Apollo 8: the shadow diaries

Mapping the shadows

Shadows on the Moon have many scientific implications, from temperature to the electrostatic properties of lunar dust. I'm more interested in the cultural and social aspects of lunar shadows, however, while noting that the lines are often blurred between these distinctions.

I've considered shadows as part of the fabric of the Apollo landing sites. In another post I looked at Apollo mission photographs in which the photographer is present only as a shadow. Here, I'm thinking about shadows cast by 'natural' features; light, perspective, and movement. 

This is a series of images taken by the Apollo 8 mission in 1968. (All these images are from the NASA archives). Apollo 8 was the first US human spaceflight mission to orbit the Moon. People usually remember this mission for the famous snap of Earthrise, claimed to be one of the most influential images of all time.

Over 20 hours, the Apollo 8 spacecraft with its three crew orbited the Moon 10 times. The aim was to map the lunar surface, supplementing data from the Lunar Orbiter in 1964. 

This wasn't all, though. The crew were scoping out possible future landing sites, and shadows were a factor. A little way into their sixth orbit, one of the astronauts says:

The sun angles that we see now from the first IP, second IP, and P 1 are just right, I think, for landing conditions. The shadows aren't too deep for you to get confused, but the land is - has texture to it, and there are enough shadows to make everything stand out.

Not too much shadow, but not too little either. So now let's look at the shadows as seen by Apollo 8.

A shadow sequence

I've chosen these images from different points in the magazine 17C roll to show how shadows change as the spacecraft flew over the surface from lunar day to lunar night. 

Figure 1: AS08-17-2813

The surface of the Moon is a bright mirror against the black of space (Figure 1).

Figure 2: AS08-17-2761

With a different camera angle, the brightness fills the entire screen. We can see even brighter white markings (Figure 2). If you didn't know this was the moon, it could almost be the surface of a stone tool under a Scanning Electron Microscope, the changes in colour representing incipient fractures too small for the naked eye to detect.

As the Apollo 8 spacecraft injected itself into lunar orbit and prepared to take the first photographs, the astronauts commented on the lack of shadows.

Figure 3: AS08-17-2704

The details start to be resolved. It's no longer a flat surface with markings or fissures; it's a raised surface where faint shadows give it depth and texture (Figure 3).

Here, we're moving away from the subsolar point where the sun is overhead. The angle of light does not produce shadows, much as on Earth.

Figure 4: AS08-17-2686

Now we see more detail, and gradations of shadows, as the Apollo craft heads towards the terminator. The craters look like footprints in deep sand interspersed with those of smaller animals and worms, such as you might see on the surface of a beach still wet from the retreating water of the tide. In fact, astronaut Jim Lovell compared the texture of the surface to greyish beach sand.

In each major depression there are two or three shades of shadow, with the deepest black on the left hand edge.

Figure 5: AS08-17-2674

The shadows are deeper and darker as Apollo 8 approaches the evening side of the Moon. They convey a sense of late afternoon with an oblique sun. At the base of the craters, the shadows are deep black and even a little sinister (Figure 5). There are surfaces on the Moon that are permanently shadowed, never exposed to sunlight.

Figure 6: AS08-17-2664

The proportion of light and dark is now starting to reverse. The shadows are taking over the craters, leaving a miniature new moon sliver of brightness on the right side (Figure 6). These are deep holes, perhaps the lair of a lunar worm waiting to propel itself towards the spacecraft with a snap and swallow it whole.

Figure 7: AS08-17-2660

It is night on the Moon and all lies in shadow. Only the rim of the craters catch residual sunlight - or is it Earthlight?

During the voyage, Bill Anders said 'There's not as much detail, of course, as in the sunlight, but you can see the - the large craters quite distinctly, and you can see the albedo contacts quite distinctly. And also, the - there's a good three-dimensional view of the rims of the large craters'.

In the debrief following their return Anders commented that 'night landing or landing on the moon in an earthshine condition would be acceptable from a visibility standpoint'.



Anders raised another interesting point in the official debrief:

I thought that the shadows were not nearly as black as there [sic] appeared to be in the simulations that I've seen on earth, particularly the Boeing simulation. We could even see the features that were on the shadowside of some rills and rims. So, although it's dark, it's not a complete black and white situation. 

Naturally I'm taken with the concept of the shadow simulation. These would have used images from the Lunar Orbiter, which was orbiting at a higher altitude. 

Shadow [moon] lander

So what's my point? These are so different to the shadows cast by the accoutrements of robotic and human landing missions on the Moon. All the ones I've shown here have a circular geometry, and they're mostly about 'bumps and holes', as one of the astronauts said (from the transcripts it's sometimes hard to tell who said what). There's a peculiar feature of these bumps and holes which is shared with microscope views: sometimes it's hard to tell which one it is. Depressions and hollows can look like hills and protruberances, and you have to 'get your eye in' to see them properly. It's a sort of optical illusion, I guess, but one in which the shadows are critical.

Most of the cultural shadows on the Moon are cast by objects resting on the surface rather than depressions into the surface (although there are some of those too). They're frequently angular or linear. More recently, the Lunar Reconnaissance Orbiter has used these shadows to identify features of the Apollo sites.

Shadows are a critical feature of the visual experience of the Moon, at least for the astronaut. I'm not sure whether we can see lunar shadows from the Earth with the naked eye, though. Light and dark areas are caused by the reflectance properties of different geologies (selenologies?), known as albedo features. I don't think we can see the movement of shadows as the light of the sun or the phases of the moon change. With a telescope, though, it's different. The elongation of shadows near the terminator can be seen and photographed. 

There's something about scale and distance here, and about technology and vision. I guess what I really want to say is that shadows aren't incidental to our experience of the Moon. They're signs that we can read, and translate into science, and into poetry too.

Numinous


A patch of the Moon
flanked by shadows: trembling sense
we shouldn’t be here.













Image and poem by @tychogirl

How geodesy created a vision of the Earth through the jewelled LAGEOS satellites

Image courtesy of NASA

Could this be the most beautiful satellite ever made? In fact it is one of twins, as there are two of these jewelled spheres in Earth orbit. They're the LAGEOS satellites, essentially inert reflectors to bounce lasers off. The jewels are fused silica, except for four made from germanium. The interior is not a void filled with instruments: it's a solid brass cylindrical core, covered in a thick aluminium shell, as you can see in the video below.

(Hang on, you say. Fused silica? Isn't that just glass? Well yes and no. It's amorphous silica, but without any of the other ingredients that make up the glass we use, like lime, soda and potash).

LAGEOS stands for  LAser GEOdynamic Satellite. The first was launched by the US on May 4 1976, and the second, made by the Italian Space Agency, was launched in 1992.  This means in 2017 the 60 cm sphere - harking back to the spherical satellites of the early space age, such as Sputnik, Vanguard and Echo, achieved 41 years in orbit. It's a veteran of space science.

And because they're completely passive, with no power, fuel, solar panels or instruments, their missions are not ending any time soon. They should be up there for about 8.4 million years according to the original prediction! They can just keep going until their reflectors are too weathered by exposure to the space environment to bounce a laser back to Earth. The glass eyes are meant to be dust and radiation-resistant, but, just like the famous space shuttle windows, they could be damaged by hypervelocity particle impact. Perhaps the quality of the return signal could even be a way of measuring deterioration in the surfaces since launch, and hence gauging something about taphonomy in space. I wonder if this is possible?

The two satellites orbit at around 6000 km in a circular polar orbit. The information they have provided has contributed to new perspectives of the Earth, as former LAGEOS project scientist David E. Smith explains: 

Today, we see Earth as one system, with the planet’s shape, rotation, atmosphere, gravitational field and the motions of the continents all connected. We take it for granted now, but LAGEOS helped us arrive at that view.

Even more importantly, the two LAGEOS define the centre point, based on the Earth's centre of mass, for the terrestrial reference system used in navigation.

One of the things they're used for is to measure the speed and direction of tectonic plate movement. Because of this, LAGEOS-1 was the recipient of one of Carl Sagan's time-travel interspecies communications.  He conceived a design - drawn by Jon Lomberg who also worked with him on the Voyager Golden Records - engraved on a thin steel plate that was wrapped around the brass cylinder core - depicting continental drift at three points in time: 268 million years ago, 1976, and in 8.4 million years. You'd have to crack the satellite open like an egg, though, to get at the message. It's precisely the sort of alien mystery object that science fiction writers imagine falling to a planet and catalysing personal and social revelations, even when the object is impenetrable. Who knows who or what might find it in 8.4 million years? Will it melt in re-entry, fall into the ocean unnoticed and unmourned, or slam into the Australian outback like Skylab, to lie under the stars for another few million years?

There's another little mystery too. LAGEOS 1 has the most precisely know orbit of any orbital object. In 1978, LAGEOS-1 began descending at a much greater rate than it should have. In 1983, as David E. Smith described in a Nature paper, the satellite rather unexpectedly began to ascend again. It's still losing altitude - 1.33 mm each day - but because it is mostly beyond the reach of the atmosphere which drags objects in lower orbits back in, the cause of the decay is still a matter of debate.

And here's another interesting fact. The Optus B series of GEO telecommunications satellites have laser retroreflectors mounted on them too. My colleague Owen Mace (one of the pioneering Australis Oscar V team) had the contract to make them. Optus B1 is in the GEO graveyard orbit; Optus B2 exploded on launch, and Optus B3 was replaced by Optus D1. This means it is still in GEO but technically classified as space junk. Is anyone ranging to the two reflectors? I don't know....


References
Dey, Uijal, Kar, Samanwita, and Amitabha Ghosh 2016 Possible effect of the Earth's intertial induction on the orbital decay of LAGEOS. Journal of Astrophysics and Astronomy 37(3):1-9

Fitzmaurice, M.W., Minott, P.O., Abshire, J.B. and H. E. Rowe 1977 Prelaunch testing of the Laser Geodynamic Satellite (LAGEOS). NASA report

Smith, David E. 1983 Celestial mechanics: Acceleration on LAGEOS spacecraft.  Nature Vol 304 p 15


Note: after I began writing this blog post, it morphed into an article for The Conversation.

Dr Space Junk's Guide to Voting For Names of Surface Features on Pluto

When the New Horizons mission reaches Pluto and its moons in July 2015, there'll be hundreds of surface features that have never been seen before and which will need new names. The theme for these names is exploration and the underworld.



New Horizons. Image courtesy of NASA

The International Astronomical Union is in charge of allocating names in the solar system. But the New Horizons mission team have got together with the SETI Institute to get the public to contribute to a shortlist for their consideration.

'Pluto belongs to everyone', says New Horizon science team member Mark Showalter, also a senior research scientist at the SETI Institute.  'So we want everyone to be involved in making the map of this distant world'.

You're my kind of guy, Mark Showalter.

But of course, one of the questions that immediately arises, to me anyway, is how many women-type of people will get a look-in in this process. So I went to the list to see what the representation was like. Let's just say, no surprises.

So with this in mind, I've done the hard work so you don't have to! Here is a list of women or female beings who are part of the longlist so far. And yes, you can vote for more than one. I'm also going to include some honourable mentions at the end that are just so cool you couldn't not want them to be the name of something on Pluto or Charon (the largest moon).

Happy voting! And remember to do it before April 24th. Full instructions are here.

History of exploration

Jeanne Baré (or Baret; botanist; first woman to circumnavigate the globe)

Alexandrine Tinné (Dutch explorer of Egypt)

Sacagawea (US Native American - Lewis and Clarke guide)

Fictional Explorers and Travelers

Eleanor Arroway (from Contact - Carl Sagan)

Alice (from Alice's Adventures in Wonderland - Lewis Carroll) VOTE FOR ALICE. As someone who has identified with Alice from earliest childhood, I most certainly will be.

Arthur Dent/Trillian/Zaphod Beeblebrox (from Hitchhiker's Guide to the Galaxy). She was smarter than the rest of them put together.

Candide/Cunegonde/Pangloss (from Voltaire's Candide)

Dorothy Gale & Toto (from Oz books - L. Frank Baum)

Kaguya-hime (Japanese folktale) You get double value with this one, as it's also the nickname of a Japanese lunar orbiter (separately listed).

Kathryn Janeway (from TV's Star Trek: Voyager)

Skywalker/Solo/Leia/Kenobi (from Star Wars films)

Exploration Authors and Artists

Octavia E. Butler (US - author of Xenogenesis trilogy) I've never read Octavia Butler, but I really, really should.

Madeleine L'Engle (US author - A Wrinkle in Time) Now I'm sorry, but I will brook no opposition on this. Vote for Madeleine. If you were not moved to fear, horror, compassion and love by A Wrinkle in Time, you are barely human. If you have not read it, get thee to a library forthwith.

Anne McCaffrey (US-Irish author - Pern and Talents series) Rollicking good science fiction-fantasy yarns that entranced millions. 

Alice Sheldon (US author - A Momentary Taste of Being) AKA James Tiptree Jnr, a wonderful science fiction author. Her family background is also discussed in Donna Haraway's Primate Visions.

Travelers to the Underworld

Proserpina (kidnapped by Hades) I prefer the Greek Persephone but whatever.

Inanna & Dumuzi (from Sumerian mythology)

Orfeo & Euridice (from Greek mythology) Please read this poem about Eurydice by H.D (Hilda Dolittle), but be warned it will break your heart.

Virgil & Beatrice (from Dante's Inferno)

Underworld Beings

Tuoni & Tuonetar (Finnish mythology)

Ereshkigal (Sumerian mythology)

Alecto/Megaera/Tisiphone (Furies or Erinyes - Greek mythology)

Ammit (Devourer of Souls - Egyptian mythology)

Melinoë (Bringer of nightmares - Greek mythology)

Honourable Mentions

Phileas Fogg (from Around the World in 80 days). However, it should really be Passepartout, who did all the hard work anyway.

Tintin (from graphic novels by Hergé)

Gallifrey (Planet of the Time Lords - Dr Who)

Heart of Gold (Infinite Improbability spaceship, from Hitchhiker's Guide to the Galaxy)

Dawn Treader (by C. S. Lewis)

Chesley Bonestell (US space artist)

Hieronymus Bosch (Dutch painter of Hellish scenes) This is so obvious I don't know why it's even a matter of voting.

Stanislaw Lem (Polish science fiction author) Because I love that man's writing so much.

Maurice Sendak (US author - Where the Wild Things Are) Nuff said.

Baralku (Yolngu culture, Australia) Baralku is the Island of the Dead. You must vote for this because it is from the same region of Australia as the Aboriginal music on the Voyager Golden Records.

Sun Wukong (Monkey King - Chinese mythology) MONKEY. Do you hear me? This is Monkey.

Cthulhu (from H. P. Lovecraft)

Notes: on the official website, they mostly link to Wikipedia, but I've linked to other sites where I think there is more interesting or nuanced information. Sometimes, Wikipedia does have the best information online so I've stuck with that.

The longlist is quite long, and it's possible I've missed a few - if so, let me know and I'll add them.

If you think there are women/entities who ought to be on the official longlist but aren't, it's worth checking the Gazetteer to see if they haven't already been used elsewhere in the solar system.

My list here, and the commentary on it, are of course my personal views, and you are free to disagree or ignore them as you wish.

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.

References

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 ppw.jpl.nasa.gov/20070607_doc/6_2PAUKE.pdf.  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

Deep space antenna in California that relayed moon landing declaration to undergo major repair

ALICIA CHANG, AP Science Writer 12:02 p.m. CST, March 8, 2010

LOS ANGELES (AP) — The deep space antenna that relayed Neil Armstrong's famous "one giant leap for mankind" declaration from the moon to a rapt American audience will be offline for eight months for repair. Work begins this week to replace a steel donut-shaped bearing on the aging 230-foot-wide dish at the NASA Deep Space Network site at Goldstone Dry Lake in the Mojave Desert about 150 miles northeast of Los Angeles.

The labor-intensive process, which will involve jacking up 9 million pounds, will keep the antenna out of service until at least November.  "It's not trivial," said Pete Hames of NASA's Jet Propulsion Laboratory, who is in charge of maintaining the antennas at the Goldstone complex.

Besides California, tracking stations in Australia and Spain make up the Deep Space Network. Together, they point nonstop to the sky, sending commands to robotic spacecraft millions of miles away and listening for their often faint replies — communication streams filled with images, scientific findings and operational data.

During the repair, interplanetary communications will not be disrupted, said deputy project manager Wayne Sible. Missions that normally depend on Goldstone, such as the Spitzer Space Telescope, the Saturn explorer Cassini, various Mars spacecraft and even the Voyager 1 probe — which sailed to the edge of the solar system — will instead communicate through other giant, bowl-shaped antennas near Madrid, Spain, and Canberra, Australia.

Engineers chose to do the repair this year — at an estimated cost of $1.25 million — so that the Goldstone antenna would be ready next year to support the launchings of the Juno spacecraft to Jupiter and the long-delayed Mars Science Laboratory to the red planet. It's the first major work done on the antenna since the 1980s when it was enlarged to its current size. Engineers said the bearing, which helps it turn sideways, has worn out after more than four decades.

The Goldstone antenna is steeped in history. During the Apollo 11 moon landing in 1969, it captured Armstrong's words and sent them on to American televisions while the image came through another antenna. Its other accomplishments include receiving the first close-up views of the outer planets and their moons.

NASA last month broke ground in Australia on a new generation of smaller but advanced antennas that would eventually replace the workhorse fleet of 230-foot-diameter dishes around the world.

http://www.chicagotribune.com/business/sns-ap-us-sci-deep-space-antenna,0,1618143.story

Your chance to communicate with Venus, courtesy of JAXA

I've been researching Venusian landing missions for a while, but have not really paid much attention to orbital material.  In fact I should; the combined terrestrial and orbital components of the exploration of Venus have a unique signature when compared to those of other celestial bodies, in terms of the nationalities represented.  (This makes me think of creating some sort of index which captures this for all of the celestial bodies.  Where is cultural material mostly located - on or above the surface? What can this reveal about spacefaring cultures?).

But I digress.  There is something very appealing about sending the messages of regular people into space, and JAXA are about to do it for Venus, as explained in the story below.

The Japan Aerospace Exploration Agency (JAXA) is enhancing people's interest in space and the Earth by holding a message campaign. People are invited to send messages that will be printed in fine letters on an aluminium plate and placed aboard the Venus Climate Orbiter AKATSUKI.

Messages are being accepted from Japan and overseas, so the feelings and thoughts of everybody in the world can be combined in a single place and injected into the orbit of Venus.

Through this campaign JAXA aims to boost the public's knowledge about space science research activities in Japan as well as abroad. This project is in cooperation with the IYA2009 Japan Committee.

The Venus Climate Orbiter AKATSUKI is the world's first planetary meteorological observation satellite to unveil the mysteries of wind on Venus. It will explore the atmospheric movement and cloud formation process. Ultimately, this mission aims to deepen our understanding of the formation process of the Earth's environment and its future by comparing Venus and the Earth. Its planned launch date is May 2010, to arrive at Venus in December 2010.

To register your message, please visit: http://www.jaxa.jp/event/akatsuki/index_e.html

Source:  IYA Newsletter and Dave Reneke's Astro Space News 23

Further digression:  a map of sites in the solar system, by nationality (where this is clear, of course).

My new career: planetary archaeologist

Just back from the Australian Space Science Conference in Canberra. After a fabulous talk by Graziella Caprarelli (UTS) about the state of planetary sciences in Australia, I have decided that I will no longer be a space archaeologist but a planetary archaeologist. This is nicely in keeping with my current research on unifying terrestrial, maritime and celestial archaeology. Planetary science is about the solar system, and is different from earth science and astronomy. So it works on all levels. (I'm imagining a T-shirt with a picture of an astronaut holding a trowel).