10 mission, which was essentially a test run for Apollo 11. Crews for Skylab were launched from it, as well as for Apollo-Soyuz.

Service towers will shortly be demolished, as they are custom made to fit the shuttle, and can't be reused for a newer vehicle.  Rather than a controlled implosion, which has been the method used in the past, the towers will be dismantled section by section and the metal recycled.  This approach protects the concrete foundations which can then be reused.

Jose Perez-Morales is the launch pad project manager.  He feels quite odd about what is about to take place:
"I'm an engineer and my job is to build things.  You feel a little bit funny when you're demolishing things because that's not your nature. As an engineer, you're trained to build and make sure things last forever. It's kind of mixed feelings that you're tearing down something that took so much effort to put together." (Spaceflight Now)

As well as the service towers, electronics and cables have to be removed and upgraded if the launch pad is to be refurbished and reused.  Approximately 246 miles (sorry, can't be bothered to convert this at the moment!) will have to be taken out.  As you know, I have been taking a much greater interest in cables since working at the Orroral Valley Tracking Station, so I would like to find out more about this. In equipment rooms beneath the launch pad surface, Apollo and Shuttle-era electronics are also being removed.

Are they documenting all of this from a heritage perspective, I wonder?  Will they keep samples of these materials? 

At the Department of Archaeology seminar yesterday, we had three excavation reports, one on the excavation of an old water works in Adelaide.  The plans had been located, but the actual structures and their arrangement differed significantly from the plans, as the archaeological survey and excavation revealed.  This reminded me once again that the historical documentary record is insufficient to capture everything we might want to know about places, technology, and society in the past, and even the recent past.

Launcher 39B (image courtesy of NASA/Troy Cryder)

Sunday, August 29, 2010

Remote sensing and space age archaeology

"Space age archaeology" is a term you often see applied to the technique of using satellite imagery to detect landscape patterns, and built environments, that are not apparent from aerial images or on the ground.  All fine stuff.

But it's not what I do.  Space people, and indeed many other people, leap to the assumption that space archaeology means the use of remote sensing in terrestrial archaeology, or the study of re-entered material (ie bits of spacecraft that survive reentry to fall to the surface of the earth). The idea that the material culture of space, both in space and on Earth, is worthy of research, often takes some time to make sense to those who have not come across it before.

And that's OK.  It's just that I am totally over remote sensing.

Saturday, August 21, 2010

A manifesto for space archaeology and its Dada precedents

I have been planning to write a manifesto for a while, but manifestos require more sustained thought that can be mustered in the overworked brain of a university lecturer.  Perhaps on my sabbatical next year.

In the meantime, I have been contemplating the appropriate pithy quote with which to open such a work. (These things are important).  I feel it ought to come from another manifesto.  Manifestos are often not a ripping read, by their very nature, but there are exceptions.  My all-time favourite would have to be Tristan Tzara's Dada manifestos.  As far as I'm concerned, Dada was over far too soon.

So, reading through Tzara's Seven Dada Manifestos and Lampisteries, I came across many that might do.  I offer a few here to see what you think.

To launch a manifesto you have to want:  A.B. & C., and fulminate against 1, 2, & 3, work yourself up and sharpen your wings to conquer and circulate lower and upper case As, Bs & Cs, sign, shout, swear, organise prose into a form that is absolutely and irrefutably obvious, prove its ne plus ultra .......

(I like that about manifestos too, that they have to be launched - just like a rocket, ha! - and then you wait for action and reaction, because manifestos are meant to upset people  ..... )

I always speak about myself because I don't want to convince, and I have no right to drag others in my wake, I'm not compelling anyone to follow me, because everyone makes his art in his own way, if he knows anything about the joy that rises like an arrow up to the astral strata, or that which descends into the mines strewn with the flowers of corpses and fertile spasms.

or this:

Every object,  all objects, feelings and obscurities, every apparition  and the precise shock of parallel lines, are means for the battle of:  DADA; the abolition of memory:  DADA; the abolition of archaeology:  DADA; the abolition of prophets:  DADA; the abolition of the future:  DADA.....

Admittedly, these do not lend themselves obviously to my purpose, but sometimes trying to see the relevance in something you like leads to new connections.  This is certainly what I found when writing a talk (which I really must write into a paper) about archaeology, space and Edwin Abbott's Flatland.  In the last quote, I like the sequence of memory, archaeology, prophecy, future.

Tzara, Tristan  1984 [1963] Seven Dada Manifestos and Lampisteries.  London:  John Calder and New York:  Riverrun Press.  Translated by Barbara Wright.

Thursday, August 12, 2010

New measures for active orbital debris mitigation

Space News (8/9, Werner, subscription required) reported, "Alliant Techsystems (ATK) is proposing plans for a small satellite designed to address one of the most vexing problems facing spacecraft operators in low Earth orbit: debris too small to be tracked by ground-based telescopes but large enough to penetrate satellite shielding." The plans are expected to be "discussed publicly" at the American Institute of Aeronautics and Astronautics small satellite conference on Wednesday. "The spacecraft would operate in low Earth orbit as a sweeper or shield, breaking up debris particles and reducing their velocity, according to Jose Guerrero, chief technologist for ATK Spacecraft Division's Systems and Advanced Technology Group." The concept has been discussed with NASA, DARPA, and the US Air Force, "Guerrero said. Further development of the concept, including testing, will require government funding, he added."
Quoted from AIAA Daily Launch

Sunday, August 08, 2010

The top ten orbital debris-producing missions of all time

This is recent data released by NASA's Orbital Debris Office.  As a result of over 4 700 launches since 1957, there are currently around 19 000 pieces of trackable debris.  Most of this derives from missions launched by the USA, the former USSR and China.  

The missions which produced the greatest quantity of debris are: 

Name                                Year        Debris          Cause of Breakup 
Fengyun-1C                    2007          2,841          Intentional Collision 
Cosmos 2251                  2009          1,267          Accidental Collision
STEP 2 Rocket Body       1996           713             Accidental Explosion
Iridium 33                     2009           521             Accidental Collision
Cosmos 2421                2008           509             Unknown
SPOT 1 Rocket Body     1986           492             Accidental Explosion 
OV2-1/LCS 2 Rocket     1965           473             Accidental Explosion 
Nimbus 4 Rocket Body  1970           374             Accidental Explosion
TES Rocket Body           2001           370             Accidental Explosion 
CBERS 1 Rocket Body   2000            343            Accidental Explosion

What's interesting to note about this is that the most frequent source of debris in the top ten is rocket bodies, and I presume this is largely due to residual fuel (there is a large amount of literature on the problem of passivation at the end of mission life).  And six are also within the last ten years, suggesting that, despite guidelines for limiting the creation of orbital debris being around for a decade or more, they may not be very effective ...... Note also that there are only two accidental collisions in this list, which supports my argument that the risks posed by large objects that may have heritage value, if they are left in orbit,  are not as great as we might think.

Of course this is only the top ten, and a more thorough investigation of the figures may be illuminating.

Sunday, August 01, 2010

Space Age Archaeology archived by the National Library

Terrified that some technical glitch will cause all of Space Age Archaeology to disappear as if it had never been? (I know I am).  Wondering how future generations will learn about space archaeology when blogs are as antiquated as cuneiform?  Well worry no more!

Space Age Archaeology has been placed on the PANDORA archive at the National Library of Australia.  This is what PANDORA is about:

PANDORA, Australia's Web Archive, is a growing collection of Australian online publications, established initially by the National Library of Australia in 1996, and now built in collaboration with nine other Australian libraries and cultural collecting organisations.   The name, PANDORA, is an acronym that encapsulates our mission: Preserving and Accessing Networked Documentary Resources of Australia.

This is, I like to feel, something of an accolade.

Friday, July 09, 2010

Random thoughts: Matrioshka brains and analogies for outer space

Well, I've spent the last week in an intense frenzy of activity - finishing my paper for the Australian Space Development Conference, attending the conference and socialising perhaps just a little too much for the good health of my liver, and then falling back to Earth to prepare an Australian Archaeological Association submission about proposed mining in the Burra State Heritage Precinct ....  but let's not go there or I shall just get angry at the utter ineffectualness of those in South Australia who are supposed to be looking after our heritage.

So today, I'm catching up on four lost days of work and, and looking over the copious notes I wrote during the conference, about all sorts of things.

While researching for my paper, I was reflecting on the analogies we use to understand space (also inspired by Peterson 1997, see below), such as sea and sky, and how these might translate into heritage principles.  A talk by Mark Dankberg, CEO of ViaSat, on the first day of the conference, led me to ponder this further.  In my notes I have written "return to the idea of noosphere + the Matrioshka brain = new ways of conceiving space".

The noosphere was proposed by the intriguing and enigmatic Teilhard de Chardin, archaeologist and theologian, and as I recall it from a meagre high school study, it was about evolutionary development from the lithosphere to the biosphere to the noosphere, as the conscious thought characterising humanity grew with the population.  The noosphere extends into space, where our thought also now extends with cultural and technological developments.

The Matrioshka brain is a set of nested Dyson spheres, which form a nano-engineered computer around a star, only attainable by a level of technological development far beyond ours.  So I see it as kind of similar in some ways - it is a sort of hardware equivalent of the noosphere.  (I suspect how I visualise this owes something to the writings of Charles Stross).  Of course this is simplifying the idea radically, but I think the conjunction of the two in my own brain is worth further contemplation in terms of how I want to re-conceptualise space.

Peterson, M.J.  1997  The use of analogies in developing outer space law.  International Organization 51(2):245-274

Saturday, July 03, 2010

Orbital cemeteries, state jurisdictions and debris

I'm hard at work on a beautiful sunny Saturday morning, trying to complete my paper for the 11th Australian Space Development Conference in Adelaide, which starts on Monday.  Oh the luxury of reading!  (And the pressures of time - aaarrrgh).

I came across this story (unfortunately unreferenced), which has little to do with my current topic but which I like a lot:

There is the anecdote of the proposal to launch an orbiting cemetery with ten thousand vials containing the ashes of deceased people with a guaranteed lifetime of a million years.  As the story goes, it met with refusal because Florida law requires that every cemetery has an access road and there are, evidently, no access roads to orbits. (Perek 1994:196)

This is in the context of not creating space missions which could equally be accomplished on Earth, thus diminishing the potential contribution to the orbital debris problem.

Perek, Lubos  1994  Management  of Outer Space.  Space Policy 10(3):189-198

Wednesday, June 23, 2010

Walking in microgravity: a fairytale version

I have been addicted to fairytales since a child, and still read them .... but normally don't expect to find anything relevant to space in them.  Hence I was very struck by this account of movement without gravity in George MacDonald's story The Light Princess, first published in 1864.  In the usual fashion, a magnificent christening is held for infant princess.  The king, however, neglects to invite his spiteful and magical sister, who deprives the little princess of her gravity.  This deprivation operates not only in the physical realm, for she can take nothing seriously and laughs at everything - although she never smiles.

Here is how MacDonald describes her "moonwalk":

I may here remark that it was very amusing to see her running, if her mode of progression could properly be called running. For first she would make a bound; then, having alighted, she would run a few steps, and make another bound.  Sometimes she would fancy she had reached the ground before she actually had, and her feet would go backwards and forwards, running upon nothing at all, like those of a chicken on its back.

I'm struck by this, I guess, because it is an attempt to describe the lack of gravity using only the imagination.  Not bad for 1864.

In fact the princess only feels her weight when immersed in water, and the lake where she loves to swim is instrumental in allowing a prince to release her from her affliction.

In Alison Lurie (ed) 1994  The Oxford Book of Modern Fairy Tales.  Oxford University Press, Oxford

Sunday, May 30, 2010

A stellar event: celebrating the AIAA registration of the ACT tracking stations

Last week I attended the ceremony at Tidbinbilla to celebrate the inscription of the three ACT tracking stations, Tidbinbilla, Orroral Valley and Honeysuckle Creek, on the AIAA Historic Aerospace Sites register.  Caught up with the darling Gordon Pike (SingTel Optus), with whom I discussed the relative advantages of spin stabilisation and three-axis stabilisation.  He also told me about Optus' tracking station at Frenchs Forest in Sydney (aha!).  I had some fascinating chats with former tracking station staff - of that more soon.  Orbital debris guru Duncan Steel (QinetiQ) was there, as well as Ian Tuohy of BAE Systems, taking a brief respite from gearing up for Hayabusa's return.  Michael West, chair of the AIAA Sydney Section, gave me a lift there and back (Tidbinbilla is about half an hour out of Canberra).  A truly wonderful occasion.

Monday, May 10, 2010

Zombiesat joins the ranks of space junk

Zombiesat! What's Next for the Out-of-Control Galaxy 15 Satellite

By Clara Moskowitz Senior Writer
posted: 04 May 2010

The Galaxy 15 commercial satellite that recently lost contact with the ground has joined the ranks of a boatload of other debris adrift in space. It's now termed a "zombiesat" by engineers who have a better sense of humor than you might have imagined. So what's next for this 4,171-pound (1,892-kg) zombiesat?

This defunct satellite will probably drift to one of two "gravity wells" that catch most out-of-control spacecraft, experts say. Galaxy 15 could threaten nearby satellites because its communications package is stuck on and it may start interfering with its neighbors by siphoning off their signals. It's the first time such an event has ever occurred, and it sent Orbital Sciences, the satellite's builder, on a dash to figure out how to stop the satellite-run-amok.

Galaxy 15, like many communications satellites, was circling Earth about 22,369 miles (36,000 km) high in what's called geosynchronous orbit, meaning that it orbited at the same speed the Earth rotates, so that it sat perched above the same part of Earth all the time. "There are two points in geosynchronous orbit called geopotential wells," explained Nicholas Johnson, chief scientist for Orbital Debris at NASA's Johnson Space Center in Houston. "These are perturbations in Earth's gravity field. Typically when satellites lose control they will drift toward the nearest geopotential well and just oscillate around it." The two spots, also called libration points, are located at longitudes of 105 degrees west and 75 degrees east. There are already between 150 and 200 objects oscillating around these points, Johnson said.

Still a large place
In that sense, the new zombiesat doesn't significantly increase the space debris problem or pose a serious risk of colliding with an operational satellite.

"Space is still a very large place," Johnson told "There are a lot of objects that are drifting back and forth. Galaxy 15 really just kind of joins a relatively large number of objects – it's not a significant new hazard from a global standpoint. But if your satellite happens to be near where Galaxy 15 is drifting then it's of more concern."  Eventually, everything in low-Earth orbit will eventually fall back down toward Earth because of atmospheric drag. The small amount of atmospheric particles in space create friction with spacecraft, causing their orbits to decay. The time it takes for an object's orbit to decay depends on its altitude.

For example, the International Space Station orbits at about 250 miles (400 kilometers) above Earth, while the Hubble Space Telescope circles much higher, at 353 miles (569 km).  "When things fall off the International Space Station, they typically fall back within a couple months, but where Hubble is, it typically takes several years to fall back to Earth," Johnson said. "At 800 km you're talking many decades or even hundreds of years."

To prevent the buildup of dead spacecraft in heavily trafficked areas of geosynchronous orbit, guidelines recommend that when a satellite reaches the end of its life it is boosted to a higher orbit out of the way. This "graveyard orbit" is about 186 miles (300 km) above where most satellites orbit. "The whole idea is to get to an altitude so they don't drift back into the operational region for a very, very long time – over 100 years," Johnson said.

It's actually easier to boost a spacecraft up just this much higher than to maneuver a craft down to where it would immediately fall back to Earth and burn up in the atmosphere, he said.

Getting rid of space junk
To actually go and collect defunct spacecraft to remove the collision risk altogether is currently beyond our ability.  "Unfortunately we haven't found a concept which appears to be both technically feasible and affordable," Johnson said. The best way to remove spent rocket stages and other large objects from orbit is to simply send up another spacecraft to rendezvous and dock with it and drag it back down to earth. This method would be extremely expensive and time-consuming, and isn't viable for the vast number of objects already in space. Some more exotic measures involving tethers and other props have been proposed, Johnson said, but aren't yet feasible.

For getting rid of very small pieces of space junk, there are two favorite ideas, he said. One involves shooting lasers at the objects to push them into lower-altitude orbits so they fall back down to Earth more quickly. "That has technical, economic, as well as policy issues," Johnson said. Another concept is to fly up a structure with a large area but low mass so that when particles strike the surface they will penetrate and lose some of their orbital energy, causing them to fall back to Earth more quickly. This option would also need many technical issues ironed out. "If it was easy we'd already be doing it," Johnson said of tackling the debris problem. "But it's prudent to be working the issue now before it becomes a serious impediment to space operations."