Is it possible to have an eco-conscious rocket? While that may seem like a laughable concept, NASA is testing new green propellants to replace hydrazine, the current toxic and corrosive standard moseying around space.

Nearly every satellite depends on hydrazine, the highly toxic and corrosive fuel that played a starring role in The Martian. NASA hopes to replace that fuel with a non-toxic green propellant. Along with being more friendly to our planet, an easier-to-handle fuel would translate into lowered costs by simplifying handling and processing time.

This is a 22 Newton thrust engine loaded with a green propellant. In the scale of things, a 22 Netwon thrust engine is tiny: that’s about 5 pounds of thrust, or utterly useless here at the surface where gravity dominates. However, up out of Earth’s gravity well, that’s enough thrust to shove even a mighty spacecraft around with ease.


The 10-second pulsing test ratcheted the temperature upwards, giving engineers critical data to see how the fuel’s chemical reactions drove heat flow within the thruster over time. Warmer colours correlate to warmer temperatures, and cooler colours to cooler temperatures.

The green propellant for this test is LMP-103S. That oh-so-catchy name is a rocket fuel based on ammonium dinitramide supplemented with methanol, ammonia, and water. It’s far more stable than hydrazine, not sensitive to shock, air, or moisture, is not particularly toxic or corrosive on the scale of rocket fuels, and has an appropriate range of temperatures for both being stored and for use. As an extra bonus, the fuel is also more efficient than hydrazine. The catch? It requires more catalyst to actually react, and when it gets started it burns about twice as hot.

The fuel already passed space qualification testing, and has been successfully used for the five years to keep the PRISMA satellite happily in position in conjunction with a traditional hydrazine system. Now, if only we can figure out how to modify our systems to burn hot, we might be on to something fantastic!


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Image credit: NASA

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