The value is too high, too low or operationally unsafe for the selected mission.Created 2026 for preliminary spacecraft worldbuilding and concept sizing.
Presentation loosely inspired by Theodore W. Hall's SpinCalc.
Last revision: 2026-05-09
Results will appear here.
The value is too high, too low or operationally unsafe for the selected mission.
The value is probably workable only with adaptation, redundancy or engineering changes.
The value is inside the simple comfort or closure zone for this preliminary model.
The value may be too low for immediate comfort, health protection or closed-loop operation.
The value is too low for the selected mission unless another subsystem covers it.
LifeSupportCalc is a preliminary sizing tool for crewed spacecraft and habitats. It estimates food, water, oxygen, carbon dioxide removal, water recycling, solid waste storage, power generation, thermal rejection, net habitable volume and artificial-gravity spin requirements.
The calculation is a mass-balance model, not a flight-certified ECLSS design. It uses published baseline assumptions where possible, then exposes the uncertain engineering values as inputs. The defaults are deliberately editable because spacecraft life support depends on the vehicle architecture, redundancy philosophy, crew workload, hygiene policy, mission phase, storage method, venting policy and maintenance plan.
| Subsystem | Equation or rule |
|---|---|
| Oxygen | O2 = crew-days x O2 per crew-day x activity multiplier. Electrolysis feed water = O2 x 18/16. |
| CO2 | CO2 = crew-days x CO2 per crew-day x activity multiplier. Regenerable scrubbers remove CO2 without bulk sorbent replacement. LiOH mode carries expendable sorbent. |
| Sabatier | CO2 + 4H2 -> CH4 + 2H2O. Water returned = reduced CO2 x 36/44. Methane vented = reduced CO2 x 16/44. |
| Water | Makeup water = potable plus hygiene plus net O2-generation water minus recovered wastewater, with reserves added to stored makeup. |
| Power | Average power is the sum of subsystem, hotel, thermal, trace-contaminant, exercise and waste-management loads, multiplied by the selected margin. |
| Artificial gravity | Acceleration = omega squared x radius. Spin rpm = 60/(2*pi) x square-root(acceleration/radius). Tangential speed = omega x radius. |
For short missions, microgravity may be acceptable with exercise and recovery planning. For missions of many weeks to months, the calculator flags artificial gravity or intensive countermeasures because microgravity affects weight-bearing bone, skeletal muscle, cardiovascular regulation, sensorimotor control and neuro-ocular risk. The correct artificial-gravity dose is still not settled. A rotating habitat may reduce risk, but radius, rpm, Coriolis forces, interior layout, exercise, sleep, and partial-gravity exposure time all matter.
| Parameter | Default | Unit |
|---|---|---|
| Oxygen consumed | 0.816 | kg per crew-day |
| Carbon dioxide produced | 1.04 | kg per crew-day |
| Edible food | 1.51 | kg per crew-day |
| Food packaging | 0.262 | kg per crew-day |
| Potable water | 2.50 | kg per crew-day |
| Personal hygiene water | 0.40 | kg per crew-day |
| Urine water | 1.62 | kg per crew-day |
| Humidity condensate from respiration and perspiration | 1.90 | kg per crew-day |
| Crew solid waste allowance | 1.00 | kg per crew-day |
| Life-support waste allowance | 0.50 | kg per crew-day |
Anderson, Molly S., Ewert, Michael K., Keener, John F. and Wagner, Steven A. (2018). Life Support Baseline Values and Assumptions Document, NASA/TP-2015-218570/REV1. NASA Technical Reports Server.
NASA (2025). Environmental Control and Life Support Systems (ECLSS). NASA Marshall Space Flight Center.
NASA (2023). NASA Achieves Water Recovery Milestone on International Space Station. NASA.
European Space Agency. Advanced Closed Loop System. ESA.
NASA Office of the Chief Health and Medical Officer (2023). NASA-STD-3001, Volume 2, Human Factors, Habitability, and Environmental Health. NASA Human System Standards.
Clément, Gilles R., Bukley, Angelia P. and Paloski, William H. (2015). Artificial gravity as a countermeasure for mitigating physiological deconditioning during long-duration space missions. Frontiers in Systems Neuroscience. Frontiers.
Man, Joey, Graham, Taylor, Squires-Donelly, Georgina, et al. (2022). The effects of microgravity on bone structure and function. npj Microgravity. Nature.
Hall, Theodore W. (2000 to 2018). SpinCalc, an artificial-gravity calculator in JavaScript. artificial-gravity.com.
This page is intentionally plain, table-heavy and old-web friendly. It should run locally from a folder with no server.
