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Cassini-2

Seven hundred million miles away the Cassini spacecraft is preparing for death this coming September (2017). Launched in 1997 (when I moved to Brooklyn) the joint Italian/American space exploration mission to Saturn has seen and done things beyond comprehension. Lifted out of Earth’s gravity well by means of a Titan IVB/Centaur It flew through the nothingness and slingshotted around Venus (twice), the Earth, and Jupiter. It discovered new oceans on Enceladus and launched a lander onto the supermoon Titan (the first ever landing in the outer solar system). Cassini was used to tested general relativity: the craft broadcast radio past the sun to the Earth so that scientists could measure how the star’s gravity distorted the electromagnetic waves. Powered only by pluck (and, uh, 33 kilograms of plutonium-238) the little probe visited 20 moons.
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But all good things come to an end, and this final phase may be the most dramatic. On April 26th the craft began weaving between Saturn’s rings and the top of the planet’s atmosphere. The image at the top is an artist’s conception of how this might look for Cassini. The second image is a picture of the enormous hexagonal storm at the north pole taken April 30th. The image below is an infrared picture of Saturn. Cassini is scheduled to make 20 more of these passes before its final fiery plunge into Saturn itself, so prepare for more mind-boggling images of the gas giant.
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As we proceed further into the Halloween season, a long dormant specter has unexpectedly emerged from the past to claim another victim.  In the early era of space exploration a shockingly high number of Mars missions were complete failures.  This led space agencies to talk about the “Galactic Ghoul” a malevolent (and wholly imaginary!) entity which devours Mars probes.  Well, actually the phrase “Galactic Ghoul” was coined in the nineties…before that, this high failure rate was attributed to “the Curse of Mars” which isn’t quite as vivid a personification of failure but which still effectively evokes a malevolent supernatural thing out in the darkness between worlds. The ghoul (or curse) was particularly hard on Soviet craft and a shockingly large number of Soviet missions just vanished into the void for no reason as detailed in this dramatic chart (which is worth looking at for all sorts of reasons).

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The curse even manifested in the late nineties when NASA screwed up the distinction between matric and non-metric units of measurement and fired the Mars Climate Orbiter straight into the Martian atmosphere where it disintegrated (although that seems like it could be chalked up to a different old nemesis: being bad at math).  At any rate, the ghoul has been quiescent for a while as NASA learned to operate on the red planet (and triple check their numbers).

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Today though brings more grim news from the Red Planet. The ESA and the Russian space agency collaborated on ExoMars a joint mission in which the two teams sent an orbiter and a lander to Mars together.  The Trace Gas Orbiter is the real scientific component of the mission.  It will assay Mars for methane sources (we would like to know where the atmospheric methane of Mars comes from since it should be scrubbed from the thin Martian atmosphere faster than it can build up).  The lander was named for Giovanni Schiaparelli, the 19th-century Italian astronomer who popularized the idea of Martian canals (a concept long since disproven but bearing elements of truth).

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 Schiaparelli’s only scientific payload was a small weather station that would have run for a few days before running out of batteries.  It was really a lander designed to test out Martian landing capabilities, however, as of press time, the lander had proceeded into the Martian gravity well and then went ominously and completely silent.  Is the galactic ghoul now sated or will it need to feed on the next charismatic lander headed to the red planet?  Elon Musk may want to do some animal sacrifice and appeasement dances before he launches his colony ship!

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Last week I meant to include an elegiac post to Rosetta, an astonishing space mission, which stretched out over a dozen years and logged 4.9 billion miles of travel.  Rosetta was launched way back in 2004.  It was originally supposed to rendezvous with comet 46P/Wirtanen in 2011, but problems with the launch in Guyana caused the probe to miss the launch window for the primary mission.  The ESA changed the mission parameters so that the spacecraft ended up exploring Comet 67P/Churyumov–Gerasimenko instead (this second comet was functionally the same as the first—except for a much more difficult-to-say name). During its journey to the comet, Rosetta also flew by Mars and two asteroids.  After flying by Mars in February of 2007, the craft flew by Earth in November of 2007.  It caused a miniature panic when astronomers of the Catalina sky survey spotted it and misidentified it as a 20 meter near-Earth asteroid on a possible collision path with Earth!

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The spacecraft arrived at  Comet 67P/Churyumov–Gerasimenko in August of 2014 and the most famous…and infamous…part of the mission took place in November of that same year, when Rosetta launched the Philae lander to harpoon itself to the comet.  Although Philae (which was named after a Rosetta-like obelisk with the same text in Greek and Egyptian) succeeded in landing and not bouncing off into the void, sadly the little lander came down in a miserable crevasse.  Scientists intimately studied pictures of the comet (from Rosetta) until they found the lander in the icy chaos.  It was a pretty ghastly scene which reminded me of my sock drawer (if it were dropped from space onto Tungnafellsjökull glacier).

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(See it there at bottom right?)

Rosetta’s long and mostly successful mission came to an end last Friday in a truly operatic fashion. Mission controllers chose to use the last vestiges of power to smash the orbiter into the comet! Well, although I am saying “smashed” what actually happened was more like a grandmother walking into a snowbank.  The lander was lowered onto the comet at about one mile per hour. Except, despite the fact that Rosetta traveled more than 5 billion miles (“uphill both ways”) it was not designed for landing and its last communication was a photo just above the comet surface.  RIP Rosetta, you were one good probe!

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Artist's conception of Venus Express above Venus (ESA)

Artist’s conception of Venus Express above Venus (ESA)

Tomorrow I will write the obligatory annual post about whom we lost in 2014.  It’s always a solemn occasion which highlights the passing of many eminent figures (as well as the passing of yet another year) and raises troubling questions about what is truly important.  But before we get to the human obituaries, I wanted to write a quick eulogy for an underappreciated figure lost to little fanfare at the end of 2014.  Last month the robot explorer craft “Venus Express” was destroyed by falling into the volatile high-pressure atmosphere of our sister planet Venus (an operatic end which overshadows all but the greatest human deeds).  The Venus Express was a satellite launched by the European Space Agency in November 2005.  It reached polar orbit around Venus in April of 2006 and has been continuously sending back data since then until November 28th of 2014 when the last remaining fuel in the satellite was used to lift it into a high orbit.  Scientists planned on monitoring the space probe during its long drift down to the top of the atmosphere, but something went wrong and the satellite was thrown into a spin (which made it unable to contact Earth).  It is now presumed destroyed.

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Venus Express was the first Venus mission undertaken by the ESA.  Now that the craft is gone, the human race has no functional probes or spacecraft on or around Venus until the Japanese climate orbiter “AKATSUKI” is scheduled to reach there sometime in 2015 (although there have been some problems with that mission and the planned rendezvous may be postponed…or never happen).

This still from a NASA animation of a concept Venus mission shows a probe, one of many, beginning its descent into the Venus atmosphere.

This still from a NASA animation of a concept Venus mission shows a probe, one of many, beginning its descent into the Venus atmosphere.

Venus’ atmosphere is believed to have once been much like that of Earth.  This is certainly not the case now! The data from Venus Express is now being analyzed in order to ascertain what happened to transform Venus into a hellish greenhouse (and strip it of its magnetosphere).  Maybe we can also analyze this data with an eye on future sky colonies as well.  Venus Express discovered hydroxyls in the atmosphere of Venus. It also discovered an ozone layer and a high cold atmospheric layer which is possibly dry ice.  It undertook a series of aerobraking experiments which could prove very relevant to future craft inserted into Venus’ atmosphere.  We need someone to analyze this data and plan those future missions! Speaking of which, why doesn’t NASA have more exploratory missions planned to this nearest planet?  We should try to put a long-term floating probe into the upper atmosphere of Venus itself!  That would be an amazing accomplishment and it would tell us more about whether floating sky colonies above Venus would even be possible. Nothing is more alluring than Venus!  Let’s honor the Venus Express by learning from it and sending some more missions there pronto!

The Birth of Venus (Henry Courtney Selous, 1852, oil on canvas)

The Birth of Venus (Henry Courtney Selous, 1852, oil on canvas)

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Congratulations to the European Space Agency for successfully landing the robot probe “Philae” on comet 67P!  The lander, which is about the size of a washing machine, made a soft touch-down on the comet at 3:30 a.m. Brooklyn time. The comet itself has a diameter of four kilometers (2.5 miles) meaning it is approximately as wide as the Verrazano Bridge is long.  To bring such objects together as they hurtle at ridiculous speeds through the vast darkness of space is a tremendous feat of engineering.  Ferrebeekeeper described the long and complex journey of Philae’s mothership, Rosetta, in this previous post.

An artist's mock-up of how the probe might look on the comet's surface (the underdressed astrophysicist is added for scale and is presumably not there)

An artist’s mock-up of how the probe might look on the comet’s surface (the underdressed astrophysicist is added for scale and is presumably not there)

Philae is equipped with space harpoons which are designed to fire into the comet’s surface–thus securing the craft to the flying iceball with lamprey-like tenacity. Actually, a lamprey might be the wrong comparison: the lander looks astonishingly like a bacteriophage (a fact which I think is exceedingly strange and funny). At any rate, it is presently unclear whether the landing harpoons correctly deployed into the comet’s surface.  We’ll know more in coming days.

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Indeed, in coming days we should be finding out lots of things regarding the comet.  The lander has a small drill which is meant to mine 20 cm (8 inches) into the icy substrate.  The sophisticated machine is also equipped with devices to analyze the core sample, gas analyzers to identify any complex organic compounds, and instruments to measure the comet’s magnetic field.   Scientists will be keeping a close eye on the comet to see what effect the solar wind has on it as 67P sweeps in close to the sun in coming months.

ayiomamitis_mcnaught2009r1November 13th UPDATE:  It seems the plucky lander had a more adventuresome landing than yesterday’s rosy headlines may have indicated.  Apparently Philae landed not once, but multiple times as it bounced down a cliff and fetched up (on two of three legs) in a shadow.  Mission controllers are contemplating whether to fire the landing harpoons, but are concerned that the resultant explosion could send Philae careening off the comet into the outer dark.  Anyone who has thrown a washing machine down an ice cliff in low gravity will surely sympathize with their predicament…

Artist's Impression of the Rosetta Mission

Artist’s Impression of the Rosetta Mission

Devoted readers have most likely been fretting and worrying about what happened to the ESA spacecraft Rosetta which Ferrebeekeeper wrote about back in January. In that article, I wrote that the spacecraft was meant to rendezvous with comet 67P/Churyumov-Gerasimenko in May—but that never happened. What’s the story? Did something go wrong?

Fortunately today’s space news is good: after a ten-year chase which has spanned back and forth across the solar system, the little spacecraft finally entered orbit around comet 67P/Churyumov-Gerasimenko. The comet and the spacecraft are currently about 405 million kilometers from Earth (which puts them between the orbits of Mars and Jupiter). It turns out that May was actually the date that pre-orbit maneuvers were first commenced—it has taken three months to bring the spacecraft into proper position for orbital insertion. I’m sorry I got your hopes up prematurely, but this is a good illustration of how delicately operations must be conducted when dealing with objects going 55,000 kilometers per hour (34,000 miles per hour).

 

 An August 3 photograph of Comet 67P/Churyumov-Gerasimenko taken by space probe Rosettas OSIRIS from a distance of 285 km (Photo: ESA/Rosetta)


An August 3 photograph of Comet 67P/Churyumov-Gerasimenko taken by space probe Rosettas OSIRIS from a distance of 285 km (Photo: ESA/Rosetta)

The probe has already taken some amazing pictures of the comet which has two distinct masses joined together by a narrow neck—rather like a rubber duck. We can expect even more stunning pictures of the weird icy surface of the comet as the probe edges nearer to the big dirty snowball over the next few months. The real excitement will(probably) take place in November which is when the probe Philae is tentatively scheduled to launch. Philae is a comet lander which looks curiously like a bacteriophage. It will shoot harpoons into the comet and then fasten down onto the surface to study the origins of the solar system! Get ready for a thrilling fall!

Artist's impression of the Philae landing craft, anchored by harpoons and drills to the comet's surface

Artist’s impression of the Philae landing craft, anchored by harpoons and drills to the comet’s surface

An Artist's Rendering of Rosetta Approaching the Comet (ESA)

An Artist’s Rendering of Rosetta Approaching the Comet (ESA)

Today a winter snow storm has transformed Brooklyn into a huge ice ball–at least metaphorically speaking–but the weather will surely improve.  Home will not be a ball of ice forever.  The same cannot be said for the Philae robotic lander which is currently aboard the European Space Agency’s Rosetta spacecraft (which, in turn, is currently in outer space returning to the inner solar system after 31 months in the dark cold outer solar system).  If all goes according to plan, the Rosetta spacecraft will enter a slow orbit around comet 67P/Churyumov–Gerasimenko in May of 2014.  Once the space probe is in orbit around the comet, it will (eventually) fire the Philae probe onto the comet itself.  Philae is equipped with space harpoons to latch on to the comet’s surface and cling to the hurtling slushball.  Once there, the little robot lander will assay the comet with its drill and ten onboard sensors in order to learn more about the birth of the solar system–when the comet (probably) came into existence.

An artist's rendering of Philae Making a Soft Landing on the Comet this coming November (ESA)

An artist’s rendering of Philae Making a Soft Landing on the Comet this coming November (ESA)

There are many remarkable aspects to this astonishing mission (which launched a decade ago), but one of the most harrowing periods just ended.  Because the spacecraft is powered by solar panels, it did not receive sufficient energy to operate during its long sojourn through the outer solar system.  For two-and-a-half years, the mission controllers in Darmstadt, Germany have been in suspense waiting to see if Rosetta had survived being all but shut down (because of a last-minute mission rewrite, the craft was not designed for any such suspended animation).  Yesterday the spaceship woke up and radioed back to Earth!  The mission is on!  I can hardly wait for May (for multiple reasons).

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A Comparison of the relative sizes of the Fomalhaut system and the solar system (image created by NASA and ESA)

Fomalhaut is a star with twice the mass of the sun located approximately 25 light-years from Earth in the constellation Piscis Austrinus.  It is a bright young star 100 to 300 million years old (out of a projected lifespan of 1 billion years). Coinicientally  the name Fomalhaut is Arabic and means “mouth of the Southern fish.”  Fomalhaut has at least one planet—Fomalhaut b, which is believed to be approximately the same size as Jupiter (but could be anywhere from the size of Neptune to 3 times as large as Jupiter).  Just as Saturn is surrounded by a ring of debris, the entire star system of Fomalhaut is surrounded by a giant toroidal circumstellar disk.   This torus is vastly greater in diameter than our entire solar system (including the Oort Belt) and is made up of somewhere between 260 billion and 83 trillion comets which are constantly colliding and annihilating each other!  The Herschel Space Observatory recently captured an infrared image of this immense comet storm.

An infrared image of the Fomalhaut system--and its huge cloud of disintegrating comets) captured by the Herschel Space Observatory (credit: ESA)

Goodbye old friend...

The space shuttle program ended this morning when the Atlantis lander touched down at 5:57 AM Eastern Standard Time at the Cape Canaveral spaceport. The national and international media has elegiacally noted the end of the 30 year program, most commonly with articles which sound a dirge-like note concerning the final end of the manned space program (with undertones of America’s decline as a spacefaring, scientific, and military power as well). I am glad those articles are out there because I feel that our inability to ensure adequate funding for basic blue sky research has put the nation’s economic future in jeopardy. Since the dawn of the Industrial Revolution, national greatness has come not from abundant natural resources or a large hard-working population (although the United States has both of those things) but from innovation after innovation.  To quote Representative Frank Wolf, a member of the NASA appropriations committee,“If we cut NASA, if we cut cancer research, we’re eating our seed corn.”

We are all the turkey...

However, I am concerned that the story is becoming a self-fulfilling prophecy of defeat and it shouldn’t be.  Despite its ever shrinking budget, NASA is actually doing a great deal in space right now as, to a lesser degree, are the world’s other space programs. Five days ago NASA the spacecraft Dawn went into orbit around the protoplanet Vesta, the second largest object in the asteroid belt.  Next July Dawn will power up its ion thrusters and fly to the dwarf planet Ceres, an enigmatic pseudo-planet which seems to harbor secrets of the solar system’s beginning under its oceans.  Dawn is only one of ten planetary missions currently in orbit (or, indeed onworld) across the rest of the solar system. These are MESSENGER, Venus Express, Chang’E 2, Lunar Reconnaissance Orbiter, Mars Odyssey, Mars Express, Mars Reconnaissance Orbiter, the Mars rover Opportunity, Dawn, and Cassini.  Additionally the following eight spacecraft are currently in flight: New Horizons is headed for the dwarf planet Pluto, Rosetta is currently flying to the comet Churymov-Gerasimenko, Japan’s Akatsuki and IKAROS are both in solar orbit, the spacecrafts Deep Impact and ICE, are awaiting further instructions, and finally Voyager 1 and 2 are still out there exploring the distant edge of the solar system.  I picked out the projects involving NASA in green (I have already written about the Japanese solar sail Ikaros and our Mercury mission so check out my hyperlinks).  These are just the far traveling missions–there are also dozens of near-Earth spacecraft studying the sun, the stars, deep space, and, most of all, the earth.

NASA Spacecraft Dawn firing its ion thrusters with Vesta and Ceres in the Backgound

The shuttle program is not quite as dead as it seems, the Air Force still has two small robot space shuttles and DARPA (the Defense Advanced Research Projects Agency which spawned all manner of world changing technology) is working on next generation spaceplanes.  A single-stage-to-orbit space plane (which takes off and lands like a normal plane) is still far off, but aerospace engineers seem confident they could build a two-stage-to-orbit crewed space plane around scramjet technology.

Artist's Concept of a Scramjet Spaceplane Entering Orbit

I’m going to miss the shuttles—the white behemoths were major features of my childhood. Back in the early eighties they seemed to hold out all sorts of promises for a glorious future in space. But childhood comes to an end and the shuttles really never lived up to expectations.  Now as we Americans sit grounded (unless we want to pay the Russians 50+ million dollars for a seat on one of their old Soyuz spacecrafts), it is time to think about what we want.  Maybe humankind will catch a break and see breakthroughs in molecular or nuclear engineering which leave us with a new range of materials and energy possibilities (despite its long quiet phase, I still have high hopes for the National Ignition Facility).  I have always harbored fantasies of a nuclear power plant on the moon with an attached rail gun for space launches.  I also like the idea of a space elevator, or a twirling toroid space habitat with false gravity.  The always deferred Mars mission is exciting too (although we have talked about it so long that some of its glitter has come off).  But I’m open to other ideas.  We all should be. We need to talk about it and then we need to decide on some ideas and fund them quickly. Seeds need to be planted to grow.

If we call it an orbital railgun, people will be upset. How about "orbital railfriend"?

Lichen (by WiseAcre)

Cast your imagination back half a billion years ago to the Cambrian geological period.  Although Earth’s oceans were seething with strange experimental life forms, the alien continents were bleak and empty.  Huge brown mountains sloughed away into giant canyons. Black volcanoes eroded into naked black beaches. Great flash floods poured over a landscape bare of plants and animals. No horsetails grew.  No dragonfly buzzed.  Not even a miserable liverwort crouched by the empty streams. But were the ancient continents entirely bare? No—bacterial films and single cell algae were believed to have covered the land, and looming above that primitive slime were the first lichens, symbiotic life forms so hardy that they alone thrive on continental Antarctica today.

Red Lichen living in Antarctica (photo by Gerhard Hüdepohl from Atacamaphoto.com)

Lichen is a bizarre composite organism in which a fungus is paired with a photosynthesizing partner (either green algae or cyanobacteria).  The thallus of lichen (which makes up the organism’s body) is very different from either the fungal or algal components living on their own.  The fungi surround and hold up the algae by sinking tendrils through the algal cell walls (in much the same manner parasitic fungi attack their hosts).  By sharing the resources of the two different partners the organism is capable of surviving extreme desiccation, and, when the lichen is again exposed to moisture, a flood of nutrients becomes available to both partners.

Lichen (from "Art Forms of Nature" E. Haeckel)

The partnership makes for an extraordinarily resilient organism which can be found everywhere on land from the rainforests to the deserts to the highest mountains to the harsh frozen rocks of Antarctica. The European Space agency explored the durability of lichen by blasting living specimens into outer space where, to quote the ESA, the organisms were “exposed to vacuum, wide fluctuations of temperature, the complete spectrum of solar UV light and bombarded with cosmic radiation. During the Foton-M2 mission, which was launched into low-Earth orbit on 31 May 2005, the lichens…(Rhizocarpon geographicum and Xanthoria elegans) were exposed for a total 14.6 days before being returned to Earth….Analysis post flight showed a full rate of survival and an unchanged ability for photosynthesis.”

Lichen dot the face of a Song Dynasty statue on Qingyuan Mountain, China.

Lichens’ strange partnership also creates strange morphological forms. In many circumstances these organisms resemble exotic corals, sponges, or plants. Additionally, many lichens are brightly colored.  The result is often a miniature landscape of bizarre beauty.  I have included some photos from sundry sources but you should check out the lichen photos at Stephen Sharnoff’s site (even disfigured by the trademark, his lichen photos are the best on the net).

Competing Lichens Growing on a Rock

Since it involves both algae and fungi, lichen reproduction can be complicated and takes many different forms depending on the species and the circumstance.  Some lichens form soredia, small groups of algal cells surrounded by fungal filaments which are dispersed as a group by wind. Others produce isidia, elongated outgrowths from the thallus which break away.  During the dry season, certain lichens crumble into dusty flakes which are blown across the landscape.  When the rains come the flakes burst into full growths.  In the most interesting and complicated pattern of reproduction, the fungal portion of the lichen produces spores (as a result of sexual exchange and meiosis) these spores are disseminated across the landscape and then must find compatible algae or cyanobacteria with which to partner.

 

Community Lichens is in the Sawtooth Mountains (photo by Mark Dimmitt)

Lichens are probably long lived and it is possible that somewhere there are those that make the bristlecone pines seem young and have lasted as long as Pando, but who knows?  We have not explored and documented the world’s lichens very completely…or even fully understood the mechanisms of their partnership.  What is certain is that they are one of life’s most efficient colonizers: in areas such as the Atacama Desert and Antarctica, plants cannot grow unless lichen lived there previously (in fact I am going to include this post in my “invaders” category for just this reason). Lichens are also efficient at exchanging carbon dioxide for oxygen, and they are a critical link in the carbon cycle capable of fixing elemental carbon back into the soil and into the ecosystem.  When you look at a tundra landscape and savor the beauty of reindeer, mountains, and arctic birds, spare a thought for the ancient lichen, one of the first organisms on the land and still one of the most important.

Lichen slowly colonize a New England gravestone from the 1700's.

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