Apollo 10 Lunar Module Snoopy Was Placed in Solar Orbit May 23, 1969

Summary: Apollo 10 Lunar Module Snoopy was placed in solar orbit May 23, 1969, about two and one-half hours after docking with Command Module Charlie Brown.

With its descent stage already jettisoned, Apollo 10 Lunar Module Snoopy’s ascent stage approaches Command Module Charlie Brown, with lunar eastern limb (about 120 degrees east longitude) in background; red/blue diagonal line is the command module’s window; photograph by Command Module Pilot (CMP) John Young, Thursday, May 22, 1969; NASA image AS10-34-5112: Generally not subject to copyright in the United States, via NASA Image and Digital Library

Apollo 10 Lunar Module Snoopy was placed in solar orbit May 23, 1969, approximately two and one-half hours after its docking with Command Module Charlie Brown.

The National Aeronautics and Space Administration’s (NASA) Apollo 10 Press Kit, released May 7, 1969, described the Apollo human spaceflight program’s lunar module as “a two-stage vehicle designed for space operations near and on the Moon” (page 42). The module stood with a height of 22 feet 11 inches and a width of 31 feet. The module’s ascent stage measured 12 feet 4 inches in height and 14 feet 1 inch in diameter. The descent stage’s dimensions were a height of 10 feet 7 inches and a diameter of one inch. The lunar module was built by NASA contractor Grumman Aircraft Engineering Corporation in Bethpage, New York.

The lunar module’s spaceflight was a one-way trip. Neither of the module’s two stages was designed for a return to Earth. The Press Kit stated: “The LM is incapable of reentering the atmosphere.”

Apollo 10 was commanded by Thomas Patten Stafford (born Sept. 17, 1930), who was joined by John Watts Young (born Sept. 24, 1930) and Eugene Andrew Cernan (born March 14, 1934) as Command Module Pilot (CMP) and Lunar Module Pilot (LMP), respectively.

The mission’s three astronauts assigned the call sign of Snoopy to the lunar module. They selected Charlie Brown as the command module’s identifier.

Apollo 10 launched Sunday, May 18, 1969, at 16:49:00 Greenwich Mean Time/Coordinated Universal Time (11:49 p.m. Eastern Standard Time; 12:49 p.m. Eastern Daylight Time) as a lunar-orbital mission. Apollo 10 was designed as a dress rehearsal, absent a lunar landing, for Apollo 11, slated for launch in mid-July.

The Apollo 10 mission objectives required undocking of Apollo Lunar Module LM-4 from the Apollo Command and Service Module CSM-106 approximately 22 hours after the spacecraft’s insertion into lunar orbit. The 356.1-second, orbital-insertion maneuver began Wednesday, May 21, at 20:44:54 GMT/UTC (3:44 p.m. EST, 4:44 p.m. EDT). The firing of the service module’s propulsion engine cut off at 20:50:50 GMT/UTC (3:50 p.m. EST, 4:50 p.m. EDT).

The lunar module undocked from the command module Thursday, May 22, at 19:00:57 GMT/UTC (2 p.m. EST, 3 p.m. EDT). The Ground Elapsed Time (GET) was 98 hours 11 minutes 57 seconds (098:11:57) after Range Zero, the integral second before liftoff.

At 23:34:16 GMT/UTC (6:34 p.m. EST, 7:34 p.m. EDT; 102:45:16.9 GET), the ascent stage separated from the descent stage. The separation occurred at an altitude of 31.4 nautical miles above the lunar surface, according to freelance space writer Richard W. Orloff’s NASA-published Apollo by the Numbers (2000: page 76).

The ascent propulsion system (APS) began a 15.55-second firing at 23:44:02 GMT/UTC (6:44:02 p.m. EST, 7:44:02 p.m. EDT; 102:55:02.13 GET) to place the module’s ascent stage into an orbit with pericynthion, or nearest point to the lunar surface, at 46.5 nautical miles and apocynthion, or farthest point from the lunar surface, at 11.0 nautical miles. The ascent stage’s orbital insertion firing cut off at 23:44:17 GMT/UTC (6:44:17 p.m. EST, 7:44:17 p.m. EDT; 102:55:17.68 GET).

Lunar module ascent stage Snoopy docked with Command Module Charlie Brown on Friday, May 23, at 03:11:02 GMT/UTC (Thursday, May 22, at 10:11 p.m. EST, 11:11 p.m. EDT; 106:22:02 GET). Docking occurred at an altitude of 54.7 nautical miles, according to Orloff’s Apollo by the Numbers (page 77).

Closeout activities for Lunar Module Snoopy began Friday, May 23, at 03:31 GMT/UTC (Thursday, May 22, at 10:31 p.m. EST, 11:31 p.m. EDT; 107:20 GET). NASA’s Apollo 10 Mission Report, released August 1969, noted the “restowage of lunar module equipment for final jettison” and stowage of “debris, such as used food containers and other disposable items, that had collected in the command module over the 4-day period” inside Lunar Module Snoopy (9.9.8: page 9-19).

The ascent stage’s jettison occurred Friday, May 23, at 05:13:36 GMT/UTC (12:13 a.m. EST, 1:13 a.m. EDT; 108:24:36 GET). The ascent propulsion system’s (APS) firing to propellant depletion, which aimed to place LM Snoopy into a solar orbit, began at 05:41:05 GMT/UTC (12:41 a.m. EST, 1:41 a.m. EDT; 108:52:05.5 GET). The depletion burn was completed 249.0 seconds later, at 05:45:14 GMT/UTC (12:45 a.m. EST, 1:45 a.m. EDT; 108:56:14.5 GET).

NASA’s Apollo 10 Mission Post Launch Mission Operation Report No. 1, released May 26, 1969, noted, after the ascent stage’s jettison, that: “The crew visually acquired the LM descent stage on several occasions” (page 5).

The Mission Report described the crew’s last view of Lunar Module Snoopy. “Sequence films were made of separation, but after approximately 13 frames the lunar module disappeared into the sunlight and was only seen momentarily during the depletion firing” (9.9.8: page 9-19).

The Post Launch Mission Operation Report stated that Snoopy was tracked via the Manned Space Flight Network (MSFN) for “about 12 hours” after separation from Charlie Brown. “LM/MSFN communications were maintained until LM ascent stage battery depletion at about 120 hours GET.”

The takeaway for Apollo 10 Lunar Module Snoopy’s placement in solar orbit May 23, 1969, is that the Apollo 10 spacecraft’s ascent stage may still be circling the sun while the descent stage’s lunar orbit likely ended in a lunar surface impact.

Lunar Module 4, known in spaceflight as Snoopy, is being moved into position, Monday, Jan. 13, 1969, for mating with the Spacecraft Lunar Module Adapter (SLA) 13 in the John F. Kennedy Space Center’s Manned Spacecraft Operations Building (MSOB); NASA ID S69-17807: Generally not subject to copyright in the United States, via NASA Image and Digital Library

Acknowledgment

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

Image credits:

With its descent stage already jettisoned, Apollo 10 Lunar Module Snoopy’s ascent stage approaches Command Module Charlie Brown, with lunar eastern limb (about 120 degrees east longitude) in background; red/blue diagonal line is the command module’s window; photograph by Command Module Pilot (CMP) John Young, Thursday, May 22, 1969; NASA image AS10-34-5112: 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 Digital Library @ https://images.nasa.gov/details-as10-34-5112

Lunar Module 4, known in spaceflight as Snoopy, is being moved into position, Monday, Jan. 13, 1969, for mating with the Spacecraft Lunar Module Adapter (SLA) 13 in the John F. Kennedy Space Center’s Manned Spacecraft Operations Building (MSOB); NASA ID S69-17807: 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 Digital Library @ https://images.nasa.gov/details-S69-17807

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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.

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

Acknowledgment

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

Image credits:

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, @ https://www.facebook.com/photo.php?fbid=10150572616589348

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

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