But at the same time this conversion is happening in an immensely smaller volume. Also it doesn't require constant maintenance of living conditions. There are a

But at the same time this conversion is happening in an immensely smaller volume. Also it doesn't require constant maintenance of living conditions. There are always tradeoffs in engineering AND nature. For instance, trees tend to have to spend tons of their energy in order to get taller. This is mostly because they have to compete with other plants for sunlight. This inefficiency leads to much more waste product (O2) being produced and tends to capture more fuel (CO2). Technology just optimizes for different things than nature. Otherwise the lander would have just carried a couple gallons of water and some algae.