S.1 Spacecraft Propulsion Systems Chapter 1: Introduction to ...

Advanced space propulsion
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In order to achieve efficient mission costs, an important application of advanced space
propulsion is to reduce cost by:
- reduction of the total mass that must be launched from Earth,
- reduction of propulsion system mass fraction, allowing for higher payload mass,
- increase of mission impulse performance, allowing for satellite extended orbit
maintenance and attitude control.
A second goal of advanced space propulsion is to perform extended (manned) exploration
of the solar system and previously ‘impossible’ missions, like interstellar travel.
Consequently, the evolution of advanced spacecraft propulsion systems will mainly focus
on increased performance, that is high values of ‘System-spec. Impulse’, Issp.
Potential improvements of propulsion performances will however require a careful analysis
of development and manufacturing cost as well as complexity, operability and reliability of
propulsion systems. This will have to be balanced against potential gain in propulsion
performance and propulsion system weight with resulting improvement of Issp.