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Do you ever miss the 70s? That time will never return (although stagflation and oil crunches might make an unexpected comeback from the weird devil’s brew of bad economic and geopolitical policies which we are experimenting with) however there is a more positive reminder of the age of disco in the very heavens themselves. At present, there are three disco balls in orbit around Earth. The first and most significant is actually a 70s artifact: LAGEOS (Laser Geodynamics Satellite) was launched from Vandenberg Air Force Base on May 4th 1976. The 408 kilogram (900 pound) satellite has no electronic components ore even moving parts: it is a brass sphere studded with 426 jewel-like retroreflectors. 422 of these retroreflectors are made from fused silica glass (to reflect visible light), however the remaining 4 are germanium, for infrared experiments.
Orbiting the entire planet every 225.70 minutes, LAGEOSl is a pretty stupendous piece of space art in its own right, however it was designed for a serious scientific purpose. Lageos provides an orbiting laser ranging benchmark. To quote space.com:
Over the past 40 years, NASA has used LAGEOS to measure the movement of Earth’s tectonic plates, detect irregularities in the rotation of the planet, weigh the Earth and track small shifts in its center of mass via tiny changes in the satellite’s orbit and distance from Earth.
Measurements made using LAGEOS have also been used to confirm Einstein’s general theory of relativity, since measurements made on this scale demonstrate a measurable “frame dragging effect” (which you are going to have to figure out with some help from your favorite physicist). The satellite also illustrates the Yarkovsky effect, which explains how an object is heated by photons on one side will later emit that heat in a way which slows the object. This latter effect will eventually cause LAGEOS’ orbit to deteriorate and bring it tumbling to Earth. Scientists estimate this will happen 8.4 million years from now, so there is still time to contemplate this sphere. Also there is a small time capsule on board to capture certain scientific truths and human ephemera for the long ages.
LAGEOS was so useful and proved to be such a success that NASA launched an identical sister craft in 1992 (how did I miss all of these interesting events?). This still leaves one disco ball satellite unaccounted for. The final craft is “The Humanity Star” which serves no purpose other than being art. Launched on January 21st of this year (2018), the humanity star is a regular polygonal solid with 65 triangular sides. It is made of carbon fiber embedded with enormously reflective panels and is meant to be seen twinkling in the night sky to make humankind collectively reflect on our shared home, the Earth. The Humanity Star orbits much lower than the LAGEOS satellites. They are 5,900 kilometres (3,700 miles) from Earth’s surface, whereas the humanity star is only 283.4 kilometers (176.1 miles) away from the planet at its perigree. It whips around the Earth every 90 minutes on a circumpolar orbit (which means it is visible from everywhere at some point. You could look up where it is online and go out and find it with fieldglasses. The object glimmers and shimmers in unusual ways, sometimes appearing as bright as Sirius (the brightest star save for the sun), but usually twinkling like barely visible stars. The Humanity Star won’t last long—it is scheduled to fall into Earth’s gravity well and burn up in fall of this year, so check it out before it is gone. The craft was controversial: some serious aerospace mavens objected to launching an object into orbit to serve no purpose other than art, yet, as an artist I am happy to know it is out there. Maybe go look at it and let me know if it inspires you.
Today (June 30th) is asteroid day. For this auspicious (yet anxious-making) holiday, I have been saving two asteroid-related miniature stories ripped from the headlines.
First, we return to the dwarf planet Ceres, the largest object in the asteroid belt. We need to revisit the bright spots upon the dwarf planet’s surface. Ever since the New Horizons spacecraft began to approach the little world, these glistening spots have fascinated the astronomy community. Initially scientists thought that the spots were composed of hydrated magnesium sulfate (a substance quite similar to the Epsom salts sold for bathing and foot-soaking), however it now seems like the shiny patches are made of something else entirely. According to astronomers, the particular chemical in these glistening patches actually turns out to be sodium carbonate–a salt formed from carbon. On Earth, this chemical usually forms in evaporitic conditions–when water evaporates from a lake, sea, or hot springs. This seems to indicate that the geology of Ceres is more complicated than initially thought—instead of a big ice crystal which has always been the same, the miniature planet has undergone changes: surface water evaporated to leave these mysterious chemical deposits. Hopefully finding out about Ceres’ past can teach us more about how planets form (or don’t form).
Second, we turn our eyes back closer to Earth to take in the newly discovered “second moon” a tiny asteroid about the size of the great pyramid of Giza which seems to be orbiting Earth. This new asteroid, called 2016 HO3, is not really a true moon but a quasi-satellite: it sometimes loops around our planet because Earth and the little rock both orbit the sun on a similar circuit. The asteroid orbits the sun in 365.93 days (just slightly longer than Earth’s orbit of 365.24 days). Thus, for the next few hundred years it will act like a true moon as our orbits converge. The rock is about 40 meters (130 feet) across by 100 meters (328 feet) wide. It is a bit strange to think about it up there hidden in the darkness, but it is a fairly comforting asteroid day story. 2016 HO3 is never destined to hit Earth. The really bad asteroids seem to be the ones we don’t know about (so it is time to keep our eyes on the skies and learn more).
Hey, did I tell you about Akatsuki? It was one of the thrilling space exploration stories of 2015—and it is just now becoming germane, but it did not get a lot of press attention in the west because of the holidays and because people were busy thinking about stupid trivia (including me). Akatsuki is a Japanese spacecraft/space mission designed to research and explore the atmosphere of Venus (its other name is Venus Climate Orbiter). The mission was launched in May of 2010 and the craft was supposed to go into orbit in December of 2010, but a catastrophic failure of the orbital maneuvering engine caused it to fly off into orbit around the sun (this failure was caused by a tiny salt deposit—which quietly says a great deal about the difficulties and dangers of space travel).
The Japanese space agency turned the probe to hibernation mode to conserve energy and waited…and waited…and waited. For five years, the craft flew through interplanetary darkness, quietly orbiting the sun as rocket scientists plotted and made corrections. Then, in December of 2015 the agency tried again. The combustion chamber throat and nozzle of the orbital maneuvering engine were horribly damaged (such a problem destroyed NASA’s Mars Observer probe in 1993) so JAXA jettisoned the craft’s oxidizing fuel and attempted to enter a strange elliptical orbit by means of four hydrazine attitude control thrusters. The rendezvous between Akatsuki and Venus occurred on 7 December 2015. Using four tiny thrusters not rated for orbital maneuvering, the spacecraft made a 20 minute burn and entered Venusian orbit! I wish I could make this sound more dramatic—it was a stupendously precise and superb piece of jerry-rigged rocket science happening around a different world. It is a miracle this craft is not a splatter on the baking surface of Venus. Kudos to JAXA!
The craft was originally slated to orbit Venus every 30 Earth hours, but its wild and bumpy 5 year journey to our sister planet changed the original plans quite a bit. In March of 2016, JAXA mission control finalized the craft’s elliptical orbit to take 9 days per orbital revolution. Planetary observations are slated to start in mid-April—right about now! Akatsuki is the only operational human craft currently at Venus. Its mission is to investigate Venutian meteorology with an infrared camera (we will be talking more about the insane Venutian atmosphere in a follow-up post) and to determine whether lightning and active volcanoes exist on the hot troubled world. This information may take a while to collate and access (considering that we are only now figuring out what the results of the last Venus mission, the ESA Venus Express, actually denote.
Anyway, stay tuned for more news from Venus! Maybe Akatsuki will be broadcasting some surprises about the little known planet next door.
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)
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
Neptune’s Moon Triton photographed by Voyager 2 (NASA)
It is absolutely freezing here in Brooklyn—a great vortex of bitter Arctic air has swirled south across huge swathes of the nation. The temperature here is 9° Fahrenheit (or -13° Celsius). Imagine how much worse things are in Minnesota, where it is -14° Fahrenheit (or -25° Celsius). Brrr! It hurts my fingers to write about it–even in my overheated study (well—bedroom, really). Now truly stretch your mind from the frozen heartland of America to the edge of the planetary solar system. The largest moon of the ice giant Neptune is the moon Triton, discovered in 1846 by English astronomer/brewer William Lassell, and named for the son of Poseidon. On the surface of Triton temperatures plunge to 36…which is to say 36 K (Kelvin). To translate that is -237° Celsius or a bone chilling -395° Fahrenheit.
Artist’s rendering of an ice volcano on Triton with Neptune in the background (NASA)
Triton is a strange moon. It is the seventh largest moon in the solar system and it is the only large moon to orbit its planet in a direction opposite from the planet’s rotation (which is called a retrograde orbit). Since there is no model for retrograde moons forming from accretion disks, Triton must be a captured object from the Oort cloud—and, indeed, the moon is extremely similar in composition to Pluto and other dwarf planets of the Solar system’s distant periphery. Despite the extreme cold of Triton’s surface, the moon is geologically active. Like Earth, the moon is probably differentiated into layers: a core, a mantle, and a crust. The crust is formed of ice: frozen water, methane, and nitrogen. A large polar cap covers the southern pole, but much of the rest of the moon is a“cantaloupe” surface of melted and refrozen ice. The surface is (geologically) young. Cryovolcanic activity and tidal forces have kept the ice active. Cryovolcanoes were first spotted on Triton during the Voyager 2 flyby in 1989 (the first time such phenomenon were ever observed). Because of tidal warming (caused by gravitational interaction with Neptune), Triton may have once had a liquid ocean beneath the crust, but this has likely solidified assuming that there is no radioactive decay from the rocky core.
A size comparison of Earth, Earth’s moon, and Triton
Triton is closer to Neptune than the Earth’s moon is to Earth…and Neptune is seventeen times more massive than Earth. This doesn’t bode well for the long term future of Triton. Within the next three and a half billion years, the moon will either be pulled into Neptune’s surface and swallowed or it will be ripped to pieces and form a spectacular ring structure like Saturn’s.
Artist’s rendering of SKYLON in orbit (by Reaction Engines Ltd)
Back in 2011, as the space shuttle program wound down, Ferrebeekeeper published what seemed like an elegy to spaceplanes—mixed-use vehicles capable of operating both as spacecraft and aircraft (most notably the space shuttles). The dwindling national interest in science and exploration once seemed to indicate that the shuttle program would be the last spaceplane program for a long time. However, as the United States abandons its interest in cutting-edge Aerospace projects, other nations and private interests are picking up the slack.
Skylon is a British spaceplane concept from a private company, Reaction Engines Limited. During the eighties, Rolls Royce and British Aerospace, poured money and knowledge into the creation of a vehicle named HOTOL (an awkward acronym which stands for HOrizontal TakeOff and Landing). Although huge amounts of human energy went into HOTOL, it was canceled because of lack of funding. Reaction Engines Limited is trying to build on the extensive HOTOL designs.
A Concept Model of HOTOL
Skylon certainly has a futuristic look. It has a long slender needle-like fuselage with stubby delta wings sticking out midway. Each of these wings is mounted at the end with a SABRE (Synthetic Air Breathing Engine). These next-generation engines are the real key to achieving single-stage-to-orbit spaceflight (a milestone which has long proven elusive for space engineers). Ideally the plane could take off from a runway and speed up to Mach 5.4 as it left the atmosphere and entered orbit. After deploying its payload it could then glide back down to Earth like a normal plane.
Skylon Diagram
Skylon would be constructed of a carbon fiber frame with heat resistant ceramic tiling and it would employ liquid hydrogen as a fuel to loft its 82 meter long (269 ft) body into near-space (before switching to internal liquid oxygen as it left the atmosphere). Like HOTOL before it, Skylon was stuck in funding purgatory for a long time, but recently a huge chunk of funding became available to test the viability of the various systems. These tests were successfully completed in November of 2012 and Reaction is now moving forward with the building of Skylon.
Skylon is designed to be vastly cheaper than the shuttle or any current rocket programs (and it would cut down on space debris). Engineers estimate that one of the crafts could be ready to launch again in only two days after a successful landing (as opposed to the shuttle which required months of refitting). Let’s hope the technology works out. Although unmanned interplanetary craft are accomplishing great things, it has been too long since there was a flashy achievement
Telstar1
Living during the communications revolution, it sometimes seems impossible to imagine how quickly the world has changed. Today is the 50th anniversary of an important step towards the instantly connected world of today: on July 10, 1962, a Thor-Delta rocket (launched from Cape Canaveral) carried the communication satellite Telstar 1 into orbit. The satellite was built by collaboration between AT&T, Bell Labs, NASA, the British General Post Office, and the French National Post, Telegraph, and Telecom Office. It was the first satellite ever to relay television, telephone and high-speed data communications. It was the first time that humans could beam such complicated information across an entire ocean via electromagnetic transmission.
It sort of looks like 2 of R2D2’s heads or a primitive disco ball.
Telstar was tiny and crude by today’s standards. The entire spacecraft weighed only 77 kg (170 lbs). The power generated by its solar panels was a mighty 14 watts (which is about what is necessary to operate a dim fluorescent nightlight). Since Telstar 1 was in non-geosynchronous orbit, its ability to transmit transatlantic signals was limited to a 20 minutes window during each 2.5 hour world orbit (and because satellite broadcasting stations only existed in England, France, and on the East Coast, the rest of the world didn’t matter) . Most contemporary telecommunications satellites are in geosynchronous orbit (and stay in place despite the solar wind thanks to thruster burns), but Telstar came in an era before all of that. The satellite’s first broadcast (on July 23rd) consisted of President John F. Kennedy talking about the dollar’s rapidly appreciating value. The initial broadcast also showed a baseball game, the American flag, Mount Rushmore, and, of course French singer Yves Montand.
Yves Montand (apparently)
Telstar 1 had a brief and memorable life broadcasting one grainy channel of black and white television and relaying perhaps a few hundred phone lines, but it has not been broadcasting since 1963. High altitude nuclear tests carried out during 1962 supercharged the Van Allen belt and overwhelmed the fragile electronics on the craft. As of May 2012 Telstar was still in orbit around Earth—presumably it is still up there, circling our planet, simultaneously a communications milestone and a cold war victim.
Artist's Interpretation of Sedna (Credit: Gemini artwork by Jon Lomberg)
After the discovery of Pluto in 1930, there was a long hiatus in discovering objects of comparable size. Then in 2003, a team of astronomers led by Mike Brown of Caltech discovered a distant icy sphere which was quickly heralded as “the tenth planet.” Mike Brown announced the discovery on his website along with his team’s rationale for naming the object. He wrote “Our newly discovered object is the coldest most distant place known in the Solar System, so we feel it is appropriate to name it in honor of Sedna, the Inuit goddess of the sea, who is thought to live at the bottom of the frigid Arctic Ocean.
It turns out that Sedna is only one of many similar snowball-like planetoids beyond Neptune. In fact, Ferrebeekeeper has already described the dwarf planet Eris (named after the Greek goddess of Strife) which is the largest currently known Kuiper belt object. Sedna was the first to be discovered since Pluto and it sparked a debate about such objects which ultimately resulted in Pluto’s downgrade to dwarf planet. Sedna also has some unique features which make it remarkable in its own right.
The orbit of Sedna (red) set against the orbits of Jupiter (orange), Saturn (yellow), Uranus (green), Neptune (blue), and Pluto (purple)
Sedna takes 11,400 years to complete its orbit around the sun and its bizarre highly elliptical orbit has given rise to much conjecture among astronomers. Although some astronomers believe it was scattered into a skewed orbit by the gravitational influence of Neptune, other astronomers believe it originated in the inner Oort cloud and was never close enough to Neptune to be affected by the giant’s gravity. Some scientists speculate that its lengthy orbit may have been caused by a passing star (perhaps from the sun’s birth cluster). A few theorists have gone one step further and conjectured that Sedna is from a different solar system and was captured by our Sun billions of years ago. A final school contends that Sedna is evidence of an unknown giant planet somewhere in the depths of space (!).
A photo of Sedna taken from a powerful telescope on Earth
We don’t know much about Sedna except that is probably 1,200–1,600 km in diameter and that its surface is extremely red. After Mars, Sedna is one of the reddest astronomical objects in our solar system. This color comes from the profusion of tholins covering the methane and nitrogen ice of which the little world is formed. Tholins are large, complex organic molecules created by the interaction of ultraviolet light on methane and other simple hydrocarbons. It is believed that early Earth (prior to obtaining an oxidizing atmosphere) was rich in Tholins and they are one of the precursors to the rise of life.
Konstantin Tsiolkovsky on a Soviet Stamp
Born in 1857, Konstantin Tsiolkovsky grew up in a remote province of Tsarist Russia with his 17 brothers and sisters. His father, Edward Ciołkowskia, was a Polish orthodox priest who had been deported deep into the heart of Russia as a result of his political activities. Edward Russianized his name and married an educated Tartar woman: the two then proceeded to have many children (of whom Konstantin was fifth). When he was 9 years old Konstantin caught scarlet fever and barely survived. Once he finally recovered, he was deaf or very nearly so. Because of his hearing problem he was denied admittance to elementary school and he quickly fell behind his peers. His mother died when he was 13 and his family’s poverty prevented him from moving forward in the world.
Konstantin Tsiolkovsky on a Soviet Stamp ( I'm sorry that I'm still thinking about stamps even in the midst of this remarkable tale)
This is a very grim and Russian story so far but here is where it becomes extraordinary. Isolated and alone, Konstantin made his way to Moscow. He was teaching himself at the Chertkovskaya Library where a very strange and brilliant man named Nikolai Fyodorovich Fyodorov was an employee. Fyodorov was a transhumanist philosopher and a futurist who believed that humankind’s path forward leads ultimately to technological transcendence and divinity. He felt that scientific progress would eventually lead to physical immortality and then ultimately to the resurrection of all people who have ever died (Fyodorov liked to think “outside of the box”). With the tutelage and mentorship of Fyodorov, Tsiolkovsky taught himself math. He took an active interest in Fyodorov’s scientific philosophy and even began to wonder what could be done with all of the immense number of dead humans if and when they returned. The thought led Konstantin Tsiolkovsky to think about outer space and the subject came to dominate the rest of his life.
Inspired by Fyodorov’s wild ideas and by the science fiction of Jules Verne, Tsiolkovsky began to invent the science necessary to carry humans up gravity’s well and beyond this world. The Encyclopedia of Science summarizes his work as follows:
Tsiolkovsky produced some of the earliest scientific literature on spaceflight, including the classic work Exploration of Space by Means of Reactive Apparatus (1896). In 1898 he derived the basic formula that determines how rockets perform – the rocket equation. This formula was first published in 1903, a few months before the Wright brothers’ historic manned flight. It appeared, together with many other of Tsilokovsky’s seminal ideas on spaceflight, in an article called “Investigating Space with Rocket Devices,” in the Russian journal Nauchnoye Obozreniye (Science Review). Unfortunately, the same issue also ran a political revolutionary piece that led to its confiscation by the Tsarist authorities. Since none of Tsiolkovsky’s subsequent writings were widely circulated at the time (he paid for their publication himself out of his meager teacher’s wage), it was many years before news of his work spread to the West.
No one understood Tsiolkovsky’s work at the time he wrote them. Today the basic concepts behind space travel—such as multistage rockets, orbital velocity, and compressed liquid fuels–are widely understood [Ed. not according to the comments of any given article about space exploration on CNN] but at the dawn of the twentieth century they were wildly fantastic and incomprehensible to international scientists much less to Tsarist Russians. Tsiolkovsky did not stop at elementary proposals of space travel and the fundamental underpinnings of rocketry. He also came up with sophisticated ideas such as using graphite rudders for rocket telemetry, cooling combustion nozzles with cryogenic propellants, and pumping fuel from storage tanks into the rocket’s combustion chamber.
Tsiolkovsky's Conception of a Spaceship
His neighbors regarded him as an eccentric outsider—a deaf schoolteacher mumbling gibberish—but Tsiolkovsky kept on coming up with brilliant ideas, some of which are still ahead of their time. In 1895 he was inspired by the Eiffel Tower to propose the creation of a 35,790 kilometer tall tower surmounted by “a celestial castle” from which objects could be launched directly into space: it was the first conception of a space elevator. By the twenties, as the scientific minds of the new Soviet Union began to realize how innovative Tsiolkovsky’s ideas were, he was contemplating sustainable space habitats and galactic colonization.
Today Konstantin Tsiolkovsky is considered the father of theoretical astronautics—or more simply the father of spaceflight. Sputnik was launched on his one hundredth birthday. Soviet propagandists built many statues and monuments to Tsiolkovsky but the greatest tribute to his legacy (apart of course from humankind’s space programs–which grew from his ideas) has been seen by only a few humans. Tsiolkovsky crater, the most prominent feature on the dark side of the moon is named in his honor.
The Dark Side of the Moon (Tsiolkovsky Crater dominates in the upper left quarter)
An artist's rendition of NASA's MESSENGER spacecraft
Yesterday NASA’s spacecraft MESSENGER entered orbit around Mercury, the least explored of the Solar system’s rocky inner planets. This is the first time a spacecraft has been in orbit around Mercury and it represents a tremendous engineering achievement. Since gravity becomes more intense the closer one comes to the sun, Messenger had to slingshot back and forth among the inner planets for some time in order to accomplish the tricky feat. The spacecraft had to undertake a 4.9 billion mile (about 7.9-billion kilometer) journey to enter orbit around the closest planet to the sun. Of course that hefty mileage only is equal to 0.00083 light years!
Having survived the grueling trip, the spaceship must now carry out its mission in the blistering bath of solar radiation. To survive next to the star, Messenger is equipped with a large sun visor which prevents the little craft from frying like a quail egg.
NO! The Messenger spacecraft is not an old lady playing golf!
Messenger will try to determine the planet’s mineralogical composition and learn about its geological history (the surface of Mercury is reckoned to be one of the oldest in the solar system). The robot probe will fully map Mercury and analyze the planet’s composition. Like Earth (but unlike Mars and Venus) Mercury has an internal magnetic field. Additionally, the tiny world is incredibly dense. In order to learn more about the planet’s core Messenger will measure the extent to which the planet wobbles on its rotational axis. Studying the partially molten interior of Mercury should provide clues about how the planet formed which will help us better understand the creation of all planets (especially in conjunction with the flood of data regarding exoplanets which we are beginning to receive).
Since the craft will be trying to learn the secrets of Mercury’s molten interior, it is worth reflecting on the deity whom the planet is named after. Although he was worshipped as a messenger, a herald, and a god of commerce, the Greco Roman god Hermes/Mercury was also quietly worshipped as a god of the underworld. The Greeks and Romans regarded him as a psychopomp who guided souls down to Hades with his magical staff. Because (like the somewhat similar African traveling god Eshu) Hermes was able to go anywhere at will he was one of the only entities in the Greco Roman pantheon free to enter and leave the underworld.
Although we are not capable like Mercury of going everywhere at our whim, I think it is a tremendous accomplishment to navigate a robot spacecraft into broiling orbit around the innermost planet. That we are using the craft to learn the secrets of the fiery underworld of the swift planet seems like a fitting tribute to the god who was slayer of Argus, giver of charms, messenger, schemer, luck bringer, and patron of travelers and wayfarers (even those voyaging to their last end or to places the ancients could never dream of).
ferrebeekeeper 