ISS Bottled Water Cost: Price per Liter

On the International Space Station, a single bottle of water costs roughly $11,000 to $22,000 per liter when you account for the full launch cost. This article explains how that number is calculated, why it is so high, and what it actually takes to get water to orbit.

Formula

The cost of a bottle of water in orbit is simply the launch cost per kilogram multiplied by the mass of the water (and its container). The formula is:

Cost per liter = Launch cost per kg × Mass of water per liter

• Launch cost per kg (USD/kg): how much it costs to send one kilogram of payload to low Earth orbit. This varies by rocket and provider, typically between $2,000 and $20,000.
• Water mass per liter (kg/L): pure water has a density of 1 kg per liter at room temperature. Adding a bottle and packaging increases this to about 1.1–1.3 kg per liter.

The result is the cost per liter of delivered water. Multiply by 0.5 for a half-liter bottle.

Worked Example

Using the default values: launch cost = $10,000/kg, water mass = 1 kg/L.

1. Cost per liter = $10,000 × 1 = $10,000 per liter
2. Cost per 0.5 L bottle = $10,000 × 0.5 = $5,000 per bottle

This matches the calculator output. If you use a higher launch cost (e.g., $20,000/kg), the cost doubles to $20,000 per liter.

Why Water Is So Expensive in Orbit

The cost is driven entirely by launch economics. To get water to the ISS, it must be launched on a rocket, and rockets are extremely expensive per kilogram. For example, a SpaceX Falcon 9 costs about $2,700 per kg, while a Russian Soyuz costs roughly $10,000–$20,000 per kg. NASA and its partners often use a mix of vehicles, so the effective cost varies.

Water is also heavy—one liter weighs one kilogram—so there is no way to reduce the cost by making it lighter. The only way to lower the price is to use a cheaper rocket or to produce water in space (which is currently done on the ISS through recycling).

How the ISS Gets Water

The ISS does not actually receive bottled water from Earth on a regular basis. Instead, it relies on a combination of:

• Recycled water: The Environmental Control and Life Support System (ECLSS) recovers about 90% of water from urine, sweat, and humidity. This is filtered and purified to drinking quality.
• Resupply missions: Cargo spacecraft (like SpaceX Dragon, Cygnus, and Progress) bring water in large bags or containers, not individual bottles. These are used for drinking, food rehydration, and experiments.
• Fuel cells: The Space Shuttle used to produce water as a byproduct of its fuel cells, but that is no longer operational.

The recycled water is actually cleaner than most municipal tap water, and astronauts drink it regularly.

Common Misconception: Bottled Water on the ISS

Many people imagine astronauts sipping from plastic water bottles like on Earth. In reality, water is stored in flexible pouches or rigid containers with straws. The water is often carbonated or flavored, but it is not sold in individual bottles. The cost of a “bottle� is a theoretical calculation—it is the cost of launching the equivalent mass of water.

Another misconception is that water is free in space. It is not—every kilogram of water has to be launched or recycled, and recycling equipment itself costs money to build and maintain.

How to Choose a Launch Provider (for Context)

If you were to send water to the ISS, you would need to choose a launch vehicle. The cost per kg varies widely:

• Falcon 9 (SpaceX): ~$2,700/kg
• Atlas V (ULA): ~$5,000–$10,000/kg
• Soyuz (Roscosmos): ~$10,000–$20,000/kg
• Space Launch System (NASA): ~$20,000+/kg (estimated)

These prices are for low Earth orbit, which is where the ISS resides. Heavier rockets or rideshare options can lower the cost, but water is a dense, heavy cargo.

Alternatives to Launching Water

To reduce the cost of water in space, several alternatives are being explored:

• Recycling: As mentioned, the ISS already recycles most of its water. This cuts the need for resupply by about 90%.
• In-situ resource utilization: On the Moon or Mars, water ice can be mined and melted, but this is not yet feasible for the ISS.
• Lighter packaging: Using collapsible containers instead of rigid bottles reduces mass, but only slightly.
• Advanced propulsion: Cheaper launch systems, like reusable rockets, are lowering the per-kg cost over time.

For now, recycling is the most effective way to keep the cost down.

Frequently Asked Questions

How much does a bottle of water cost on the ISS?

A 0.5-liter bottle would cost between $5,500 and $11,000, based on launch costs of $11,000–$22,000 per liter. This is the cost to deliver the water, not the retail price.

Do astronauts drink recycled urine?

Yes, they do. The water recycling system purifies urine, sweat, and humidity to a purity that exceeds Earth’s drinking water standards. It is safe and tastes like normal water.

How much water does an astronaut need per day?

Each astronaut needs about 3.5 liters of water per day for drinking, food rehydration, and hygiene. That means a crew of six needs about 21 liters per day, or 7,700 liters per year.

Why don’t they just send more water?

Because it is extremely expensive. Sending one liter costs thousands of dollars, so recycling is much more economical. The ISS recycles about 90% of its water, reducing the need for resupply.

Is the water on the ISS carbonated?

Some of it is. The ISS has a carbonation system that can add fizz to water, which astronauts enjoy because it tastes different from the flat recycled water. However, carbonated water is a luxury, not a staple.

Could you buy a bottle of water on the ISS?

No, there is no commercial sale of water on the ISS. Water is a shared resource, managed by the crew and ground control. The cost is borne by the space agencies, not individual astronauts.

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in t | Launch cost per kg | USD/kg | 10000 | 0
in m | Water mass per liter | kg | 1 | 0.1
out cost | Cost per liter | USD | t * m | 0
out cost2 | Cost per 0.5 L bottle | USD | t * m * 0.5 | 0