Water Recycling Efficiency Calculator
Calculate water needs with and without recycling, autonomy days, and launch mass savings for space missions.
Inputs
%
Results
Daily water usage (kg)
16.3
Without recycling (kg)2,938
Fresh water needed (kg)206
Water saved (kg)2,732
Days of autonomy1,751
Net launch mass saved (kg)1,932
How to Use This Calculator
- Enter the number of crew and daily water consumption per person (drinking, hygiene, food prep).
- Set the water recovery efficiency of your recycling system (ECLSS: ~93%, advanced: up to 98%).
- Input the mission duration in days.
- Review the daily fresh water production, recycled water volume, and makeup water required.
- Calculate total launch mass savings from recycling vs. carrying all water from Earth.
How the result changes with Crew size
| Crew size | Daily water usage (kg) |
|---|---|
| 11 | 29.9 |
| 36 | 97.9 |
| 65 | 176.8 |
| 90 | 244.8 |
What each input means
- Crew size
- Number of crew members.
- Mission duration (days)
- Total mission length.
- Recycling efficiency (%)
- Water recovery system efficiency (ISS: ~93%).
- Initial water supply (kg)
- Water launched with the mission.
What each result means
- Daily water usage (kg)
- Total crew daily water consumption.
- Without recycling (kg)
- Total water needed without recovery.
- Fresh water needed (kg)
- New water needed with recycling.
- Water saved (kg)
- Mass saved through recycling.
- Days of autonomy
- How long initial supply lasts.
- Net launch mass saved (kg)
- Savings minus system mass.
How this is calculated
Worked example, using the default values
- Identify Input Parameters4 parametersCrew size = 6, Mission duration (days) = 180, Recycling efficiency (%) = 93, Initial water supply (kg) = 2000 = 4 input(s) provided
- Calculate Daily water usageDaily water usage = crewSize * dailyWaterPerPerson16.3 = 16.3
- Calculate Without recyclingWithout recycling = round(dailyWaterTotal * missionDays)2938 = 2938
- Calculate Fresh water neededFresh water needed = round(dailyFreshWaterNeeded * missionDays)206 = 206
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