I am working with Steve Eves who last year launched a 36' tall scale Saturn V rocket and in so doing, set a record for the largest model rocket ever launched and safely recovered. Having accomplished that he has now set out to build a 1/10 scale Saturn 1b with two stages. What he needs, and what I am researching is a method to determine whether the second stage is at or near a vertical attitude before the second stage engines are ignited. I have been palying with a Parallax Javelin board and a Sparkfun two axis rate gyro, but as you have probably already guessed, a rate gyro in this application is useless. So, I am currently looking at the 9dof Razor IMU and would welcome input on the best way to go about accomplishing my task. We basically need a go or no go signal if the vehical is off of local vertical by more than 10 degrees or so. Any input would be appreciated. Remember that at first stage burn out, the vehical will be experiencing zero G flight. Thanks!!