Hab Consumable Masses in Mars Direct - Revision history

Jumpboy11j: /* References */

2010-03-23T20:04:07Z

‎References

Mark Friedenbach: /* Whole Food */

2010-03-22T06:36:31Z

‎Whole Food

Mark Friedenbach: can't foget about whole food!

2010-03-22T06:06:29Z

can't foget about whole food!

Mark Friedenbach: /* Reuse Rate */

2010-03-22T05:51:12Z

‎Reuse Rate

Jumpboy11j at 01:29, 22 March 2010

2010-03-22T01:29:33Z

Jumpboy11j at 00:29, 22 March 2010

2010-03-22T00:29:48Z

Jumpboy11j: /* Consumption Rate */

2010-03-21T04:41:49Z

‎Consumption Rate

Jumpboy11j: /* References */

2010-03-20T19:03:14Z

‎References

Jumpboy11j: /* References */

2010-03-20T19:02:55Z

‎References

Jumpboy11j: Consumable Masses in Mars Direct moved to Hab Consumable Masses in Mars Direct: Contrast with ERV Consumable Masses in Mars Direct

2010-03-20T18:59:22Z

Consumable Masses in Mars Direct moved to Hab Consumable Masses in Mars Direct: Contrast with ERV Consumable Masses in Mars Direct

@@ Line 62: / Line 62: @@
 *1. [http://www.marsjournal.org/contents/2006/0005/files/rapp_mars_2006_0005.pdf Commercial Report-pdf (Goes to acrobat file: 373 KB)]
-*2. [http://www.nasa.gov/mission_pages/station/expeditions/expedition19/earthday_recycle.html For use of resources]
+*2. [http://www.nasa.gov/mission_pages/station/expeditions/expedition19/earthday_recycle.html For use of resources on ISS]
 *3. [http://science.ksc.nasa.gov/shuttle/technology/sts-newsref/sts_eclss.html#sts_eclss NASA document on Space Shuttle Life Support]

← Older revision		Revision as of 06:36, 22 March 2010
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	=Whole Food=		=Whole Food=
		+
		+	== Consumption Rate ==
		+
		+	Reference [2] does not mention whole food, so presumably none is consumed on the ISS. However resupply missions do bring whole food with them to boost morale, so presumably we should be able to find some numbers.
		+
		+	== Reuse Rate ==
		+
		+	Not relevant (see discussion of dry food).
		+
		+	== Total Mass for 600 day Mission ==
		+
		+	One ISS crew member consumes in one day 1.77 kg of dry food (with 0.8 kg of water to hydrate it), and 1.62 kg of drinking water. One Mars Direct crew member consumes in one day 0.5 kg dried food, 1.0 kg of whole food, and 4.0 kg of drinking water.
		+
		+	If the same water/dried food mass ratios are used for Mars Direct as for the ISS, then 0.3 kg water is required to hydrate the dried food [0.5 kg MD dried food * (0.8 kg ISS water / 1.77 kg ISS dried food), conservatively rounding up to significant figures]. This totals to 1.8 kg [0.3 kg water + 0.5 kg dried food + 1.0 kg whole food] of whole food per crew member per day. As an ISS crew member consumes 2.6 kg of whole food per day (1.77 kg dried food + 0.8 kg water], Mars Direct's 1.8 kg is suspiciously low (67% of ISS consumption levels).
		+
		+	For a conservative estimate, ISS levels of food consumption should be assumed (which includes only dry food). [[The Case for Mars]] presents good arguments for the inclusion of whole food, however, so further research should be done find accurate assessments of whole food requirements and consumptions rates on real space missions.

	=Potable Water=		=Potable Water=

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 ==Total Mass for 600 day Mission==
-.77 kilograms per day over 600 days is a total of 1,062 kg per person over the course of the mission.  With the standard 4 person Mars Direct crew, that is a total mass of 4,248 kg of food.  Zubrin uses the much lower estimate of just 1,000 kg total based off .5 kg per day.  This is a huge discrepancy, and appears to show that Zubrin is being overly optimistic.  On the other hand, based on the minimum possible energy content for totally dry food of 4 calories per gram, and a daily calorie intake of 2,500 calories, which is on the high side if the crew is mixed-gender [http://www.fatfreekitchen.com/weightloss/weightloss.html], each crewmember will need .625 kg/day of food.  Since the food will also contain significant amounts of fats and proteins which have a higher specific energy, .5 kg/person per day for totally dehydrated food is theoretically possible.  However, 1.77 kg per person*day is more realistic given that is what is used in real life.
+.77 kilograms per day over 600 days is a total of 1,062 kg per person over the course of the mission.  With the standard 4 person Mars Direct crew, that is a total mass of 4,248 kg of food.  Zubrin uses the much lower estimate of just 1,000 kg total based off .5 kg per day.  However Zubrin also includes whole (non-dehydrated) food in his launch manifest, which presumably makes up the difference (see the discussion of whole food below).
 =Whole Food=

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 ==Reuse Rate==
-Based on technologies pioneered on the ISS, 90-95% closure for oxygen seems reasonable [citation needed].  Assuming the lower number, that is 0.1 kg per day of oxygen.  Over 600 says with 4 people, that is 240 kg.  With 95% closure, that is 120 kg of oxygen.  An intermediate value falls at 180 kg, right near Zubrin's 160 kg.
+Based on technologies pioneered on the ISS, 90-95% closure for oxygen seems reasonable [citation needed].  Assuming the lower number, that is 0.1 kg per day of oxygen.  Over 600 days with 4 people, that is 240 kg.  With 95% closure, that is 120 kg of oxygen.  An intermediate value falls at 180 kg, right near Zubrin's 160 kg.
 ==Total Mass for 600 day Mission==

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 ==Consumption Rate==
-On the space shuttle, Oxygen is used at a rate of .8 kg per person*day [http://science.ksc.nasa.gov/shuttle/technology/sts-newsref/sts_eclss.html#sts_eclss].  Zubrin's 1 kg per day seems reasonable, especially considering that astronauts will be using this Oxygen at a high rate.  [http://www.marsjournal.org/contents/2006/0005/files/rapp_mars_2006_0005.pdf This reference] suggests that under a high metabolic load, such as that will probably exist for astronauts doing work on Mars, .96 kg per day is more reasonable.  1 kg per day is a good starting point considering margin necessities and losses.
+On the space shuttle, Oxygen is used at a rate of .8 kg per person*day [3].  Zubrin's 1 kg per day seems reasonable, especially considering that astronauts will be using this Oxygen at a high rate.  This reference [1] suggests that under a high metabolic load, such as that will probably exist for astronauts doing work on Mars, .96 kg per day is more reasonable.  1 kg per day is a good starting point considering margin necessities and losses.
 ==Reuse Rate==
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 =Dry Food=
 =Whole Food=
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 =References=
-*[http://www.marsjournal.org/contents/2006/0005/files/rapp_mars_2006_0005.pdf Commercial Report-pdf (Goes to acrobat file: 373 KB)]
+*1. [http://www.marsjournal.org/contents/2006/0005/files/rapp_mars_2006_0005.pdf Commercial Report-pdf (Goes to acrobat file: 373 KB)]
-*[http://www.nasa.gov/mission_pages/station/expeditions/expedition19/earthday_recycle.html For use of resources]
+*2. [http://www.nasa.gov/mission_pages/station/expeditions/expedition19/earthday_recycle.html For use of resources]

← Older revision		Revision as of 00:29, 22 March 2010
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	=References=		=References=

−	~~Add information from~~ [http://www.marsjournal.org/contents/2006/0005/files/rapp_mars_2006_0005.pdf ~~this~~ pdf (Goes to acrobat file: 373 KB)]	+	*[http://www.marsjournal.org/contents/2006/0005/files/rapp_mars_2006_0005.pdf Commercial Report-pdf (Goes to acrobat file: 373 KB)]
		+	*[http://www.nasa.gov/mission_pages/station/expeditions/expedition19/earthday_recycle.html For use of resources]

← Older revision		Revision as of 19:03, 20 March 2010
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	=References=		=References=

−	Add information from [http://www.marsjournal.org/contents/2006/0005/files/rapp_mars_2006_0005.pdf this pdf (Goes to acrobat file: 373 KB)	+	Add information from [http://www.marsjournal.org/contents/2006/0005/files/rapp_mars_2006_0005.pdf this pdf (Goes to acrobat file: 373 KB)]

← Older revision		Revision as of 19:02, 20 March 2010
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	=References=		=References=
		+
		+	Add information from [http://www.marsjournal.org/contents/2006/0005/files/rapp_mars_2006_0005.pdf this pdf (Goes to acrobat file: 373 KB)

← Older revision	Revision as of 18:59, 20 March 2010
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