Showing posts with label Apollo 15. Show all posts
Showing posts with label Apollo 15. Show all posts

Saturday, January 24, 2015

Al Worden: 'NASA took a giant step backwards'

Brief walk in Deep Space: Apollo 15 command module pilot Al Worden leaves the confines of Endeavour for the first time in ten days, to retrieve film and data from the SIMS bay of the service module. The 39 minute spacewalk, August 5, 1971, took place as spacecraft, crew and cargo (including 77 kg of lunar samples) were steadily accelerating toward high-speed reentry and splashdown 30 hours later [NASA/JSC].
Apollo 15 command module pilot
Al Worden, with one of the controversial
souvenir flags flown with 1971 mission.
Cornelia Borrmann
Deutsche Welle

DW: What comes to mind when you see the moon at night?

Alfred M. Worden: Well, it's been more than 43 years since I was there. And I think if you go anywhere, 43 years later those memories are pretty dim in your mind, and it's pretty hard to recapture that. But I will tell you - if the moon is right, and particularly if I have some young people with me, I use it as a training tool to get them excited about astronomy. So I do use the moon, but don't just look at the moon and philosophize about what I did.

You witnessed magic moments of manned space flight - the Apollo era. How was it?

Every single person who worked on the program had one goal in mind: Get the guys on the moon and bring them back safely. There was no bureaucracy. If we had a problem, we sat around a table, we discussed it, and we decided then what to do. We listened to everybody. And then we gave an opinion. And we got through a lot of technical issues very quickly and came to the right conclusions, because everybody came together at the work level.

Nobody was trying to improve their position or ensure that their position did not go away. We did not have any managers that were jockeying for position to go higher. Everybody tried to do what was right to go to moon.

Read the full Berlin interview, HERE.

Wednesday, June 18, 2014

Soaring over the Apennines

This is another LROC NAC mosaic viewers may really want to see using the "see all sizes" download option that accompany slideshow images in Flickr. An oblique view, looking west over the Apennine Mountains toward Hadley Rille (above -north is to the right).  The morning shadows are much as they were July 30, 1971, when Dave Scott and Jim Irwin flew on their backs over range at bottom, flipped forward and landed on the broad plain between those hills and Rima Hadley. Hadley Base, their landing site, and the descent stage of the Apollo 15 lunar module Falcon is right where they left it, just within the resolution of full scale reproductions of this image. 
Notable features in a thumbnail of LROC NAC oblique mosaic M1123519889LR, LRO orbit 17751, May 18, 2013; spacecraft and cameras slew 55.22° from orbital nadir, 76.87° incidence angle, average resolution 2.87 meters from 130.27 km over 26.11°N, 11.75°E [NASA/GSFC/Arizona State University].
J. Stopar
LROC News System

Apollo mission planners selected an adventurous landing site for Apollo 15 (26.132219°N, 3.633861°E), on a relatively small patch of lava plains (mare). 

This site is nestled between the towering Apennine mountains to the east, attaining heights of 3-5 km, and the 200 meter deep, v-shaped valley of Hadley Rille to the west.

The experience gained from the successful landings of the preceding Apollo missions afforded mission controllers confidence that a landing descending through a mountain range was possible, though it required a steeper descent angle (25° rather than 14°).

The landing site of Apollo 15 (direct center), on Hadley Rille Delta between the Apennine mountain range on the southeast periphery of Mare Imbrium and Rima Hadley, winding through the distinctly darker mare material of Palus Putredinis. LROC WAC GLD100 elevation overlain atop LROC 100 meter global mosaic. The peaks of the Apennine Mountains rise more than 5 km over the interior of the Imbrium basin [NASA/GSFC/Arizona State University].
A captioned video of the descent of Apollo 15 conveys the excitement of astronauts David Scott and James Irwin as they set down near Hadley Rille. The Hadley Rille landing site also presented an opportunity to test the capabilities of the new lunar roving vehicle (LRV).


"Down on the plain at Hadley." Newly realigned video (3:37) of the landing of Apollo 15, July 30, 1971. [LunarModule5].

The Apennine Mountain Range formed during the Imbrium basin-forming event, and it was hoped these mountains contained materials from very early in the Moon's history (which they did!). As astronauts Irwin and Scott descended over the Apennines, they reported a floating sensation that resulted from glimpsing mountain peaks passing by the windows of the Lunar Module (LM). The descent was a complete success, and the LM set down near the planned site! Although, the astronauts were a little surprised to land with one foot-pad in a small crater, placing the vehicle on a slant.

Cmdr. Dave Scott captured this view of the Apollo 15 lunar module Falcon where it came to rest tilting toward the Apennine mountains beyond, while Jim Irwin checked out the first of the three Apollo "J mission" lunar rovers. See full-size mosaic of two color images from the panorama (AS15-86-11600 and 11601) HERE [NASA/JSC/ALSJ].
Three EVAs (or traverses) were planned for Apollo 15 using the LRV, two of which allowed sampling part of the Apennine Mountain Range to the south and southeast and required long (multi-kilometer) traverses.

Thumbnail of a mosaic of black and white images from Science Station 6, during the second EVA of the Apollo 15 expedition, on the slopes of the "Apennine Front." In the full-size panorama, HERE, the lunar module Falcon is visible, several kilometers away, between Hadley rille on the far left and Mt. Hadley, dominating the center of this mosaic [AS15-85-11481-11492, NASA/JSC/ALSJ].
Astronauts Scott and Irwin were accomplished field geologists; listen HERE as Commander Scott recently reflected on his Apollo 15 experience, including the importance of field-geology training.

The tiny arrow marks the location of the LM, just barely within the resolution of the LROC NAC mosaic (at full-scale), while LRO orbited over a spot 130 km away. Of course, the landing zone has been documented with remarkable detail from LRO, from better vantages [NASA/GSFC/Arizona State University].
Related Posts:

Wednesday, June 11, 2014

The original interplanetary mountaineers

Traverse plots of Apollo 15 EVA 1 & 2 (August 1 and 2, respectively), the routes astronauts Dave Scott and Jim Irwin drove south to the lower slope of Mons Hadley Delta (from the "Elbow" bend in Rima Hadley, southward, toward the left). Elevations above that of the landing site (LM). For scale, the dogleg distance the astronauts travelled from the LM to Elbow crater along the edge of Hadley Rille over EVA 1 is roughly 4.5 km. Oblique LROC NAC mosaic M1123519889RL, LRO orbit 17751, May 18, 2013; spacecraft and camera slew 55.21° from orbital nadir, 76.87° angle of incidence, resolution 2.87 meters from 130.27 km over 26.11°N, 11.15°E  [NASA/GSFC/Arizona State University].
J. Stopar
LROC News System

The lofty Apennine Mountain Range has two prominent peaks near the Apollo 15 landing site: Mons) Hadley (relative height 4 km) to the northeast and Mons Hadley Delta (3.5 km) toward the south.

Between these two peaks lies the "Swann Range," named for Apollo 15 Geology Team Leader Gordon Swann.

The Apennine Mountain Range contains some of the largest peaks on the Moon Mons Hadley rivals the prominences of notable terrestrial mountains like Mt. Rainier and Mt. Fuji, and Mt. Erebus in Antarctica when measured from base to summit.

Elevation profile of Mons Hadley Delta, measured from the Apollo 15 landing site (left) through the peak (right); data from the LROC WAC-derived GLD100 Digital Terrain Model (DTM), with relative heights of notable terrestrial mountains shown for scale. Mons Hadley Delta is not the largest peak in the Apennines, and Scott and Irwin scaled only a small portion of the mountain's contact zone with the Hadley Delta plain [NASA/GSFC/Arizona State University].
The first Apollo 15 EVA took astronauts David Scott and James Irving southward along the edge of Hadley Rille and to the base of Mt. Hadley Delta near St. George crater. This traverse took them to a height of just over 65 meters above the landing site on the mare plain. At this height, much of the surface material of the mountain comprises debris that, over eons, slid down the upper slopes through mass-wasting. Materials collected in this area primarily consist of regolith, as there are very few surface boulders.

Mons Hadley Delta (high-resolution mosaics HERE); Mosaic of Dave Scott's Station 9 panorama (AS15-82-11084-88), from northeastern wall of the "Station 9 crater," a relatively fresh 15 meter-wide feature characterized by soft clod-like blocks of pressure-pressed regolith formed at small impact. Station 9 crater is about 240 meters immediately northeast of Rima Hadley; Apollo 15 (EVA 3), August 2, 1971 [Dave Scott/NASA/JSC/ALSJ].
The second EVA took the astronauts southeast to "South Cluster" and Spur craters. At Spur crater, a very old crystalline rock fragment was collected, containing evidence of geologic processes more than 4 billion years old and representing a piece of the original anorthositic crust of the Moon. They also discovered an unusual green material composed of volcanic glass.

This traverse ascended about 95 meters in elevation, up the base of Mons Hadley Delta. At times, the slope was steep enough (~ 18°) that the rover had difficulty getting traction, and the mountain peak loomed so high overhead, that the astronauts could not lean back far enough to get it in the frame of their cameras.

Apparent outcrops (arrows) may represent a high-lava mark approximately 85 meter up the south slope of Mons Hadley. AS15 magazine 84. View a more dramatic mosaic from this panorama HERE [NASA/JSC/Apollo 15 Lunar Surface Journal/Arizona State University].
During this traverse, the astronauts commented that they thought they could detect a high-mark where lava might once have filled the basin at the base of nearby Mt. Hadley around a height of 85 meters above the current mare plain.

LROC projection with traverse courses of Apollo 15 expedition to Hadley Delta, July 30-August 2, 1971 [NASA/GSFC/Arizona State University].
From Science Station 6. It definitely worthwhile to see a larger, high-resolution mosaic of this, reported to be Dave Scott's favorite photograph from the expedition (HERE). Through a 500-mm lens, from Science Station 6 up on the Apennine Front, the lunar module Falcon and ALSEP components are seen from 4.7 km, backdropped by the North Complex crater group and flank of Mons Hadley, on the plain's opposite bank [NASA/JSC].
Apollo 15, Science Station 6, Spur Crater, on the Apennine Front, August 1, 1971. Dave Scott employs his 500 mm lens and black and white magazine 84 to capture the image immediately above, the Apollo 15 lunar module Falcon and North Complex crater group in context of the high mountains surrounding the Hadley Delta landing site. Still clipped from live video transmission relayed from remote-operated color TV camera on the lunar rover [NASA/JSC/ALSJ].
After capturing his black and white 500 mm panorama, Cmdr. Scott returned employed color magazine 86 and a less awkward smaller focal length. The reproduction here is too small to see the lunar module, but a much cleaner full resolution version is available HERE. Though it is not as detailed, and coherent backscatter is more problematic than the black and white at 500 mm, the full-resolution color image more closely matches the unaided human eye.  AS15-86-11618 [NASA/JSC/ALSJ].
While the Apollo 15 astronauts scarcely climbed the lower slopes of a lunar mountain, they made many important discoveries. What challenges, findings, and fun (like slope skiing) might future explorers experience on the powdery mountains of the Moon?

Explore the first two of the Apollo 15 traverses in more detail below by panning and zooming. The numbers indicate relative elevations of the paths travelled by the astronauts.

Related Posts:
Soaring Over Mighty Mt. Hadley
Apollo 15 departs Hadley Rille Delta
Water found in the Apollo 15 Genesis Rock
Follow the Tracks (Apollo 15)
Hadley Rille and the Mountains of the Moon
Retracing the Steps of Apollo 15 Constellation Region of Interest
Apollo 15 Laser Ranging Retroreflector: a Fundamental Point on the Moon
LROC's First Look at the Apollo Landing Sites
'Man's first wheels on the Moon' at 41 years
Bowditch Lava Terraces
Lunar Kipuka
Remnants of the Imbrium Impact
Hadley-Apennine: the Apollo 15 Landing Site
The Mighty Apennine Mountain Range
Layers near Apollo 15 Landing Site
LROC Explores Apollo 15 (YouTube video)
Kaguya captures Rima Hadley

Tuesday, November 19, 2013

Lunar Laser Ranging: The Millimeter Challenge

Lunar Laser Range Reflector arrays
The five Lunar Laser Range Reflector (LLR or LLRR) arrays deployed on the lunar surface, one each at the landing sites of Apollo 11, 14 and 15, and also to the Soviet rovers Lunokhod 1 and 2. The sublime accuracy of the decades-long measurements are priceless to astrophysics. Nearside view from "Synthetic View of the Moon," LROC Featured Image released October 15, 2013 [NASA/GSFC/Arizona State University].
T. W. Murphy, Jr.
Center for Astrophysics and Space Sciences
University of California

Lunar laser ranging has provided many of the best tests of gravitation since the first Apollo astronauts landed on the Moon. The march to higher precision continues to this day, now entering the millimeter regime and promising continued improvement in scientific results. This review introduces key aspects of the technique, details the motivations, observables, and results for a variety of science objectives, summarizes the current state of the art, highlights new developments in the field, describes the modeling challenges and looks to the future of the enterprise.

Since 1969, lunar laser ranging (LLR) has provided high-precision measurements of the Earth-Moon distance, contributing to the foundations of our knowledge in gravitation and planetary physics. While being the most evident force of nature, gravity is in fact the weakest of the fundamental forces, and consequently the most poorly tested by modern experiments. Einstein's general relativity, currently our best description of gravity, is fundamentally incompatible with quantum mechanics and is likely to be replaced by a more complete theory in the future. A modified theory would, for example, predict small deviations in the solar system that, if seen, could have profound consequences for understanding the universe as a whole.

Utilizing reflectors placed on the lunar surface by American astronauts and Soviet rovers, LLR measures the round-trip travel time of short pulses of laser light directed to one reflector at a time. By mapping the shape of the lunar orbit, LLR is able to distinguish between competing theories of gravity. Range precision has improved from a few decimeters initially to a few millimeters recently, constituting a relative precision of 10-9 through 10-11. Leveraging the raw measurement across the Earth-Sun distance provides another two orders of magnitude for gauging relativistic effects in the Earth-Moon-Sun system.

The largest of the Apollo lunar laser range reflectors (LLRR) arrays, deployed at Hadley Rille by Scott and Irwin of the Apollo 15 surface expedition in February 1971. The instrument is still a regularly acquired critical part of on-going experimental astrophysics. AS15-85-11468 [NASA/JSC].
As LLR precision has improved over time, the technique has remained at the cutting edge of tests of gravitational phenomenology and probes of the lunar interior, and has informed our knowledge of Earth orientation, precession, and coordinate systems. LLR was last reviewed in this series in 1982; this update describes the key science drivers and findings of LLR, the apparatus and technologies involved, the requisite modeling techniques, and future prospects on all fronts.

Lunokhod 1 rover in its final parking place (38.315°N, 324.992°E) on the surface of Mare Imbrium. LROC Narrow Angle Camera (NAC) observation M175502049RE, orbit 10998, November 9, 2011, resolution 33 cm per pixel. View original Featured Image released March 14, 2012 (with enlarged inset) HERE [NASA/GSFC/Arizona State University].
LLR is expected to continue on its trajectory of improvement, maintaining a leading role in contributions to science. Other recent reviews by Merkowitz (2010) and by Muller, et al. (2012) complement the present one. The Merkowitz review, like this one, stresses gravitational tests of LLR, but with greater emphasis on associated range signals. Next-generation reflector and transponder technologies are more thoroughly covered. The Muller et al. review (for which this author is a co-author) covers a more complete history of LLR, has statistics on the LLR data set, and provides greater emphasis on geophysics, selenophysics, and coordinate systems.

This review is organized as follows: Section 1 provides an overview of the subject; Section 2 reviews the science delivered by LLR, with an emphasis on gravitation; Section 3 describes current LLR capabilities; Section 4 relates recent surprises from LLR, including the finding of the lost Lunokhod 1 reflector and evidence for dust accumulation on the reflectors; Section 5 treats the modeling challenges associated with millimeter-level LLR accuracy; and Section 6 covers possible future directions for the practice of LLR.

Thursday, June 27, 2013

Rima Marius Layering

Basalt layering, a slice through the floor of Oceanus Procellarum, is visible along the wall of this section of Rima Marius. LROC Narrow Angle Camera (NAC) Extended Science Mission observation M1103881010R, LRO orbit 14991, October 3, 2012; 21.88° angle of incidence over a 1.3 km-wide field of view, resolution 0.99 meters from 121.1 km  [NASA/GSFC/Arizona State University].
Sarah Braden
LROC News System

Mare basalt layering is visible in the walls of a number of impact craters such as Caroline Herschel Crater and Pytheas Crater. Layers were seen in the wall of Hadley Rille near the Apollo 15 landing site and Today's Featured Image shows a few layers of mare basalt along the top edge of the wall of Rima Marius.

Look closely at the Featured Image to see the individual layers.

Rima Marius is about 280 km long, sinuously slicing through large extents of mare basalt. The are seen in the Featured Image is centered at 14.986°N, 311.565°E.

LROC Wide Angle Camera context view of the southern leg of winding Rima Marius. The arrow marks the location of the field of view shown at high resolution in the LROC Featured Image. LROC WAC M166161047CE (604 nm) spacecraft orbit 9621, July 2, 2011, 63.53° angle of incidence, 58.9 meters resolution from 42.35 km [NASA/GSFC/Arizona State University].
Rilles form when large volumes of low viscosity magma erupt and flow turbulently. The erosive force of the turbulent flow carves a channel into the lunar surface and then drains away, leaving behind an empty groove in the Moon. Studying the thickness of mare basalt layers using areas like the Feature Image help scientists model the viscosity and eruption volume of single eruption events.

The 280 km length of Rima Marius and the LROC Featured Image field of view (arrow) as seen from Earth is more easily seen through telescopes from Earth with the lengthening shadows of local late afternoon illumination, a few days after a Full Moon. In this crop, from a high-resolution lunar mosaic captured by Yuri Goryachko and colleagues at Astronominsk in Belarus, September 25, 2008, shows vast context for Rima Marius within central Oceanus Procellarum, from the Aristarchus Plateau in the North to the Marius Hills, Marius crater and Reiner Gamma swirl albedo to the south [Astronominsk].
Explore the entire LROC NAC for more Rima Marius, HERE.

Related Images:
Dark surface materials surrounding Rima Marius
Discontinuous rilles
Hadley Rille and the Mountains of the Moon
Layers near Apollo 15 landing site

Tuesday, February 19, 2013

Water found in the Apollo 15 'Genesis Rock'

Called the "Genesis Rock," Apollo 15 sample of unbrecciated anorthosite was thought to be a piece of the moon's primordial crust. In a paper published online February 17 in Nature Geoscience a University of Michigan researcher and colleagues report traces of water have been found in the sample [NASA/Johnson Space Center].
Jim Erickson
University of Michigan News Service

Traces of water have been detected within the crystalline structure of mineral samples from the lunar highland upper crust obtained during the Apollo missions, according to a University of Michigan researcher and his colleagues.

The lunar highlands are thought to represent the original crust, crystallized from a magma ocean on a mostly molten early Moon. The new findings indicate the early Moon was wet and that water there was not substantially lost during the Moon's formation.

The results seem to contradict the predominant lunar formation theory -- that the Moon was formed from debris generated during a giant impact between Earth and another planetary body, approximately the size of Mars, according to U-M's Youxue Zhang and his colleagues.

"Because these are some of the oldest rocks from the Moon, the water is inferred to have been in the Moon when it formed," Zhang said. "That is somewhat difficult to explain with the current popular Moon-formation model, in which the Moon formed by collecting the hot ejecta as the result of a super-giant impact of a Martian-size body with the proto-Earth.

"Under that model, the hot ejecta should have been degassed almost completely, eliminating all water," Zhang said.

A paper titled "Water in lunar anorthosites and evidence for a wet early Moon" was published online February 17 in the journal Nature Geoscience. The first author is Hejiu Hui, postdoctoral research associate of civil & environmental engineering & Earth sciences at the University of Notre Dame. Hui received his doctorate at U-M under Zhang, a professor in the Department of Earth and Environmental Sciences and one of three co-authors of the Nature Geoscience paper.

The Genesis Rock presented itself in situ on top of a pedestal, "as though it had been waiting for someone to retrieve it." Apollo 15 Dave Scott and Jim Irwin, aware on sight of the sample's potential value, were careful to photograph the find both before and after retrieval. AS15-86-11670 [NASA/ALSJ].
Over the last five years, spacecraft observations and new lab measurements of Apollo lunar samples have overturned the long-held belief that the Moon is bone-dry. In 2008, laboratory measurement of Apollo lunar samples by ion microprobe detected indigenous hydrogen, inferred to be the water-related chemical species hydroxyl, in lunar volcanic glasses. In 2009, NASA's Lunar Crater Observation and Sensing satellite, known as LCROSS, slammed into a permanently shadowed lunar crater and ejected a plume of material that was surprisingly rich in water ice.

Hydroxyls have also been detected in other volcanic rocks and in the lunar regolith, the layer of fine powder and rock fragments that coats the lunar surface. Hydroxyls, which consist of one atom of hydrogen and one of oxygen, were also detected in the lunar anorthosite study reported in Nature Geoscience.

In the latest work, Fourier-transform infrared spectroscopy was used to analyze the water content in grains of plagioclase feldspar from lunar anorthosites, highland rocks composed of more than 90 percent plagioclase. The bright-colored highlands rocks are thought to have formed early in the Moon's history when plagioclase crystallized from a magma ocean and floated to the surface.

The infrared spectroscopy work, which was conducted at Zhang's U-M lab and co-author Anne H. Peslier's lab, detected about 6 parts per million of water in the lunar anorthosites.

"The surprise discovery of this work is that in lunar rocks, even in nominally water-free minerals such as plagioclase feldspar, the water content can be detected," said Zhang, James R. O'Neil Collegiate Professor of Geological Sciences.

"It's not 'liquid' water that was measured during these studies but hydroxyl groups distributed within the mineral grain," said Notre Dame's Hui. "We are able to detect those hydroxyl groups in the crystalline structure of the Apollo samples."

The hydroxyl groups the team detected are evidence that the lunar interior contained significant water during the Moon's early molten state, before the crust solidified, and may have played a key role in the development of lunar basalts. "The presence of water," said Hui, "could imply a more prolonged solidification of the lunar magma ocean than the once-popular anhydrous Moon scenario suggests."

The researchers analyzed grains from ferroan anorthosites 15415 and 60015, as well as troctolite 76535. Ferroan anorthosite 15415 is one the best known rocks of the Apollo collection and is popularly called the Genesis Rock because the astronauts thought they had a piece of the Moon's primordial crust. It was collected on the rim of Spur Crater (Science Station 7) during the Apollo 15 mission.

Rock 60015 is highly shocked ferroan anorthosite collected near the lunar module during the Apollo 16 mission. Troctolite 76535 is a coarse-grained plutonic rock collected during the Apollo 17 mission.

Co-author Peslier is at Jacobs Technology and NASA Johnson Space Center. Fourth author of the Nature Geoscience paper, Clive R. Neal, is a professor of civil and environmental engineering and earth sciences at the University of Notre Dame.

Tuesday, December 4, 2012

"Physics is fun, especially on the Moon!"

A gradational distribution of boulders inside a crater. LROC Narrow Angle Camera (NAC) observation M176224625L, LRO orbit 11105, November 18, 2011; field of view 500 meters across at 0.51 meters resolution from 47.61 kilometers, incidence angle 55.29° [NASA/GSFC/Arizona State University].
Sarah Braden
LROC News System

A distribution of boulders within the floor of an unnamed crater demonstrates physics at work. In the Featured Image (located in the lunar highlands at 6.275°N, 214.770°E) you can see that smaller boulders are (on average) closer to the boundary where the wall of the crater meets the floor. As distance increases from this boundary, the size of the individual boulders increases.

Why is this happening?

The larger boulders have more kinetic energy at the bottom of the slope due to their greater mass. Kinetic energy is 1/2 the mass times the velocity squared. So at the bottom of the crater wall, the more massive boulders will have more kinetic energy than the small boulders, even though they are all subject to the same acceleration due to the Moon's gravity. The crater floor is relatively flat, so the larger boulders will travel further than the small boulders before coming to a halt. An alternative explanation is that larger boulders originate preferentially from the rim of the crater and thus fall from a greater height on average compared to small boulders. Either way, the larger boulders have more kinetic energy when the reach the bottom of the crater.

Full width, 4000 lines in a mosaic of both left and right frames of LROC NAC M176224625 shows the tumbled mix of impact melt typical of craters with larger floors. The field of view at shown at full resolution in the Featured Image is the upper most contact between the crater floor and north wall [NASA/GSFC/Arizona State University].
August 2, 1971, Hadley Rille Delta Apollo 15 commander Dave Scott demonstrates the basic physics of falling objects on the surface of an airless body. In tribute to Galileo, Scott simultaneously drops a 1.32-kg aluminum geological hammer and a 0.03 kg falcon feather and both objects, falling at identical acceleration, reach the surface at the same time [NASA].
During the Apollo 15 mission, Commander David Scott performed a related physics experiment live for the TV cameras! You can watch the video here: Apollo 15 Hammer and Feather Drop. He dropped a rock hammer and a feather from the same height at the same time. The point of the experiment was to show that in an environment with no atmospheric drag (a vacuum) the feather and the hammer will fall at the same speed (and hit the ground at the same time) regardless of the difference in mass. This basic idea is attributed to Galileo. Read more about the Apollo 15 experiment HERE.

Physics is fun, especially on the Moon!

LROC Wide Angle Camera (WAC) context image, photographed as the LROC NAC (and LROC Featured Image) captured a much higher resolution field of view (asterisk) of the boulder distribution deep within this unnamed, young 12 km crater in the farside lunar highlands. LROC WAC observation M176217257C (643nm) LRO orbit 11105, November 18, 2011; resolution 62 meters per pixel [NASA/GSFC/Arizona State University]

The crater is shown in greater, smaller-scale context, within a roughly 82 km-wide field of view; from a mosaic of LROC WAC observations captured in orbits 11104 and 11105, November 18, 2011. The wider region, northwest of Vavilov crater and northeast of the ancient South Pole-Aitken impact basin, is characterized by some of the highest elevations (and thickest crust) on the Moon. The nearest named crater, Artem'ev L, at upper right, received its official designation in 2006 [NASA/GSFC/Arizona State University].

Explore the entire NAC frame, HERE.

Related LROC Featured Images:
Crater Covered With Boulders
Ray of Boulders
Sampling a Central Peak

Tuesday, August 28, 2012

Passing of an Era

Neil Armstrong examines a sample from the Sierra Madera impact crater, west Texas during geology training for the Apollo program.

Paul Spudis
The Once & Future Moon
Smithsonian Air & Space


Because of his flying career and the life that he led, Neil Armstrong’s passing has many recounting his place in the history of spaceflight and remembering a life well lived.  He holds a special place in our hearts and a unique place in history – and he always will.

I met Neil Armstrong at a conference, an encounter I won’t forget.  A quiet, unassuming man of medium height and build, pleasant and genial, surrounded by a horde of admirers and well-wishers, I could tell he was slightly uncomfortable with (but resigned to) the adulation he received.  In his mind, the 1969 flight of Apollo 11 was simply another professional assignment he flew as a test pilot – the landing on the Moon was of more significance than his first step on it.  He was an aviator, in every sense of that word.  The landing was an accomplishment for humanity – a giant step for mankind.

My glimpses of Neil come not from personal encounters with him, but from others who knew him.  During a discussion several years ago with Dave Scott (Apollo astronaut and Commander of the 1971 Apollo 15 mission), I inquired about an obscure incident during the 1966 flight of Gemini 8 (flown by Neil and Dave).  That mission conducted the first docking of two spacecraft in space and I wanted to know some details of the emergency experienced by the crew on that flight.

The incident had occurred shortly after the docking, when the Gemini-Agena spacecraft began to roll slightly.  The rate of rotation became greater with time and it was evident that something was very wrong.  Neil, as commander, was responsible for “flying” the spacecraft but couldn’t get the rolling under control.  Thinking that the Agena (their unmanned target vehicle) was responsible, the crew made the decision to undock from it (they were out of contact with Mission Control at the time).  As soon as they did, the Gemini spacecraft started to roll and tumble at an ever increasing and alarming rate.  Dave recalled with a chuckle that Neil looked over at him, pointed at the attitude control stick and said “See if you can do anything with it!”  Dave’s recollection of their exchange gave me a glimpse of a very human moment in a life and death situation.  This was serious – if they couldn’t regain control, they would black out from the centrifugal forces in the tumbling vehicle.  Neil kept his cool, activated the re-entry thrusters and soon stabilized the bucking Gemini spacecraft.  The solution saved their lives but ended the mission, sending them home prematurely but safely.

The story of the first lunar landing is well known.  The automatic systems of the Apollo 11 Lunar Module Eagle were targeting the vehicle into a large crater filled with automobile-sized boulders.  Landing there would be disastrous, as the LM would likely topple over on touchdown, eliminating the crew’s ability to liftoff from the Moon and return home.  Taking manual control, Neil (with Mission Control advising the crew they had thirty seconds of fuel left) guided the LM over the hazardous debris field to a safe touchdown a few hundred meters beyond the original landing site.  Tension during the agonizingly long pause in the air-to-ground communications was palpable.  Relief could be heard in Capcom Charlie Duke’s voice as Neil calmly announced that the Eagle had landed.  Yet again, a critical situation expertly handled by a test pilot just doing his job – the calm and collected decision making necessary when flying finicky machines near the edges of their performance envelopes.

Neil’s scientific work on the Moon during his EVA warrants special mention.  Being the first humans to  land on another world, it is understandable that the crew had many ceremonial duties to perform.  Although they had been carefully instructed to stay close to the LM, without informing Mission Control, Neil walked back a hundred meters or so to Little West crater (overflown earlier) to examine and photograph its interior.  Those photos showed the basaltic bedrock of Tranquility Base – documenting that the Eagle had landed amidst ejecta from that crater thereby establishing the provenance of samples collected during the crew’s limited time on the surface.  According to Gene Shoemaker and Gordon Swann, both of the U.S. Geological Survey, Neil was one of the best students of geology among the Apollo astronauts.  Through his work on the Moon, he showed an ability beyond mere mastery of the facts of geology – he intuitively grasped its objectives, as well as the philosophy of the science.  Like every other facet of the mission, Neil understood and took this role seriously.  No matter what topic was addressed or which role was taken, he could always be counted on to turn in his best performance.

Armstrong understood the historic role of being the first man on the Moon but he never succumbed to the siren call of fame.  He could have cashed in on his status but choose a different path.  He was the quintessence of quiet dignity, possessing the “Aw shucks, t’weren’t nothin’” Gary Cooper-ish manner of understated heroism.  After retirement, he lived happily in his home state of Ohio, taught aeronautics (his first love) at the University of Cincinnati, and advised on various engineering topics and problems for both government and industry.  Throughout NASA’s post-Apollo efforts – without fanfare – he often and freely lent his efforts to the space program.  He served his country with honor and dignity.

As a test pilot, Neil routinely showed his ability to make quick, life saving decisions in dangerous situations.  As a senior spokesman for space, he clearly voiced his concern over the dismantling and destruction of our national space program.  Neil understood that our civil space program is a critical national asset, both as a technology innovator and a source of inspiration for the public.  Who would recognize this more clearly than Neil Armstrong?  From long experience, he knew what kinds of government programs worked and what kind didn’t.  He knew his fellow man.  In appearances before Congress in recent years, he outlined specific objections to our current direction in space.  A true patriot, Neil did not hesitate to voice his opinions, whether they aligned with current policy or not.

It’s become cliché to say that Neil Armstrong holds a unique place in history.  On this occasion, we should pause to consider just how singular his place is.  No one – not the first human to Mars nor the first crew to venture beyond the Solar System – will ever achieve the same level of significance as the first human to step onto the surface of another world.  The flight of Apollo 11 was truly a once in a lifetime event – and by that, I mean in the lifetime of humanity.  That first step was indeed one to “divide history,” as the NASA Public Affairs Office put it at the time.

Goodbye, Neil Armstrong – and thank you.  We’ve lost one of our most authoritative and articulate spokesmen for human spaceflight.  I mourn him and share his valid concerns for our dysfunctional national space program.

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.

Thursday, August 2, 2012

Apollo 15 departs Hadley Rille Delta - 41 years ago


August 3, 1971 - 1:11 pm (EDT-US): Hadley Delta, Palus Putridanis, Earth's Moon. Lift off of Apollo 15 lunar module ascent stage, with Dave Scott and Jim Irwin on-board, as captured by remote-operated live color television camera on Apollo's first lunar rover.


From automated DAC camera - on-board lunar module Falcon: From ascent stage ignition through pitch-forward and an excellent - though brief - view of the descent stage/launch pad left behind and below. This footage shows the range track west, over Hadley Delta and Hadley Rille, through a slight roll maneuver allowing a longer view of Hadley Rille north of the landing site and points west over the Palus Putridanis formation on the southeastern frontier of Mare Imbrium.

 [NASA/GSFC/Arizona State University].
The animation above views the Apollo 15 landing site through shifting shadows of a lunar day, courtesy of the LROC Featured Sites index which premiered ;ast month. After the dust settled, almost immediately following the departure of Scott and Irwin expedition 41 years ago, the Sun has passed overhead 548 times, and very little appears to have changed.

A Lasting Legacy: Short of a large erasing impact or interference by future visitors, the relentless bombardment of micro-meteorites will eventually "garden" the top three centimeters or so of regolith, finally erasing all traces of the rover tracks and footprints in about 2 million years. After that, it's anyone's guess how long it might take to pummel away the artifacts of Apollo 15.

Tuesday, July 31, 2012

'Man's First Wheels on the Moon,' at 41 years

Loading up the first of the Apollo lunar rovers, lunar module pilot Jim Irwin paused to memorialize the placard commemorating 'Man's first wheels on the Moon, Delivered by Falcon, July 30, 1971. Forty-one years later, the relatively low mileage electric car still sits on the plain north of Hadley Rille. Strictly speaking, the Lunokhod teleoperated rover on the opposite side of Mare Iridium were the first "wheels," on the Moon. In American parlance, however, this first of the three Apollo J mission Lunar Electric Rovers, operated by men behind the 'wheel,' were correctly designated the first "wheels" on the Moon AS15-88-11862 [NASA/JSC/ALSJ].
J. Terry White
President and CEO
White Eagle Aerospace, LLC
American Aerospace blog, Seattle Post Intelligencer

Forty-one years ago today, Apollo 15 landed in the Hadley-Appennine region of the Moon. The fourth manned lunar landing, Apollo 15 was one of the most scientifically successful and geologically diverse of the Apollo Lunar Landing Program.

The Apollo 15 Lunar Module Falcon, with Dave Scott and Jim Irwin onboard, landed at 22:16:29 UTC in the Hadley-Appennine region of the Moon on Friday, 30 July 1971.  High overhead, Al Worden orbited the Moon alone in the Command Module (CM) Endeavor.

Read this mission summary, HERE.
And explore the full mission record, videos and pictures 
at the Apollo 15 Lunar Surface Journal, HERE.

Apollo 15 Related Posts:

Tuesday, March 6, 2012

Follow the tracks (Apollo 15)

1971 Landing site of Apollo 15, from unusually low altitude - From only 25 kilometers (LROC observation M175252641, L and R frames). The Lunar Roving Vehicle (LRV) is parked to the far right, the Lunar Module descent stage is at center; LRV tracks are indicated with arrows. View the larger Featured Image HERE [NASA/GSFC/Arizona State University].
Mark Robinson
Principal Investigator
Lunar Reconnaissance Orbiter Camera
Arizona State University


Apollo 15 from unusually low altitude - Apollo 15 landing site imaged from an altitude of 25 km (M175252641L,R) allowing an even higher resolution view! The Lunar Roving Vehicle (LRV) is parked to the far right, and the Lunar Module descent stage is in the center, LRV tracks indicated with arrows [NASA/GSFC/Arizona State University].

The Apollo 15 Lunar Module (LM) Falcon set down on the Hadley plains (26.132°N, 3.634°E) a mere 2 kilometers from Hadley Rille. The goals: sample the basalts that compose the mare deposit, explore a lunar rille for the first time, and search for ancient crustal rocks. Additionally, Dave Scott and Jim Irwin deployed the third Apollo Lunar Surface Experiments Package (ALSEP) and unveiled the first Lunar Roving Vehicle (LRV). The ALSEP consisted of several experiments that were powered by a Radioisotope Thermoelectric Generator (RTG) and sent back valuable scientific data to the Earth for over six years after the astronauts left. This new LROC NAC image taken from low altitude shows the hardware and tracks in even more detail.

Mons Hadley Delta, where Hadley Rille, the mountains of the Apennine range and the Palus Putredinis mare plain all intersect near the landing site of Apollo 15 (yellow arrow), first of the Apollo "J" missions, devoted to lunar science. 30 kilometer-wide monochrome (604 nm) field of view from LROC Wide Angle Camera observation M150497920CE, LRO orbit 7313, January 24, 2011; incidence = 65.77° at 54 meters resolution from 39.36 kilometers altitude. [NASA/GSFC/Arizona State University].
The LRV, a lunar "dune buggy", allowed the astronauts to traverse far from the LM and explore much more local geology than the astronauts on previous missions (Apollo 11, 12, 14). Not only did the LRV allow the astronauts to move from place-to-place at a lively rate of eight to sixteen kilometers per hour (five to ten miles per hour), but the LRV also allowed brief periods of rest that in turn helped to conserve oxygen.

LROC Apollo 15 Traverse Map - Apollo 15 traverse routes sketched on subsampled NAC M106855508L/R. Red letters mark locations of images in the next figure [NASA/GSFC/Arizona State University].
The LRV wheels were 82 centimeters (32 inches) in diameter, and 23 centimeters (9 inches) wide. Typically LROC NAC pixels are about 50 centimeters square, so it is not always easy to pick out the LRV tracks. In previous LROC images, the LRV tracks are usually only visible near the LM where the descent engine exhaust plume disturbed the surface. The LRV wheels broke through the changed surface and thus the tracks have more contrast near the LM.

For two one-month periods last year (2011), the LRO orbit was lowered such that overflights of the Apollo sites were only 25 to 30 kilometers, rather than the usual 50 kilometers. These low passes resulted in NAC pixel scales near 25 centimeters! LRO has a ground speed of a bit over 1600 meters (5249 feet) per second, and the shortest NAC exposure time is 0.34 millseconds, so images taken from this low altitude are smeared down track a bit. However, the smear is hardly noticeable and features at the Apollo sites definitely come into sharper focus. In this new low-altitude NAC image of the LRV, tracks are visible about half of the time, usually when the tracks are at an angle to the Sun direction, rather than parallel.




Apollo 15 LRV Tracks - Details showing Apollo 15 LRV track from traverse map above [NASA/GSFC/Arizona State University].

It was during Apollo 15 that the rover was driven on the steepest slopes while exploring the base of a mountain named Hadley Delta (it was named Delta because of its shape, not because it was a river delta). In fact at Station 6a, as Dave Scott stepped off the rover, it started to slide downhill. He was able to grab the rover and stabilize it with no problem.

Apollo 15 LRV Station 6a - Note the slope is steep enough one of the wheels is off the ground. But how steep is steep? The boulder in the foreground is indicated with a white arrow in the next figure. AS15-86-11659 (high resolution) [Dave Scott- NASA/ALSJ/JSC].
How steep is steep? At the time, the astronauts estimated the slope at Station 6a between 15 and 20 degrees. With NAC stereo observations the LROC team is able to make detailed topographic maps (see below). Instead of estimating the steepness of the slope, we can now measure the slope.

Station 6a Topography Map - LROC NAC-derived topographic contours superposed on low altitude image. Black arrows indicate LRV tracks, white arrow the Station 6a boulder seen in Dave Scott's photograph above, while the black line shows the trace of the slope profile represented in plot below. (Contour interval 5 meters, elevations relative to average lunar radius) [NASA/GSFC/Arizona State University].


Station 6a profile - LROC NAC derived topographic profile through Station 6a (profile location shown in the above figure). The straight red line shows a consistent slope in the area of 18°, right in the middle of the range estimated by Jim Irwin while they were taking samples.

Following the tracks of Irwin and Scott is a lot fun - join the adventure, HERE.

Previous Apollo 15 Featured Images:

Hadley Rille and the Mountains of the Moon
Retracing the Steps of Apollo 15
40th Anniversary of Apollo 15 celebrated at Kennedy Space Center 
A Fundamental Point on the Moon
Kaguya captures Hadley Rille, Apollo 15
Water found in Apollo samples 
Apollo metric camera digital elevation model completed
Long-term degradation of optics on the Moon