美國衛星協會計畫2018於月球軌道放轉頻器 5 GHz to 10 GHz Lunar Transponder Mission
AMSAT-NA plans 5 GHz to 10 GHz transponders on a spacecraft expected to
launch
in September 2018 into a Lunar orbit.
Heimdallr is a 3 axis stabilized 6U CubeSat with a mass of approximately
8 kg. It will have a Cold Gas Thruster for inertia dump and a star tracker for
navigation. Deployable, gimbled solar panels will produce up to 100
watts of DC power, electric propulsion will be used to achieve lunar orbit.
There will be a combination of omni and directional patch antennas on
one side of spacecraft.
The first part of mission is to provide Telemetry, Tracking, and Command
(TT&C) to obtain lunar orbit. The second part is to perform the data
downlink experiment while the final part is to provide a two way regenerative
repeater and analog repeater in lunar orbit for lifetime of satellite.
Proposing these downlinks:
• Omni transponder: 10.451 GHz +/- 0.5 MHz
• Directional transponder: 10.4575 GHz. +/- 3.5 MHz
• Analog transponder: 10.4665 GHz. +/- 2.0 MHz
For the first part of the mission (TT&C) using 300 bps BPSK 1/2 rate viterbi
Ranging 1.5 Mbps BPSK DSSS. For the second part of mission 4.5 Mbps QPSK ½
rate DVB-S2. For the final part of mission 25 kbps BPSK 1/5 rate DVB-S2.
Proposing these Uplinks
• Omni transponder: 5.651 GHz +/- 0.5 MHz
• Directional transponder: 5.6575 GHz. +/- 3.5 MHz
• Analog transponder: 5.665 GHz. +/- 2 MHz
