Name the algae useful for prolonged space flight Why?

Explanation

**Step-by-Step Solution:**

1. **Identify the Algae**: The algae that is useful for prolonged space flight is called **Chlorella**.

2. **Reason for Use**: Chlorella is beneficial for space missions for several reasons:
- **Oxygen Production**: It liberates oxygen through the process of photosynthesis, which is essential for human survival in space.
- **Carbon Dioxide Consumption**: Chlorella absorbs carbon dioxide (CO2), helping to reduce the levels of this gas in a closed environment, which is crucial for maintaining a breathable atmosphere.
- **Waste Treatment**: It can assist in sewage treatment and waste disposal, making it useful for managing waste in space habitats.
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