S.1 Spacecraft Propulsion Systems Chapter 1: Introduction to ...
S.1 Spacecraft Propulsion Systems Chapter 1: Introduction to ...
S.1 Spacecraft Propulsion Systems Chapter 1: Introduction to ...
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Under Development:<br />
- 47-<br />
A new family of environmentally friendly monopropellants has been identified as an<br />
alternative <strong>to</strong> hydrazine. These new propellants are based on blends of e.g. hydroxyl<br />
ammonium nitrate (HAN), ammonium dinitramide (AND), hydrazinium nitroformate (HNF),<br />
nitrous oxide (N2O), and hydrogen peroxide (H2O2)<br />
When compared <strong>to</strong> hydrazine, e.g. HAN blends have a range of specific impulse (Isp) which<br />
can exceed that of hydrazine. Testing of HAN based propellants has begun <strong>to</strong> show<br />
promise and could soon be adopted for on-board propulsion systems of LEO satellites<br />
and constellations.<br />
Advantages:<br />
Safer propellants (also called ‘green’ or ‘reduced hazard propellants’) reduce costs by:<br />
• Eliminating the need for self-contained atmospheric protective ensemble (SCAPE)<br />
suits needed for <strong>to</strong>xic propellants.<br />
• No extensive and prohibitive propellant safety precautions and isolation of the<br />
space vehicle from parallel activities during propellant loading operations.