Tuesday, September 11, 2012

Breached Levee at Tycho

Impact melt breached a levee to flow downhill on the terraced walls of Tycho. Downslope is toward image bottom, re-sampled from the roughly 500 meter-wide field of view seen in the LROC Featured Image released September 11, 2012, itself derived from LROC Narrow Angle Camera (NAC) observation M170634588L, spacecraft orbit 10280, September 14, 2011; angle of incidence 41.67° at 50 cm per pixel resolution, imaged from 45.9 kilometers [NASA/GSFC/Arizona State University].
Lillian Ostrach
LROC News System

The geology within and surrounding Tycho crater is nothing short of spectacular. LROC images have shown the beauty of Tycho's 2 km-tall central peak, the morphology of impact melt on the crater floor, and the complexity of the exterior impact melt flows. Today's Featured Image once again highlights a geologically fascinating impact melt flow located on a terrace of Tycho's northern wall (42.428°S, 349.190°E).

When substantial amounts of impact melt are generated during the impact process, evidence of ejected melt is observed in the form of exterior melt ponds and flows, as well as veneers and channels within the crater walls. Whether interior melt coalesces to form channels or flows on the crater walls depends on numerous factors, including the viscosity of the melt and the volume of melt distributed on the walls. As melt cools, it becomes more viscous and less prone to flow, and thin veneers of melt splashed on crater walls will cool very quickly compared to thick melt ponds. However, if lots of melt is splashed onto the crater walls, the melt may coalesce and take longer to cool, perhaps allowing flows to form with the increased volume of melt. Channels, however, are believed to require melts of higher temperature (low viscosity) in order to form levees and mechanically and/or thermally erode the terrain in which the channels form. Knowing this information, can you explain the impact melt morphology in the opening image?

LROC WAC (GLD100) monochrome mosaic draped over LOLA altimetry elevation data (128ppd, v.2) in LMMP ILIADS simulated perspective over Tycho crater (85 km diameter). Arrow notes location of field of view shown at high-resolution in LROC Featured Image released September 11, 2012. View original LROC WAC context image HERE [NASA/GSFC/Arizona State University].
The opening image is an area on the northern terraced wall of Tycho that is covered in impact melt. Since Tycho wasn't formed yesterday, a thin regolith layer covers the melt (created by small impacts and micrometeorite impact gardening) and there are boulders eroding out of the slope. Cracks, softened by the thin regolith, abound in this region, and probably represent cooling cracks. There is a levee-like feature winding from the upper left to the lower right that probably was formed by impact melt that coalesced and flowed down the interior walls, essentially representing the flow boundary. However, a tongue-like flow obscures a portion of the levee-like boundary. Assuming that a large volume of melt was channelized where the inside of the channel was toward the right side of the opening image, this late-stage small flow (or drip) bypassed the leveed wall on its descent toward the crater floor. Where did the material composing the small flow come from? Perhaps some melt from the surrounding walls flowed toward the levee-like boundary but got "stuck" and pooled on the top portion of the levee, until the weight of material overcame the levee barrier. Or maybe the tongue-like flow represents a late-stage splash of melt that was ejected and then landed on the wall to drip down toward the crater floor.

What do you think? Scour the full LROC NAC image, HERE, and see what other impact melt morphologies you can find!

Related Posts:

Marshall's new-generation lunar lander flies again

Overcast skies didn't deter the "Mighty Eagle," flying high above the historic F-1 test stand, once used to test turbopumps for the Saturn booster first stage engines [NASA/MSFC/Dennis Olive].
Long under development, completing a round of flight test objectives, following up on a successful August 28 pre-programmed flight profile test, the "Mighty Eagle," NASA robotic prototype lunar lander, flew to 30.48 meters (100 feet) and descended gently to a controlled landing during a successful free flight September 5 at NASA's Marshall Space Flight Center (MSFC) in Huntsville, Alabama.

Guided by autonomous rendezvous and capture software, the vehicle located an on-ground target using an on-board camera and then flew directly to the target on its own. 

The flight of August 28 followed a pre-programmed flight profile, but the test on September 5 operated "closed loop," with the vehicle seeking and finding its target using internal software to guide its flight.

"The ‘Mighty Eagle’ had a great flight, fulfilling the objectives we had for this test -- finding and landing on its target using a closed-loop system," said Greg Chavers, test lead for the project. "Given this is one of our last tests in this series, it is a worthy finale of a lot of people’s hard work -- including our young engineers. They did a remarkable job running today’s flight."

New for this test, the "Mighty Eagle" project managers turned over the vehicle’s keys to three young Marshall engineers, Adam Lacock, flight manager; Jake Parton, test conductor; and Logan Kennedy, systems engineer.

Nicknamed the "Mighty Eagle" after one of the characters in the popular "Angry Birds" game, the vehicle is a three-legged prototype that resembles an actual flight lander design. It is 4 feet tall and 8 feet in diameter and, when fueled, weighs 700 pounds. It is a “green” vehicle, fueled by 90 percent pure hydrogen peroxide The vehicle is guided by an on-board computer that activates thrusters to power the craft’s movements.

"We’ve surpassed our expectations and flew the most challenging run to date," said Mike Hannan, a controls engineer in Marshall's Engineering Directorate. "It was an overcast, extremely humid day, and we were concerned steam might block the vehicle’s camera. We didn’t see that, and the lander sought and found its target successfully."

"It was an invaluable experience managing today’s test,” added Lacock. "This is the kind of experience young engineers, like myself, need to learn more about flight mechanics, vehicle hardware and project management. It was a good day for our team."

NASA will use the "Mighty Eagle" to mature the technology needed to develop a new generation of small, smart, versatile robotic landers capable of achieving scientific and exploration goals on the surface of the moon, asteroids or other airless bodies.

The "Mighty Eagle" was developed by the Marshall Center and Johns Hopkins University Applied Physics Laboratory in Laurel, Md., for NASA’s Planetary Sciences Division, Headquarters Science Mission Directorate. Key partners in this project include the Von Braun Center for Science and Innovation, which includes the Science Applications International Corporation, Dynetics Corp., and Teledyne Brown Engineering Inc., all of Huntsville.

Related and Background Posts:
Mighty Eagle lander 100 foot flight at Redstone (November 4, 2011)
New Robotic Lander Prototype skates tests (January 29, 2011)
NASA update; ILN Anchor Nodes and Robotic Lunar Lander Project (August 17, 2010)
The Lunar Quest Program and the International Lunar Network (September 6, 2009)

ILOA to study deep space from Chang'e-3

Steve Durst, founding director of ILOA, and Jun Yan, Director General of NAOC, after signing Memorandum of Understanding for collaboration on galaxy imaging from Chang'e-3 on the lunar surface [ILOA].
Keith Stein
DC Space News Examiner

The International Lunar Observatory Association (ILOA) in Hawaii has signed a Memorandum of Understanding with the National Astronomical Observatories (NAOC), Chinese Academy of Sciences, to use a telescope on China‘s Chang'e-3 lunar lander, still planned for launch in 2013.

The MOU was signed during a ceremony that took place in Kamuela, Hawaii on Sept. 4.

“This science collaboration will be part of a mission that will conduct the first soft controlled landing of any spacecraft on the Moon in almost 40 years” the ILOA said in a statement on Friday.

"It will be the first ever program to conduct astronomical imaging from the lunar surface." ILOA Founding Director Steve Durst noted.

China’s NAOC is responsible for the ultraviolet lunar telescope onboard the Chang'e-3 lander, which will be operated by the China National Space Administration (CNSA).

Related Posts:
Remote-operated Moon-based deep space telescope concept demonstrated in Hawai'i (July 26, 2012)
Will China deploy first lunar rover since 1976? (April 30, 2012)
SpaceDev flies prototype hybrid rocket lunar lander (December 20, 2007)

Other Chang'E-3 Related Posts, HERE.

Chang'e-3 lunar lander - stationary science platform illustrated together with planned remote-operated lunar rover may be deployed at Sinus Iridum in 2013 [Lunar Pioneer].

2012 Geological Society of America, Annual Meeting & Exposition, Charlotte, NC - 4-7 November


New Moon Rising: The Latest Geologic Results from the Lunar Surface
Charlotte Convention Center: 213BC
8:00 AM-12:00 PM, Wednesday, 7 November 2012

Paper No. 224-15: LUNAR ORIENTALE BASIN: A COMPREHENSIVE CONCEPTUAL MODEL FOR THE ORIGIN OF BASIN RINGS AND GEOLOGICAL UNITS FROM NEW SPACECRAFT DATA -- James HEAD, David M.H. BAKER, Gregory A. NEUMANN, David E SMITH, Maria T. ZUBER, and William M. VAUGHAN

Paper No. 224-6: TESTING HYPOTHESES OF ORIGIN FOR LUNAR FLOOR-FRACTURED CRATERS: VISCOUS RELAXATION VERSUS MAGMATIC INTRUSION AND PREDICTIONS OF ASSOCIATED GRAVITY ANOMALIES -- Lauren JOZWIAK, James W. HEAD, Maria T. ZUBER, David E. SMITH, David E. and Gregory NEUMANN

Paper No. 224-1: EXPLORING THE MOON WITH LRO: CHARACTERIZING VOLCANISM ON THE LUNAR SURFACE -- Samuel J. LAWRENCE, B.L. JOLLIFF, Timothy GLOTCH, B. Ray HAWKE, Benjamin T. GREENHAGEN, Julie STOPAR, Mark ROBINSON, W. Brent GARRY, and J. Olaf GUSTAFSON

Paper No. 224-14: CONSTRUCTION AND EROSION IN THE FORMATION OF LUNAR SINUOUS RILLES -- Tracy GREGG, Carolyn ROBERTS, and R. Aileen YINGST

Paper No. 103-5: CHARACTERISTICS OF SMALL-SCALE GRABEN ON THE MOON DISCOVERED BY THE LUNAR RECONNAISSANCE ORBITER CAMERA (LROC) -- Renee FRENCH, Craig BINA, Mark ROBINSON, and Donna M. JURDY



Paper No. 224-9: LRO DIVINER LUNAR RADIOMETER EXPERIMENT RESULTS -- David Paige

Paper No. 202-6: STATISTICS OF SMALL LUNAR CRATERS: ORIGIN OF DIFFERENCES BETWEEN IMPACT MELT AND EJECTA UNITS -- Carolyn H. VAN DER BOGERT, Harald HIESINGER, Colin DUNDAS, Lillian OSTRACH, Mark ROBINSON, Alfred MCEWEN, and Michael ZANETTI


Canadian Lunar Exploration Light Rover prototype

Stylized View of the Lunar Exploration Light Rover (LELR) Design, Figure 3 from "A Canadian Lunar Exploration Light Rover Prototype," McCoubry & Langley, et al, (Sept. 2012).
McCoubrey & Langley, et al
MacDonald, Dettwiler, and Associates, CANADA
Centre de technologies avancées BRP – Universite de Sherbrooke
University of Toronto Institute for Aerospace Studies

CANADA

In 2010, the Canadian Space Agency (CSA) commenced the Lunar Exploration Light Rover (LELR) project as part of its Exploration Surface Mobility program. The LELR project consists of building rovers, integrating them with tools and instruments, and executing representative mission deployments. The LELR is designed for mobility tasks related to science prospecting, in-situ resource utilization (ISRU), and future upgrades for crew transportation. The vehicle is based on a rugged, custom mobility platform built by Bombardier Recreational Products Centre for Advanced Technology.

Onboard sensors provide feedback and situational awareness for tele-operation, autonomy, and onboard control (future upgrade). Modular onboard software is used to ensure future upgradeability, and offers such features as localization without external aids and visual teach and repeat software developed by the University of Toronto. Future work may involve adding onboard human control, further integration with payloads and deployments in coordination with the international space exploration community.

Figure 2: "Artist’s Concept of the Lunar Exploration Light Rover’s Various Mission Configurations."
In the context of returning systems to the surface of the Moon, there have been several recent developments in the area of Lunar mobility. The Chariot rover is a large-class system designed to carry astronauts and perform regolith moving tasks such as bulldozing. The Eurobot Ground Prototype (EGP) rover is a medium-class system designed to accomplish both science exploration and transport of a single standing astronaut. The Scarab rover is a small-class rover designed to carry resource prospecting instruments and sensors. The goal of the Lunar Exploration Rover (LELR) program is to develop a mobility solution that can accomplish all of these tasks and thereby provide a flexible and versatile platform for development and testing including integration with exploration tools and instruments. This will then allow development and simulation of analogue mission scenarios. The LELR vehicle is a key part of the Canadian Space Agency (CSA) Exploration Surface Mobility program.

The remainder of this paper will discuss the mission scenarios used to define the LELR requirements, the LELR design, and the current program status and upcoming test plan.

View the full paper, HERE.

Some Related Posts

Monday, September 10, 2012

LROC: Boulder or Crater?

A roughly circular feature near Albufeda E, in the Moon's nearside southern highlands. A 140 meter-wide field of view from LROC Narrow Angle Camera (NAC) observation M175212953R, LRO orbit 10955, November 6, 2011; angle of incidence 44.11° at 40 cm per pixel resolution from 24.26 km overhead [NASA/GSFC/Arizona State University].
Sarah Braden
LROC News System

At first glance, the object in the center of today's Featured Image may look like a crater. The direction of illumination is from the right-to-left. What may look like a crater is actually a boulder about 29 meters across, which is just one meter shy of the length of a blue whale!

The lighting in the image and the circular appearance of the boulder may initially fool the human eye into interpreting this feature as a crater. However, there are several important clues in the image which clearly indicate that we are indeed looking at a boulder. Click on the image for a full resolution version. First, notice the other smaller boulders in the image. These are identified as boulders because they are irregular in shape, and relatively higher reflectance compared to the surrounding impact melt. Next, look at the direction of the shadows of the boulders. The boulders are all positive topographic features and cast shadows in the same direction. In contrast, a crater is a negative topographic feature. Looking at the full resolution version of the Featured Image shows many small craters in the surrounding impact melt. Look at these craters and compare them to the boulders until your eyes interpret the boulders as topographic highs and the craters as lows. If you still have difficulty, pick up your laptop and rotate the image 180 degrees (rotating your head might be more convenient).

NASA LMMP ILIADS simulated perspective of the area of interest projected from a point 40 km over the Moon and 100 km east. LROC Wide Angle Camera WAC Global Mosaic (100m) draped over LOLA digital elevation model shows Abulfeda E and its larger neighbor Abulfeda A. The red asterisk marks the location of the area seen at exceptionally high resolution in the LROC Featured Image released September 9, 2012 [NASA/GSFC/Arizona State University].
This field of boulders is located on the eastern side of the crater Abulfeda E, a Copernican-aged crater in the highlands, located at 16.769°S, 10.141°E and is 5.6 km in diameter. Many other large boulders are scattered around in the impact melt deposits surrounding the crater. Some of the boulders are partially buried by impact melt and debris.

Explore the entire NAC image HERE.

Related Posts:
"Boulder 668" at Descartes C
If you were an Astronaut, would you land here?
Weaving boulder trails on the Moon
Boulder on the Edge
Sunset Boulder
LROC QuickMap WAC-NAC mosaic of Albefuda E sampled at 8 meters resolution. From the WAC-derived and laser altimetry (LOLA)-derived DEM it appears the northeastern rim of Albefula E where the large boulder feature is situated (arrow), does not rise above the landscape, unlike an area further south, on the eastern slope,  where a large boulder field has accumulated [NASA/GSFC/Arizona State University].

Sunday, September 9, 2012

Free Enterprise and 'New Space'

Enterprise in space: Free markets or government subsidies?
Paul Spudis
The Once & Future Moon
Smithsonian Air & Space

Free Enterprise:  Business governed by the laws of supply and demand, not restrained by government interference, regulation or subsidy – also called free market.

Rick Tumlinson of the Space Frontier Foundation published a “free-enterprise” critique of the Republican platform in regard to the American civil space program. Indeed, the text of the space plank is vague (no doubt intentionally, so as to give the candidate maximum flexibility to structure the space program to align with his vision and goals for the country).  But what I found most interesting was the underlying premise and assumptions in Tumlinson’s article, a worldview that I find striking.

In brief, Tumlinson approves of the current administration’s direction for our civil space program.  The U.S. has stepped back from pushing toward the Moon, Mars and beyond and redirected NASA on a quest for “game-changing” technologies (to make spaceflight easier and less costly), while simultaneously transitioning launch to low Earth orbit (LEO) operations to private “commercial space” companies selected by our government to compete for research and development funding and contracts.  Many see this as gutting NASA and the U.S. national space program.  To be clear, the term “commercial space” in this context does not refer to the long-established commercial aerospace industry (e.g., Lockheed-Martin, Boeing) but to a collection of startup companies dubbed “New Space” (typically, companies founded by internet billionaires who have spoken much and often about lofty space plans, but have actually flown in space very little).

Tumlinson criticizes the Republican space plank because it does not explicitly declare that a new administration would continue the current policy.  In his view, the very idea of a federal government space program, including a NASA-developed and operated launch and flight system, is a throwback to 1960’s Cold War thinking.  Instead, he envisions space as a field for new, flexible and innovative companies, untainted by stodgy engineering traditions or bloated bureaucracy.  Many space advocates on the web hold this viewpoint – “If only government would get out of the way and give New Space a chance, there will be a renaissance in space travel!”  But travel to where?  And why?

The idea that LEO flight operations should be transitioned to the commercial sector is not new.  It was a recommendation of the 2004 Aldridge Commission report on implementing the Vision for Space Exploration (VSE).  NASA itself started the Commercial Orbital Transportation Services program (COTS) in 2006, designed to nurture a nascent spaceflight industry by offering subsidies to companies to develop and fly vehicles that could provision and exchange crew aboard the International Space Station.  That effort was envisioned as an adjunct to – not a replacement of – federal government spaceflight capability.

The termination of the VSE and the announcement of the “new direction” in space received high cover from the 2009 Augustine committee report, which concluded that the current “program of record” (e.g., Constellation) was unaffordable.  The Augustine Committee received presentations with options to reconfigure Constellation whereby America could have returned to the Moon (to learn how to use resources found in space) under the existing budgetary cap, but they elected to start from first principles.  Hence, we have something called Flexible Path, which doesn’t set a destination or a mission but calls on us “to develop technology” to go anywhere (unspecified) sometime in the future (also unspecified).  With target dates of 2025 for a “possible” human mission to a near-Earth asteroid and a trip to Mars “sometime in the 2030’s,” timelines and milestones for the Flexible Path offer no clarity or purpose.  Try getting a loan or finding investors using a “flexible” business plan.

Tumlinson argues that both political parties should embrace this new direction because New Space will create greater capability for lower cost sooner.  He also makes much about the philosophical inclinations of the Republican Party (the “conservative” major party in American politics) – Why don’t the Republicans support free enterprise in space?  Why are they putting obstacles in the way of all these new trailblazing entrepreneurs?  As to those obstacles, it is unclear exactly what they are.  True enough, there are regulatory and liability issues with private launch services, but not of such magnitude that they cannot be handled through the traditional means of indemnification (e.g., launch insurance).

The COTS program record of the past decade largely has not been a contract let for services, but a government grant for the technical development of launch vehicles and spacecraft.   Close reading reveals the real issue:  Tumlinson wants more of NASA’s shrinking budget to finance New Space companies. He is concerned that a new administration might cut off this flow of funding.  However, what will cut off the flow of funding is having no market, no direction, and no architectural commitment – regardless of who occupies the White House.

The belief of many New Space advocates is that once they are established to supply and crew the ISS, abundant and robust private commercial markets will emerge for their transportation services.  Although many possible services are envisioned, space tourism is the activity most often mentioned.  Whether such a market emerges is problematic.  Although Richard Branson’s Virgin Galactic has a back-listed manifest of dozens of people desiring a suborbital thrill ride (at a cost of a few hundred thousand dollars), those journeys are infinitely more affordable than a possible orbital trek (which will cost several tens of millions of dollars, at least initially).  Nevertheless, there will no doubt be takers for a ticket.  But what will happen to a commercial space tourism market after the first fatal accident?  New Space advocates often tout their indifference to danger, but such bravado is neither a common nor wise attitude in today’s lawsuit-happy society (not to mention, the inevitable loss of confidence from a limited customer base).  My opinion is that after the first major accident with loss of life, a nascent space tourism industry will become immersed in an avalanche of litigation and will probably fully or partly collapse under the ensuing financial burden.  We are no longer the barnstorming America of the 1920’s and spaceflight is much more difficult than aviation.

Despite labeling themselves “free marketers,” New Space (in its current configuration) looks no different than any other contractor furiously lobbying for government sponsorship through continuation of its subsidies.  True free-market capitalists do not seek government funding to develop a product.  Rather, they devise an answer to an unmet need, identify a market, seek investors and invest their own capital, provide a product or service and only remain viable by making a profit through the sale of their goods and services.

Tumlinson bemoans the attitude of some politicians, ascribing venal and petty motives as to why they do not fully embrace the administration’s new direction, e.g., the oft-thrown label “space pork” to describe support for NASA’s Space Launch System.  In regard to New Space companies, Tumlinson asserts that, “[We] have to both give them a chance and get out of the way.”  But in fact, he does not want government to “get out of the way” – at least not while they’re still shoveling millions into New Space company coffers – nor when they need (and they will) a ruling on, or protection of, their property rights in space.  Any entity that accepts government money is making a “deal with the devil,” whereby it is understood that such money comes with oversight requirements (as well it should, consisting of taxpayer dollars).

"Questions about the vision boil down to whether we want to incorporate the Solar System in our economic sphere, or not.” – Presidential Science Advisor John Marburger, 2006

Successful commercialization of space has occurred in the past (e.g., COMSAT) and will occur in the future.  But the creation of a select, subsidized, quasi-governmental industry is not by any stretch of the imagination what we commonly understand free market capitalism to mean.  It is more akin to oligarchical corporatism, a common feature of the post-Soviet, Russian economy.  True private sector space will be created and welcomed, but not through this mechanism, whose most worrisome accomplishment to date has been to effectively distract Americans from noticing the dismantling of their civil space program and preeminence in space.

Originally published at his Smithsonian Air & Space blog The Once and Future Moon, Dr. Spudis is a senior staff scientist at the Lunar and Planetary Institute. The opinions expressed are those of the author and are better informed than average.

Friday, September 7, 2012

LROC: America's last unmanned lunar lander

Surveyor 7, on the ejecta blanket of Tycho, the last of the Surveyor spacecraft (1967-1968), and the only one of the series to land in the lunar highlands. LROC Narrow Angle Camera NAC frame M175355093L, LRO orbit 10976, November 8, 2011; field of view is 500 meters across, viewed at the original scaled 43 cm per pixel resolution at an illumination incidence angle of 56.22° Inset, from the LROC Featured Image released September 7, 2012, is enlarged 4x [NASA/GSFC/Arizona State University].
Ryan Clegg
LROC News System

Surveyor 7 landed in the lunar highlands (40.980°S, 348.486°E) on 10 January 1968, on an impact-melt coated ejecta blanket 46.6 km (29 miles) north of the rim of Tycho Crater. The last spacecraft of the Surveyor series, it was sent to an area far from the mare in the southern highlands, in order to sample and analyze materials different from those of the other Surveyor missions. Surveyor 7 was the only Surveyor spacecraft to be sent to a region solely for scientific interest, rather than to obtain more data for the upcoming Apollo program, since program managers had decided that the previous Surveyor missions had already provided sufficient data to enable a safe Apollo landing. Results from the spacecraft’s alpha scattering detector showed that the highland crust is poorer in iron than the maria analyzed by the other Surveyors.

Landing site of Surveyor 7 captured at a higher angle of incidence (83.96°) and altitude (44.94 km),  in context with the prominent impact melt pond to the northeast, its intended landing site. LROC NAC observation M131724362L, spacecraft orbit 4545, June 21, 2010; resolution 50 cm [NASA/GSFC/Arizona State University].
Panorama of the Surveyor 7 landing site, taken by Surveyor 7 [NSSDC].

A total of 21,091 pictures were transmitted to Earth by Surveyor 7. One of the most stunning image sets is a photomosaic panorama of the landing site, which shows the rim of the 82-km diameter Tycho Crater on the horizon. On the surface of the Moon, as on Earth and elsewhere, impact craters are typically hidden from sight until you are standing right up on the rim. The Apollo 14 astronauts encountered this problem as well, when taking samples during a radial traverse of Cone crater. They lost sight of the crater rim during their traverse and eventually had to turn back before catching a glimpse of the interior of the crater in order to save enough oxygen for the journey back to the Lunar Module. LROC images (February 4, 2011, August 19, 2009) later confirmed that the crew came within 30 yards of the crater rim.

Surveyor 7 could only just make out the rim of Tycho Crater from its landing site. However, from an orbit of 50 km above the surface the panoramic view of the stunningly well preserved impact crater and its majestic central peaks is spectacular.

Simulated view from several kilometers above a point north of the Surveyor 7 (blue square) shows it's proximity with Tycho [NASA/LMMP/GSFC/Arizona State University].
The Surveyor missions not only provided critical engineering data that helped enable the safe Apollo landings that followed, but also showed that powered descent to the lunar surface was feasible and straightforward. Robotic precursor missions (such as automated sample return missions and in-situ resource utilization demonstrations) will undoubtedly play a similarly important role as we prepare for the seventh human lunar landing and beyond.

Be sure to explore the entire NAC frame (M175355093L) HERE. covering the Surveyor 7 site, and check out the central peaks of Tycho in the June 29, 2011 and May 21, 2012 Featured Images.

WAC context image of Tycho and the Surveyor 7 landing site [NASA/GSFC/Arizona State University].

Previous Posts Related to Surveyor 7:
LROC: Giant flow of Tycho impact melt (August 14, 2012)
Polygonal fractures on Tycho ejecta (June 15, 2011)
Surveyor 7 (February 12, 2011)
Surveyor 7: Our fragile lunar LDEF (October 27, 2010)
LOLA's Tycho and the Apollo era (March 28, 2010)

Related LROC Posts:
New View of Apollo 14
Trail of Discovery at Fra Mauro
Tycho Central Peak Spectacular!
View From The Other Side
Surveyor 1
Surveyor 3 and Apollo 12
Surveyor 5
Surveyor 6

Thursday, September 6, 2012

LROC: Pyroclastic Trails

Northeastern rim of unnamed crater 340 km southeast of Copernicus, among the Schröter and Gambart crater groups in Southern Sinus Aestuum (5.65°N, 8.71°W). A 612 meter-wide field of view from LROC Narrow Angle Camera (NAC) observation M144680787R, spacecraft orbit 6455, November 18, 2010; angle of incidence 49.39° at an original 50 cm per pixel resolution from 46.42 km. Downslope is to the bottom-right, view the original 1200 x 1200 LROC Featured Image HERE [NASA/GSFC/Arizona State University]
Hiroyuki Sato
LROC News System

The pyroclastic Southern Sinus Aestuum (5.42°N, 351.36°E) is famous for extensive dark mantle deposits (DMD), materials which have the lowest albedo (or highest optical maturity, or 'OMAT') on the Moon.

The DMD were likely formed as explosive eruptions threw out a blanket of small particles (pyroclasts).

Today's Featured Image shows a portion of unnamed crater rim located inside this DMD unit, about 2.4 km in diameter, with 4 or 5 dark streaks on its slope (see the crater's full profile in the NAC mosaic below).

The opening image highlights one of the sources for a dark streak. The right half of the image is the crater wall, and the left half is the surrounding flat area. The streak originates at nearly the top portion of the crater wall and extends down the slope. Notice that the streak is darker than the surrounding flat area some buried low reflectance materials were exposed on the middle of the slope and slid downhill.

Zoom out view of a mosaic of both the right and left frames of LROC NAC observation M144680787 (M144680787R and M144680787L). About a 3.93 km-wide field of view, sunlight from the east. Blue box indicates the location of the area shown in the LROC Featured Image released September 6, 2012. View the full size context image HERE [NASA/GSFC/Arizona State University].
Actually, the albedo around this unnamed crater is not as low as the main DMD area. The contrast is very, small but you can see a slightly higher albedo halo around the crater in the WAC context image. The dark streaks inside this crater all originate from almost the same level of the crater wall. Probably this unnamed crater excavated higher reflectance bedrock under the DMD, and spread it around the crater. Then the pyroclastic materials exposed in the wall (sandwiched between the bedrock and the ejecta) slumped down the crater wall leaving the dark streaks.

Careful investigations of the craters in the DMD by NAC images are quite useful to understand the thickness, the volume, and formation process of DMD. More and more NAC observations of DMD are expected. 

Southern Sinus Aestuum in context with Copernicus, 340 km away. Note dark streaks from rim to floor are also a feature of nearby Schröter D crater. LROC WAC monochrome mosaic (100 m/pix) centered on the subject unnamed crater (arrow), draped over LOLA altimetry data using the NASA LMMP ILIADS application  [NASA/LMMP/GSFC/Arizona State University].

Explore this pyroclastic slides by full NAC frame yourself, HERE.

Related Posts:
Dark streaks in Diophantus crater
Dark Craters on a Bright Ejecta Blanket
Alphonsus crater mantled floor fracture
Dark-haloed crater in Mare Humorum
Pyroclastic Excavation

Pyroclastic Southern Sinus Aestuum, including the unnamed crater of interest at center, as seen from Earth. 4100 x 5000 pixel Mosaic of the Moon captured by Astronominsk, August 8, 2012.

Wednesday, September 5, 2012

Pyroclastics and an unnamed Procellarum vent

Southern rim of an unnamed vent near Rimae Hevelius. This half-kilometer field of view from LROC Narrow Angle Camera (NAC) observation M137977638R, LRO orbit 5467, September 1, 2010; Resolution 0.5 meters from 45.55 km altitude [NASA/GSFC/Arizona State University].
Hiroyuki Sato
LROC News System

Today's Featured Image highlights a portion of an unnamed vent (0.80°S,  294.69°E), about 20 km south of Lohrmann D crater, that extends northwest to southeast and parallel to Rimae Hevelius.

The size of this vent is about 12.5 by 3 km.

Due to the surrounding relatively smooth and low albedo materials in this area (see WAC context image below), a volcanic eruption associated with pyroclastic deposits is suspected here.

Zoom out, showing the full 2.1 km width footprint of LROC NAC M137977638R. The blue box outlines the area included in the LROC Featured Image above [NASA/GSFC/Arizona State University].
As seen in the NAC zoom out view (above), there is a sharp boundary between the slope covered by relatively high reflectance materials and the dark, possibly pyroclastic materials at the top of the flat area surrounding the vent. The sharp boundary of the two different layers shows the stratigraphic bedding plane. Other rim portions of this vent were collapsed and the dark materials slid down the slope, so it is hard to recognize the bedding plane.

Estimating the volume of erupted dark material is, in theory, simple. First map the surface extent of the unit and then measure its thickness exposed in the vent wall. However in the opening image, you can see that it is hard to distinguish the actual top of the dark mantle because it has slumped into the vent, blurring the real edge.

In polar orbit, traveling north over western Oceanus Procellarum, Japan's lunar orbiter SELENE-1 (Kaguya) caught this view through it's HDTV camera in 2007. At southwest is the edges of mini-impact basin Grimaldi, with a ridge of highlands between it and the unnamed pyroclastic vent at the center of darker material, above center [JAXA/SELENE]..
Carrying the view further north, the vent can be seen in this simulated view at bottom center [NASA/LMMP/GSFC/Arizona State University].
A NAC DTM (high resolution digital terrain model from NAC stereo images) may provide a better estimate of the layer thickness and thus the volumes, by constructing a three dimensional surface model of the bedding plane. Also the depth, void volume, slope angles, and the layer structures of the vent will help to model the eruption mechanisms, which allows us to understand the ancient volcanic activities on the Moon.

For context, the unnamed vent and surrounding landmarks can are also seen in this LROC Wide Angle Camera (WAC) monochrome mosaic (100 m/pix), centered on 1.13°S, 295.09°E. The blue box outlines of full NAC frame [NASA/GSFC/Arizona State University].
Explore this unnamed volcanic vent by full NAC frame yourself, HERE.

Related Posts:
Pyroclastic Excavation
A Dark Cascade at Sulpicius Gallus
Rima Bode: Constellation region of interest
Alphonsus crater mantled floor fracture
Dark surface materials surrounding Rima Marius

View of the vent from 110 km (LROC NAC mosaic M181594956LR)
View of the vent from 25 km (LROC NAC mosaic M168631915LR)

From the LROC QuickMap , views of two better-known, very similarly shaped vents. Above, at 500 meters resolution, on the southwest side the Orientale basin is the north-south vent at center of the Rimae Focas  formation, with its "smoke ring" of darker material surrounding.  Below, a 16 meter resolution view of the Sulpicius Gallus vent of southwest Mare Serenitatis [NASA/GSFC/Arizona State University].

Tuesday, September 4, 2012

LROC: Dark Ejecta

Southwestern rim of crater Copernicus H (6.88°N, 341.68°E). A 930 meter-wide field of view from LROC Narrow Angle Camera observation NAC M186005514L, spacecraft orbit 12940, March 10, 2010; incidence angle is 10° at 0.93 meters per pixel resolution. View the 1000 px original LROC Featured Image HERE [NASA/GSFC/Arizona State University].
Hiroyuki Sato
LROC News System

Copernicus H (about 4.4 km in diameter, latitude 6.88°N, longitude 341.71°E) , a satellite crater of Copernicus crater, is located 56 km southeast of Copernicus (93 km diameter crater located in eastern Oceanus Procellarum). The opening image highlights a part of the Copernicus H crater rim (see blue square in the next image). The upper right portion of the image with bright/dark streaks corresponds to the crater wall, and the bottom left low reflectance part is the surrounding flat area. The low reflectance materials extend from the rim down the slope into the crater. What is the origin of these dark materials? Is the material mature soil? Impact melts? Pyroclastic deposits?

Zoomed out view of NAC M186005514L. Field of view about 5.7 km. Blue box indicates the location of today's Featured Image [NASA/GSFC/Arizona State University].
As seen in the subsampled NAC image (above) and WAC context image (below), the ejecta blanket of Copernicus H shows relatively lower reflectance than the surrounding area. Normally crater ejecta has a higher reflectance because the newly-exposed material is "immature" in a space-weathered sense. Notice that the crater floor is largely filled by lower reflectance impact melt, and the high reflectance materials extend radially from the floor to the crater rim. These brighter materials are the debris on the slope of the crater wall that are mass-wasting gravitationally toward the crater center.

Looking at the WAC context image below, it is likely that Copernicus H excavated some low reflectance materials underlying the ejecta of Copernicus. Several craters located at least 45 km away from the Copernicus rim also show similar dark ejecta. Therefore, the underlying dark material must be widely distributed. What might these materials be? Pyroclastic deposits at Southern Sinus Aestuum are located at about 90 km southeast of Copernicus H, and are underlying the Copernicus ejecta. If this layer is extensively distributed under the Copernicus ejecta, subsequent impacts with sufficient energy could have excavated the dark materials.

To unravel these complicated stratigraphic relations from orbit, accurate spectral data and an understanding of the effects of space weathering are necessary. New measurements from LRO, SELENE-1 (Kaguya), and Chandrayaan-1 are providing lunar scientists with the needed information!

Copernicus H and surrounding area in WAC monochrome mosaic (100 m/pix). Image center is 6.88°N, 341.73°E. The blue box indicates the footprint of full NAC frame [NASA/GSFC/Arizona State University].

Explore this dark ejecta in full LROC NAC image yourself, HERE.

Related Posts:
Dark Craters on a Bright Ejecta Blanket
Dark halo crater
Just Another Crater?
Dark Impact Melt Sheet
A Beautiful Impact
Pyroclastic Excavation

NASA ILIADS (LMMP) simulated mid-day point of view 40 km over the lunar surface southeast of Copernicus. Copernicus H and it's floor are at upper center in this compilation from LROC Global 100 meter resolution WAC mosaic with LOLA altimetry at 128 meters per pixel. The darker surface further southeast from Copernicus past Copernicus H is identified as a radioactive hotspot, with signatures of thorium and uranium in Lunar Prospector, SELENE and other surveys [NASA/GSFC/LMMP/Arizona State University].

Saturday, September 1, 2012

Mini-RF adds to evidence of ice on Shackleton walls

LRO Mini-RF instrument radar data indicate the walls of Shackleton crater may, indeed, hold ice, confirming exacting measurements of laser altimeter (LOLA) point brightness studies revealed in June. Actual observations (CPR) are compared to calculated radar values for 0.5% to 10% ice [NASA ].
Scientists using the Mini-RF radar on NASA's Lunar Reconnaissance Orbiter (LRO) have estimated the maximum amount of ice likely to be found inside a permanently shadowed lunar crater located near the moon's South Pole. As much as five to ten percent of material, by weight, could be patchy ice, according to the team of researchers led by Bradley Thomson at Boston University's Center for Remote Sensing, in Mass.

"These terrific results from the Mini-RF team contribute to the evolving story of water on the moon," says LRO's deputy project scientist, John Keller of NASA's Goddard Space Flight Center in Greenbelt, Md. "Several of the instruments on LRO have made unique contributions to this story, but only the radar penetrates beneath the surface to look for signatures of blocky ice deposits."

These are the first orbital radar measurements of Shackleton crater, a high-priority target for future exploration. The observations indicate an enhanced radar polarization signature, which is consistent with the presence of small amounts of ice in the rough inner wall slopes of the crater. Thomson and his colleagues reported the findings in a paper recently published in the journal Geophysical Research Letters.

"The interior of this crater lies in permanent shadow and is a 'cold trap'—a place cold enough to permit ice to accumulate," says Mini-RF's principal investigator, Ben Bussey of the Johns Hopkins University Applied Physics Laboratory in Laurel, Md. "The radar results are consistent with the interior of Shackleton containing a few percent ice mixed into the dry lunar soil."

Ice Station Zebra - an otherwise unofficially named small crater with a permanently shadowed interior not far from the Moon's north pole, within the crater Rozhdestvenskiy. Circular Polarization Ratio (CPR) values mapped using the Mini-RF radar instrument released in 2010 all but confirmed the presence of vast hectares of water ice, together with confirmation of a hydrogen signature at Goldschmidt, a lower center [NASA].
These findings support the long-recognized possibility that areas of permanent shadow inside polar impact craters are sites of the potential accumulation of water. Numerous lines of evidence from recent spacecraft observations have revised the view that the lunar surface is a completely dry, inhospitable landscape. Thin films of water and hydroxyl have been detected across the lunar surface using several space-borne near-infrared spectrometers. Additionally, orbital neutron measurements indicate elevated levels of near‐surface hydrogen in the polar regions; if in the form of water, this hydrogen would represent an average ice concentration of about 1.5% by weight in the polar regions.

The Shackleton findings are also consistent with those of the recent LCROSS spacecraft's controlled collision with a nearby permanently shadowed polar region near the lunar South Pole, which revealed evidence for water in the plume kicked up by its impact. A radar instrument flown on India's Chandrayaan-1 spacecraft in 2009 found evidence for ice deposits in craters at the lunar North Pole. Measurements of the albedo (surface reflectance) inside Shackleton crater using LRO's laser altimeter and far‐ultraviolet detector are also consistent with the presence of a small amount of ice.

"Inside the crater, we don't see evidence for glaciers like on Earth," says Thomson. "Glacial ice has a whopping radar signal, and these measurements reveal a much weaker signal consistent with rugged terrain and limited ice."

The radar measurements of Shackleton crater were made during three separate observations between December 2009 and June 2010. Radar illuminates shadowed regions and can detect deposits of water or ice, which have a distinctive radar polarization signature compared to the surrounding material. In addition, radar penetrates the terrain to depths of a meter or two and can measure water or ice buried beneath the surface. Radar measurements of Shackleton crater place an upper bound on the ice content of the uppermost meter of loose material of the crater's walls at between five and ten percent ice by weight.

"We are following up these tantalizing results with additional observations," says Bussey. "Mini-RF is currently acquiring new bistatic radar images of the moon using a signal transmitted by the Arecibo radio telescope in Puerto Rico. These bistatic images will help us distinguish between surface roughness and ice, providing further unique insights into the locations of volatile deposits."

LROC Wide Angle Camera (WAC) Digital Terrain Model (DTM) of the Moon's southern polar region. It's long been hoped that Shackleton, at lower center, might harbor water ice because of its location under every pass by spacecraft in a polar orbit. A strong safety concern for astronaut crews in emergency situation [NASA/DLR/GSFC/Arizona State University].
Related Posts:
Shackleton harbors ice after all (June 12, 2012)
1000 Day Anniversary of LROC Imaging (March 27, 2012)
Shackleton on a Summer's Day (March 26, 2012)
Shadowed fluffy lunar frost detected in starlight (January 14, 2012)
Shackleton: Out of the Shadows (September 17, 2009)


The Mini-RF instrument, operated at the Johns Hopkins Applied Physics Laboratory in Laurel, Md., is one of seven instruments on board NASA's LRO spacecraft. NASA Goddard developed and manages the LRO mission. LRO's current Science Mission is implemented for NASA's Science Mission Directorate. NASA's Exploration Systems Mission Directorate sponsored LRO's initial one-year Exploration Mission that concluded in September 2010.

Mission and Optimal Trajectory Design for the Korean Lunar Exploration Mission

The design and future of the Republic of Korea's KSLV-2, jointly engineered with Roscosmos, is uncertain. A Korean unmanned lunar orbiter in 2020, a lander in 2025 and sampler in 2030 as envisioned in this detailed student study might depend, instead, on a KSLV-3 of undetermined capacity [GlobalSecurity.org].
So Hyung Kim, Kwang Ho Ahn, Ho Jin Park, Heekun Roh
Korea Science Academy of KAIST
Prof. Jaemyung Ahn
Korea Advanced Institute of Science and Technology
APEC Youth Scientist Journal Vol. IV, No.1

The design of the mission and the trajectory for the Korean lunar exploration program. For this research, previous lunar missions carried out by other countries were benchmarked. Korean experts who are involved in the lunar exploration program were interviewed so that various perspectives on Korean lunar program can be collected. Using the space exploration simulation program STK (Satellite Tool Kit), we designed three Korean lunar exploration missions, called Boreum-1, Boreum-2, and Boreum-3.

Boreum-1 mission is a lunar orbiter mission using direct injection trajectory.

Boreum-2 mission is a lunar landing and sample return mission. Boreum3 mission is a Earth-Moon lagrange point (L1) exploration mission. We expect that the results of this research will contribute to the future Korean lunar exploration program.

By this research we designed three lunar exploration missions and named it ‘Boreum’.

Boreum means full moon in Korean. To have symbolic meaning as a first Korean lunar exploration project, we designed each mission to be held on Chuseok in year 2020, 2025, and 2030. Chuseok is a Korean thanksgiving day, which is represented with a full moon (Boreum). Boreum 1 mission uses Korean Space Launch Vehicle 2 (KSLV-2) which is now in research process. Boreum 2 and Boreum 3 mission requires technological advancement from Boreum 1, so that Boreum 2 and Boreum 3 to be placed after conductiong Boreum 1 mission.
Review this comprehensive student scenario, HERE (pdf).

From left to right, So Hyung Kim, Kwang Ho Ahn, Ho Jin Park and Heekun Roh [KSA/KAIST].

GRAIL extended science mission begins

GRAIL MoonKAM Student Expo - Maria Zuber, GRAIL Principal Investigator, from the Massachusetts Institute of Technology in Cambridge, describes how NASA's solar-powered Gravity Recovery And Interior Laboratory (GRAIL)-A and GRAIL-B work to students and parents during the GRAIL MoonKAM student expo, Friday, June 1, 2012, in Washington. GRAIL MoonKAM (Moon Knowledge Acquired by Middle school students) is GRAIL's signature education and public outreach program. It was pioneered by Dr. Sally Ride, America's first woman in space, and the team at Sally Ride Science in collaboration with undergraduate students at the University of California, San Diego. Photo Credit [NASA/Paul E. Alers].
NASA's twin, lunar-orbiting Gravity Recovery and Interior Laboratory (GRAIL) spacecraft began data collection for the start of the mission's extended operations.

At 1628 UT, Thursday, while the two spacecraft were 30 kilometers above Oceanus Procellarum, the Lunar Gravity Ranging System - the mission's sole science instrument aboard both GRAIL twins -- was activated.

"The data collected during GRAIL's primary mission team are currently being analyzed and hold the promise of producing a gravity field map of extraordinary quality and resolution," said Maria Zuber, principal investigator for GRAIL from the Massachusetts Institute of Technology in Cambridge. "Mapping at a substantially lower altitude during the extended mission, and getting an even more intimate glimpse of our nearest celestial neighbor, provides the unique opportunity to globally map the shallow crust of a planetary body beyond Earth."

The science phase of GRAIL's extended mission runs from Aug. 30 to Dec. 3. Its goals are to take an even closer look at the moon's gravity field, deriving the gravitational influence of surface and subsurface features as small as simple craters, mountains and rilles. To achieve this unprecedented resolution, GRAIL mission planners are halving the operating altitude - flying at the lowest altitude that can be safely maintained.

During the prime mission, which stretched from March 1 to May 29, the two GRAIL spacecraft, named Ebb and Flow, orbited at an average altitude of 55 kilometers. The average orbital altitude during extended mission will be 23 kilometers, which places the GRAIL twins within five miles (eight kilometers) of some of the moon's higher surface features.

"Ebb and Flow, and our mission operations team, are both doing great, which is certainly notable considering all the milestones and challenges they have experienced," said David Lehman, GRAIL project manager from NASA's Jet Propulsion Laboratory in Pasadena, Calif. "The twins have endured the lunar eclipse of June 4, 2012, and 26 rocket burns since arriving in lunar orbit at the beginning of the year. Down here in our control room, with all the planning and mission operations we have been doing, it feels as though we've been riding right along with them. Of course, they have the better view."

Science data are collected when the Lunar Gravity Ranging System transmit radio signals between the two spacecraft, precisely defining the rate of change of distance between Ebb and Flow. The distance between the twins change slightly as they fly over areas of greater and lesser gravity caused by visible features, such as mountains and craters, and by masses hidden beneath the lunar surface.

Mission scientists calculated that even as the last data were downlinked, four of the mission's six principal science measurement goals had already been achieved. The objective of the GRAIL mission is to generate the most accurate gravity map of the moon and from that derive the internal structure and evolution of Earth's natural satellite.

JPL manages the GRAIL mission for NASA's Science Mission Directorate in Washington. The GRAIL mission is part of the Discovery Program managed at NASA's Marshall Space Flight Center in Huntsville, Ala. Lockheed Martin Space Systems in Denver built the spacecraft.

For more information about GRAIL, visit: http://solarsystem.nasa.gov/grail/

"Blue Moon over Nottingham"

This color image captured hours prior to the second Full Moon of August, through "clear skies over Nottingham," UK [Simon Smith / WordlessTech].
Hat Tip: WordlessTech