Flight Computer [schematic]

The flight computer contains an HC I 1 and two ADC chips.  It samples the outputs from the rest of the payload, packetizes the information and sends it to the transmitter.  The packet format is attached.  The data is transmitted at 230.4 kbaud.  The two external 13-bit ADC chips are talked to over a serial port and are used for the low speed data.  The internal 8-bit ADC on the HC I I are used for the high speed data.  Twelve low speed channels and four high speed channels are used.

Housekeeping [schematic]

This board monitors the status of the payload as well as measuring temperatures.  It measures one K type thermocouple that is mounted in the nose tip to provide the nose tip temperature. It monitors the voltages of the power board to make sure that they are stable.  It has an air pressure sensor routed to a plenum to measure outside air pressure.  This board has other capabilities that are not being used for this flight to keep the wiring harness from changing.  For example, the functions in the skin temp. board have been integrated into the housekeeping board.

The transmitter takes the serial stream of data from the flight computer and transmits it to the ground.  It operates in the 220 to 230 MHz range and will be set as need by Poker Flat.  The transmitter is currently set to 222.75 MHz.  It puts out 10.5-11 watts of RF power that will radiate through a whip antenna in the nose.

This board has the supporting hardware to measure a K type thermocouple.  The intended use is to measure the skin temperature of the nose cone.  This board also measures the internal temperature of the payload (temp of skin temp. board).  This board is also the mounting point for the test thermocouple.  The continuity of the thermocouple is monitored by the housekeeping board.

Accelerometer [schematic]

The accelerometer board provides four acceleration channels in high and low speed.  The channels are radial, tangential, longitudinal, and y-axis.  The high-speed channel is for vibration information and the dc is cut off, while the low speed channels are for the acceleration curve and the vibration is cut off.  The low speed y-axis is not sampled in this mission.

Power [schematic]

The power board regulates the power from the battery back to +- 15v for the low voltage electronics.  It does this with a DCIDC converter for maximum efficiency.  It also switches the power to the payload on and off from a +-I Ov signal from the umbilical box.

Magnetometer

The magnetometer was built by the students at Tokai University.  It measures the rocket's orientation on three axis using the earth's magnetic field.