Notes

A GSE system should be capable of the following:
- Control the flow or N2O into the oxidizer tank.
- Provide the signal for engine ignition
- Safe mode the vehicle by rapidly dumping N2O from the vehicle via the nozzle without ignition (purge system, accomplished with CO2)
Receiver only needed on GSE, not on rocket (electrical quick disconnect)
- Electrical quick disconnect routed along N2O line
- Pressure from fluid quick disconnect forces electrical connector apart
Ignition sequence:
- Igniter first, then open engine valves
- Manually timed (RC transceiver channels)
Electrical system completely independent from rocket/avionics electrical power
- 12V battery within GSE enclosure
- Electrical quick disconnect leading to vehicle servos
- Servos, transceiver run off of regulated 5VDC

Polaris GSE Components

Nitrous feed system
- Connects to N2O tank via CGA 326 connection
- Pressure gauge to measure pressure
- Check valve to prevent contamination
- Servo actuated ball valve
Purge system
- Connects to CO2 tank via push-to-connect
- Servo actuated ball valve
Fill system connection
- Connects the rocket to both Nitrous feed system and Purge system
RC Transceiver
- Allows for control of Servo actuated ball valves (in GSE and on rocket)
- Accepts regulated 5V from power supply
- CH1: Igniter relay
- CH2: Nitrous fill valve
- CH3: Vehicle nitrous valve
- CH4: Vehicle ethanol valve
- CH5: Purge valve
- CH6: unused
Power supply
- 12V car battery, used for powering igniter on rocket
- Regulated down to 5V for use with servos and RC Transceiver
Relay
- Controls 12V battery power via 5V signal sent by RC Transceiver
- Connected to igniter on rocket to allow remote ignition
Enclosure
- Steel toolbox with holes drilled for fluid and electrical connection
Electrical quick disconnect
- Four wires: Power (+5V), Ground, Nitrous valve servo and Ethanol valve servo
- Header pin connector placed on fluid quick disconnect
- Fluid pressure from quick disconnect forces header pins apart on launch

MIT Rocket Team > Polaris Ground Support Equipment > image-2024-10-13_16-45-48.png

MIT Rocket Team > Polaris Ground Support Equipment > Screenshot 2024-10-18 210544.png

Part	Desc.	Quantity	Link
Battery 12V		1	Harbor Freight
Servo	Used to actuate ball valves	2	Amazon
Transceiver	6 channels; controls servos and igniter	1	Amazon
Ball Valve		2	McMaster-Carr
Regulator	Generates regulated 5V from battery voltage	1	Amazon
Enclosure	Steel toolbox	1	Harbor Freight
20AWG wire	Red, black, white; for interconnecting		N/A
Relay	PWM controlled, driven off of 5V	1	Amazon
Adapters	High pressure adapters & fittings		McMaster-Carr
Tubing	High pressure chemical hoses		McMaster-Carr
Check valve		2	McMaster-Carr
PTFE Tape	Seals NPT fittings