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Mars Survival Simulator
Input your life support reserves — oxygen, water, and food — to calculate exactly how many days you would survive on Mars if your resupply mission failed. All consumption rates are based on real NASA life support data used for ISS and Mars mission planning.
Quick Answer
Human survival on Mars is strictly mathematically governed by three factors: Oxygen (O2), Water, and Caloric Food intake. If any one of these resources depletes, survival drops to zero regardless of the others. A typical human requires about 840 liters of O2, 3 liters of water, and 1.5kg of dehydrated food per day to remain operational.
Survival Assessment
The Mathematics of Staying Alive
On Earth, the biosphere provides our life support systems for free. Plants recycle our CO2 back into oxygen, the water cycle purifies our drinking water, and complex food webs provide our nutrition. On Mars, every single one of these processes must be artificially maintained and monitored. Read our full guide on whether humans can live on Mars for a complete breakdown of all survival challenges.
The Oxygen Problem
An average adult human consumes roughly 550 liters of pure oxygen per day, but considering the mixing of gases required to prevent oxygen toxicity, the overall volume of "air" cycled is much higher. On Mars, oxygen can be extracted from the thin CO2 atmosphere using In-Situ Resource Utilization (ISRU) technology, such as the MOXIE experiment flown on the Perseverance rover. However, if power fails and the ISRU shuts down, colonists are entirely dependent on their compressed reserves.
Water Recycling
Water is heavy, making it incredibly expensive to launch from Earth. Therefore, Mars colonies must achieve nearly 100% water recycling efficiency. This includes recovering moisture from exhalations, sweat, and processing urine. The International Space Station (ISS) already utilizes this technology, famously described as making "today's coffee into tomorrow's coffee."
Food Logistics
Food must initially be shipped from Earth in dehydrated, vacuum-sealed packages. While hydroponics and aeroponics can supplement diets with fresh greens, growing high-calorie staple crops (like wheat or potatoes) requires massive amounts of space, power for artificial lighting, and water. A catastrophic failure in the colony's greenhouse could result in starvation long before a resupply ship could traverse the distance between Earth and Mars.
Power — The Resource Behind All Resources
Every life support system on Mars depends entirely on a continuous power supply. Oxygen generators, water recyclers, food growing lights, habitat heaters, and communication systems all consume electricity around the clock. Solar panels provide power during daylight hours, but Mars receives only 43% of the solar energy that Earth does — and global dust storms can reduce solar output to nearly zero for months. This is why most serious Mars colony designs rely on small nuclear fission reactors as the primary power source. A power failure on Mars is not an inconvenience — it is a cascading death sentence that starts with heating failure, followed by life support shutdown, within hours.
Real Survival Numbers — What NASA Uses
- Oxygen: ~840 liters per person per day (accounting for atmospheric mixing ratios to prevent O2 toxicity)
- Water: ~3 liters per person per day for drinking (an additional ~20 liters for hygiene if recycling is available)
- Food: ~1.5 kg per person per day (dehydrated, approximately 2,000 calories)
- Power: ~3 kilowatts per person continuously for basic life support
- Habitat pressure: Must be maintained at ~14.7 PSI (same as Earth sea level) or a lower but safe mixed-gas equivalent
- Temperature: Habitat must stay between 18-24°C while outside temperatures range from +20°C to -130°C
The Resupply Problem
On the International Space Station, a resupply mission from Earth takes approximately 2-3 days. On Mars, resupply is not a quick fix. Launch windows to Mars only open every 26 months when Earth and Mars are favorably aligned. The journey itself takes 6-9 months. This means that if a critical resource runs out on Mars, the minimum wait for resupply is over 2.5 years from the moment of failure. Every Mars colony must therefore maintain minimum 3-year reserves of all critical consumables — making the numbers in this simulator a matter of genuine life and death planning, not just a fun exercise.
Frequently Asked Questions
No — and death would be rapid. The Martian surface has atmospheric pressure of only 0.6% of Earth's sea level pressure. An unprotected human would experience immediate hypoxia (oxygen deprivation) and lose consciousness within 15 seconds. The low pressure would cause gases dissolved in the blood to bubble (similar to decompression sickness). Exposed skin would experience severe frostbite within seconds as temperatures average -62°C. Death would occur within 1-2 minutes. A pressurized spacesuit is non-negotiable for any surface activity on Mars.
A human uses approximately 840 liters of oxygen per day in a pressurized Mars habitat. At rest, the minimum survival requirement is closer to 550 liters per day. If oxygen supply failed completely, a person in a sealed habitat would survive only as long as the oxygen already in the air — typically a few hours depending on habitat volume. With 10,000 liters of compressed oxygen reserves (a realistic emergency supply), a single colonist could survive approximately 11-18 days. This is why redundant oxygen generation systems and large reserves are critical design requirements for Mars habitats.
Yes. Mars has vast amounts of water ice trapped in its polar ice caps and in subsurface glaciers at mid-latitudes. NASA's ground-penetrating radar has confirmed massive buried ice deposits. Future colonists will use robotic drills to extract this ice, melt and purify it, and use it for drinking, agriculture, and splitting into hydrogen and oxygen for rocket propellant. However, Martian water contains toxic perchlorates that must be removed before it is safe to drink — making purification systems a critical survival technology.
The most immediate threat is equipment failure — a breach in the habitat, a spacesuit failure, or a life support system breakdown. The most insidious long-term threat is radiation. Mars has no global magnetic field and almost no atmospheric shielding, meaning the surface receives 40-50 times more radiation than Earth. During a solar particle event (solar storm), radiation levels can spike to immediately dangerous levels within minutes. Colonists would need to shelter in specially shielded underground rooms during these events. Long-term radiation exposure dramatically increases cancer risk over a multi-year mission.
In a true emergency, Earth cannot send immediate help. The communication delay alone is 3-22 minutes one-way — meaning just asking for help and receiving a response takes 6-44 minutes. More critically, a physical resupply or rescue mission requires waiting for the next Earth-Mars launch window (every 26 months) and then a 6-9 month transit. This means Mars colonists are completely self-reliant in any emergency. There is no calling 911. Every colony member must be trained for medical emergencies, equipment repair, and survival scenarios — which is exactly what this simulator helps you understand.