Planetary Pros: You’ve probably not heard of this fuel before – Hydrazine is something called a “hypergolic propellant”, that’s quite a tongue twister!
It just means it ignites spontaneously when in contact with another chemical called an oxidizer.
Basically, this makes it super reliable and easy to ignite.
Unlike Hydrogen, Hydrazine has high energy density, meaning it makes for compact fuel storage. It’s a popular choice in spacecraft for attitude control, manoeuvring, and small thrusters due to its simplicity and stability.
Cosmic Cons: Hydrazine is highly toxic and carcinogenic, meaning it creates a lot of safety and environmental risks from when its being made to when it’s being handled and stored – and of course again at launch.
There have to be very strict rules around producing and disposing of it – and these can be expensive. It’s also not great for the environment, creating toxic by-products such as nitrogen oxides.