Detailed Description
Launched September 5, 1996. MO-30 is the twin spacecraft of UNAMSAT-1 (see above). Unfortunately, it failed after about a day of transmitting due to a dead uplink receiver.
MO-30 was constructed at the National University of Mexico (UNAM). The satellite had two telemetry transmitters with BPSK modulation at 1200 baud using AX.25 protocol in Ultra High Frequency of 437 MHz. Every telemetry frame sends to Earth about 60 parameters, consisting of voltages, currents, temperatures and binary states.
The main computer had a V40 microprocessor from NEC (equivalent to Intel's 80186), hardened to radiation, a bank of EDAC memory of 256 Kbytes, and a SRAM memory bank of 4 Mbytes. The typical power consumption of this computer was 1 watt.
In one of the modules, the energy collected from the solar panels was stored in niquel-cadmium batteries. In this same module there was a circuit that regulates the voltages in use in the rest of the satellite. The use of internal batteries guaranties proper operation even when the satellite is in eclipse.
The experiment requires a pulse transmitter, a broad band echo receiver in the same frequency of the transmitter, and a controller based in a HC05 family microcontroller from Motorola. This controller digitized the echoes received by the receptor and, with help of the main computer, evaluated if those echoes met the criteria to be considered a valid event, in which case the event was stored in the main computer.
The satellite had a 5 channel digital receptor that allowed communication from earth. Four channels were for users, and one was reserved for commanding and software loading purposes.
Externally, the satellite had a set of antennas for UHF transmission using circular polarization, a dipole antenna for pulse transmission and reception and, in the upper part, an antenna for reception of telecommands and software sent from Earth.
The body of the satellite is surrounded by Gallium Arseniure solar cells, recovered with a thin quartz crystal as protection against erosion
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