Earth and Space News: 2011

Wednesday, December 28, 2011

Apollo 8 Was Only, Second and Third Flight for Anders, Borman and Lovell

Summary: Lunar-orbiting mission Apollo 8 was the only, second and third flight for Anders, Borman and Lovell, respectively.

Apollo 8 astronauts (left to right) Command Module Pilot (CMP) James Lovell Jr., Lunar Module Pilot (LMP) William Anders and Commander Frank Borman stand beside the Kennedy Space Center’s (KSC) Apollo Mission Simulator, Nov. 13, 1968; NASA ID S68-50265: National Aeronautics and Space Administration (NASA), Public Domain, via NASA Human Spaceflight

First crewed, lunar-orbiting mission Apollo 8 was the only, second and third flight for Anders, Borman and Lovell, respectively, and marked the second spaceflight mission shared by Borman and Lovell.

The three astronauts launched from the National Aeronautics and Space Administration’s (NASA) John F. Kennedy Space Center on Florida’s Merritt Island Saturday, Dec. 21, 1968. The Apollo 8 spacecraft successfully completed the mission’s objective of 10 lunar orbits. The mission’s command module splashed down Friday, Dec. 27, in the North Pacific Ocean. Mission duration was 6 days 3 hours 0 minutes 42 seconds.

Frank Frederick Borman II (born March 14, 1928) led Apollo 8 as the prime crew’s Commander. James “Jim” Arthur Lovell Jr. (born March 25, 1928) flew as the Command Module Pilot (CMP). William Alison Anders (born Oct. 17, 1933) was designated as Lunar Module Pilot (LMP), even though Apollo 8 did not carry a lunar module (LM). Anders served as the mission’s primary photographer.

Air Force test pilot Frank Borman entered NASA via Astronaut Group 2, also known as the New Nine or the Next Nine. On Wednesday, Sept. 17, 1962, NASA publicly introduced the nine selectees, who included Navy pilot James “Jim” Arthur Lovell Jr. (born March 25, 1928), at the University of Houston’s Cullen Performance Hall.

The first spaceflight for both Borman and Lovell occurred during the Gemini VII (Gemini 7) mission. Gemini 7 (Dec. 4-Dec. 18, 1965) flew as the Gemini spaceflight program’s fourth crewed flight.

In an interview April 13, 1999, for the Johnson Space Center’s Oral History Project, Borman explained his decision to make Apollo 8 his second and last spaceflight. He had joined NASA “. . . to participate in the Apollo Program, the lunar program, and hopefully beat the Russians. I never looked at it for any individual goals. I never wanted to be the first person on the Moon . . .” (page 12-6).

Assignment as Command Pilot for Gemini XII (Gemini 12) occasioned James Lovell’s second spaceflight. The 10th and final crewed Gemini flight started Friday, Nov. 11, 1966, and ended Tuesday, Nov. 15.

Lovell’s fourth and last spaceflight was via Apollo 13, the “lost moon” mission. A cryogenic oxygen tank explosion had compelled returning to Earth without a lunar landing.

In his NASA Oral History interview May 25, 1999, Lovell enthusiastically recalled Apollo 8. “We saw the far side of the Moon, which no had ever seen, you know, before. Live,” Lovell noted. “That was the high point of my career. And I can agree with a lot of people at NASA. I think that was the high point of NASA’s career, too” (pages 12-66, 12-67).

Air Force fighter pilot William Anders joined NASA as one of 14 selectees in Astronaut Group 3. NASA publicly announced The Fourteen Friday, Oct. 18, 1963, at Houston’s Manned Spacecraft Center (MSC), known since Monday, Feb. 19, 1973, as the Lyndon B. Johnson Space Center (JSC).

Participation in the Apollo 8 mission garnered for Anders his only spaceflight. Prior to Apollo 8, he had been designated as Pilot for the backup crew of the Gemini XI (Gemini 11) mission Gemini 11 (Sept. 12-Sept. 15, 1966).

After Apollo 8, Anders was assigned as Command Module Pilot in the backup crew for lunar-landing mission Apollo 11 (July 16-July 24, 1969). His participation in the backup crew reunited him with Lovell, who was designated as Commander of the backup crew.

In his NASA Oral History interview Oct. 8, 1997, Anders described his NASA career as channeling him away from his interests in lunar landing and geology and toward command module expertise. He explained: “. . . and the hook there was that the more expert I became in the Command Module, the more I became welded to the Command Module [and] Command Module guys . . . don’t land.” As for his only spaceflight, Anders observed: “So I feel extremely fortunate to have been able to participate on man’s first flight away from [our] own planet but I would have traded the last lunar landing for the first flight away from the planet” (page 12-10).

The takeaways for Apollo 8 as only, second and third flight for Anders, Borman and Lovell are that Anders only flew via Apollo 8, that Borman made both his spaceflights with Lovell and that Lovell’s later command of Apollo 13 marked his fourth and last spaceflight.

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

Apollo 8 astronauts (left to right) Commander Frank Borman, Command Module Pilot (CMP) James Lovell Jr. and Lunar Module Pilot (LMP) William Anders stand in foreground as Apollo space vehicle (Spacecraft 103/Saturn 503) leaves Kennedy Space Center’s (KSC) Vehicle Assembly Building (VAB) for transport to Launch Complex 39, Pad A: National Aeronautics and Space Administration (NASA), Public Domain, via NASA Human Spaceflight @ https://spaceflight.nasa.gov/gallery/images/apollo/apollo8/html/s68-49397.html; via Flickr @ https://www.flickr.com/photos/nasa2explore/9351677598; via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:The_Apollo_8_prime_crew_stands_in_foreground_as_the_Apollo_space_vehicle.jpg

For further information:

Borman, Frank; and Robert J. Serling. Countdown: An Autobiography. New York NY: Silver Arrow, 1988.

Consolmagno, Guy; and Dan M. Davis. Turn Left at Orion. Fourth edition. Cambridge UK; New York NY: Cambridge University Press, 2011.

Godwin, Robert, comp. and ed. Apollo 8: The NASA Mission Reports. Second edition. Burlington, Canada: Apogee Books, 1971.

Harwood, Catherine. “Frank Borman Oral History Interviews.” NASA History Portal > NASA Johnson Space Center Oral History Project. April 13, 1999.
Available @ https://historycollection.jsc.nasa.gov/JSCHistoryPortal/history/oral_histories/BormanF/bormanff.htm

Kluger, Jeffrey. Apollo 8: The Thrilling Story of the First Mission to the Moon. New York NY: Henry Holt and Company, 2017.

Levy, David H. Skywatching. Revised and updated. San Francisco CA: Fog City Press, 1994.

Lovell, Jim; and Jeffrey Kluger. Apollo 13. First Mariner Books edition. Boston MA; New York NY: Houghton Mifflin, 2006.

Lovell, Jim; and Jeffrey Kluger. Lost Moon: The Perilous Voyage of Apollo 13. Boston MA: Houghton Mifflin, 1994.

Marriner, Derdriu. “First Crewed Lunar Orbiting Mission Apollo 8 Launched Dec. 21, 1968.” Earth and Space News. Wednesday, Dec. 21, 2011.
Available @ https://earth-and-space-news.blogspot.com/2011/12/first-crewed-lunar-orbiting-mission.html

Moore, Patrick, Sir. Philip’s Atlas of the Universe. Revised edition. London UK: Philip’s, 2005.

Orloff, Richard W. “Apollo 8 The Second Mission: Testing the CSM in Lunar Orbit.” Apollo by the Numbers: A Statistical Reference: 31-50. NASA History Series. NASA SP 4029. Washington DC: NASA Headquarters Office of Policy and Plans, 2000.
Available via NASA History @ https://history.nasa.gov/SP-4029.pdf

Rollins, Paul. “William A. Anders Oral History Interviews.” NASA History Portal > NASA Johnson Space Center Oral History Project. Oct. 8, 1997.
Available @ https://historycollection.jsc.nasa.gov/JSCHistoryPortal/history/oral_histories/AndersWA/anderswa.htm

Stone, Ron. “James A. Lovell Oral History Interviews.” NASA History Portal > NASA Johnson Space Center Oral History Project. May 25, 1999.
Available @ https://historycollection.jsc.nasa.gov/JSCHistoryPortal/history/oral_histories/LovellJA/lovellja.htm

Williams, David R.; and E. (Edwin) Bell II, cur. “Apollo 8.” NASA Goddard Space Flight Center > NMC (NASA Space Science Data Coordinated Archive Master Catalog) > Spacecraft. Version 5.1.2.
Available @ https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1969-043A

Wednesday, December 21, 2011

First Crewed Lunar Orbiting Mission Apollo 8 Launched Dec. 21, 1968

Summary: First crewed lunar orbiting mission Apollo 8 launched Dec. 21, 1968, made 10 lunar orbits and splashed down Dec. 27.

North American Rockwell artist’s concept illustrates Command Service Modules (CSM), still attached to Saturn V third stage (S-IVB), heading away from Earth at approximately 24,300 miles per hour; NASA ID S68-51304: National Aeronautics and Space Administration (NASA), Generally not subject to copyright in the United States; may use this material for educational or informational purposes, including photo collections, textbooks, public exhibits, computer graphical simulations and Internet Web pages; general permission extends to personal Web pages, via NASA Image and Video Library

First crewed lunar orbiting mission Apollo 8 launched Dec. 21, 1968, made 10 revolutions around Earth’s moon and successfully splashed down Dec. 27 in the North Pacific Ocean.

The National Aeronautics and Space Administration (NASA) configured the Apollo 8 mission as “its first mission designed to orbit men around the Moon,” according to the agency’s Apollo 8 Press Kit (page 1), released Dec. 15, 1968. The Press Kit described Apollo 8 as “the second manned flight in the Apollo program and the first manned flight on the Saturn V rocket, the United States’ largest launch vehicle.”

About two and one-third months earlier, the Saturn IB rocket had launched Apollo 7 on Friday, Oct. 11, 1968, at 15:02:45 GMT/UTC (11:02 a.m. EST) from Launch Complex 34 (LC-34) as the first crewed Apollo space mission. The Apollo 7 crew of Commander Walter “Wally” Marty Schirra Jr. (March 12, 1923-May 3, 2007), Command Module Pilot (CMP) Donn Fulton Eisele (June 23, 1930-Dec. 2, 1987) and Lunar Module Pilot (LMP) Ronnie Walter Cunningham (born March 16, 1932) completed 163 low Earth orbits. Splashdown occurred Tuesday, Oct. 22, in the North Atlantic Ocean.

Apollo 8 launched on time Saturday, Dec. 21, 1968, at 12:51:00 Greenwich Mean Time/Coordinated Universal Time (7:51 a.m. Eastern Standard Time). The launch, which took place at central Florida’s John F. Kennedy Space Center (KSC), marked the first use of Launch Pad 39-A. The mission’s astronauts were Commander Frank Frederick Borman II (born March 14, 1928), CMP James “Jim” Arthur Lovell Jr. (born March 25, 1928) and LMP William Alison Anders (born Oct. 17, 1933).

The Saturn V launch vehicle’s S-IVB third stage achieved translunar injection after one and one-half Earth orbits, according to freelance space writer Richard Orloff’s Apollo by the Numbers, published by NASA in 2000 (page 35). Translunar injection occurred at 15:47:05 GMT/UTC (10:47 a.m. EST), 2 hours 56 minutes 05.51 seconds after liftoff (002:56:05.51 Ground Elapsed Time GET). The injection occurred at a velocity of 35, 504.41 feet per second (fps; 24,207.55 miles per hour) and at an altitude of 187.221 nautical miles.

A maneuver 24 minutes 54 seconds later by the Apollo 8 mission’s service module reaction control system (RCS) separated Command-Service Module (CSM) 103 from the S-IVB. The separation occurred at 16:11:59 GMT/UTC (11:11 a.m. EST; 003:20:59.3 GET).

Two evasive maneuvers, instigated by the service module’s reaction control system (RCS), were performed to keep the spacecraft at a safe distance from the S-IVB. The first maneuver was performed at 16:31:01 GMT/UTC (11:31 a.m. EST; 003:40:01 GET), at 1.1 feet per second. The second maneuver occurred at 17:36:01 (12:36 p.m. EST; 004:45:01 GET), at 7.7 feet per second.

The separation was intended to place the S-IVB on a slingshot trajectory for a flyby of the moon’s trailing edge prior to insertion into a solar orbit. The slingshot maneuver was initiated at 17:35:56 GMT/UTC (12:35 p.m. EST; 004:44:56.63 GET).

The S-IVB made its closest lunar approach, at 682 nautical miles, Christmas Eve, Tuesday, Dec. 24, at 10:49:55 (5:49 a.m. EST; 069:58:55.2 GET). The selenographic coordinates of the closest approach were 19.2 degrees north latitude at 88.0 degrees east longitude. Apollo by the Numbers details the S-IVB’s solar orbit with a periodicity of 340.8 days and with apsides of 79.770 million nautical miles for aphelion and 74.490 million nautical miles for perihelion.

Insertion of CSM-103 into lunar orbit happened Christmas Eve at 09:59:20 GMT/UTC (4:59 a.m. EST; 069:08:20.4 GET). NASA’s Apollo 8 Mission Report states: “Ten revolutions were completed during the 20 hours 11 minutes spent in lunar orbit” (1-1).

The mission’s trans-Earth injection for leaving lunar orbit for a return-to-Earth trajectory began with ignition of the service propulsion system (SPS) engine at 06:10:16 GMT/UTC (1:10 a.m. EST; 089:19:16.6 GET) on Christmas, Wednesday, Dec. 25. The 203.7-second maneuver was initiated at an altitude of 60.2 nautical miles.

The command and service modules separated Friday, Dec. 27, at 15:19:48 GMT/UTC (10:19 a.m. EST; 146:28:48.0 GET). Apollo by the Numbers noted the unavailability of radar tracking data for the service module’s re-entry into Earth’s atmosphere but suggested a good correlation of photographic coverage information with the service module’s predicted trajectory.

The command module splashed down at 15:51:42 GMT/UTC (10:51 a.m. EST; 147:00:42.0 GET) in the North Pacific Ocean. NASA’s Apollo 8 Mission Report noted: “The total flight duration was 147 hours 42 seconds” (1-2). The recovery ship, USS Yorktown, reached the command module at 18:13 GMT/UTC (1:13 p.m. EST; 149:22 GET). The Mission Report placed splashdown at “8 degrees 8 minutes north latitude and 165 degrees 1 minute west longitude, as determined by the primary recovery ship USS Yorktown” (1-2).

The takeaways for first crewed lunar orbiting mission Apollo 8’s launch Dec. 21, 1968, is that the spaceflight of 147 hours 42 minutes demonstrated the viability of crewed flight to the moon and suggested the possibility of lunar landing missions in the near future.

North American Rockwell artist’s concept illustrates starting of 20,500-pound thrust engine over lunar far side in preparation for return to Earth; NASA ID S68-51302: National Aeronautics and Space Administration (NASA), Generally not subject to copyright in the United States; may use this material for educational or informational purposes, including photo collections, textbooks, public exhibits, computer graphical simulations and Internet Web pages; general permission extends to personal Web pages, via NASA Image and Video Library

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

Borman, Frank; and Robert J. Serling. Countdown: An Autobiography. New York NY: Silver Arrow, 1988.

Consolmagno, Guy; and Dan M. Davis. Turn Left at Orion. Fourth edition. Cambridge UK; New York NY: Cambridge University Press, 2011.

Godwin, Robert, comp. and ed. Apollo 8: The NASA Mission Reports. Second edition. Burlington, Canada: Apogee Books, 1971.

Levy, David H. Skywatching. Revised and updated. San Francisco CA: Fog City Press, 1994.

Lovell, Jim; and Jeffrey Kluger. Apollo 13. First Mariner Books edition. Boston MA; New York NY: Houghton Mifflin, 2006.

Lovell, Jim; and Jeffrey Kluger. Lost Moon: The Perilous Voyage of Apollo 13. Boston MA: Houghton Mifflin, 1994.

Marriner, Derdriu. “Jettisoned LM Snoopy Descent Stage Appeared Near Taruntius Crater.” Earth and Space News. Wednesday, May 11, 2011.
Available @ https://earth-and-space-news.blogspot.com/2011/05/jettisoned-lm-snoopy-descent-stage.html

Moore, Patrick, Sir. Philip’s Atlas of the Universe. Revised edition. London UK: Philip’s, 2005.

NASA JSC Web Team. “Apollo: 1963-1972.” NASA JSC (National Aeronautics and Space Administration Johnson Space Center) History Portal. Updated July 16, 2010.
Available @ https://historycollection.jsc.nasa.gov/JSCHistoryPortal/history/apollo.htm

NASA JSC Web. “Mission Transcripts: Apollo 8.” NASA JSC (National Aeronautics and Space Administration Johnson Space Center) History Portal. Updated July 16, 2010.
Available @ https://historycollection.jsc.nasa.gov/JSCHistoryPortal/history/mission_trans/apollo8.htm

NASA Manned Spacecraft Center, comp. Analysis of Apollo 8 Photography and Visual Observations. NASA SP-201. Washington DC: National Aeronautics and Space Administration Office of Technology Utilization Scientific and Technical Information Division, 1969.
Available via NASA NTRS (NASA Technical Reports Server) @ https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19700005062.pdf

National Aeronautics and Space Administration. Apollo 8 Mission Report. Prepared by Mission Evaluation Team. MSC-PA-R-69-1. Houston TX: National Aeronautics and Space Administration Manned Spacecraft Center, February 1969.
Available via NASA History-Apollo Flight Journal @ https://history.nasa.gov/afj/ap08fj/pdf/a08-missionreport.pdf

National Aeronautics and Space Administration. Apollo 8 Mission (AS-503) Post Launch Mission Operation Report No. 1. Prepared by Apollo Program Office-MAO. Report No. M-932-68-08. Washington DC: National Aeronautics and Space Administration Office of Manned Space Flight, Feb. 10, 1969.
Available @ https://history.nasa.gov/afj/ap08fj/pdf/a08-postlaunch-rep.pdf

National Aeronautics and Space Administration. Apollo 8 Press Kit. Release no. 68-208. Dec. 15, 1968. Washington DC: National Aeronautics and Space Administration, 1969.
Available via NASA History-Apollo Flight Journal @ https://history.nasa.gov/afj/ap08fj/pdf/a08-presskit.pdf
Available @ https://www.nasa.gov/specials/apollo50th/pdf/A08_PressKit.pdf
Available via NASA NTRS (NASA Technical Reports Server) @ https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19690003059.pdf

National Aeronautics and Space Administration. Apollo 8 Technical Air-to-Ground Voice Transcription (Goss Net 1). Prepared for Data Logistics Office Test Division Apollo Spacecraft Program Office. Houston TX: National Aeronautics and Space Administration Manned Spacecraft Center, December 1968.
Available via Johnson Space Center (JSC) History Portal @ https://historycollection.jsc.nasa.gov/JSCHistoryPortal/history/mission_trans/AS08_TEC.PDF

National Aeronautics and Space Administration. Apollo 8 Technical Crew Debriefing. Prepared by Mission Operations Branch Flight Crew Support Division. Houston TX: Manned Spacecraft Center, Jan. 2, 1969.
Part 1 (pages i-70): Available via ibiblio @ https://www.ibiblio.org/apollo/Documents/Apollo8-TechnicalDebriefing-Martin-1.pdf
Part 2 (pages 71-149): Available via ibiblio @ https://www.ibiblio.org/apollo/Documents/Apollo8-TechnicalDebriefing-Martin-1.pdf

Ransford, Gary A.; Wilbur R. Wollenhaupt; and Robert M. Bizzell. Lunar Landmark Locations -- Apollo 8, 10, 11, and 12 Missions. NASA Technical Note TN D-6082. Washington DC: National Aeronautics and Space Administration, November 1970.
Available via NASA History @ https://history.nasa.gov/afj/ap10fj/pdf/19710002567_lunar-landmark-locations-a8-a10-a11-a12.pdf
Available via NASA NTRS (NASA Technical Reports Server) @ https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19710002567.pdf

Smithsonian National Air and Space Museum. “Apollo 10 (AS-505).” Smithsonian National Air and Space Museum > Missions > Apollo 10.
Available @ https://airandspace.si.edu/explore-and-learn/topics/apollo/apollo-program/orbital-missions/apollo10.cfm

Smithsonian National Air and Space Museum. “Saturn V Launch Vehicle.” Smithsonian National Air and Space Museum > Spacecraft & Vehicles > Saturn V Launch Vehicle.
Available @ https://airandspace.si.edu/explore-and-learn/topics/apollo/apollo-program/spacecraft/saturn_v.cfm

Woods, W. David; and Frank O’Brien. “Apollo 8 Photography Index.” NASA History > Apollo Flight Journal > The Apollo 8 Flight Journal.
Available @ https://history.nasa.gov/afj/ap08fj/a08-photoindex.html

Woods, W. David; and Frank O’Brien. “Apollo 8 Documents.” NASA History > Apollo Flight Journal > The Apollo 8 Flight Journal.
Available @ https://history.nasa.gov/afj/ap08fj/index.html

Zimmerman, Robert. Genesis: The Story of Apollo 8: The First Manned Flight to Another World. New York NY: Four Walls Eight Windows, 1998.

Wednesday, December 14, 2011

Nick Howes Considers Possible Orbits for Apollo 10 Lunar Module Snoopy

Summary: Royal Astronomical Society Fellow Nick Howes considers possible orbits for Apollo 10 Lunar Module Snoopy, lost in a solar orbit since May 23, 1969.

The Snoopy_ES trajectory devised by trajectory specialist Mike Loucks, based on retired NASA orbit expert Emil Schiesser’s spherical post-burn state vector, might guide Nick Howes and Faulkes Telescope Project’s (FTP) Project Snoopy: Nick Howes to Faulkes Telescope Project, via Facebook Nov. 28, 2011

Royal Astronomical Society Fellow Nick Howes considers possible orbits for Apollo 10 Lunar Module Snoopy, lost in an unknown orbit around the sun since Friday, May 23, 1969.

Two months ago, in September, announcements of Project Snoopy, conducted by Nick Howes and Faulkes Telescope Project (FTP), appeared in articles published Monday, Sept. 19, by United Kingdom astronomer and Meteorwatch website creator Adrian West (moniker: VirtualAstro) in Universe Today and by science and tech journalist Alasdair Wilkings for io9 Gizmodo. Space historian Robert Zane Pearlman introduced the daunting project Tuesday, Sept. 20, in articles for Space. com and on his collectSPACE website.

In his Sept. 28, 2011, post, “Finding Snoopy,” on The Astrogator’s Guild, “Finding Snoopy,” lunar, libration-point and deep-space trajectory expert and Space Exploration Engineering (SEE) co-founder Mike Loucks (moniker: Astrogator Mike) announced his involvement with Nick Howes and the Faulkes Telescope Project. Loucks is closely collaborating with two Apollo mission veterans to determine Lunar Module Snoopy’s trajectory. Charles “Chuck” F. Deiterich operated as a Retrofire (RETRO) Officer in Mission Control at the Manned Space Center, known as the Lyndon B. Johnson Space Center (JSC) since Feb. 19, 1973. Emil Ray Schiesser’s responsibilities in the Mission Planning and Analysis Division (MPAD) included orbit determination.

Loucks also acknowledges invaluable input from SEE co-owner John Carrico, who posts as Astrogator John on The Astrogator’s Guild, and Galaxy Zooite Mark Redgwell (@Blackprojects). Loucks notes that he had had “several discussions (and will have several more) with my good friend John Carrico (Astrogator_John).” Loucks devised a spherical post-burn state vector from Apollo 10 transcript excerpts tweeted to him by Redgwell. The excerpts concern the post-docking separation that jettisoned Lunar Module Snoopy toward a solar orbit.

Loucks determines three possible trajectories for Lunar Module Snoopy’s departure from a lunar orbit and entrance into a solar orbit. He produces trajectory number one from Emil Schiesser’s spherical post-burn state vector. Trajectory number two derives from the Apollo 10 transcript. Schiesser’s combined pre-burn state and delta-v (∆v; orbital velocity) vector yields trajectory number three.

All three trajectories leave lunar orbit with radial velocity away from the sun. A retrograde component reduces the major semi-axis (also known as semi-major axis), which represents half of an elllipse’s major axis, or longest diameter. Snoopy’s orbital period emerges, at approximately 342 days, as shorter than Earth’s solar revoluation. Snoopy’s synodic period, the time for returning to the same position relative to the sun as seen from Earth, approximates 14.7 years.

Loucks presents graphics for the first two trajectories. Trajectory number one is labeled as Snoopy_ES_PostBurn (Snoopy_ES). Trajectory number two is referenced as Snoopy_Report_Vec (Snoopy_RV).

The trajectories reveal initial closeness to Earth after Snoopy’s expulsion from lunar orbit. Then, Snoopy’s solar orbit distanced the lunar module from Earth over the next one and one-half decades. On Thursday, Feb. 23, 1984, the two trajectories neared the Earth-sun, with placement between Earth and the sun.

Loucks’ plotting of the two trajectories’ orbital period history shows much perturbation of their orbits by Earth. His findings reveal that the “drastically different” Earth encounters and perturbations experienced by the two trajectories account for increasing spread between the two scenarios.

The graphics for Saturday, Oct. 1, 2011, find Snoopy away from Earth. Trajectory one, Snoopy_ES, bests trajectory two with a radius of 0.68 astronomical units (au) from Earth. Trajectory two, Snoopy_RV, has a radius of 1.64 au from Earth. The International Astronomical Union (IAU) defines the Sun-Earth distance as one astronomical unit, equal exactly to 149,597,870,700 meters (149,597,870.7 kilometers).

Loucks concludes that Project Snoopy is “going to be very hard” because the Apollo 10 lunar module is “both far away and receding.” He makes a hopeful assessment of Nick Howes and Faulkes Telescope Project’s use of his calculations: “I’ll let Nick and his folks solve that. They are the gurus in that part. They know how to find asteroids and comets and have the people-power (and the mojo: Sir Patrick Moore!).”

In a Facebook post Monday, Nov. 28, Nick Howes announced the near-completion of orbital calculations for Project Snoopy. The attached graphic depicts the trajectory for Snoopy_ES.

The takeaway for Nick Howes’ consideration of possible orbits for Apollo 10 Lunar Module Snoopy is that the Faulkes Telescope Project’s search for the lost artifact may be guided by the first trajectory devised by trajectory specialist Mike Loucks and based on retired NASA orbit expert Emil Schiesser’s post-burn state vector.

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

Apollo 10 Lunar Module (LM) Snoopy’s ascent stage, photographed May 26, 1969, from Command Module Charlie Brown, during approach, from below, for docking; background shows near side’s eastrn limb, at about 120 degrees east longitude; red/blue diagonal line is spacecraft window; NASA ID AS10-34-5112; created Dec. 1, 1965; NAID 16682242: Access Unrestricted, Use Unrestricted, via National Archives Catalog @ https://catalog.archives.gov/id/16682242; Public Domain, via NASA Image and Digital Library @ https://images.nasa.gov/details-as10-34-5112; Project Apollo Archive (Apollo Image Gallery), Public Domain, via Flickr @ https://www.flickr.com/photos/projectapolloarchive/21298941434; Public Domain, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:AS10-34-5112_-_Apollo_10_-_Apollo_10_Mission_image_-_LM_approaching_CSM_-_NARA_-_16682242.jpgvia NASA Human Spaceflight @ https://spaceflight.nasa.gov/gallery/images/apollo/apollo10/html/as10-34-5112.html

For further information:

Ashford, Adrian R. “Faulkes Telescope Project Launched.” Sky & Telescope > Astronomy News. March 29, 2004.
Available @ https://www.skyandtelescope.com/astronomy-news/faulkes-telescope-project-launched/

Astrogator Mike (Mike Loucks). “Finding Snoopy.” The Astrogator’s Guild. Sept. 28, 2011.
Available @ https://astrogatorsguild.com/?p=240

Cernan, Eugene. The Last Man on the Moon: Eugene Cernan and America’s Race in Space. New York NY: St. Martin’s Press, 1999.

Dunbar, Brian; and Kathleen Zona, ed. “Snoopy Soars With NASA at Charles Schulz Museum.” NASA > News & Features > News Topics > NASA History & People. Jan. 5, 2009.
Available @ https://www.nasa.gov/topics/history/features/snoopy.html

Gladden, Becca. “Nick Howes Talks Science and the Importance of Following Your Dreams.” CareerThoughts. Jan. 15, 2011.
Available @ http://careerthoughts.com/nick-howes/

Godwin, Robert, comp. and ed. Apollo 10: The NASA Mission Reports. Second edition. Burlington, Canada: Apogee Books, 2000.

Marriner, Derdriu. “Nick Howes and Faulkes Telescope Project Seek Lost Apollo 10 LM Snoopy.” Earth and Space News. Wednesday, Sept. 28, 2011.
Available @ https://earth-and-space-news.blogspot.com/2011/09/nick-howes-and-faulkes-telescope.html

Marriner, Derdriu. “Snoopy and Charlie Brown Are Hugging Each Other in Apollo 10 Docking.” Earth and Space News. Wednesday, May 18, 2011.
Available @ https://earth-and-space-news.blogspot.com/2011/05/snoopy-and-charlie-brown-are-hugging.html

NASA JSC Web. “Mission Transcripts: Apollo 10.” NASA JSC (National Aeronautics and Space Administration Johnson Space Center) History Portal. Updated July 16, 2010.
Available @ https://historycollection.jsc.nasa.gov/JSCHistoryPortal/history/mission_trans/apollo10.htm

National Aeronautics and Space Administration. “11.3 Photographic Results.” Apollo 10 Mission Report: 11.3-11.5. MSC-00126. Houston TX: National Aeronautics and Space Administration Manned Spacecraft Center, August 1969.
Available @ https://www.hq.nasa.gov/alsj/a410/A10_MissionReport.pdf

National Aeronautics and Space Administration. Apollo 10 Mission (AS-505) Post Launch Mission Operation Report No. 1. Report No. M-932-69-10. Washington DC: National Aeronautics and Space Administration, May 26, 1969.
Available @ https://history.nasa.gov/afj/ap10fj/pdf/a10-postlaunch-rep.pdf

National Aeronautics and Space Administration. Apollo 10 Mission Report. MSC-00126. Houston TX: National Aeronautics and Space Administration Manned Spacecraft Center, August 1969.
Available @ https://www.hq.nasa.gov/alsj/a410/A10_MissionReport.pdf

National Aeronautics and Space Administration. Apollo 10 Press Kit. Release no. 69-68. May 7, 1969. Washington DC: National Aeronautics and Space Administration, 1969.
Available @ https://www.history.nasa.gov/alsj/a410/A10_PressKit.pdf

National Aeronautics and Space Administration. Apollo 10 Technical Air-to-Ground Voice Transcription (Goss Net 1). Prepared for Data Logistics Office Test Division Apollo Spacecraft Program Office. Houston TX: National Aeronautics and Space Administration Manned Spacecraft Center, May 1969.
Available via Johnson Space Center (JSC) History Portal @ https://historycollection.jsc.nasa.gov/JSCHistoryPortal/history/mission_trans/AS10_TEC.PDF

NickAstronomer (Nick Howes). “Faulkes Telescopes.” Space Is Ace. Oct. 19, 2011.
Available @ http://spaceisace-nickastronomer.blogspot.com/2011/10/faulkes-telescopes.html

Nick Astronomer (Nick Howes). “In the Beginning.” Space Is Ace. Oct. 18, 2011.
Available @ http://spaceisace-nickastronomer.blogspot.com/2011/10/in-beginning.html

Nick Howes‎ to Faulkes Telescope Project. “Project Snoopy to start up soon, latest orbital calculations almost complete. We may need to cone search back through a few years of archive data, and maybe see if other large survey scopes have also got data for the past few years . . . but here's a nice orbital image to whet your appetite! Complex isn't the word!” Facebook. Nov. 28, 2011.
Available @ https://www.facebook.com/photo.php?fbid=10150572616589348

Orloff, Richard W. “Apollo 10 The Fourth Mission: Testing the LM in Lunar Orbit.” Apollo by the Numbers: A Statistical Reference: 71-88. NASA History Series. NASA SP 4029. Washington DC: NASA Headquarters Office of Policy and Plans, 2000.
Available @ https://history.nasa.gov/SP-4029.pdf

Pearlman, Robert. “The Search for Snoopy: Astronomers and Students to Look for Lost Apollo 10 Module.” collectSpace. Sept. 20, 2011.
Available @ http://www.collectspace.com/news/news-092011a.html

Pearlman, Robert Z. (Zane). “The Search for ‘Snoopy’: Astronomers & Students Hunt for NASA’s Lost Apollo 10 Module.” Space.com > Spaceflight. Sept. 20, 2011.
Available @ https://www.space.com/13010-snoopy-nasa-lost-apollo-10-lunar-module-search.html

Seligman, Courtney. “Radial Velocity.” CSeligman.com > Online Astronomy Text > Stars and Stellar Systems.
Available @ https://cseligman.com/text/stars/radialvelocity.htm

Shepard, Alan; Deke Slayton; Jay Barbree; and Howard Benedict. Moon Shot: The Inside Story of America's Race to the Moon. Atlanta GA: Turner Publishing Inc., 1994.

Stanley, Will. “The Last Man on the Moon.” Science Museum Blog. Sept. 24, 2013.
Available @ https://blog.sciencemuseum.org.uk/the-last-man-on-the-moon/

STEM Learning Limited. “Teaching Astronomy in UK Schools.” STEM Learning Limited > Resources.
Available @ https://www.stem.org.uk/elibrary/resource/31566

TRW Systems Group. Apollo 10 Mission Report Supplement 2: Guidance, Navigation, and Control Systems Performance Analysis. MSC-00126. Houston TX: National Aeronautics and Space Administration Manned Spacecraft Center, November 1969.
Available @ http://www.ibiblio.org/apollo/Documents/Apollo10MissionReport-Supplement2-GuidanceAnalysis.pdf

VirtualAstro (Adrian West). “The Mission to Find the Missing Lunar Module.” Universe Today. Sept. 19, 2011.
Available @ https://www.universetoday.com/89043/the-mission-to-find-the-missing-lunar-module/

Wilkins, Alasdair. “The Search Is on for a Lost Piece of the Apollo Program’s History.” io9 Gizmodo > Space Exploration. Sept. 19, 2011.
Available @ https://io9.gizmodo.com/the-search-is-on-for-a-lost-piece-of-the-apollo-program-5841869

Williams, David R.; and E. (Edwin) Bell II, cur. “Apollo 10.” NASA Goddard Space Flight Center > NMC (NASA Space Science Data Coordinated Archive Master Catalog) > Spacecraft. Version 5.1.0, July 10, 2019.
Available @ https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1969-043A

Woods, W. David; Robin Wheeler; and Ian Roberts. “Apollo 10 Image Library.” NASA History > Apollo Flight Journal > The Apollo 10 Flight Journal. 2011.
Available @ https://history.nasa.gov/afj/ap10fj/as10-image-library.html

Woods, W. David; Robin Wheeler; and Ian Roberts. “Apollo 10 Mission Documents.” NASA History > Apollo Flight Journal > The Apollo 10 Flight Journal. 2011.
Available @ https://history.nasa.gov/afj/ap10fj/as10-documents.html

Saturday, December 10, 2011

Tree Risk Assessment: Tree Failures From Defects and From Wind Loads

Summary: Tree risk assessment helps tree specialists Sharon Lilly, Nelda Matheny and E. Thomas Smiley to associate tree failures with defects or with wind loads.

Open-grown trees in windy areas need to be monitored for severity of wind load effects; windswept Monterey cypresses (Cupressus macrocarpa) in San Mateo, Silicon Valley, Northern California; Thursday, March 29, 2007, 22:00:00: Philippe Teuwen (doegox), CC BY SA 2.0 Generic, via Flickr

Tree risk assessment, evaluation and management allow arborists, assessors and managers to anticipate and treat tree failure, according to Tree Risk Assessment: A Foundation in the December 2011 issue of Arborist News.

Sharon Lilly of the International Society of Arboriculture, Nelda Matheny of HortScience, Inc., and E. Thomas Smiley of Bartlett Tree Research Laboratory balance benefits and safety. Beauty and security concern tree risk managers whose responsibilities in property management and ownership count upon budgets and resources for contracting tree risk assessors and arborists. Considerations of aesthetics and of well-being dominate tree risk assessment since prescient inspections and preventative interventions depend upon identification and interpretation of hidden and visible defects.

Arborists emphasize cosmetic and practical aspects of providing lightning protection, pruning, removal, replacement, support and transplant services that enhance quality of life and value of property.

Trees function as beneficial beauties by anchoring soil against erosion, breathing in carbon dioxide, breathing out oxygen, offering fruits and nuts, providing shade and sheltering wildlife. The compaction, extreme temperatures, mechanical injuries, nutrient deficiencies, overfeeding, overwatering, pathogens, pests, pH imbalances, poisons and under-watering that do not kill trees given them shorter lifespans.

Tree risk assessment has a "limited ability to predict natural processes" such as decay progression rates and response growth and non-visible defects such as bark occlusions. Tree risk assessors inspect branch patterns and sizes since branches that are low-lying, thick-clustered and under 1 inch (2.5 centimeters) in diameter generally fail less forcefully.

Treetop-high branches over 4 inches (10 centimeters) in diameter join dead, decayed, decaying, dying trunks in enlarging impact zones to more than 1.5 times tree heights.

Gravity keeps fallen branches over 4 inches (10 centimeters) in diameter within drip circles the radii of the longest branches and root circles thrice tree heights. It leads to identifications of targets that may suffer "serious damage, injury, or death" since "Tree failures during normal weather conditions are sometimes predictable and preventable."

Tree risk assessment mentions targets by "the amount of time that they are within the target zone" to determine constant, frequent, occasional or rare occupancy rates. Targets such as buildings, electric lines, parking and play areas and roadways need to receive constant, static classifications since they are "fixed or not readily moved."

Mobile targets such as animals, pedestrians and vehicles and such movable targets as picnic tables, sculptures and swing sets occupy constant, frequent, occasional or rare classifications.

Constant, static targets prompt predictable if not preventative tree risk assessment damage estimates that prove to be less or more prescriptive and proscriptive through site factors. Construction, extreme weather events, groundwater levels, microbursts, precipitation patterns, prevailing winds and wind exposure as well as soil compaction, erosion and saturation qualify as site factors.

Trees reveal lower wind load tolerances where freezing rain, heavy snow and severe storms are rare by tolerating "wind speeds that commonly occur in an area." Research shows that "Tree failures under normal wind speeds are usually associated with serious, uncorrected, or unmitigated structural defects or other conditions, alone or in combination."

Tree risk assessment tells arborists, master gardeners, master naturalists and tree stewards to watch for hidden and visible defects and for prevailing and severe wind loads.

field demonstration of pre-removal inspection of wind load-caused damage to English oak (Quercus robur): Victoria Whaley/Bugwood.org, CC BY 3.0 United States, via Forestry Images

Acknowledgment

My special thanks to:
talented artists and photographers/concerned organizations who make their fine images available on the internet;
University of Illinois at Urbana-Champaign for superior on-campus and on-line resources.

Image credits:

Wind load effects may be severe for open-grown trees in windy areas; windswept Monterey cypresses (Cupressus macrocarpa) in San Mateo, Silicon Valley, Northern California; Thursday, March 29, 2007, 22:00:00: Philippe Teuwen (doegox), CC BY SA 2.0 Generic, via Flickr @ https://www.flickr.com/photos/doegox/477454523/

field demonstration of pre-removal inspection of wind load-caused damage to English oak (Quercus robur): Victoria Whaley/Bugwood.org, CC BY 3.0 United States, via Forestry Images @ https://www.forestryimages.org/browse/detail.cfm?imgnum=5432254

For further information:

Gilman, Ed. 2011. An Illustrated Guide to Pruning. Third Edition. Boston MA: Cengage.

Hayes, Ed. 2001. Evaluating Tree Defects. Revised, Special Edition. Rochester MN: Safe Trees.

Marriner, Derdriu. 15 October 2011. “Five Tree Felling Plan Steps for Successful Removals and Worker Safety.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2011/10/five-tree-felling-plan-steps-for.html

Marriner, Derdriu. 13 August 2011. “Natives and Non-Natives as Successfully Urbanized Plant Species.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2011/08/natives-and-non-natives-as-successfully.html

Marriner, Derdriu. 11 June 2011. “Tree Ring Patterns for Ecosystem Ages, Dates, Health and Stress.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2011/06/tree-ring-patterns-for-ecosystem-ages.html

Marriner, Derdriu. 9 April 2011. “Benignly Ugly Tree Disorders: Oak Galls, Powdery Mildew, Sooty Mold, Tar Spot.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2011/04/benignly-ugly-tree-disorders-oak-galls.html

Marriner, Derdriu. 12 February 2011. “Tree Load Can Turn Tree Health Into Tree Failure or Tree Fatigue.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2011/02/tree-load-can-turn-tree-health-into.html

Marriner, Derdriu. 11 December 2010. “Tree Electrical Safety Knowledge, Precautions, Risks and Standards.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2010/12/tree-electrical-safety-knowledge.html

Smiley, E. Thomas; Nelda Matheny; and Sharon Lilly. December 2011. "Tree Risk Assessment: A Foundation." Arborist News 20(6): 12-20.

Smiley, E. Thomas; Nelda Matheny; Sharon Lilly. 2011. Best Management Practices - Tree Risk Assessment. Champaign IL: International Society of Arboriculture.

Wednesday, December 7, 2011

Second of Two 2011 Total Lunar Eclipses Happens Saturday, Dec. 10

Summary: The second of two 2011 total lunar eclipses happens Saturday, Dec. 10, and disfavors Antarctica, South America and parts of West and Southern Africa.

details of total lunar eclipse of Saturday, Dec. 10, 2011: "Permission is freely granted to reproduce this data when accompanied by an acknowledgment, Eclipse Predictions by Fred Espenak and Jean Meeus (NASA's GSFC)," via NASA Eclipse Web Site

The second of two 2011 total lunar eclipses happens Saturday, Dec. 10, disfavors Antarctica, South America, most of West Africa and a slice of Southern Africa, and favors Australia, northernmost North America, northern Europe and most of Asia with visibility of the entire event.

In northernmost North America, all of Alaska, northern Canada and most of Greenland enjoy visibility of the entire eclipse. Northern Europe’s all eclipse visibility encompasses northern Scandinavia and northwesternmost Russia, especially the Kola Peninsula. Asia’s visibility of the entire event spans Asian Russia, East Asia, Southeast Asia, eastern Central Asia and northeastern South Asia.

Antarctica, South America, parts of West and a slice of South Africa (southern Angola, western Namibia, western South Africa) are excluded from visibility of 2011’s second lunar eclipse. Visibility of portions of the lunar event is available to those areas of Asia, Europe and North America that fall outside the complete viewing path. Fred Espenak, known as “Mr. Eclipse,” notes on the NASA Eclipse Web Site that occurrence of the ecliptic event’s early phases before moonrise precludes their observation by viewers in Africa and Europe. Most of North America misses out on visibility of the entire event because the moon is setting while the eclipse is in progress.

According to NASA’s Eclipse Web Site, the second of two 2011 total lunar eclipses begins with the moon’s entrance into Earth’s penumbra (P1) at 11:33:32 Universal Time (6:33 a.m. Eastern Standard Time) and finishes with the moon’s exit from Earth’s penumbra (P4) of 17:30 UT (12:30 p.m. EST). The penumbra consists of the lighter outer region of Earth’s shadow.

The eclipse begins partiality, designated as U1, at 12:45:42 UT (7:45 a.m. EST). Partiality comprises partial coverage of the lunar surface by Earth’s umbra, the shadow’s darkest, inner region.

Totality, designated as U2, begins at 14:06:16 UT (9:06 a.m. EST). During totality, Earth’s umbra covers the visible lunar surface.

Greatest eclipse takes place at 14:31:49 UT (9:31 a.m. EST). Greatest eclipse indicates the instant of the moon’s closest passage to the axis of Earth’s shadow.

The end of totality happens at 14:57:24 UTC (9:57 a.m. EST). U3 designates the instant of exit from totality.

Partiality ends at 16:17:58 UT (11:17 a.m. EST). U4 is the designator for partiality’s end time.

The lunar event ends with the moon’s exit from Earth’s penumbra at 17:30:00 UT (12:30 p.m. EST). P4 designates the end of the penumbral eclipse.

The second of two 2011 lunar eclipses has a total duration of 5 hours 56 minutes 28 seconds. Within the total time frame, partiality takes up 3 hours 32 minutes 16 seconds. Totality accounts for 51 minutes 8 seconds within the total time frame.

The December 2011 total lunar eclipse closes a year that featured only two lunar eclipses, with both categorized as total lunar eclipses from Earth’s perspective. A lag of two and one-third years separates the December 2011 total lunar eclipse and the next total lunar eclipse, which takes place Tuesday, April 15, 2014.

The second of two 2011 total lunar eclipses belongs to Saros Series 135. The Saros cycle groups lunar and solar eclipses into families, known as series. A Saros cycle lasts for approximately 6,585.3 days (18 years 11 days 8 hours).

The second of two 2011 total lunar eclipses closes the year’s lineup of eclipses and also signals an absence of total lunar eclipses from subsequent eclipse lineups for two and one-third years.

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

graphic of "orientation of the earth as viewed from the center of the moon during greatest eclipse" for total lunar eclipse of Saturday, Dec. 10, 2011: SockPuppetForTomruen at English Wikipedia, Public Domain, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:Lunar_eclipse_from_moon-2011Dec10.png

For further information:

“December 10 / December 11, 2011 -- Total Lunar Eclipse.” Time And Date > Sun & Moon > Eclipses.
Available via Time And Date @ https://www.timeanddate.com/eclipse/lunar/2011-december-10

Espenak, Fred. “Eclipses During 2011.” NASA Eclipse Web Site > Lunar Eclipses.
Available via NASA Eclipse Web Site @ https://eclipse.gsfc.nasa.gov/OH/OH2011.html

Espenak, Fred. “Greatest Eclipse.” NASA Eclipse Web Site > Solar Eclipses > Glossary of Solar Eclipse Terms.
Available via NASA Eclipse Web Site @ https://eclipse.gsfc.nasa.gov/SEhelp/SEglossary.html

Espenak, Fred. “June 15 / June 16, 2011 Total Lunar Eclipse.” Time And Date > Sun & Moon > Eclipses.
Available via Time And Date @ https://www.timeanddate.com/eclipse/lunar/2011-june-15

Espenak, Fred. “Lunar Eclipses: 2011-2020.” NASA Eclipse Web Site > Lunar Eclipses.
Available via NASA Eclipse Web Site @ https://eclipse.gsfc.nasa.gov/LEdecade/LEdecade2011.html

Espenak, Fred. "Table 5 -- Crater Immersion and Emersion Times for the Total Lunar Eclipse of 2011 December 10." NASA Eclipse Web Site > Observer's Handbook > Observer's Handbook Tables > Observer's Handbook 2011.
Available via NASA Eclipse Web Site @ https://eclipse.gsfc.nasa.gov/OH/OHtables/OH2011-Tab05.pdf

Espenak, Fred. "Total 2011 Dec. 10." NASA Eclipse Web Site > Lunar Eclipses > Lunar Eclipse Publications Online: NASA TP-2009-214172: Five Millennium Canon of Lunar Eclipses: -1999 to +3000 (2000 BCE to 3000 CE) > Five Millennium Canon of Lunar Eclipses: -1999 to +3000 NASA Technical Publication TP-2009-214172 by Fred Espenak and Jean Meeus > Supplementary Data: Five Millennium Catalog of Lunar Eclipses: -1999 to +3000 - web-based catalog (with links to individual color figures) > Index to Five Millennium Catalog of Lunar Eclipses: -1999 to +3000 (2000 BCE to 3000 CE): Five Millennium Catalog of Lunar Eclipses: -1999 to +3000 (2000 BCE to 3000 CE): Five Millennium Catalog of Lunar Eclipses: 2001 to 2100 > Five Millennium Catalog of Lunar Eclipses: 2001 to 2100 (2001 CE to 2100 CE): Catalog of Lunar Eclipses: 2001 to 2100 (2001 CE to 2100 CE) > 09676 2011 Dec 10.
Available via NASA Eclipse Web Site @ https://eclipse.gsfc.nasa.gov/5MCLEmap/2001-2100/LE2011-12-10T.gif

Marriner, Derdriu. "First of Two 2011 Total Lunar Eclipses Happens Wednesday, June 15." Earth and Space News. Wednesday, June 8, 2011.
Available @ https://earth-and-space-news.blogspot.com/2011/06/first-of-two-2011-total-lunar-eclipses.html

Marriner, Derdriu. "First of Four 2011 Partial Solar Eclipses Happens Tuesday, Jan. 4." Earth and Space News. Wednesday, Dec. 29, 2010.
Available @ https://earth-and-space-news.blogspot.com/2010/12/first-of-four-2011-partial-solar.html

Marriner, Derdriu. "Fourth of Four 2011 Partial Solar Eclipses Happens Friday, Nov. 25." Earth and Space News. Wednesday, Nov. 16, 2011.
Available @ https://earth-and-space-news.blogspot.com/2011/11/fourth-of-four-2011-partial-solar.html

Marriner, Derdriu. "Second of Four 2011 Partial Solar Eclipses Happens Wednesday, June 1." Earth and Space News. Wednesday, May 25, 2011.
Available @ https://earth-and-space-news.blogspot.com/2011/05/second-of-four-2011-partial-solar.html

Marriner, Derdriu. "Third of Four 2011 Partial Solar Eclipses Happens Friday, July 1." Earth and Space News. Wednesday, June 29, 2011.
Available @ https://earth-and-space-news.blogspot.com/2011/06/third-of-four-2011-partial-solar.html