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Changes
→Propulsion: update with L395
== Propulsion ==
== Propulsion ==
The rocket will be powered by a M1230 from Cesaroni, which was chosen for several reasons. First, it allows us to attain our desired apogee ~ 10,000ft, and second, this is a 75mm M motor which will allow us sufficient room on the exterior of a 98-75mm motor adapter to mount our static stability fins.
The unloaded mass of the system is 12.9 lbs and 25.5 lbs loaded, using a Cesaroni Pro75 L395. The center of gravity is at 52.19”, and the center of pressure is at 61.45”, giving us a stability of 2.55 cal. Both the forward and aft airframes contain an avionics bay with dual altimeters that will control the separation and reefing charges, executed by redundant cable cutters. The forward airframe will additionally contain the avionics necessary for the PID controller including a Raspberry Pi B+, a Teensy 3.2, redundant 9-DOF Absolute Orientation Sensors from Adafruit, a Big Red Bee GPS Radio, servos to control the fins, and several cameras. The aft airframe will contain an additional GPS radio using a different frequency to ensure recovery of the booster section.
=== Motor Performance ===
=== Motor Performance ===
{|
{|
|align="right"| Motor
|align="right"| Motor
| M1230
| Pro75 4937L395-P
|-
|-
|align="right"| Type
|align="right"| Type
|-
|-
|align="right"| Diameter
|align="right"| Diameter
|
| 2.95 in (75 mm)
|-
|-
|align="right"| Length
|align="right"| Length
|
| 29.8 in
|-
|-
|align="right"| Total Weight
|align="right"| Total Weight
|
| 5706 g
|-
|-
|align="right"| Prop. Weight
|align="right"| Prop. Weight
|
| 3423 g
|-
|-
|align="right"| Avg. Thrust
|align="right"| Avg. Thrust
|
| 393.7 N
|-
|-
|align="right"| Max Thrust
|align="right"| Max Thrust
|
| 587.5 N
|-
|-
|align="right"| Total Impulse
|align="right"| Total Impulse
|
|936.8 Ns
|-
|-
|align="right"| Burn Time
|align="right"| Burn Time
|
|12.54 s
|-
|-
|align="right"| ISP
|align="right"| ISP
|
|147.08 s
|}
|}