I could not answer that without knowing the entire layout of the rocket.
Can valves be locked out with a device that is removed?
Remote filling?
Me personally I've had servos go wonky at any given moment they can't be
trusted IMO. Can a lock out device be used?
Even remote valves should be locked out.
Solenoid valves should have manual valve back ups.
pyro devices should be locked out including the ignition source.
That's just the basic stuff. I'd need to know more about the avionics.
Tag out Lock out in the check list.
Me personally I'd want more than a few dry runs of the checklist until I
was comfortable with it as well.
I would also have to know that rocket very well to actually help on the
pad.
#1 No real rockets do I want to help on the pad with if I didn't build
it myself or have a large hand in it. I don't mind observing with
binoculars from a safe distance though :)
Sorry I don't think this is actually helpful. I just don't know enough
about your rocket to make helpful suggestions. I just threw out some
stuff you probably already thought of.
-------- Original Message --------
Subject: [AR] Safing of liquid vehicle
From: Robert Watzlavick <rocket@xxxxxxxxxxxxxx>
Date: Sun, November 08, 2015 9:11 am
To: "arocket@xxxxxxxxxxxxx" <arocket@xxxxxxxxxxxxx>
I'm working on the power electronics for my liquid rocket and I'm trying
to decide the best way to handle safing of the vehicle during pad
activities. The absolutely safest way is to just turn off all power to
the vehicle during propellant loading and troubleshooting but I'd like
to keep the avionics (IMU, pressure sensors, etc.) powered and warmed up
for best stability. The valves are controlled via RS-232 servos (AX-12)
so there's little chance they would get an uncommanded actuation. I
thought about having a SAFE/ARM switch that controls power to the
igniter CDI, igniter valves, recovery system, and maybe also the servo
valves (main, vent, helium). However, I'd want to make sure that switch
is appropriately vibration and shock rated so I don't get intermittent
power interruptions when the vehicle is operating. What has been done
in the past? Here's a good question - if you were helping me out on the
pad, what level of safing would you want to see for your personal safety?
Thanks,
-Bob
