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135:. A voltage of 4500 V is applied to the anode which results in a sustained flow of electrons between the electrodes. Any gas molecules/atoms entering the detector are ionised by the flow of electrons. These ions are then attracted to cathode, whereby the frequency of these ions striking the cathode is a proxy for measuring the gas density. A magnetic field inside the sensor was provided by a permanent magnet.
29:
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operations were changed to reduce arcing potential due to gas build up. This included a) allowing a longer time before initialisation of the instrument to allow for degassing of built-up volatiles during transit to the Moon, and b) switching the instrument off during periods of higher temperatures in the event of gas build up during the lunar day.
166:
The cold cathode gauge with the Apollo 12 ALSEP package was turned on at approximately 19:18 UTC on
November 19, 1969. The Apollo 12 ALSEP central station was located at 3.0094 S latitude, 23.4246 W longitude. The CCGE was deployed approximately 50 feet (15 m) southwest of the central station.
184:
Whilst improvements had been made to the cable, there still were some difficulties in deployment; however proper placement was ultimately achieved. The gauge did not have a line of sight of other instruments or the lunar module. Following the failure of the Apollo 12 instrument, the instrument's
193:
The instrument would initially provide elevated responses due to gas build up inside the vehicle during transit to the Moon. This would saturate the sensor initially, but after a short period (1 hour during Apollo 12), the instrument would begin to show a perceptible change in readings. The
209:
The daytime recordings of gases were substantially greater than those recorded during the lunar night. It is believed that this would frequently be caused by contamination from the lunar excursion modules. These sources would disappear at night, likely owing to freezing out due to the low
167:
After fourteen hours of operation, the instrument experienced a deleterious failure when the power supply to generate the 4500 v potential in the anode failed. Stiffness in the cable made deployment difficult and the gauge was tipped at an angle with gauge facing in an upward direction.
175:
The CCGE was significantly modified for Apollo 13. However, the Apollo 13 mission experienced an in-flight issue whilst en route to the Moon. As a result, the mission to land on the Moon was aborted and the CCGE was not deployed.
120:(SIDE) which also housed the electronics for the CCGE. The SIDE command and control circuits also supported the CCGE. The CCGE was separated from SIDE by a 1-metre-long (3 ft 3 in) cable.
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saturation of the instrument limited the ability to use this to assess diffusion of these gases. The instrument could detect the depressurisation of the
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would consist of solar wind–derived origins but that there may be extant sources of lunar atmosphere that had geochemical origins.
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temperatures. Apollo 14 and 15 found the lunar nighttime atmosphere to correspond with a density of 2 x 10 particles per m.
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142:. A temperature sensor allowed corrections to collected data to account for variations in environmental temperature.
781:
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80:. The goal of the experiment was to measure the density of the Moon's tenuous atmosphere, but not its composition.
108:
The Cold
Cathode Gauge Experiment (CCGE) was built by Norton Research Corporation and was included as part of the
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The entrance to the instrument was closed by a spring-loaded cover that was released via a
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Proceedings of the Third Lunar
Science Conference, Houston, Texas, January 10–13, 1972
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Johnson, Francis S.; Carroll, James M.; Evans, Dallas E. (1973).
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Calibration of two gauges, S/N 2 and S/N 12, occurred at the
116:(ALSEP). It was contained as part of the same housing as the
88:
Prior to lunar exploration it was known that at minimum the
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Part of the Apollo Lunar
Surface Experiments Package (ALSEP)
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and the presence of nearby astronauts during lunar surface
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The Apollo 12 Cold
Cathode Gauge Experiment on the Moon
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Letter – NASA Contract NAS 9-5964 UTD Account El473
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576:Primary guidance, navigation, and control system
332:Final Report for Cold Cathode Gauge Experiment
329:Johnson, F.S.; Evans, D. E. (March 12, 1974),
64:, was a scientific package that flew on board
694:Charged Particle Lunar Environment Experiment
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8:
21:
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402:
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674:Apollo Lunar Surface Experiments Package
114:Apollo Lunar Surface Experiments Package
219:
699:Lunar Ejecta and Meteorites Experiment
359:"Apollo Cold Cathode Gauge Experiment"
247:"Apollo 12 Preliminary Science Report"
123:The CCGE sensor consists of a spooled
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324:
7:
746:Suprathermal Ion Detector Experiment
689:Apollo 14 Passive Seismic Experiment
684:Apollo 12 Passive Seismic Experiment
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118:Suprathermal Ion Detector Experiment
716:Lunar Seismic Profiling Experiment
704:Solar Wind Spectrometer Experiment
14:
669:Solar Wind Composition Experiment
149:. Gauge S/N 13 was calibrated at
859:Category:Apollo program hardware
854:
853:
202:due to gases leaking from their
487:Launch Vehicle Digital Computer
279:. Vol. 3. Pergamon Press.
273:"Lunar atmosphere measurements"
777:Lunar Landing Research Vehicle
657:Lunar Laser Ranging experiment
627:Thermal Micrometeoroid Garment
1:
736:Cold Cathode Gauge Experiment
711:Modular Equipment Transporter
58:Cold Cathode Gauge Experiment
22:Cold Cathode Gauge Experiment
836:Rendezvous Docking Simulator
647:Portable Life Support System
556:Apollo Abort Guidance System
127:surrounded by a cylindrical
815:Apollo 11 goodwill messages
894:
782:Mobile quarantine facility
726:Lunar Surface Magnetometer
147:Midwest Research Institute
851:
731:Lunar Traverse Gravimeter
679:Active Seismic Experiment
591:Descent propulsion system
62:Lunar Atmosphere Detector
50:Apollo 12, 13, 14, and 15
26:
721:Lunar Surface Gravimeter
596:Ascent propulsion system
571:Lunar Sounder Experiment
566:Apollo Guidance Computer
561:Apollo Docking Mechanism
383:Apollo 13 Mission Report
878:Apollo program hardware
662:list of retroreflectors
425:Apollo program hardware
200:extravehicular activity
151:Langley Research Center
767:Launch Umbilical Tower
581:Apollo Telescope Mount
105:
522:Apollo service module
508:Apollo command module
103:
831:Lunar escape systems
741:Heat Flow Experiment
652:Lunar Roving Vehicle
60:, also known as the
803:Lunar Flag Assembly
772:Crawler-transporter
527:Apollo Lunar Module
386:, September 1, 1970
285:1972LPSC....3.2231J
47:Notable experiments
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106:
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617:Apollo/Skylab A7L
294:978-0-262-12060-9
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53:
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809:Fallen Astronaut
601:Scimitar antenna
586:Apollo TV camera
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251:history.nasa.gov
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90:lunar atmosphere
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762:Mobile Launcher
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204:PLSS backpacks
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110:Apollo program
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638:Lunar surface
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439:Little Joe II
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798:Lunar plaque
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341:December 17,
339:, retrieved
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256:December 17,
254:. Retrieved
250:
208:
196:Lunar Module
192:
183:
174:
165:
144:
137:
122:
107:
87:
61:
57:
55:
18:
842:Moon Museum
610:Space suits
791:Ceremonial
622:Beta cloth
549:components
547:Spacecraft
496:Spacecraft
477:J-2 engine
472:F-1 engine
465:components
214:References
96:Instrument
84:Background
640:equipment
449:Saturn IB
180:Apollo 14
171:Apollo 13
162:Apollo 12
78:Apollo 15
74:Apollo 14
70:Apollo 13
66:Apollo 12
872:Category
514:Columbia
454:Saturn V
444:Saturn I
157:Missions
824:Related
503:Apollo
281:Bibcode
189:Science
125:cathode
104:Diagram
39:Acronym
291:
76:, and
533:Eagle
362:(PDF)
336:(PDF)
140:squib
129:anode
343:2023
289:ISBN
258:2023
56:The
42:CCGE
206:.
112:'s
874::
373:^
364:,
350:^
303:^
287:.
275:.
249:.
222:^
153:.
72:,
68:,
417:e
410:t
403:v
297:.
283::
260:.
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
