Session
Technical Session XI: Advanced Subsystems and Components II
Abstract
Small satellites are emerging as the preferred platform for a wide variety of earth orbit and even interplanetary missions. These spacecraft are, by their very nature, extremely limited in budget, volume, mass and power. Existing fluid propulsion options are too large, costly and complex for many small satellite applications. In an attempt to address this problem VACCO has produced an inexpensive, modular system specifically designed for the special needs of small satellites. This paper documents the results of a development program conducted for NASA and administered by the Applied Physics Laboratory of John Hopkins University. The Cold Gas Propulsion System (CGPS) resulting from this effort is unique in several ways. It utilizes a simple “blow down” architecture which requires the entire system to operate at up to full storage tank pressure. The traditional pressure regulator has been eliminated. This required the development of unique thrusters capable of functioning with inlet pressures to 207 bar. To minimize power consumption, the thrusters feature latching valves that require an electrical pulse to open and another to close. Between pulses the thruster is magnetically latched in either the open or closed position as required. This dramatically reduces the power required by the thruster valves while preserving small impulse bit capability. In order to minimize mass and cost, the system uses only four thrusters. By mounting these thrusters in a double canted orientation to the spacecraft, pitch, yaw and roll control as well as delta V can be accomplished. In conclusion, the subject Cold Gas Propulsion System represents an important advance in propulsion technology suitable for small satellites. As a result of this work, the size, mass, power requirements and cost of these systems has been reduced.
Design and Test of an Economical Cold Gas Propulsion System
Small satellites are emerging as the preferred platform for a wide variety of earth orbit and even interplanetary missions. These spacecraft are, by their very nature, extremely limited in budget, volume, mass and power. Existing fluid propulsion options are too large, costly and complex for many small satellite applications. In an attempt to address this problem VACCO has produced an inexpensive, modular system specifically designed for the special needs of small satellites. This paper documents the results of a development program conducted for NASA and administered by the Applied Physics Laboratory of John Hopkins University. The Cold Gas Propulsion System (CGPS) resulting from this effort is unique in several ways. It utilizes a simple “blow down” architecture which requires the entire system to operate at up to full storage tank pressure. The traditional pressure regulator has been eliminated. This required the development of unique thrusters capable of functioning with inlet pressures to 207 bar. To minimize power consumption, the thrusters feature latching valves that require an electrical pulse to open and another to close. Between pulses the thruster is magnetically latched in either the open or closed position as required. This dramatically reduces the power required by the thruster valves while preserving small impulse bit capability. In order to minimize mass and cost, the system uses only four thrusters. By mounting these thrusters in a double canted orientation to the spacecraft, pitch, yaw and roll control as well as delta V can be accomplished. In conclusion, the subject Cold Gas Propulsion System represents an important advance in propulsion technology suitable for small satellites. As a result of this work, the size, mass, power requirements and cost of these systems has been reduced.
