Why is liquid hypergolic important to aerospace systems? 

Liquid hypergolic propellants are crucial to aerospace systems due to their ability to spontaneously ignite upon contact between the fuel and oxidizer, eliminating the need for an external ignition source. This characteristic significantly simplifies engine design and operation, enhancing the reliability and safety of rocket systems, which is particularly beneficial for missions requiring precise control and immediate thrust, such as satellite positioning and manned spacecraft maneuvers . The development of hypergolic propellants has been driven by the need for high-performance, environmentally friendly, and less toxic alternatives to traditional hydrazine-based fuels . Recent advancements have focused on green hypergolic propellants, such as hydrogen peroxide and hypergolic ionic liquids (HILs), which offer high performance while being less harmful to the environment and safer for handling and storage . The introduction of hypergolic metal-organic frameworks (HMOFs) as additives has further expanded the possibilities for creating safer hypergolic fuels by providing tunable ignition and combustion properties . Moreover, the spontaneous ignition characteristic of hypergolic propellants has been leveraged in innovative preparative methods for synthesizing various carbon and inorganic nanomaterials, demonstrating the versatility and utility of hypergolic reactions beyond traditional aerospace applications . The exploration of new energetic complexes and borohydride cluster-based salts as hypergolic materials has shown promising results in improving the specific impulse and reducing ignition delay times, further enhancing the efficiency and responsiveness of propulsion systems . Additionally, the development of non-toxic fuel mixtures incorporating amine azides and tertiary diamine compounds represents a significant step towards safer and more environmentally friendly hypergolic propellants . In summary, liquid hypergolic propellants are indispensable to aerospace systems for their immediate ignition, operational simplicity, and the potential for safer, more efficient, and environmentally compatible propulsion solutions .

Metal–organic frameworks as hypergolic additives for hybrid rockets

Liquid hypergolic fuels are crucial in aerospace due to their spontaneous ignition upon contact, simplifying engine design and operation, eliminating the need for an ignition system, and enhancing safety.

Hypergolic Ignition of 1,3-Cyclodienes by Fuming Nitric Acid toward the Fast and Spontaneous Formation of Carbon Nanosheets at Ambient Conditions

Liquid hypergolics are crucial in aerospace due to their spontaneous ignition, eliminating the need for external ignition sources. This paper highlights their role in producing carbon nanosheets and useful energy.

Hypergolic Systems based on Hydrogen Peroxide Oxidizer

Liquid hypergolic systems are crucial in aerospace due to their simplicity, reusability, high performance, environmental friendliness, and low toxicity, making them preferable for rocket propulsion applications.

Theoretical Study on Hydrolytic Stability of Borohydride-Rich Hypergolic Ionic Liquids.

Liquid hypergolic fuels like Borohydride-Rich Hypergolic Ionic Liquids are crucial in aerospace due to their green nature, potential to replace toxic propellants, and enhance safety and efficiency in rocket propulsion.