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Some Questions re CubeSat Kit

PostPosted: Fri Oct 22, 2004 10:05 am
by aek
I spoke to our hardware expert and he asked a few questions: 1) What exactly is on the flight processor board?

The "Flight Module" board is an _electrically_ identical subset of the Development ("Dev") Board electronics. It omits LEDs, jumpers, binding posts, sockets, the regulator for 6-24V input and the RS-232 hardware (level shifter, connector, etc.) that's in the bottom right corner of the Dev Board. IOW, it gets rid of all the extra stuff for lab work, but it runs _exactly_ the same code as the Dev Board.

The Flight Module is the one that's in the CubeSat Kit's Flight Model (i.e. the CubeSat that is launched into space).

You can see Flight Modules on page 15 (16) of this document: There's also a block diagram on page 21 (22).

2) Do you have a data sheet for the tranceivers?

Microhard supplies that on their website:

3) What is the exact part number for the TI microprocessor? There are many TI MSP430's

The Flight MCU is the MSP430F149. The Flight MCU is on the Dev Board (socketed) and the Flight Module (soldered)

4) What have you used for power sources in addition to solar?

We've left power up to the users -- I have a unit I cart around (the one you saw at the SmallSat conference) that flashes a bunch of LEDs and transmits wirelessly as a demo -- it (still) runs off 4 AA batteries. The CubeSat Kit is a 5V design in the sense that 5V is the main power available on the CubeSat Kit Bus. PC/104 is 5V. The actual electronics on the Flight Module and Dev Board are a mix of 3.3V (all the MSP430 and internal stuff) and 5V (the modem and USB). A CubeSat Kit design must provide the CubeSat Kit Bus with 5V. The external power jack on the CubeSat expects 5V (5.5V max).

5) What is peak current draw of your whole kit?

The Flight Module draws 25uA in sleep mode, and around 2mA running full bore (7.32MHz). The modem draws 200mA (?) to 4A, depending on its output power (which is programmable). The modem's 5V power is under complete control of the Flight MCU.

This document has a lot of info in it with a big FAQ, etc:


[This message has been edited by aek (edited October 22, 2004).]