re cold gas tanks for sounding rockets in article eagle ukc ac uk rdl ukc ac uk r d lorenz writes does anyone know how to size cold gas roll control thruster tanks for sounding rockets well first you work out how much cold gas you need then make the tanks big enough our sounding rocket payload with telemetry guidance etc etc and a telescope cluster weighs around pounds it uses freon jets for steering and a pulse width modulated controller for alignment ie during our eight minutes in space the jets are pretty much continuously firing on a duty cycle or so the jets also need to kill residual angular momentum from the spin stabilization and flip the payload around to look at the sun we have two freon tanks each holding liters of freon i m speaking only from memory of the last flight the ground crew at wsmr choose how much freon to use based on some black magic algorithm they have extra tank modules that just bolt into the payload stack this should give you an idea of the order of magnitude for cold gas quantity if you really need to know send me email and i ll try to get you in touch with our ground crew people cheers craig don t drink soap dilute dilute ok
