Artist's conception of the NASA Dawn spacecraft approaching Ceres. Credit: NASA
NASA’s Dawn spacecraft experienced technical problems in the past week that will force it to arrive at dwarf planet Ceres one month later than planned, the agency said in a statement yesterday (Sept. 16).
Controllers discovered Dawn was in safe mode Sept. 11 after radiation disabled its ion engine, which uses electrical fields to “push” the spacecraft along. The radiation stopped all engine thrusting activities. The thrusting resumed Monday (Sept. 15) after controllers identified and fixed the problem, but then they found another anomaly troubling the spacecraft.
Dawn’s main antenna was also disabled, forcing the spacecraft to send signals to Earth (a 53-minute roundtrip by light speed) through a weaker secondary antenna and slowing communications. The cause of this problem hasn’t been figured out yet, but controllers suspect radiation affected the computer’s software. A computer reset has solved the issue, NASA added. The spacecraft is now functioning normally.
Vesta (left) and Ceres. Vesta was photographed up close by the Dawn spacecraft from July 2011-Sept. 2012, while the best views we have to date of Ceres come from the Hubble Space Telescope. The bright white spot is still a mystery. Credit: NASA
“As a result of the change in the thrust plan, Dawn will enter into orbit around dwarf planet Ceres in April 2015, about a month later than previously planned. The plans for exploring Ceres once the spacecraft is in orbit, however, are not affected,” NASA’s Jet Propulsion Laboratory stated in a press release.
Dawn is en route to Ceres after orbiting the huge asteroid Vesta between July 2011 and September 2012. A similar suspected radiation blast three years ago also disabled Dawn’s engine before it reached Vesta, but the ion system worked perfectly in moving Dawn away from Vesta when that phase of its mission was complete, NASA noted.
Among Dawn’s findings at Vesta is that the asteroid is full of hydrogen, and it contains the hydrated mineral hydroxyl. This likely came to the asteroid when smaller space rocks brought the volatiles to its surface through low-speed collisions.
Spacecraft can experience radiation through energy from the Sun (particularly from solar flares) and also from cosmic rays, which are electrically charged particles that originate outside the Solar System. Earth’s atmosphere shields the surface from most space-based radiation.
The Opportunity rover is at the west rim of Endeavour Crater on Mars in this image sent on Sol 3,783 in September 2014 -- after a successful Flash memory reset. Credit: NASA/JPL-Caltech/Cornell Univ./Arizona State Univ.
With a newly cleared memory, it’s time for Opportunity to resume the next stage of its long, long Martian drive. The next major goal for the long-lived rover is to go to Marathon Valley, a spot that (in images from orbit) appears to have clay minerals on site. Clay tends to form in the presence of water, so examining the region could provide more information about Mars’ wet, ancient past.
Ready to roll: the Opportunity rover’s wheels and tracks are visible in this picture taken on Mars on Sol 3,783 in September 2014. Credit: NASA/JPL-Caltech/Cornell Univ./Arizona State Univ.
A NASA planetary senior review panel from early September, which was evaluating the science value of several extended missions, said there are “software and communication issues that afflict the rover” that could affect its ability to send data. (This was written before the memory reformat.)
The major goal of Opportunity’s latest extended mission, the review continued, is to find out what habitability conditions existed on Mars. This includes looking at the water, the geology and the environment.
“This will be achieved by measurements of rocks and soils, as well as atmospheric observations, as it traverses from Murray Ridge to Cape Tribulation,” the report read.
A still from the Opportunity rover’s navigation camera taken on Sol 3,783 in September 2014. At bottom is part of the solar panel cells used to power the Martian rover. Credit: NASA/JPL-Caltech/Cornell Univ./Arizona State Univ.
“This extended mission will focus on the orbitally detected phyllosilicate deposits near Endeavour crater, which are considered to represent deposits from the ancient Noachian period. This would represent the first time that such ancient deposits have been analyzed on the Martian surface.”
The report further cautioned that there is no proof yet that the phyllosilicates (which are sheet salt silicate materials made of silicon and oxygen) are from the Noachian era, which represents geology that is more than 3.5 billion years old (depending on which source you consult). It added, however, that Opportunity is expected to be able to complete the science.
Meanwhile, enjoy these pictures from the rim of Endeavour Crater that Opportunity sent in the past few days.
Rocks scattered across the Martian vista in this picture captured by the Opportunity rover on Sol 3,783. Credit: NASA/JPL-Caltech/Cornell Univ./Arizona State Univ.Two of Opportunity’s six wheels are visible in this shot from the rear hazcam on Sol 3,780, taken on Mars in September 2014. Credit: NASA/JPL-Caltech/Cornell Univ./Arizona State Univ.Tracks from Opportunity stretch across this vista taken by the rover on Sol 3,781 in September 2014. Credit: NASA/JPL-Caltech/Cornell Univ./Arizona State Univ.
Artist's conception of the New Horizons spacecraft flying past Pluto and Charon, one of the dwarf planet's moons. Credit: Johns Hopkins University/APL
Here’s Hydra! The New Horizons team spotted the tiny moon of Pluto in July, about six months ahead of when they expected to. You can check it out in the images below. The find is exciting in itself, but it also bodes well for the spacecraft’s search for orbital debris to prepare for its close encounter with the system in July 2015.
Most of Pluto’s moons were discovered while New Horizons was under development, or already on its way. Mission planners are thus concerned that there could be moons out there that aren’t discovered yet — moons that could pose a danger to the spacecraft if it ended up in the wrong spot at the wrong time. That’s why the team is engaging in long-range views to see what else is lurking in Pluto’s vicinity.
“We’re thrilled to see it, because it shows that our satellite-search techniques work, and that our camera is operating superbly. But it’s also exciting just to see a third member of the Pluto system come into view, as proof that we’re almost there,” stated science team member John Spencer, of the Southwest Research Institute.
Watch the difference: Pluto’s moon Hydra stands out in these images taken by the New Horizons spacecraft on July 18 and 20, 2014. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
Hydra was spotted using the spacecraft’s Long Range Reconnaissance Imager (LORRI), which took 48 images of 10 seconds apiece between July 18 and July 20. Then the team used half the images, the ones that show Hydra better, to create the images you see above.
The spacecraft was still 267 million miles (430 million kilometers) from Pluto when the images were taken. Another moon discovered around the same time as Hydra — Nix — is still too close to be seen given it’s so close to Pluto, but just wait.
Meanwhile, scientists are busily trying to figure out where to send New Horizons after Pluto. In July, researchers using the Hubble Space Telescope began a full-scale search for a suitable Kuiper Belt Object, which would be one of trillions of icy or rocky objects beyond Neptune’s orbit. Flying past a KBO would provide more clues as to how the Solar System formed, since these objects are considered leftovers of the chunks of matter that came together to form the planets.
A self-portrait of the Opportunity rover shortly after dust cleared its solar panels in March 2014. Credit: NASA/JPL-Caltech/Cornell Univ./Arizona State Univ.
In fantastic news for the long-running Opportunity mission on Mars, NASA says the rover’s much-needed memory reset worked out perfectly. The rover was unable to perform science or beam pictures back to Earth because portions of its flash memory — which can store information even when the rover is turned off — were beginning to wear out.
The reboot means the rover is soon going to be on the move again as it continues exploring the rim of Endeavour Crater, tacking on nearly a marathon of miles that Opportunity has racked up on Mars since 2004.
“The rover’s Flash file system was successfully reformatted on Sol 3773 (Sept. 4, 2014),” NASA wrote in an update on the Mars Exploration Rover website late last week. “The Flash space available is slightly smaller (<1%) than before the reformat, consistent with the reformatting process flagging some bad cells to avoid.”
Traverse Map for NASA’s Opportunity rover from 2004 to 2014 – A Decade on Mars. This map shows the entire path the rover has driven during a decade on Mars and over 3692 Sols, or Martian days, since landing inside Eagle Crater on Jan 24, 2004 to current location along Pillinger Point ridge south of Solander Point summit at the western rim of Endeavour Crater and heading to clay minerals at Cape Tribulation. Opportunity discovered clay minerals at Esperance – indicative of a habitable zone. Credit: NASA/JPL/Cornell/ASU/Marco Di Lorenzo/Ken Kremer
After performing related activities to the reformat on Sept. 6 and 7, controllers tried to take Opportunity out for a drive. They decided to stop shortly after beginning on Sept. 9 because the visual odometry Opportunity was using wasn’t enough for navigation. The controllers plan to try it again, using different landmarks next time. Current odometer on the rover: 25.28 miles (40.69 kilometers).
Sept. 9 marked the 3,778th Martian day or “sol” that Opportunity has been at work on Mars. The rover was originally designed to last three Earth months on the Martian surface, but is still performing drives and science in its 11th year. (The rover’s twin, Spirit, died in a sand trap after sending its last transmission March 22, 2010.)
Opportunity, however, is facing funding challenges on Earth as NASA and its political stakeholders weigh which of the agency’s long-term missions should continue.
Context image showing the location of the primary landing site for Rosetta’s lander Philae. Site J is located on the head of Comet 67P/Churyumov–Gerasimenko. An inset showing a close up of the landing site is also shown. The inset image was taken by Rosetta’s OSIRIS narrow-angle camera on 20 August 2014 from a distance of about 67 km. The image scale is 1.2 metres/pixel. The background image was taken on 16 August from a distance of about 100 km. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
Scientists leading the European Space Agency’s Rosetta mission announced the primary landing site at a media briefing today, Sept. 15, at ESA headquarters.
After weeks of detailed study and debate focused on balancing scientific interest with finding a ‘technically feasible’ and safe Philae touchdown site, the team chose a target dubbed Site J as the primary landing site from among a list of five initially selected sites, said Stephan Ulamec, Philae Lander Manager at the DLR German Aerospace Center, at the briefing.
“Site J is the primary landing site around the head of the comet,” Ulamec announced.
“Site C is the backup site on the body [near the bottom of the comet].”
“This was not an easy task. Site J is a mix of flat areas and rough terrain. It’s not a perfectly flat area. There is still risk with high slope areas.”
Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
He also made clear that there is still some landing uncertainty with the targeting of the lander onto the comet.
Site J is an intriguing region on Comet 67P/Churyumov–Gerasimenko that offers unique scientific potential, with hints of activity nearby, and minimum risk to the lander compared to the other candidate sites, according to ESA.
“As we have seen from recent close-up images, the comet is a beautiful but dramatic world – it is scientifically exciting, but its shape makes it operationally challenging,” says Ulamec.
“None of the candidate landing sites met all of the operational criteria at the 100% level, but Site J is clearly the best solution.”
Philae’s history-making landing on comet 67P is currently scheduled for around Nov. 11, 2014, and will be entirely automatic. The 100 kg lander is equipped with 10 science instruments.
“All of Rosetta’s instruments are supporting the landing site selection,” said Holger Sierks, principal investigator for Rosetta’s OSIRIS camera from the Max Planck Institute for Solar System Research in Gottingen, Germany.
“Site J is just 500-600 meters away from some pits and an area of comet outgassing activity. They will become more active as we get closer to the sun.
The team is in a race against time to select a suitable landing zone quickly and develop the complex landing sequence since the comet warms up and the surface becomes ever more active as it swings in closer to the sun and makes the landing ever more hazardous.
Since the descent to the comet is passive it is only possible to predict that the landing point will place within a ‘landing ellipse’ typically a few hundred metres in size, the team elaborated.
The three-legged lander will fire two harpoons and use ice screws to anchor itself to the 4 kilometer (2.5 mile) wide comet’s surface. Philae will collect stereo and panoramic images and also drill 20 to 30 centimeters into and sample its incredibly varied surface.
“We will make the first ever in situ analysis of a comet at this site, giving us an unparalleled insight into the composition, structure and evolution of a comet,” says Jean-Pierre Bibring, a lead lander scientist and principal investigator of the CIVA instrument at the IAS in Orsay, France.
“Site J in particular offers us the chance to analyse pristine material, characterise the properties of the nucleus, and study the processes that drive its activity.”
“It’s amazing how much we have learned so far.”
“We are in a true revolution of how we think Planets form and evolve,” Bibring elaborated at the briefing.
“We will make many types of scientific measurements of the comet from the surface. We will get a complete panoramic view of the comet on the macroscopic and microscopic scale.”
Rosetta is currently orbiting the comet from a distance of 30 km, said ESA Rosetta flight director Andrea Accomazzo. He said it will likely go even closer to 20 km and perhaps 10 km.
Four-image photo mosaic comprising images taken by Rosetta’s navigation camera on 2 September 2014 from a distance of 56 km from comet 67P/Churyumov-Gerasimenko. The mosaic has been contrast enhanced to bring out details of the coma, especially of jets of dust emanating from the neck region. Credits: ESA/Rosetta/NAVCAM/Marco Di Lorenzo/Ken Kremer – kenkremer.com
“Now that we’re closer to the comet, continued science and mapping operations will help us improve the analysis of the primary and backup landing sites,” says ESA Rosetta flight director Andrea Accomazzo.
“Of course, we cannot predict the activity of the comet between now and landing, and on landing day itself. A sudden increase in activity could affect the position of Rosetta in its orbit at the moment of deployment and in turn the exact location where Philae will land, and that’s what makes this a risky operation.”
Four-image photo mosaic comprising images taken by Rosetta’s navigation camera on 31 August 2014 from a distance of 61 km from comet 67P/Churyumov-Gerasimenko. The mosaic has been rotated and contrast enhanced to bring out details. The comet nucleus is about 4 km across. Credits: ESA/Rosetta/NAVCAM/Ken Kremer/Marco Di Lorenzo
The final landing site selections were made at a meeting being held this weekend on 13 and 14 September 2014 between the Rosetta Lander Team and the Rosetta orbiter team at CNES in Toulouse, France.
“No one has ever attempted to land on a comet before, so it is a real challenge,” says Fred Jansen, ESA Rosetta mission manager.
“The complicated ‘double’ structure of the comet has had a considerable impact on the overall risks related to landing, but they are risks worth taking to have the chance of making the first ever soft landing on a comet.”
Five candidate sites were identified on Comet 67P/Churyumov-Gerasimenko for Rosetta’s Philae lander. The approximate locations of the five regions are marked on these OSIRIS narrow-angle camera images taken on 16 August 2014 from a distance of about 100 km. Enlarged insets below highlight 5 landing zones. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA Processing: Marco Di Lorenzo/Ken Kremer
Stay tuned here for Ken’s continuing Rosetta, Earth and Planetary science and human spaceflight news.
NASA’s Orion EFT 1 crew module departs Neil Armstrong Operation and Checkout Building on Sept. 11, 2014 at the Kennedy Space Center, FL, beginning the long journey to the launch pad and planned liftoff on Dec. 4, 2014. Credit: Ken Kremer - kenkremer.com
NASA’s Orion EFT 1 crew module departs Neil Armstrong Operation and Checkout Building on Sept. 11, 2014 at the Kennedy Space Center, FL, beginning the long journey to the launch pad and planned liftoff on Dec. 4, 2014. Credit: Ken Kremer – kenkremer.com
Story updated[/caption]
KENNEDY SPACE CENTER – NASA’s first space worthy Orion crew module rolled out of its assembly facility at the Kennedy Space Center (KSC) on Thursday, Sept. 11, taking the first step on its nearly two month journey to the launch pad and planned blastoff this coming December.
The Orion spacecraft is NASA’s next generation human rated vehicle and is scheduled to launch on its maiden uncrewed mission dubbed Exploration Flight Test-1 (EFT-1) in December 2014.
Orion’s assembly was just completed this past weekend by technicians and engineers from prime contractor Lockheed Martin inside the agency’s Neil Armstrong Operations and Checkout (O & C) Facility. They have been working 24/7 to manufacture the capsule and prepare it for launch.
“I’m excited as can be,” said Scott Wilson, NASA’s Orion Manager of Production Operations at KSC during the move. “For some of us this has been ten years in the making.”
The black tiled Orion crew module (CM) was stacked atop an inert white colored service module (SM) in the O & C high bay in June. The CM/SM stack was placed on top of the Orion-to-stage adapter ring that will mate them to the booster rocket. Altogether the capsule, service module and adapter ring stack stands 40 feet tall and 16 feet in diameter.
“This is awesome,” Bob Cabana, Kennedy Space Center director and former shuttle commander, told the media during the rollout.
NASA’s Orion EFT 1 crew module enters the Payload Hazardous Servicing Facility on Sept. 11, 2014 at the Kennedy Space Center, FL, beginning the long journey to the launch pad and planned liftoff on Dec. 4, 2014. Credit: Ken Kremer – kenkremer.com
Workers subsequently covered the crew module and its thermal insulating tiles with a see through foil to shield the capsule and blanket it under a protective climate controlled atmosphere to guard against humidity.
The CM/SM stack was then lifted and placed onto a 36-wheeled transporter and moved about 1 mile to a KSC facility named the Payload Hazardous Servicing Facility (PHFS) for fueling. The move took about an hour.
“Orion will stay at the PHFS for about a month,” Wilson told me in a KSC interview during the move.
Orion will be fueled with ammonia and hyper-propellants for its flight test, said Wilson.
NASA’s completed Orion EFT 1 crew module loaded on wheeled transporter during move to the Payload Hazardous Servicing Facility (PHSF) on Sept. 11, 2014 at the Kennedy Space Center, FL. Credit: Ken Kremer – kenkremer.com
The fueled Orion will then move yet again to the Launch Abort System Facility (LASF) for the installation of the launch abort system (LAS).
The full Orion stack will rollout to Space Launch Complex 37 in early November.
“Nothing about building the first of a brand new space transportation system is easy,” said Mark Geyer, Orion Program manager.
“But the crew module is undoubtedly the most complex component that will fly in December. The pressure vessel, the heat shield, parachute system, avionics — piecing all of that together into a working spacecraft is an accomplishment. Seeing it fly in three months is going to be amazing.”
The Orion EFT-1 test flight is slated to soar to space atop the mammoth, triple barreled United Launch Alliance (ULA) Delta IV Heavy rocket from Cape Canaveral, Florida, on Dec. 4, 2014.
The state-of-the-art Orion spacecraft will carry America’s astronauts on voyages venturing farther into deep space than ever before – past the Moon to Asteroids, Mars and Beyond!
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.
Stay tuned here for Ken’s continuing Orion, SLS, Boeing, Sierra Nevada, Orbital Sciences, SpaceX, commercial space, Curiosity, Mars rover, MAVEN, MOM and more Earth and planetary science and human spaceflight news.
Scott Wilson, NASA’s Orion Manager of Production Operations at KSC and Ken Kremer/Universe Today discuss Orion EFT-1 mission during capsule rollout on Sept. 11, 2014 at the Kennedy Space Center, FL. Credit: Ken Kremer – kenkremer.com
The gibbous moon shines on Sept. 5, 2014. Credit: Christian Kamber
While the SuperMoon of earlier this week got a lot of attention — and rightly so, given the Moon was closest in its orbit to Earth when it was full — the waning and waxing phases around our celestial neighbor are also beautiful. Haunting, in fact.
These shots were taken by members of our Universe Today Flickr pool, with the moon either entering or exiting the full moon phase. Got some stunning astronomy shots to share? Feel free to add your contributions to the group (which says you will give us permission to publish) and we may include them in a future story.
The moon in its waning gibbous phase on Sept. 12, 2014. Photo taken with a Canon 700D attached to a Maksutov 127mm telescope. Credit: Sarah&Simon FisherThe moon shines red in this photo taken from Newcastle upon Tyne, England on Sept. 11, 2014. Credit: David BlanchflowerThe large craters Atlas (left) and Hercules (below) on the moon. Taken using a Canon 1100D. Credit: Paul M. Hutchinson
EDIT: We just received a nice sequence of shots from Laura Austin:
A solar blast erupts in this picture captured by the Solar and Heliospheric Observatory on Sept. 10, 2014. Credit: ESA / NASA / SOHO
Bim, bam, smash! The Sun hurled two clouds of particles in our general direction, putting space weather watchers on alert. There’s now a high chance of auroras on Sept. 12 (Friday), according to the National Oceanic and Atmospheric Administration, with more activity possible during the weekend.
The coronal mass ejections erupted Sept. 9 and Sept. 10 from sunspot AR2158. The Sept. 10 flare packed the strongest class punch the sun has, an X-flare, which briefly caused HF radio blackouts on Earth. We have some amateur shots of the sunspot and Sun below.
“Radio emissions from shock waves at the leading edge of the CME suggest that the cloud tore through the sun’s atmosphere at speeds as high as 3,750 km/s [2,330 miles per second],” wrote SpaceWeather.com. “That would make this a very fast moving storm, and likely to reach Earth before the weekend. Auroras are definitely in the offing.”
Photographer John Chumack captured the Sun and AR2158 in these pictures from Monday (Sept. 8). If you’ve got some great Sun shots to share, be sure to put it on our Universe Today Flickr group!
Sunspot AR2158 taken on Sept. 8, 2014. Credit: John ChumackThe Sun on Sept. 8, 2014, including active sunspots. Credit: John Chumack
NASA’s first completed Orion crew module sits atop its service module at the Neil Armstrong Operations and Checkout Facility at Kennedy Space Center in Florida in early September 2014. The crew and service module will be transferred soon to another facility for fueling. Credit: NASA/Rad Sinyak
This past weekend technicians completed assembly of NASA’s first Orion crew module at the agency’s Neil Armstrong Operations and Checkout (O & C) Facility at the Kennedy Space Center (KSC) in Florida, signifying a major milestone in the vehicles transition from fabrication to full scale launch operations.
The black Orion crew module (CM) sits stacked atop the white service module (SM) in the O & C high bay photos, shown above and below.
The black area is comprised of the thermal insulating back shell tiles. The back shell and heat shield protect the capsule from the scorching heat of re-entry into the Earth’s atmosphere at excruciating temperatures reaching over 4000 degrees Fahrenheit (2200 C) – detailed in my story here.
Technicians and engineers from prime contractor Lockheed Martin subsequently covered the crew module with protective foil. The CM/SM stack was then lifted and moved for the installation of the Orion-to-stage adapter ring that will mate them to the booster rocket.
Lifting and stacking NASA’s first completed Orion crew and service modules at the Neil Armstrong Operations and Checkout Facility at Kennedy Space Center in Florida in early September 2014. Credit: NASA/Rad Sinyak
At the conclusion of the EFT-1 flight, the detached Orion capsule plunges back and hits the Earth’s atmosphere at 20,000 MPH (32,000 kilometers per hour).
“That’s about 80% of the reentry speed experienced by the Apollo capsule after returning from the Apollo moon landing missions,” Scott Wilson, NASA’s Orion Manager of Production Operations at KSC, told me during an interview at KSC.
The next step in Orion’s multi stage journey to the launch pad follows later this week with transport of the CM/SM stack to another KSC facility named the Payload Hazardous Servicing Facility (PHFS) for fueling, before moving again for the installation of the launch abort system (LAS) in yet another KSC facility.
Stacking NASA’s first completed Orion crew and service modules at the Neil Armstrong Operations and Checkout Facility at Kennedy Space Center in Florida in early September 2014. Credit: NASA/Rad Sinyak
The Orion EFT-1 test flight is slated to soar to space atop the mammoth, triple barreled United Launch Alliance (ULA) Delta IV Heavy rocket from Cape Canaveral, Florida, on Dec. 4, 2014 .
The state-of-the-art Orion spacecraft will carry America’s astronauts on voyages venturing farther into deep space than ever before – past the Moon to Asteroids, Mars and Beyond!
NASA’s first completed Orion crew and service modules being moved inside the High Bay at the Neil Armstrong Operations and Checkout Facility at Kennedy Space Center in Florida in early September 2014. Credit: NASA/Rad Sinyak
NASA is simultaneously developing a monster heavy lift rocket known as the Space Launch System or SLS, that will eventually launch Orion on its deep space missions.
The maiden SLS/Orion launch on the Exploration Mission-1 (EM-1) unmanned test flight is now scheduled for no later than November 2018 – read my story here.
SLS will be the world’s most powerful rocket ever built.
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 service module assembly in the Operations and Checkout facility at Kennedy Space Center – now renamed in honor of Neil Armstrong. Credit: Ken Kremer/kenkremer.com
The EFT-1 mission will test the systems critical for EM-1 and future human missions to deep space that follow.
The Orion EFT-1 capsule has come a long way over the past two years of assembly.
The bare bones, welded shell structure of the Orion crew cabin arrived at KSC in Florida from NASA’s Michoud facility in New Orleans in June 2012 and was officially unveiled at a KSC welcoming ceremony on 2 July 2012, attended by this author.
“Everyone is very excited to be working on the Orion. We have a lot of work to do. It’s a marathon not a sprint to build and test the vehicle,” said Jules Schneider, Orion Project manager for Lockheed Martin at KSC, during an exclusive 2012 interview with Universe Today inside the Orion clean room at KSC.
Orion crew capsule, Service Module and 6 ton Launch Abort System (LAS) mock up stack inside the transfer aisle of the Vehicle Assembly Building (VAB) at the Kennedy Space Center (KSC) in Florida. Service module at bottom. Credit: Ken Kremer/kenkremer.com
Stay tuned here for Ken’s continuing Orion, SLS, Boeing, Sierra Nevada, Orbital Sciences, SpaceX, commercial space, Curiosity, Mars rover, MAVEN, MOM and more Earth and planetary science and human spaceflight news.
Orion crew module back shell tiles and panels inside the Neil Armstrong Operations and Checkout Building high bay at the Kennedy Space Center in Florida. Credit: Ken Kremer – kenkremer.comOrion EFT-1 capsule under construction inside the Structural Assembly Jig at the Operations and Checkout Building (O & C) at the Kennedy Space Center (KSC); Jules Schneider, Orion Project Manager for Lockheed Martin and Ken Kremer, Universe Today. Credit: Ken Kremer – kenkremer.com
A map of Saturn's F ring from 2006 shows one of the few bright, extended clumps (indicated by a green box) seen during six years of observation by Cassini. Image credit: NASA/JPL-Caltech/SSI
Nothing stands still. Everything evolves. So why shouldn’t Saturn’s kookie, clumpy F ring put on a new face from time to time?
A recent NASA-funded study compared the F ring’s appearance in six years of observations by the Cassini mission to its appearance during the Saturn flybys of NASA’s Voyager mission, 30 years earlier.
A kink in part of Saturn’s F ring. While the ring is held together by the shepherd moons Prometheus and Pandora, which orbit just inside and outside the ring, embedded moonlets are believed responsible for the kinks and clumps. The rings is several hundred kilometers wide. Credit: NASA
While the F ring has always displayed clumps of icy matter, the study team found that the number of bright clumps has nose-dived since the Voyager space probes saw them routinely during their brief flybys 30 years ago. Cassini spied only two of the features during a six-year period.
Scientists have long suspected that moonlets up to 3 miles (5 km) wide hiding in the F ring are responsible for its uneven texture. Kinks and knots appear and disappear within months compared to the years of observation needed changes in many of the other rings.
Saturn’s F ring is extremely narrow compared to the historic A, B and C rings. It measures just a few hundred kilometers across. Credit: NASA/Cassini
“Saturn’s F ring looks fundamentally different from the time of Voyager to the Cassini era,” said Robert French of the SETI Institute in Mountain View, California, who led the study along with SETI Principal Investigator Mark Showalter. “It makes for an irresistible mystery for us to investigate.”
A 2007 artist impression of small boulder-like chunks of ice that comprise Saturn’s rings. The largest are about 10-12 feet across.They clump together to form elongated, curved aggregates, continually forming and dispersing. Credit: NASA/JPL/Univ. of Colorado
Because the moonlets lie close to the ring and cross through it every orbit, the research team hypothesizes that the clumps are created when they crash into and pulverize smaller ring particles during each pass. They suspect that the decline in the number of exceptionally bright kinks and the clumps echoes a decline in the number of moonlets available to do the job.
So what happened between Voyager and Cassini? Blame it on Prometheus. The F ring circles Saturn at a delicate point called the Roche Limit. Any moons orbiting closer than the limit would be torn apart by Saturn’s gravitational force.
The culprit? Prometheus measures 74 miles (119 km) across and orbits the inner edge of Saturn’s F ring. Credit: NASA
“Material at this distance from Saturn can’t decide whether it wants to remain as a ring or coalesce to form a moon,” said French. “Prometheus orbits just inside the F ring, and adds to the pandemonium by stirring up the ring particles, sometimes leading to the creation of moonlets, and sometimes leading to their destruction.”
Every 17 years the orbit of Prometheus aligns with the orbit of the F ring in a way that enhances its gravitational influence. The researchers think the alignment spurs the creation of lots of extra moonlets which then go crashing into the ring, creating bright clumps of material as they smash themselves to bits against other ring material.
Sounds like a terrifying version of carnival bumper cars. In this scenario, the number of moonlets would gradually drop off until another favorable Prometheus alignment.
The Voyagers encounters with Saturn occurred a few years after the 1975 alignment between Prometheus and the F ring, and Cassini was present for the 2009 alignment. Assuming Prometheus has been “working” to build new moons since 2009, we should see the F ring light up once again with bright clumps in the next couple years.
