10.3 Analysis of Technical Characteristics
337
10.3 Analysis of Technical Characteristics
10.3.1 Requirements
The mission of the lunar lander was to realize soft-landing on the surface. Generally
there were 5 phases in flight profile.
(1) Launch: from lift-off of the launch vehicle to separation of the lunar lander
and the launch vehicle. The lunar lander was injected into LTO by the launch
vehicle.
(2) Lunar Transfer orbit: from separation of the lunar lander and the launch vehicle
to LOI.
(3) Circumlunar orbit: from LOI to the beginning of powered descent.
(4) Powered descent: from predefined altitude of circumlunar orbit to landing on
lunar surface.
(5) Operation on lunar surface: exploration on lunar surface.
During launch, a telemetry and telecommand channel should be established between
the lunar lander and ground to complete telemetry monitoring, command transmission and orbit determination. During such flight phase, usually the lunar lander could
not be accessed by deep space network, and the telemetry and telecommand should
be implemented by other ground stations and telecommunication ships. During LTO
phase from separation of the lunar lander with launch vehicle to LOI, there were
crucial actions such as trajectory maneuver correction when the lunar lander could
be accessed by ground stations. Before LOI, precise orbit determination by means of
telemetry and telecommand channel was necessary. After LOI, the lunar lander was
inserted into circumlunar orbit. When the lunar lander was above predefined landing
site and accessed by deep space network, the powered descent was initiated and
telecommunication channels should be established. After landed, the lunar lander
would conduct exploration on lunar surface.
The realization of telemetry/telecommand and telecommunication for lunar softlanding mission required the mutual coordination of the lunar lander and ground. The
ground telemetry/telecommand and telecommunication terminals generally were
composed of ground stations of telemetry/telecommand system, telecommunication
ships and ground stations of ground application system. The telemetry and telecommand system were mainly based on deep space network with large aperture antenna,
high-power transmitter and high sensitivity receiving system to realize the telemetry
and telecommand of the lunar lander. The ground stations of ground application
system were designed to receive scientific payload data of the lunar lander.
In order to ensure normal implementation of telemetry/telecommand and
telecommunication, it was necessary to make sure the coincident match of
lander-ground telemetry/telecommand and telecommunication interface, including
telemetry/telecommand and telecommunication architecture, frequency band and
antenna polarization.
337
10.3 Analysis of Technical Characteristics
10.3.1 Requirements
The mission of the lunar lander was to realize soft-landing on the surface. Generally
there were 5 phases in flight profile.
(1) Launch: from lift-off of the launch vehicle to separation of the lunar lander
and the launch vehicle. The lunar lander was injected into LTO by the launch
vehicle.
(2) Lunar Transfer orbit: from separation of the lunar lander and the launch vehicle
to LOI.
(3) Circumlunar orbit: from LOI to the beginning of powered descent.
(4) Powered descent: from predefined altitude of circumlunar orbit to landing on
lunar surface.
(5) Operation on lunar surface: exploration on lunar surface.
During launch, a telemetry and telecommand channel should be established between
the lunar lander and ground to complete telemetry monitoring, command transmission and orbit determination. During such flight phase, usually the lunar lander could
not be accessed by deep space network, and the telemetry and telecommand should
be implemented by other ground stations and telecommunication ships. During LTO
phase from separation of the lunar lander with launch vehicle to LOI, there were
crucial actions such as trajectory maneuver correction when the lunar lander could
be accessed by ground stations. Before LOI, precise orbit determination by means of
telemetry and telecommand channel was necessary. After LOI, the lunar lander was
inserted into circumlunar orbit. When the lunar lander was above predefined landing
site and accessed by deep space network, the powered descent was initiated and
telecommunication channels should be established. After landed, the lunar lander
would conduct exploration on lunar surface.
The realization of telemetry/telecommand and telecommunication for lunar softlanding mission required the mutual coordination of the lunar lander and ground. The
ground telemetry/telecommand and telecommunication terminals generally were
composed of ground stations of telemetry/telecommand system, telecommunication
ships and ground stations of ground application system. The telemetry and telecommand system were mainly based on deep space network with large aperture antenna,
high-power transmitter and high sensitivity receiving system to realize the telemetry
and telecommand of the lunar lander. The ground stations of ground application
system were designed to receive scientific payload data of the lunar lander.
In order to ensure normal implementation of telemetry/telecommand and
telecommunication, it was necessary to make sure the coincident match of
lander-ground telemetry/telecommand and telecommunication interface, including
telemetry/telecommand and telecommunication architecture, frequency band and
antenna polarization.