ERPS Site:
Experimental Rocket Propulsion Society
What's New The SF Bay Area's Non-profit Liquid-Fuel Rocket Engine Team


Propellant Production

Obtaining adequate supplies of HTP has been a recurring problem. Our propellants team consists of Pierce Nichols and Dave Weinshenker. They are currently building the components that will let us manufacture our own rocket-grade hydrogen peroxide.

Solving the problem this way involves two operations: Raising the concentration of the peroxide, and removing impurities. The process starts with peroxide of about 50% concentration. This is raised to 85% or higher by a sparging operation — basically, blowing warm air through the peroxide solution to drive off water. It works because the water evalorates a bit more easily. Next, a fractional-freezing apparatus removes impurities such as the stabilizing compounds added to prevent peroxide decomposition during storage or handling. Many of these compounds will "poison" (deactivate) the catalysts we use in our engines.

As documented on our e-mail list, both of these operations have been done successfully in prototype equipment. These were batch-process devices and required constant monitoring. The propellant team's current effort, therefore, is to develop continuous-process devices which can safely be left alone for periods of time, and which have self-monitoring and auto-shutdown features.

This equipment will be installed in a location approved for operations with hazardous materials — the Rocket Ranch. A suitable building is being prepared, and efforts are under way to "beef up" the electricity supply, since the generator we have now can't supply enough power for the new equipment.


POGO project lead Dave Masten has completed the structural design of that vehicle. Fabrication of POGO's fuselage and some internal parts (engines, tanks, plumbing) is under way. This work is proceeding with all deliberate speed.


The "brain" of Gizmocopter is a PC-104 computer made by Diamond Systems. A development system was recently purchased to expedite development of the flight control software. That work is nearing completion. A Falcon IMU just arrived and is being integrated with Gizmo's other systems. We expect to have this testbed ready for flight within a few days.

Copyright 2004 E.R.P.S.

Last Updated: 21:04:34 on 01 Apr 04

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