Development of a Cold Gas Propulsion System for the ... - SSL - MIT

was controlled manually; later, modules were added to the software to allow for sequences of multiple
pulses of predefined pulse width and spacing to be launched with a single command.
5.2.2 Laboratory Nitrogen Cylinders
Some early single-stream characterization tests were performed by feeding the instrumented thruster
from a standard laboratory cylinder of compressed nitrogen, with the pressure controlled by the
cylinder regulator. This was done for several reasons. First and foremost, the Tescom regulator meant
for the flight system could not easily interface with a laboratory cylinder, so using it essentially required
constructing the entire high side of the CGSE as shown in Figure 3-3. It was believed that it would be
faster and simpler to run off of a laboratory gas cylinder instead of going through the process of filling
up the CGSE flight tanks for every test, especially since even though most laboratory cylinders were
filled to pressures less than 4500 psia, they could still hold more nitrogen than the flight tanks.
Furthermore, it was known that the flow rates required by a single thruster solenoid valve were far
below the full capacity of the flight regulator, so it was believed that single-stream testing would provide
relatively little useful information about flight regulator performance, and that useful data could be
collected about the CGSE thruster without using the flight regulator.
The first setup for collecting single-stream thruster data is shown in Figure 5-3.
Figure 5-3. First configuration for single-stream characterization tests.
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