Orion flight test profile for the Exploration Flight Test-1 (EFT-1) launching on Dec. 4, 2014. Credit: NASA
After moving out to the launch pad earlier this week, NASA’s first Orion spacecraft was hoisted atop the most powerful rocket in the world and awaits blastoff from Cape Canaveral, Florida, in early December on a critical test flight that will pave the way for human missions to deep space for the first time in more than four decades since NASA’s Apollo moon landing missions ended in 1972.
NASA’s cool new set of infographics above and below explain 8 key events on Orion’s Exploration Flight Test-1 (EFT-1) mission and its first trip to orbit and back.
Orion will lift off on a Delta IV Heavy rocket on its inaugural test flight to space on the uncrewed EFT-1 mission at 7:05 a.m. EST on December 4, 2014, from Space Launch Complex 37 (SLC-37) at Cape Canaveral Air Force Station in Florida.
The two-orbit, four and a half hour Orion EFT-1 flight around Earth will lift the Orion spacecraft and its attached second stage to an orbital altitude of 3,600 miles, about 15 times higher than the International Space Station (ISS) – and farther than any human spacecraft has journeyed in 40 years.
Launch – It’s going to be loud. It’s going to be bright. It’s going to be smoky. Engines are fired, the countdown ends, and Orion lifts off into space atop the United Launch Alliance Delta IV Heavy rocket from the launch pad at Cape Canaveral in Florida. Credit: NASA
EFT-1 will test the rocket, second stage, jettison mechanisms, as well as avionics, attitude control, computers, and electronic systems inside the Orion spacecraft.
Then the spacecraft will carry out a high speed re-entry through the atmosphere at speeds approaching 20,000 mph and scorching temperatures near 4,000 degrees Fahrenheit to test the heat shield, before splashing down for a parachute assisted landing in the Pacific Ocean.
Exposure – It’s time to fly! The protective panels surrounding the service module are jettisoned and the launch abort system separates from the spacecraft. Credit: NASARe-ignition – Orbit 1 is complete! The upper stage will now fire up again to propel Orion to an altitude of 3,600 miles during its second trip around Earth. Credit: NASASeparation – It’s now time to prepare for reentry. The service module and upper stage separate so that only the crew module will return to Earth. Credit: NASAOrientation – Orion’s first flight will be uncrewed, but that doesn’t mean we can allow Orion to return to Earth upside down. This test flight will help us test the control jets to ensure that they can orient the capsule in the correct reentry position. Credit: NASAHeating – Things are heating up as Orion slams into the atmosphere at almost 20,000 mph and encounters temperatures near 4,000 degrees F. Credit: NASADeploy – After initial air friction slows the capsule from 20,000 mph, Orion will still be descending at 300 mph—too fast for a safe splashdown. A sequence of parachute deployments will create drag to further slow the spacecraft to a comfortable 20 mph. Credit: NASALanding – Orion will splashdown in the Pacific Ocean off the coast of Baja California, where it will be recovered with help from the United States Navy. Credit: NASA
Here’s what Orion’s ocean splashdown and recovery by Navy divers will look like:
US Navy divers on four boats attached tow lines to the Orion test capsule and guide it to the well deck on the USS Arlington during Aug. 15, 2013, recovery test at Norfolk Naval Base, VA. Credit: Ken Kremer/kenkremer.com
Orion is NASA’s next generation human rated vehicle that will carry America’s astronauts beyond Earth on voyages venturing farther into deep space than ever before – beyond the Moon to Asteroids, Mars, and other destinations in our Solar System.
The United Launch Alliance Delta IV Heavy rocket is the world’s most powerful rocket. The triple barreled Delta IV Heavy booster is the only rocket sufficiently powerful to launch the 50,000 pound Orion EFT-1 spacecraft to orbit.
The first stage of the mammoth Delta IV Heavy generates some 2 million pounds of liftoff thrust.
Watch for Ken’s Orion coverage, and he’ll be at KSC for the historic launch on Dec. 4.
Stay tuned here for Ken’s continuing Orion and Earth and planetary science and human spaceflight news.
First photo released of Comet 67P/C-G taken by Philae during its descent. The view is just 1.8 miles above the comet. Credit: ESA
Update, 10 p.m. EST: Philae is now asleep, according to the European Space Agency, for what could prove to be a long nap (at the least). It’s in “idle mode” with depleted batteries, and little sunlight to gain energy. For more information, check out this ESA blog post.
There’s power problems looming for the Philae probe after it made not one, not two, but three landings on 67P/Churyumov–Gerasimenko this Wednesday. The primary battery that the lander is using right now for its primary mission (a few days) is expected to run out in less than a day. As for surface comet observations for the next several months … that’s now in doubt.
Philae was supposed to touch down in a spot that provided seven hours of illumination per day on the comet (with a “day” there being 12.4 hours). But after doing a hop, skip and leap on the surface, the lander is now nestled in a spot that provides only 1.5 hours of sunlight daily to recharge the solar panels. “There is an impact on the energy budget to conduct science for a longer period of time,” the European Space Agency warned in a blog post.
Philae (and its parent craft Rosetta, which is in good health and will observe the comet from orbit through at least part of 2015) went sailing through space for more than a decade before Philae successfully touched down on the surface. After early telemetry came through showing harpoons had fired to secure the lander on 67P, more detailed information showed the harpoons had failed to fire. And this led to an incredible journey.
After touching down about where it was supposed to — controllers know this based on its descent camera and previous images from the Rosetta spacecraft — Philae then lifted off again and floated for nearly two hours. This is possible due to the extremely low gravity field on the comet, which had it drifting gently for one hour and 50 minutes.
First panorama sent by Philae from the surface of the comet. At upper right we see the reflection of the Sun and the top of the CONSERT instrument antenna. Credit: ESA
Philae travelled about one kilometer (0.62 miles) in this time before brushing the surface. Then it began another seven-minute journey before settling down in its current location. Exactly where is not known.
“Preliminary data from the CONSERT experiment suggest that Philae could have travelled closer to the large depression known as Site B, perhaps sitting on its rim. High-resolution orbiter images, some of which are still stored on Rosetta, have yet to confirm the location,” the European Space Agency wrote in a blog post.
“The lander remains unanchored to the surface at an as-yet undetermined orientation. The science instruments are running and are delivering images and data, helping the team to learn more about the final landing site.”
So far, the team knows that the area has dust and other stuff covering the surface, and a panoramic image released yesterday suggests that at least one of the lander’s three feet is “in open space.”
Artist's impression of the New Horizons spacecraft. Image Credit: NASA
It’s not quite the cryogenic sleep featured in Interstellar, but all the same, NASA’s New Horizons probe has spent most of its long, long journey to Pluto in hibernation. So far it’s been asleep periodically for 1,873 days — two-thirds of its journey in space since 2006 — to save energy, money and the risk of instrument failure.
But it’s just about time for the probe to wake up. On Dec. 6, seven months before New Horizons encounters Pluto, the spacecraft will emerge from its last long nap to get ready for humanity’s first flight past the dwarf planet.
“New Horizons is healthy and cruising quietly through deep space – nearly three billion miles from home – but its rest is nearly over,” stated Alice Bowman, New Horizons mission operations manager at the Johns Hopkins University Applied Physics Laboratory (JHUAPL) in Maryland. “It’s time for New Horizons to wake up, get to work, and start making history.”
Artist’s conception of the Pluto system from the surface of one of its moons. Credit: NASA, ESA and G. Bacon (STScI)
Hibernation periods have lasted anywhere from 36 days to 202 days. Controllers usually rouse the spacecraft about twice a year to make sure all is well, and to do a little bit of science (such as taking distant pictures of Pluto of its moons). This means the next wakeup will be a new phase for the mission — a sustained effort instead of a burst of activity.
Confirmation of the wakeup should come six hours after it takes place, around 9:30 p.m. EST (2:30 p.m. UTC). This will be after the light signal takes an incredible 4.5 hours to reach Earth from New Horizons. What’s next will be a very busy few days — checking out navigation, downloading new science data, then getting the spacecraft ready for Pluto’s big closeup July 2015.
“Tops on the mission’s science list are characterizing the global geology and topography of Pluto and its large moon Charon, mapping their surface compositions and temperatures, examining Pluto’s atmospheric composition and structure, studying Pluto’s smaller moons and searching for new moons and rings,” JHUAPL stated.
First panorama sent by Philae from the surface of the comet. At upper right we see the reflection of the Sun and the top of the CONSERT instrument antenna. Credit: ESA
We may not know exactly where Philae is, but it’s doing a bang-up job sending its first photos from comet 67P/Churyumov-Gerasimenko. After bouncing three times on the surface, the lander is tilted vertically with one foot in open space in a “handstand” position. When viewing the photographs, it’s good to keep that in mind.
Philae landed nearly vertically on its side with one leg up in outer space. Here we see it in relation to the panoramic photos taken with the CIVA cameras. Credit: ESA
Although it’s difficult to say how far away the features are in the image. In an update today at a press briefing, Jean Pierre Biebring, principal investigator of CIVA/ROLIS (lander cameras), said that the features shown in the frame at lower left are about 1-meter or 3 feet away. Philae settled into its final landing spot after a harrowing first bounce that sent it flying as high as a kilometer above the comet’s surface.
After hovering for two hours, it landed a second time only to bounce back up again a short distance – this time 3 cm or about 1.5 inches. Seven minutes later it made its third and final landing. Incredibly, the little craft still functions after trampolining for hours!
Stephan Ulamec, Philae Lander manager, describes how Philae first landed less than 100 meters from the planned Agilkia site (red square). Without functioning harpoons and thrusters to fix it to the ground there, it rebounded and shot a kilometer above the comet. Right now, it’s somewhere in the blue diamond. Credit: ESA
Despite its awkward stance, Philae continues to do a surprising amount of good science. Scientists are still hoping to come up with a solution to better orientate the lander. Their time is probably limited. The craft landed in the shadow of a cliff, blocking sunlight to the solar panels used to charge its battery. Philae receives only 1.5 hours instead of the planned 6-7 hours of sunlight each day. That makes tomorrow a critical day. Our own Tim Reyes of Universe Today had this to say about Philae’s power requirements:
One of the lander’s three feet can be seen in the foreground in this high-resolution two-image mosaic. Credit: ESA/Rosetta/Philae/CIVA
“Philae must function on a small amount of stored energy upon arrival: 1000 watt-hours (equivalent of a 100 watt bulb running for 10 hours). Once that power is drained, it will produce a maximum of 8 watts of electricity from solar panels to be stored in a 130 watt-hour battery.” You can read more about Philae’s functions in Tim’s recent article.
Ever inventive, the lander team is going to try and nudge Philae into the sunlight by operating the moving instrument called MUPUS tonight. The operation is a delicate one, since too much movement could send the probe flying off the surface once again.
Here are additional photos from the press conference showing individual segments of the panorama and other aspects of Philae’s next-to-impossible landing. As you study the crags and boulders, consider how ancient this landscape is. 67P originated in the Kuiper Belt, a large reservoir of small icy bodies located just beyond Neptune, more than 4.5 billion years ago. Either through a collision with another comet or asteroid, or through gravitational interaction with other planets, it was ejected from the Belt and fell inward toward the Sun.
Astronomers have analyzed its orbit and discovered that up until 1840, the future comet 67P never came closer than 4 times Earth’s distance from the Sun, ensuring that its ices remained as pristine as the day they formed. After that date, the comet passed near Jupiter and its orbit changed to bring it within the inner Solar System. We’re seeing a relic, a piece of dirty ice rich with history. Even a Rosetta stone of its own we can use to interpret the molecular script revealing the origin and evolution of comets.
Philae falls to the craggy comet photographed by the Rosetta mothership. Credit: ESAAn image of Comet 67P/Churyumov–Gerasimenko at less than 10 km from its surface. This selection of previously unpublished ‘beauty shots’, taken by Rosetta’s navigation camera, presents the varied and dramatic terrain of this mysterious world from this close orbit phase of the mission. Credit: ESA.Frame from panoramic image. This has been heavily toned to reveal details in the shadow of the cliff. Credit: ESAFrame from panoramic image. Credit: ESAFrame from panoramic image. Credit: ESAFrame from panoramic image. Credit: ESAFrame from panoramic image. Credit: ESAImage from the Philae lander as it approached the surface. The dust-covered boulder at upper right is about 5 meters (16.4 feet) across. The dust might have originated through vaporization of ice in the boulder itself or settled there from active jets elsewhere on the comet. Credit: ESA
At NASA's Kennedy Space Center in Florida, the agency's Orion spacecraft pauses in front of the spaceport's iconic Vehicle Assembly Building as it is transported to Launch Complex 37 at Cape Canaveral Air Force Station. After arrival at the launch pad, United Launch Alliance engineers and technicians will lift Orion and mount it atop its Delta IV Heavy rocket.
Credit: NASA/Frankie Martin
After years of effort, NASA’s pathfinding Orion spacecraft was rolled out to the launch pad early this morning, Wednesday, Nov. 12, and hoisted atop the rocket that will blast it to space on its history making maiden test flight in December.
Orion’s penultimate journey began late Tuesday, when the spacecraft was moved 22 miles on a wheeled transporter from the Kennedy Space Center assembly site to the Cape Canaveral launch site at pad 37 for an eight hour ride.
Watch a timelapse of the journey, below:
Technicians then lifted the 50,000 pound spacecraft about 200 feet onto a United Launch Alliance Delta IV Heavy rocket, the world’s most powerful rocket, in preparation for its first trip to space.
Orion’s promise is that it will fly America’s astronauts back to deep space for the first time in over four decades since the NASA’s Apollo moon landing missions ended in 1972.
Liftoff of the state-of-the-art Orion spacecraft on the unmanned Exploration Flight Test-1 (EFT-1) mission is slated for December 4, 2014, from Space Launch Complex 37 (SLC-37) at Cape Canaveral Air Force Station in Florida.
“This is the next step on our journey to Mars, and it’s a big one,” said William Gerstenmaier, NASA’s associate administrator for human exploration and operations.
“In less than a month, Orion will travel farther than any spacecraft built for humans has been in more than 40 years. That’s a huge milestone for NASA, and for all of us who want to see humans go to deep space.”
NASA’s Orion spacecraft arrived at Space Launch Complex 37 at Cape Canaveral Air Force Station to complete its 22 mile move from the agency’s Kennedy Space Center in Florida. Orion is the exploration spacecraft designed to carry astronauts to deep space destinations, including an asteroid and on the journey to Mars. It will have emergency abort capability, sustain the crew during space travel and provide safe re-entry from deep space return velocities. The first uncrewed flight test of Orion is scheduled to launch Dec. 4, 2014, atop a United Launch Alliance Delta IV Heavy rocket. Credit: NASA/Kim Shiflett
Orion is NASA’s next generation human rated vehicle that will eventually carry America’s astronauts beyond Earth on voyages venturing farther into deep space than ever before – beyond the Moon to Asteroids, Mars, and other destinations in our Solar System.
The fully assembled Orion vehicle stack consists of the crew module, service module, launch abort system, and adapter that connect it to the Delta IV Heavy rocket. It was completed in October inside Kennedy’s Launch Abort System Facility.
Today’s move was completed without issue after a one day delay due to storms in the KSC area.
The triple barreled Delta IV Heavy booster became the world’s most powerful rocket upon the retirement of NASA’s Space Shuttle program in 2011 and is the only rocket sufficiently powerful to launch the Orion EFT-1 spacecraft.
The two-orbit, four and a half hour EFT-1 flight will lift the Orion spacecraft and its attached second stage to an orbital altitude of 3,600 miles, about 15 times higher than the International Space Station (ISS) – and farther than any human spacecraft has journeyed in 40 years.
Orion will travel almost 60,000 miles into space during the uncrewed Dec. 4 test flight.
Stay tuned here for Ken’s continuing Orion and Earth and planetary science and human spaceflight news.
A composite image of Uranus in two infrared bands, showing the planet and its ring system. Picture taken by the Keck II telescope and released in 2007. Credit: W. M. Keck Observatory (Marcos van Dam)
Sometimes first impressions are poor ones. When the Voyager 2 spacecraft whizzed by Uranus in 1986, the close-up view of the gas giant revealed what appeared to a be a relatively featureless ball. By that point, scientists were used to seeing bright colors and bands on Jupiter and Saturn. Uranus wasn’t quite deemed uninteresting, but the lack of activity was something that was usually remarked upon when describing the planet.
Fast-forward 28 years and we are learning that Uranus is a more complex world than imagined at the time. Two new studies, discussed at an American Astronomical Society meeting today, show that Uranus is a stormy place and also that the images from Voyager 2 had more interesting information than previously believed.
Showing the value of going over old data, University of Arizona astronomer Erich Karkoschka reprocessed old images of Voyager 2 data — including stacking 1,600 pictures on top of each other.
He found elements of Uranus’ atmosphere that reveals the southern hemisphere moves differently than other regions in fellow gas giants. Since only the top 1% of the atmosphere is easily observable from orbit, scientists try to make inferences about the 99% that lie underneath by looking at how the upper atmosphere behaves.
“Some of these features probably are convective clouds caused by updraft and condensation. Some of the brighter features look like clouds that extend over hundreds of kilometers,” he stated in a press release.
Voyager 2. Credit: NASA
“The unusual rotation of high southern latitudes of Uranus is probably due to an unusual feature in the interior of Uranus,” he added. “While the nature of the feature and its interaction with the atmosphere are not yet known, the fact that I found this unusual rotation offers new possibilities to learn about the interior of a giant planet.”
It’s difficult to get more information about the inner atmosphere without sending down a probe, but other methods of getting a bit of information include using radio (which shows magnetic field rotation) or gravitational fields. The university stated that Karkoschka’s work could help improve models of Uranus’ interior.
So that was Uranus three decades ago. What about today? Turns out that storms are popping up on Uranus that are so large that for the first time, amateur astronomers can track them from Earth. A separate study on Uranus shows the planet is “incredibly active”, and what’s more, it took place at an unexpected time.
Summer happened in 2007 when the Sun shone on its equator, which should have produced more heat and stormy weather at the time. (Uranus has no internal heat source, so the Sun is believed to be the primary driver of energy on the planet.) However, a team led by Imke de Pater, chair of astronomy at the University of California, Berkeley, spotted eight big storms in the northern hemisphere while looking at the planet with the Keck Telescope on Aug. 5 and 6.
Infrared images of Uranus showing storms at 1.6 and 2.2 microns obtained Aug. 6, 2014 by the 10-meter Keck telescope. Credit: Imke de Pater (UC Berkeley) & Keck Observatory images.
Keck’s eye revealed a big, bright storm that represented 30% of light reflected by the planet at a wavelength of 2.2 microns, which provides information about clouds below the tropopause. Amateurs, meanwhile, spotted a storm of a different sort. Between September and October, several observations were reported of a storm at 1.6 microns, deeper in the atmosphere.
“The colors and morphology of this [latter] cloud complex suggests that the storm may be tied to a vortex in the deeper atmosphere similar to two large cloud complexes seen during the equinox,” stated Larry Sromovsky, a planetary scientist at the University of Wisconsin, Madison.
What is causing the storms now is still unknown, but the team continues to watch the Uranian weather to see what will happen next. Results from both studies were presented at the Division for Planetary Sciences meeting of the American Astronomical Society in Tucson, Arizona today. Plans for publication and whether the research was peer-reviewed were not disclosed in press releases concerning the findings.
Reprocessed view by Bjorn Jonsson of the Great Red Spot taken by Voyager 1 in 1979 reveals an incredible wealth of detail.
If it weren’t for the Sun, Jupiter’s Great Red Spot would be a much blander feature on the gas giant, a new study reveals. This stands apart from what most scientists think about why for why the spot looks so colorful: that there are features in the clouds that give it its distinctive shade.
The new data comes from observations with the Cassini spacecraft, combined with experiments in the lab. They conclude that the Red Spot’s immense height, combined with sunlight breaking apart the atmosphere there into certain chemicals, make the feature that red that is visible even in small telescopes.
“Our models suggest most of the Great Red Spot is actually pretty bland in color, beneath the upper cloud layer of reddish material,” said Kevin Baines, a Cassini team scientist based at NASA’s Jet Propulsion Laboratory in California, in a statement. “Under the reddish ‘sunburn’ the clouds are probably whitish or grayish.”
The lab experiments combined ammonia and acetylene gases (atmospheric components from Jupiter) with ultraviolet light (simulating what the Sun produces), which created a ruddy substance that matched observations made with the Cassini spacecraft back in 2000. They also tried breaking apart ammonium hydrosulfide, a common element in Jupiter’s high clouds, but the color produced was actually a bright green.
The Great Red Spot is a storm that has been raging on Jupiter since at least when telescopes were first used in the 1600s. Over the past few decades, its size has shrunk considerably –it’s now half of what historical measurements showed — but it is still much larger than Earth. Scientists are hoping the forthcoming Juno mission, which will arrive at Jupiter at 2016, will help learn more about what is going on.
Results were presented at the Division for Planetary Science of the American Astronomical Society’s annual meeting this week in Tucson, Arizona. A press release did not disclose publication plans or if the research is peer-reviewed.
Magnetic field lines bound up in the sun’s wind pile up and drape around a comet’s nucleus to shape the blue ion tail. Notice the oppositely-directed fields on the comet’s backside. The top set points away from the comet; the bottom set toward. In strong wind gusts, the two can be squeezed together and reconnect, releasing energy that snaps off a comet’s tail. Credit: Tufts University
Tune in to the song of Comet Churyumov-Gerasimenko
Scientists can’t figure exactly why yet, but Comet 67P/Churyumov-Gerasimenko has been singing since at least August. Listen to the video – what do you think? I hear a patter that sounds like frogs, purring and ping-pong balls. The song is being sung at a frequency of 40-50 millihertz, much lower than the 20 hertz – 20 kilohertz range of human hearing. Rosetta’s magnetometer experiment first clearly picked up the sounds in August, when the spacecraft drew to within 62 miles (100 km) of the comet. To make them audible Rosetta scientists increased their pitch 10,000 times.
The sounds are thought to be oscillations in the magnetic field around the comet. They were picked up by the Rosetta Plasma Consortium, a suite of five instruments on the spacecraft devoted to observing interactions between the solar plasma and the comet’s tenuous coma as well as the physical properties of the nucleus. A far cry from the stuff you donate at the local plasma center, plasma in physics is an ionized gas. Ionized means the atoms in the gas have lost or gained an electron through heating or collisions to become positively or negatively charged ions. Common forms of plasma include the electric glow of neon signs, lightning and of course the Sun itself.
Having lost their neutrality, electric and magnetic fields can now affect the motion of particles in the plasma. Likewise, moving electrified particles affect the very magnetic field controlling them.
Scientists think that neutral gas particles from vaporizing ice shot into the coma become ionized under the action of ultraviolet light from the Sun. While the exact mechanism that creates the curious oscillations is still unknown, it might have something to do with the electrified atoms or ions interacting with the magnetic fields bundled with the Sun’s everyday outpouring of plasma called the solar wind. It’s long been known that a comet’s electrified or ionized gases present an obstacle to the solar wind, causing it to drape around the nucleus and shape the streamlined blue-tinted ion or gas tail.
“This is exciting because it is completely new to us. We did not expect this, and we are still working to understand the physics of what is happening,” said Karl-Heinz Glassmeier, head of Space Physics and Space Sensorics at the Technical University of Braunschweig, Germany.
While 67P C-G’s song probably won’t make the Top 40, we might listen to it just as we would any other piece of music to learn what message is being communicated.
After a ten year journey that began with the launch from the jungles of French Guyana, landing Philae is not the end of mission, it is the beginning of a new phase. A successful landing is not guaranteed but the ESA Rosetta team is now ready to release Philae on its one way journey. (Photo Credits: ESA/NASA, Illustration: J.Schmidt)
We are now in the final hours before Rosetta’s Philae lander is released to attempt a first-ever landing on a comet. At 9:03 GMT (1:03 AM PST) on Wednesday, November 12, 2014, Philae will be released and directed towards the surface of comet 67P/Churyumov–Gerasimenko. 7 hours later, the lander will touch down.
Below you’ll find a timeline of events, info on how to watch the landing, and an overview of how the landing will (hopefully) work.
In human affairs, we build contingencies for missteps, failures. With spacecraft, engineers try to eliminate all single point failures and likewise have contingency plans. The landing of a spacecraft, be it on Mars, Earth, or the Moon, always involves unavoidable single point failures and points of no return, and with comet 67P/Churyumov–Gerasimenko, Rosetta’s Philae lander is no exception.
Rosetta’s and Philae’s software and hardware must work near flawlessly to give Philae the best chance possible of landing safely. And even with flawless execution, it all depends on Philae’s intercepting a good landing spot on the surface. Philae’s trajectory is ballistic on this one way trip to a comet’s surface. It’s like a 1 mile per hour bullet. Once fired, it’s on its own, and for Philae, its trajectory could lead to a pristine flat step or it could be crevasse, ledge, or sharp rock.
The accuracy of the landing is critical but it has left a 1 square kilometer of uncertainty. For this reason, engineers and scientists had to survey the whole surface for the most mild features. Comet 67P has few areas that are not extreme in one way or another. Site J, now called Agilkia, is one such site.
When first announced in late September, the time of release was 08:35 GMT (12:35 AM PST). Now the time is 9:03 GMT. The engineers and computer scientists have had six weeks to further refine their trajectory. It’s a complicated calculation that has required running the computer simulation of the descent backwards. Backwards because they can set a landing time then run Philae backwards to the moment of release. The solution is not just one but many, thousands or millions if you want to look in such detail. With each release point, the engineers had to determine how, or if, Rosetta could be navigated to that coordinate point in space and time.
Arrival time of the radio signal with landing status: 16:30 GMT
Rosetta/Philae at 500 million km [320 million miles], 28.5 minutes light time
Arrival of First Images: 06:00 GMT, November 13, 2014
The gravity field of the comet is so weak, it is primarily the initial velocity from Rosetta that delivers Philae to the surface. But the gravity is there and because of the chaotic shape and unknown (as yet) mass distribution inside, the gravity will make Philae move like a major league knuckleball wobbling to the plate and a batter. Furthermore, the comet during the seven hour trip will make half a rotation. The landing site will not be in site when Philae is released.
And as Philae is on final approach, it will use a small rocket not to slow down but rather thrust it at the comet, landing harpoons will be fired, foot screws will try to burrow into the comet, and everyone on Earth will wait several minutes for a message to be relayed from Philae to Rosetta to the Deep Space Network (DSN) antennas on Earth. Philae will be on its own as soon as it leaves Rosetta and its fate is a few hours away.
Why travel to a comet? Comets represent primordial material leftover from the formation of the solar system. Because cometary bodies were formed and remained at a distance from the heat of the sun, the materials have remained nearly unchanged since formation, ~4.5 billion years ago. By looking at Rosetta’s comet, 67P/Churyumov–Gerasimenko, scientists will gain the best yet measurements of a comet’s chemical makeup, its internal structure created during formation, and the dynamics of the comet as it approaches the warmth of the Sun. Theories propose that comets impacting on Earth delivered most of the water of our oceans. If correct, then we are not just made of star-stuff, as Carl Sagan proclaimed, we are made of comet stuff, too. Comets may also have delivered the raw organic materials needed to start the formation of life on Earth.
Besides the ESA live feeds, one can take a peek at NASA’s Deep Space Network (DSN) at work to see which telescopes are communicating with Rosetta. JPL’s webcast can watched below:
Artist's conception of early planetary formation from gas and dust around a young star. Outbursts from newborn and adolescent stars might drive planetary water beneath the surface of rocky worlds.
Credit: NASA/NASA/JPL-Caltech
This isn’t a clone of our Solar System, but it’s close enough. Scientists eagerly scrutinized a young star system called HD 95086 to learn more about how dust belts and giant planets grow up together. This is an important finding for our own neighborhood, where the gas giants of Jupiter, Saturn, Uranus and Neptune are also wedged between dusty areas.
“By looking at other star systems like these, we can piece together how our own Solar System came to be,” stated lead author Kate Su, an associate astronomer at the University of Arizona, Tucson.
The system is about 295 light-years from Earth, and is suspected to have two dust belts: a warmer one (similar to our asteroid belt) and a cooler one (similar to the Kuiper Belt that has icy objects.) The system is host to at least one planet that is five times the mass of Jupiter, and other planets could also be hiding between the dusty lanes. This planet, called HD 95086 b, was imaged by the European Southern Observatory’s Very Large Observatory in 2013.
Planet HD95086 b is shown at lower left in this picture. Astronomers blocked out the light of the star (center) to image the exoplanet. The blue circle represents the equivalent orbit of Neptune in this star system. Credit: ESO/J. Rameau
The next step was a comparison study with another star system called HR 8799, which also has two dusty rings and in this case, at least four planets in between. These planets have also been caught on camera. Comparing the structure of the two systems indicates that HD 95086 may have more planets lurking for astronomers to discover.
“By knowing where the debris is, plus the properties of the known planet in the system, we can get an idea of what other kinds of planets can be there,” stated Sarah Morrison, a co-author of the paper and a PhD student at the University of Arizona. “We know that we should be looking for multiple planets instead of a single giant planet.”
The researchers presented their work at the Division for Planetary Science Meeting of the American Astronomical Society in Tucson, Arizona. A press release did not disclose publication plans or if the work was peer-reviewed.
