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4 Structure and Mechanism Technology of Lunar Lander
Table 4.5 Typical requirements for the lunar rover transfer mechanism
Requirements
Definition
Description
Information required
Strength
The components did
not produce damage
(such as fractures,
instability, excessive
deformation, etc.)
that could imperil
mission of the lunar
lander under the
specified load
1) The transfer
mechanism usually
had the highest load
during launch and
landing. The load of
transfer mechanism
was withstood by its
structure and hold
down mechanism
2) Load was derived
from launch
environment,
landing impact and
mass properties of
the lander and the
lunar rover
3) Same requirements
should be satisfied
in all phase
including launch,
flight, powered
descent and landing
1) General mechanical
environmental
conditions
2) landing impact load
3) mass properties of
the lunar rover
Natural frequency
(or stiffness)
The natural
frequency (usually
the fundamental
frequency, i.e. the
lowest natural
frequency, with
directionality)
should be greater
than specific value or
beyond a certain
frequency range
1) The fundamental
frequency of system
requirement should
be met
2) During launch, the
stiffness of transfer
mechanism in hold
down status should
be enough to keep
the lunar lander
within the dynamic
envelope
1) Fundamental
frequency specified
by system design 2)
mass properties
(continued)