  The traditional celestial navigation system (CNS) is used the moon, stars,
and planets as celestial guides. Then the star tracker (i.e. track one star or
planet or angle between it) and star sensor (i.e. sense many star simultaneous)
be used to determine the attitude of the spacecraft. Pulsar navigation also be
introduced to CNS. Maser is another interested celestial in radio astronomy
which has strong flux density as spectral line. Now we analysis the principle
of maser navigation which base on measuring Doppler shift frequency spectra and
the feasibility that use the exist instrument. We give the navigation equations
of maser-based navigation system and discuss the integrated navigation use
maser, then give the perspective in the Milky Way and the intergalatic. Our
analysis show that use one meter antenna can achieve tens of meters position
accuracy which better than today's star sensor. After integrated with maser
navigation, pulsar navigation and star sensor in CNS and inertial navigation
system, is it not only increase the reliability and redundancy of navigation or
guiding system but also can less or abolish the depend of Global Navigation
Satellite System (GNSS) which include GPS, GRONSS, Galileo and BeiDou et al.
Maser navigation can give the continuous position in deep space, that means we
can freedom fly successfully in the Milky Way which use celestial navigation
that include maser, pulsar and traditional star sensor. Maser as nature beacon
in the universe will make human freely fly in the space of the Milky Way, even
outer of it. That is extraordinary in the human evolution to type III of
Kardashev civilizations.
