Washcarso at 00:25, 14 October 2026

2026-10-14T00:25:08Z

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	[[Category:Apollo ~~program~~]]		[[Category:Apollo oxygen]]
	[[Category:Apollo evidence]]		[[Category:Apollo evidence]]
	[[Category:Moon]]		[[Category:Moon]]
	[[Category:Spaceflight]]		[[Category:Spaceflight]]

Flerf Whisperer: Chart of planned oxygen use and the tank loads and pressure ratings

2026-10-14T00:20:29Z

Chart of planned oxygen use and the tank loads and pressure ratings

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{{series apollo}}
'''Apollo oxygen chart''' is the planned use and the tank loads for the command module, the lunar module, and the backpack. Pressures are in [[Pounds per square inch|psi]] unless the source prints psia or psig. Where two documents disagree, both numbers are in the table.

The long accounts are on [[Apollo oxygen]], [[Apollo command module oxygen]], [[Apollo lunar module oxygen]], and [[Apollo PLSS oxygen]].

== Planned use ==
{| class="wikitable"
! Place !! Planned oxygen per person !! What the document is counting
|-
| Command module || 1.8 pounds per person per day || Crew use on a 14-day, three-man design mission. Three men for 14 days is 75.6 pounds. The environmental-control share of the tanks, including leakage and repressurization, was about 173 pounds.<ref name="csm">F. H. Samonski Jr. and E. M. Tucker, [https://ntrs.nasa.gov/citations/19720012252 ''Apollo Experience Report: Command and Service Module Environmental Control System''], NASA TN D-6718 (1972).</ref>
|-
| Lunar module || Not given as a daily rate per person || Two men share the descent oxygen for the landing and the stay. The ascent tanks are the climb. The consumables table prints vehicle loads, not a pounds-per-person day.<ref name="consumables">NASA TN D-7140, ''Apollo Experience Report: Consumables Budgeting'', table VI.</ref>
|-
| Backpack || One primary bottle per walker || Earlier flights: 1.12 pounds in the bottle. Apollo 15, 16, and 17: 1.75 pounds in the bottle. The J-mission planning charge is 1.803 pounds loaded, of which 1.345 pounds is left for the walk after checkout, a cabin refill, gauge error, and a 30-minute reserve.<ref name="early">Hamilton Standard, [https://ibiblio.org/apollo/Documents/apollo_portable_life_support_and_oxygen_purge_systems.pdf ''Apollo Portable Life Support and Oxygen Purge Systems'']. Primary oxygen bottle, item 271, and the purge bottle, item 511.</ref><ref name="jman">Hamilton Standard, [https://ibiblio.org/apollo/Documents/apollo_portable_life_support_systems.pdf ''Portable Life Support System''], the J-mission backpack manual.</ref><ref name="beggs">J. C. Beggs and F. H. Goodwin, [https://ntrs.nasa.gov/citations/19720019459 ''Apollo PLSS: Environmental Control of the Smallest Manned Space Vehicle''], Hamilton Standard (1972).</ref>
|}

== Service module tanks ==
The command module drew its oxygen from cryogenic tanks in the service module. Flights through Apollo 13 carried two. Apollo 14 and the later landings carried three.<ref name="trw">R. K. M. Seto, C. E. Barton, and J. E. Cunningham, [https://ntrs.nasa.gov/citations/19710015627 ''Apollo Cryogenic Integrated Systems''], TRW for NASA Manned Spacecraft Center (1971, changed 1972).</ref> The May 1970 vessel survey still counts two.<ref name="panel7">MSC Apollo 13 Investigation Team, [https://ntrs.nasa.gov/api/citations/19710010491/downloads/19710010491.pdf ''Reaction Processes in High Pressure Fluid Systems''], Panel 7 final report, May 1970, table A-I.</ref>

{| class="wikitable"
! Tank !! Oxygen in each tank !! Pressure when full !! Vessel rating
|-
| Cryogenic oxygen tank, Inconel 718, 26.28 inches in diameter, wall 0.020 inch || 330.1 pounds at the 100 percent gauge. Usable 323.45 pounds. Maximum fill 337.9 pounds. The handbook rounds two tanks to about 640 pounds.<ref name="trw" /><ref name="aohcm">NASA, ''Apollo Operations Handbook, Command and Service Module'', Block II, the oxygen subsystem. The handbook line is quoted on [[Apollo command module oxygen]].</ref> || 900 psia, plus or minus 35. The handbook says the heaters hold 900 psig. The 1970 survey lists a normal operating pressure of 900 psia.<ref name="trw" /><ref name="csm" /><ref name="panel7" /> || Limit 1,020 psia. Proof 1,356 psia. Burst 1,530 psia.<ref name="panel7" />
|}

== Command module tanks ==
These two supplies sat in the command module. They covered short peaks and entry, after the service module was gone.

{| class="wikitable"
! Tank !! How many !! Oxygen !! Pressure when full !! Vessel rating
|-
| Surge tank, Inconel 718, 14.00 by 13.00 inches, wall 0.033 and 0.078 inch. News reference: 13 inches in diameter, 14 inches high, empty weight 8.86 pounds, volume 0.742 cubic foot. Left-hand equipment bay.<ref name="panel7" /><ref name="news">[https://apollojournals.org/alsj/CSM14_Environmental_Control_Subsystem_pp117-136.pdf Apollo command and service module news reference], environmental control, oxygen surge tank and repressurization unit.</ref> || 1 || 3.7 pounds<ref name="csm" /><ref name="news" /> || 900 psig in the handbook. 900 psia in the flight report and in the vessel survey.<ref name="csm" /><ref name="panel7" /> || Limit 1,070 psia. Proof 1,356 psia. Burst 1,530 psia. Normal operating pressure in the survey: 900 psia.<ref name="panel7" />
|-
| Repressurization bottles, Inconel 718, 12.62 by 7.00 inches, wall 0.028 and 0.045 inch. Below the hatch.<ref name="panel7" /><ref name="news" /> || 3 || 1 pound in each bottle. The flight report calls the package 3 pounds.<ref name="news" /><ref name="csm" /> || 900 psi<ref name="news" /><ref name="csm" /> || Limit 1,070 psia. Proof 1,600 psia. Burst 1,800 psia. Normal operating pressure in the survey: 900 psia.<ref name="panel7" />
|}

== Lunar module tanks ==
The lunar module had no cryogenic tanks. Early landing vehicles carried one descent tank. From LM-10, Apollo 15 and later, a second descent tank was added. Two ascent tanks flew on every landing vehicle.<ref name="lm">R. J. Gillen, J. C. Brady, and F. Collier, [https://ntrs.nasa.gov/citations/19720013195 ''Apollo Experience Report: Lunar Module Environmental Control Subsystem''], NASA TN D-6724 (1972).</ref><ref name="aoh">NASA, [https://www.ibiblio.org/apollo/Documents/LMA790-3-LM10-ApolloOperationsHandbookLunarModuleLM10AndSubsequent-Volume1-SubsystemsData.pdf ''Apollo Operations Handbook, Lunar Module, LM 10 and Subsequent'', Volume I], LMA790-3-LM, 1 April 1971, section 2.6.</ref>

{| class="wikitable"
! Tank !! How many !! Oxygen in each tank !! Pressure when full !! Vessel rating
|-
| Descent, one-tank vehicles. D6AC steel, 23.522 by 21.722 inches, wall 0.118 inch. Quadrant 3.<ref name="panel7" /> || 1 || 48.0 pounds loaded. 44.4 pounds available for the mission. The experience report sizes the tank at about 48 pounds.<ref name="consumables" /><ref name="lm" /> || About 3,000 psi in the sizing sentence. The supply the regulator saw is given as 2,800 psi. The 1970 survey lists a normal operating pressure of 2,869 psia.<ref name="lm" /><ref name="panel7" /> || Limit 3,000 psia. Proof 3,990 psia. Burst 4,500 psia.<ref name="panel7" />
|-
| Descent, LM-10 and later. One tank in quadrant 3 and one in quadrant 4.<ref name="aoh" /> || 2 || 48.01 pounds at 70 degrees Fahrenheit. Residual 0.84 pound at 50 psia.<ref name="aoh" /> || 2,690 psia<ref name="aoh" /> || Burst 4,500 psi in the LM-10 handbook. The 1970 survey, written for the single tank, is the limit, proof, and burst line above.<ref name="aoh" /><ref name="panel7" />
|-
| Ascent. Inconel 718, 14.500 by 11.968 inches, wall 0.029 inch. Aft equipment bay.<ref name="panel7" /> || 2 || 2.4 pounds loaded, 2.0 pounds available, in the consumables table. The experience report says about 2.4 pounds. The LM-10 handbook says 2.43 pounds at 70 degrees Fahrenheit, with 0.14 pound left at 50 psia.<ref name="consumables" /><ref name="lm" /><ref name="aoh" /> || About 900 psi in the experience report. 840 psia in the LM-10 handbook. 850 psia normal operating pressure in the 1970 survey.<ref name="lm" /><ref name="aoh" /><ref name="panel7" /> || Limit 1,000 psia. Proof 1,330 psia. Burst 1,500 psia. The handbook burst is also 1,500 psia.<ref name="panel7" /><ref name="aoh" />
|}

== Backpack tanks ==
One primary bottle per walker. The purge system is a second supply, two spheres on top of the pack, used if the backpack fails.

{| class="wikitable"
! Tank !! Oxygen !! Pressure when full !! Vessel rating
|-
| Primary bottle, Apollo 11 through 14. 302 stainless steel. Specified empty weight 3.50 pounds.<ref name="early" /> || 1.12 pounds at 78 degrees Fahrenheit<ref name="early" /> || 850 psig on the capacity line. The 1972 requirements table charges these packs to 1,020 psia at 70 degrees Fahrenheit.<ref name="early" /><ref name="beggs" /> || Proof 1,665 psig. The specification does not print a burst pressure.<ref name="early" />
|-
| Primary bottle, Apollo 15, 16, and 17. 301 stainless steel, cryoformed. Specified empty weight 3.90 pounds.<ref name="jman" /> || 1.75 pounds at 70 degrees Fahrenheit. Planning load 1.803 pounds.<ref name="jman" /><ref name="beggs" /> || 1,410 psi on the capacity line, and 1,410 psia in the requirements table.<ref name="jman" /><ref name="beggs" /> || External leakage is specified at 1,500 psia. The specification does not print a proof or a burst pressure.<ref name="jman" />
|-
| Purge sphere, one of the pair. Inconel 718. Specified empty weight 9.5 pounds.<ref name="early" /> || 2.85 pounds at 70 degrees Fahrenheit. The pair is described as 5.8 pounds.<ref name="early" /><ref name="beggs" /> || 5,880 psia for the one bottle. 5,800 psi for the pair.<ref name="early" /><ref name="beggs" /> || Operating pressure 0 to 6,750 psia. The specification does not print a separate burst pressure.<ref name="early" />
|}

== See also ==
* [[Apollo oxygen]]
* [[Apollo command module oxygen]]
* [[Apollo lunar module oxygen]]
* [[Apollo PLSS oxygen]]
* [[Pounds per square inch]]

== References ==
<references />

[[Category:Apollo program]]
[[Category:Apollo evidence]]
[[Category:Moon]]
[[Category:Spaceflight]]

Apollo oxygen chart - Revision history

Washcarso at 00:25, 14 October 2026

Flerf Whisperer: Chart of planned oxygen use and the tank loads and pressure ratings