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Space News Update — September 18, 2015 —

Contents

In the News

Story 1: Pluto ‘Wows’ in Spectacular New Backlit Panorama

Story 2: Orion spacecraft may not fly with astronauts until 2023

Story 3: Cassini Finds Global Ocean in Saturn's Moon Enceladus

Departments

The Night Sky

ISS Sighting Opportunities

Space Calendar

NASA-TV Highlights

Food for Thought

Space Image of the Week

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1. Pluto ‘Wows’ in Spectacular New Backlit Panorama

The latest images from NASA’s New Horizons spacecraft have scientists stunned – not only for their breathtaking views of Pluto’s majestic icy mountains, streams of frozen nitrogen and haunting low-lying hazes, but also for their strangely familiar, arctic look.

This new view of Pluto’s crescent -- taken by New Horizons’ wide-angle Ralph/Multispectral Visual Imaging Camera (MVIC) on July 14 and downlinked to Earth on Sept. 13 -- offers an oblique look across Plutonian landscapes with dramatic backlighting from the sun. It spectacularly highlights Pluto’s varied terrains and extended atmosphere. The scene measures 780 miles (1,250 kilometers) across.

“This image really makes you feel you are there, at Pluto, surveying the landscape for yourself,” said New Horizons Principal Investigator Alan Stern, of the Southwest Research Institute, Boulder, Colorado. “But this image is also a scientific bonanza, revealing new details about Pluto’s atmosphere, mountains, glaciers and plains.”

Owing to its favorable backlighting and high resolution, this MVIC image also reveals new details of hazes throughout Pluto’s tenuous but extended nitrogen atmosphere. The image shows more than a dozen thin haze layers extending from near the ground to at least 60 miles (100 kilometers) above the surface. In addition, the image reveals at least one bank of fog-like, low-lying haze illuminated by the setting sun against Pluto’s dark side, raked by shadows from nearby mountains.

"In addition to being visually stunning, these low-lying hazes hint at the weather changing from day to day on Pluto, just like it does here on Earth," said Will Grundy, lead of the New Horizons Composition team from Lowell Observatory, Flagstaff, Arizona.

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Combined with other recently downloaded pictures, this new image also provides evidence for a remarkably Earth-like “hydrological” cycle on Pluto – but involving soft and exotic ices, including nitrogen, rather than water ice.

Bright areas east of the vast icy plain informally named Sputnik Planum appear to have been blanketed by these ices, which may have evaporated from the surface of Sputnik and then been redeposited to the east. The new Ralph imager panorama also reveals glaciers flowing back into Sputnik Planum from this blanketed region; these features are similar to the frozen streams on the margins of ice caps on Greenland and Antarctica.

"We did not expect to find hints of a nitrogen-based glacial cycle on Pluto operating in the frigid conditions of the outer solar system,” said Alan Howard, a member of the mission’s Geology, Geophysics and Imaging team from the University of Virginia, Charlottesville. “Driven by dim sunlight, this would be directly comparable to the hydrological cycle that feeds ice caps on Earth, where water is evaporated from the oceans, falls as snow, and returns to the seas through glacial flow.”

“Pluto is surprisingly Earth-like in this regard,” added Stern, “and no one predicted it.”

Source: NASA Return to Contents

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2. Orion spacecraft may not fly with astronauts until 2023

The first piloted flight of NASA’s Orion space capsule, a vehicle designed to carry astronauts away from Earth for the first time in two generations, may slip from 2021 to 2023, agency officials said Wednesday.

A thorough review of the program in recent weeks highlighted risks that threaten the crewed flight’s target launch date in August 2021, and managers concluded the mission is likely to fly some time later.

NASA officials set April 2023 as the timeframe when they expect the Orion spacecraft to be ready to host humans on a flight around the moon.

“The team is going to continue to work toward the August 2021 date, but we’re committing that we’ll be no later than April 2023,” said Robert Lightfoot, NASA’s associate administrator. “I saw no reason this early in the process to change that ‘working to’ date for the team, and neither did the standing review board.”

Lightfoot said an April 2023 launch for the first Orion mission with astronauts is achievable with 70 percent confidence, keeping with NASA’s policy.

NASA did not run models to calculate a confidence level for the flight’s target launch date in 2021, but “it’s not a very high confidence level, I’ll tell you that, just because of the things we see historically pop up,” Lightfoot said.

The Orion spacecraft, designed to host four astronauts for up to 21 days in deep space, will blast off on top of NASA’s Space Launch System, a huge rocket in development borrowing propulsion and technologies from the retired space shuttle program.

A test flight of the heavy-lift launcher and the Orion capsule without a crew, called Exploration Mission-1, remains on track for late 2018, Lightfoot said, but will undergo another review later this year. The Exploration Mission-2 flight, now targeted for no later than April 2023, is the program’s first space shot with astronauts aboard.

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The Orion program’s confirmation review, held at NASA Headquarters in Washington with participation from an independent board, also set a budget to take the spacecraft through its first piloted mission.

NASA says it needs another $6.77 billion to complete development of Orion through 2023, atop $10.5 billion spent on the spacecraft since the project dawned with the Constellation program, an initiative started in 2005 under the Bush administration.

That brings the program’s total projected cost to more than $17 billion through the first flight with astronauts. The Space Launch System budget is forecast to be more than $7 billion from early 2014 through the first demonstration launch in 2018.

Bill Gerstenmaier, head of NASA’s directorate responsible for human exploration and operations, said the Orion project is making “solid technical progress” after a successful orbital test flight in December 2014.

Technicians at NASA’s Michoud Assembly Facility in New Orleans have started welding the pressure shell for the next Orion vehicle, which will fly in 2018 on its next uncrewed test flight. NASA will deliver the capsule’s basic structure to the Kennedy Space Center in Florida early next year for final assembly, outfitting and testing.

Reviewers charged with measuring the progress of the Orion program raised concerns about NASA’s plans to reuse hardware on multiple flights of the capsule, software development efforts, and structural testing, officials said.

NASA and Lockheed Martin, the agency’s prime contractor for Orion, plan to take key avionics boxes from the EM-1 Orion capsule and reuse them for EM-2.

“The intent right now is to refly those boxes on EM-2,” Gerstenmaier said. “The concern is if you have any kind of problem with the box on EM-1, and it’s not available for EM-2, you could run into a problem where that impacts the build of EM-2.”

Lockheed Martin is currently under contract to deliver three complete Orion crew capsules, including the vehicle flown on the EFT-1 demo flight in 2014 and spacecraft for EM-1 and EM-2.

“Right now, we’re not seeing any issues in those areas, but we have to account for those because we’ve got a lot of runway in front of us,” Lightfoot said.

“I think we’re being somewhat conservative,” Gerstenmaier said in a conference call with reporters Wednesday. “My teams will tell you that they’re trying to retire every risk out there.”

“Each times these guys hit a milestone in their testing and their predictions, we either retire risk or actually realize it,” Lightfoot told reporters.

Gerstenmaier gave high marks to engineers working on a redesign of Orion’s heat shield. Instead of installing the thermal shell on to the capsule in one monolithic piece, technicians will bolt on the Avcoat ablative heat shield in blocks for future flights.

It is a lesson learned by engineers after it took ground crews longer than planned to fabricate and install the heat shield for the EFT-1 test flight last year, in which a Delta 4-Heavy rocket lofted the capsule on a trajectory 3,600 miles above Earth in a major test of the craft’s thermal protection system and guidance, navigation and control algorithms.

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“We are making a heat shield change, but the engineering test article for that heat shield is already going to be complete by the end of this month, so that’s moving at a very good pace moving forward,” Gerstenmaier said.

Another potential problem area identified by the review board involved the European-built service module for Orion. NASA cinched an agreement with the European Space Agency in early 2013 to supply the power and propulsion unit for the EM-1 robotic test flight in 2018.

ESA and its service module contractor, Airbus Defense and Space, are working on the component with technologies derived from Europe’s Automated Transfer Vehicle, which made five successful supply deliveries to the International Space Station before its retirement earlier this year.

The service module’s schedule is at the top of the list of threats that could delay the EM-1 test flight in 2018, according to Bill Hill, NASA’s deputy associate administrator for exploration systems.

But the concerns coming out of the Orion confirmation review focused on NASA’s plans for the service module for EM-2. NASA and ESA have not agreed on whether Europe will contribute a full-up service module for Orion’s first crewed mission.

“We’ve got the first (European service module) coming in for EM-1, and what we learn from EM-1 actually feeds into what happens for EM-2,” Lightfoot said.

The Exploration Mission-1 flight plan calls for the Orion module and its four-person crew to go into a distant retrograde orbit about 44,000 miles from the moon for a mission lasting up to three weeks.

“We use EM-1 to check out the service module to make sure we can do the burns in and and out of the distrant retrograde orbit around the moon,” Gerstenmaier said. “We’ll make sure the communications systems work, we’ll make sure the navigation stuff works, (and) we’ll make sure all the software works.

“Then comes EM-2, and the big thing there is the crew interfaces,” Gerstenmaier said. “How does the crew interact with the vehicle? What are the displays and controls like? What do they do during entry configuration?”

EM-2 also introduces Orion’s life support systems, such as oxygen supplies, devices to scrub carbon dioxide out of the atmosphere, plus temperature and humidity controls, according to Gerstenmaier.

It is unlikely the EM-2 crew will rendezvous with an asteroid as part of NASA’s asteroid retrieval mission, an initiative to send out a robotic space probe to tow a small rock back into lunar orbit for human visits, according to Gerstenmaier. That mission, if approved by Congress, will come later.

Gerstenmaier said NASA plans to launch an SLS/Orion mission once per year after EM-2, assuming budgets allow. Later missions in a region around the moon dubbed “cis-lunar space” may test out rendezvous techniques, spacewalks, asteroid docking, and in-space habitats to prove out technologies required for Mars missions.

“It’s important to note that we are building a big program,” Lightfoot said. “We’re building a multi-decadal human exploration program, and while the individual launches of EM-1 and EM-2 are very important, and they are great indicators of our progress and how we’re doing, we’ve got to balance those individual missions with the overall context of this exploration journey we’re on.”

Source: Spaceflight Now Return to Contents

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3. Cassini Finds Global Ocean in Saturn's Moon Enceladus

A global ocean lies beneath the icy crust of Saturn's geologically active moon Enceladus, according to new research using data from NASA's Cassini mission.

Researchers found the magnitude of the moon's very slight wobble, as it orbits Saturn, can only be accounted for if its outer ice shell is not frozen solid to its interior, meaning a global ocean must be present.

The finding implies the fine spray of water vapor, icy particles and simple organic molecules Cassini has observed coming from fractures near the moon's south pole is being fed by this vast liquid water reservoir. The research is presented in a paper published online this week in the journal Icarus.

Previous analysis of Cassini data suggested the presence of a lens-shaped body of water, or sea, underlying the moon's south polar region. However, gravity data collected during the spacecraft's several close passes over the south polar region lent support to the possibility the sea might be global. The new results -- derived using an independent line of evidence based on Cassini's images -- confirm this to be the case.

"This was a hard problem that required years of observations, and calculations involving a diverse collection of disciplines, but we are confident we finally got it right," said Peter Thomas, a Cassini imaging team member at Cornell University, Ithaca, New York, and lead author of the paper.

Cassini scientists analyzed more than seven years' worth of images of Enceladus taken by the spacecraft, which has been orbiting Saturn since mid-2004. They carefully mapped the positions of features on Enceladus -- mostly craters -- across hundreds of images, in order to measure changes in the moon's rotation with extreme precision.

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As a result, they found Enceladus has a tiny, but measurable wobble as it orbits Saturn. Because the icy moon is not perfectly spherical -- and because it goes slightly faster and slower during different portions of its orbit around Saturn -- the giant planet subtly rocks Enceladus back and forth as it rotates.

The team plugged their measurement of the wobble, called a libration, into different models for how Enceladus might be arranged on the inside, including ones in which the moon was frozen from surface to core.

"If the surface and core were rigidly connected, the core would provide so much dead weight the wobble would be far smaller than we observe it to be," said Matthew Tiscareno, a Cassini participating scientist at the SETI Institute, Mountain View, California, and a co-author of the paper. "This proves that there must be a global layer of liquid separating the surface from the core."

The mechanisms that might have prevented Enceladus' ocean from freezing remain a mystery. Thomas and colleagues suggest a few ideas for future study that might help resolve the question, including the surprising possibility that tidal forces due to Saturn's gravity could be generating much more heat within Enceladus than previously thought.

"This is a major step beyond what we understood about this moon before, and it demonstrates the kind of deep-dive discoveries we can make with long-lived orbiter missions to other planets," said co-author Carolyn Porco, Cassini imaging team lead at Space Science Institute, Boulder, Colorado, and visiting scholar at the University of California, Berkeley. "Cassini has been exemplary in this regard."

The unfolding story of Enceladus has been one of the great triumphs of Cassini's long mission at Saturn. Scientists first detected signs of the moon's icy plume in early 2005, and followed up with a series of discoveries about the material gushing from warm fractures near its south pole. They announced strong evidence for a regional sea in 2014, and more recently, in 2015, they shared results that suggest hydrothermal activity is taking place on the ocean floor.

Cassini is scheduled to make a close flyby of Enceladus on Oct. 28, in the mission's deepest-ever dive through the moon's active plume of icy material. The spacecraft will pass a mere 30 miles (49 kilometers) above the moon's surface.

Source: JPL Return to Contents

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The Night Sky Friday, September 18

As twilight fades, look low in the southwest for Saturn close to the waxing crescent Moon, as shown here. To their left are Antares and other stars of upper Scorpius.

Saturday, September 19

The crescent Moon at dusk now forms a triangle with Antares below it and Saturn to their right, as shown here.

Sunday, September 20

This is the time of year when, during the evening, the dim Little Dipper in the north "dumps water" into the bowl of the Big Dipper way down below it. The Big Dipper dumps it back in the evenings of spring.

Monday, September 21

First-quarter Moon (exact at 4:59 a.m. Monday morning EDT). This evening the Moon shines above the Teapot of Sagittarius. At this time of year, the Teapot is tipping increasingly far over, as if pouring out the last of summer.

Tuesday, September 22

The eclipsing binary star Algol should be at minimum brightness, magnitude 3.4 instead of its usual 2.1, for a couple hours centered on 9:20 p.m. EDT according to Algol's recently updated schedule.

Source: Sky & Telescope Return to Contents

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ISS Sighting Opportunities

Date Visible Max Height Appears Disappears

Fri Sep 18, 4:56 AM 1 min 12° 11 above NNW 10 above N

Sat Sep 19, 5:40 AM 1 min 10° 10 above N 10 above NNE

Sun Sep 20, 4:48 AM 1 min 10° 10 above N 10 above N

Sun Sep 20, 6:24 AM < 1 min 12° 10 above NNW 12 above NNW

Mon Sep 21, 5:32 AM 3 min 12° 10 above NNW 10 above NE

Tue Sep 22, 4:40 AM 1 min 11° 10 above N 10 above NNE

Tue Sep 22, 6:16 AM 3 min 25° 11 above NNW 24 above NE

Sighting information for other cities can be found at NASA’s Satellite Sighting Information

NASA-TV Highlights (all times Eastern Daylight Time)

1 p.m., Friday, September 18 - Replay of “The Martian” to the Real Martians: Science Fiction to Science Fact on NASA’s Journey to Mars – a Discussion with NASA Leaders, Scientists, Engineers and Andy Weir the Author of “The Martian” (all channels)

2 p.m., Friday, September 18 - Replay of NASA’s Digital Learning Network Presents a Discussion on Surviving & Thriving on MARS with Author of “The Martian” Andy Weir Network (all channels)

Watch NASA TV on the Net by going to the NASA website. Return to Contents

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Space Calendar • Sep 18 - Comet P/1999 XN120 (Catalina) Closest Approach To Earth (3.112 AU) • Sep 18 - Comet 282P/2003 BM80 At Opposition (3.638 AU) • Sep 18 - Comet C/2015 B1 (PANSTARRS) Perihelion (5.976 AU) • Sep 18 - Asteroid 742 Edisona Closest Approach To Earth (1.678 AU) • Sep 18 - 50th Anniversary (1965), 1st Episode of "I Dream of Jeannie" Airs on TV

• Sep 19 - [Sep 12] Astronomy Day • Sep 19 - International Observe the Moon Night • Sep 19 - LilacSat 2/Tiantuo-3/ XW-2/ ZDPS 2A & 2B CZ-6 Launch • Sep 19 - Comet 34D/Gale At Opposition (0.828 AU) • Sep 19 - Comet C/2013 P3 (Palomar) At Opposition (7.847 AU) • Sep 19 - Asteroid 8277 Machu-Picchu Closest Approach To Earth (1.618 AU) • Sep 19 - Asteroid 6136 Gryphon Closest Approach To Earth (2.057 AU) • Sep 19 - Griffith Observatory Star Party, Los Angeles, California • Sep 19 - Sunita Williams' 50th Birthday (1965) • Sep 20 - Comet 144P/Kushida Closest Approach To Earth (2.513 AU) • Sep 20 - Comet 212P/NEAT At Opposition (2.535 AU) • Sep 20 - Asteroid 51828 Ilanramon Closest Approach To Earth (1.742 AU) • Sep 20 - 65th Anniversary (1950), Murray Meteorite Fall (Hit Buildings in Kentucky) • Sep 21 - Comet P/2015 P4 (PANSTARRS) Closest Approach To Earth (1.734 AU) • Sep 21 - Comet 7P/Pons-Winnecke Closest Approach To Earth (1.915 AU) • Sep 21 - Comet C/2014 XB8 (PANSTARRS) Closest Approach To Earth (2.505 AU) • Sep 21 - Comet C/2014 W8 (PANSTARRS) Perihelion (4.910 AU) • Sep 21 - Centaur Object 10199 Chariklo Occults UCAC4-274-115943 (14.9 Magnitude Star) • Sep 21 - Aten Asteroid 2007 TD Near-Earth Flyby (0.077 AU) • Sep 21 - Asteroid 99905 Jeffgrossman Closest Approach To Earth (2.334 AU) • Sep 21 - Kuiper Belt Object 308933 (2006 SQ372) At Opposition (25.707 AU) • Sep 21 - Kuiper Belt Object 2010 RE64 At Opposition (52.026 AU) • Sep 21 - Phobos and Deimos Webcast: The Age and Cratering History of Phobos and Deimos • Sep 22 - Comet 227P/Catalina-LINEAR At Opposition (3.434 AU) • Sep 22 - Asteroid 70715 Allancheuvront Closest Approach To Earth (1.551 AU) • Sep 22 - Kuiper Belt Object 120347 Salacia At Opposition (43.654 AU)

Source: JPL Space Calendar Return to Contents

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Food for Thought

New Evidence for Black Hole Binary

Astronomers have confirmed that the quasar PG 1302-102 is probably a binary supermassive black hole, its members less than a tenth of a light-year apart.

Black holes are fickle. Their emission is often unpredictable, especially for the gargantuan ones that sit munching on gas disks in galactic centers. That’s why it was so odd earlier this year when Matthew Graham (Caltech) and colleagues found 20 of these quasars glowing with a regular beat. (They later upped the tally to 111.)

The best explanation for this periodic behavior, the team argued, was that these quasars are actually doubles: two supermassive black holes inexorably spiraling in toward each other. The time between repeated signals — in this case, on the order of several years — would then be the time it took for the black holes to orbit each other once. Analyzing the cleanest-looking of the lot, PG 1302-102, Graham’s team estimated that the black holes were less than a tenth of a light-year apart.

But the scientists didn’t know why the periodicity existed. They had several ideas — such as wobbly jets or warped accretion disks — and all of them required a binary black hole. But the team didn’t know which solution was correct.

So Daniel D’Orazio (Columbia University) and colleagues decided to take a computational whack at explaining PG 1302-102’s beat. They realized that, if a smaller black hole was circling a larger one, we would see what’s called a Doppler boost in the quasar’s emission.

Doppler shifts are common phenomena in astronomy. The Doppler shift is the change in light’s (or sound’s) wavelength because its source is moving toward or away from you. (The classic example is the ambulance siren that sounds higher pitched when the ambulance is racing towards you and lower pitched when it’s zooming away.) Light shifts to bluer (shorter) wavelengths when the star, planet, or whatchamacallit is moving toward us along our line of sight, and to redder (longer) wavelengths when it moves away.

Doppler boosting is the Doppler shift on steroids. With PG 1302-102’s black holes so close together, the smaller one is whipping around its big brother at 7% the speed of light — 22,000 km/s, or 49 million mph. That dramatically shifts the wavelength, by 14%. So if we’re observing the quasar at an optical wavelength of 600 nm, that means that when the smaller black hole is moving toward us, we’re actually seeing 700-nm light that’s been blueshifted, but when it’s moving away, we’re seeing 530-nm light that’s been redshifted.

If the quasar’s emission were the same intensity at all wavelengths, then we wouldn’t notice the difference. But it’s not: it increases as we move from optical to ultraviolet. So moving 14% up and down the wavelength

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scale samples different intensities, meaning that as the small black hole orbits, we’ll see a periodic change. The team reports the result in the September 17th Nature.

Graham agrees that the team’s scenario is a reasonable one. The team does have to make some assumptions, such as how close the system is to being edge on to our line of sight. But the nice thing is that the researchers make a specific prediction that can provide a thumb’s up or down for the theory.

That prediction says that PG 1302-102’s brightness variations ought to be more than twice as large at ultraviolet wavelengths as at optical ones. That’s because the quasar’s emission doesn’t just get more intense as we move from optical to ultraviolet; it also increases more rapidly in ultraviolet than in optical, explains study coauthor Zoltán Haiman (also Columbia). So if an optical wavelength shifts toward a shorter wavelength, we’ll see a bit of an increase in intensity, but if an ultraviolet wavelength shifts the same amount, we’ll see a greater increase in intensity.

The team compared PG 1302-102’s multiwavelength variations using archival spectra from the Hubble (optical) and Galaxy Evolution Explorer (GALEX, ultraviolet) space telescopes. The astronomers found the expected extra oomph in ultraviolet.

All-out confirmation will require simultaneous multiwavelength observations spanning longer time scales, but at least initially, the results do seem to confirm that a binary black hole exists in this quasar.

Source: Sky & Telescope Return to Contents

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Space Image of the Week

Pluto’s Majestic Mountains, Frozen Plains and Foggy Hazes

Couldn’t resist just one more Pluto image…

Just 15 minutes after its closest approach to Pluto on July 14, 2015, NASA’s New Horizons spacecraft looked back toward the sun and captured this near-sunset view of the rugged, icy mountains and flat ice plains extending to Pluto’s horizon. The smooth expanse of the informally named icy plain Sputnik Planum (right) is flanked to the west (left) by rugged mountains up to 11,000 feet (3,500 meters) high, including the informally named Norgay Montes in the foreground and Hillary Montes on the skyline. To the right, east of Sputnik, rougher terrain is cut by apparent glaciers. The backlighting highlights over a dozen layers of haze in Pluto’s tenuous but distended atmosphere. The image was taken from a distance of 11,000 miles (18,000 kilometers) to Pluto; the scene is 780 miles (1,250 kilometers) wide.

Source: NASA Return to Contents