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MISSILE WORKS MISSILE WORKS User Manual and Instructions CORPORATION CORPORATION 1
MISSILE WORKS
MISSILE WORKS


User Manual and Instructions
CORPORATION
CORPORATION


Model RRC² - Rocket Recovery Controller
System Overview
The RRC
2
Rocket Recovery Controller provides two stage barometrically controlled deployment of rocket recovery
systems and equipment. Two-stage (or dual) deployment is preferable to single parachute or streamer recovery
systems for high-power rocketry. Recovery of large, heavy rockets with a small parachute or streamer alone does not
supply enough drag to safely recover the rocket without damage. An adequately sized parachute deployed at a high
altitude may cause the rocket to drift out of the launch area, making recovery difficult if not impossible.
Two stage (or dual) deployment recovery systems either separate the rocket airframe into two sections or eject a small
drogue parachute or streamer at apogee, allowing the rocket to descend at a rapid yet controlled rate. When the
rocket descends to a predetermined altitude above its initial launch elevation, it then deploys the main parachute,
allowing the rocket to make a safe landing.
Specifications
Operational range
0-25,000 ft. MSL
Test Current
80
µ
a
Arming mode
barometric
Firing Current
1.25 amps @ 1 sec
Minimum altitude for arming
300 ft. AGL
Dimensions
1.45" W x 5.7" L
Main stage deployment altitudes
1000/500 ft. AGL
Weight
3.4 oz. w/battery
Battery
9V or external 8-12V
Nominal Battery load
15ma
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Handling Precautions
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These units are sensitive to damage from ESD (electro-static discharge) and should always be handled in a
properly grounded environment. ESD damage is not covered under your warranty.
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Never directly handle the unit when it is armed and connected to live pyrotechnic charges as this may
cause the premature detonation of the charges.
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Always allow the unit and the battery system to adjust to ambient temperature conditions prior to
connecting, arming and flying.
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Avoid exposure of an armed unit to high intensity light (including direct sunlight), heat, cold, wind, or other
extreme environmental conditions.
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Always prepare your rocket and recovery system components with the unit powered off. Never cycle the
power switch off, then immidiately back on. Always allow at least 10 seconds prior to restoring power.
Operational Overview
Figure 1 depicts the general component layout of the RRC
2
Rocket Recovery Controller. The unit is designed for
several different modes of operation. Selection of these modes is made by the bank of switches located on the circuit
board.
Figure 1 - General component layout of the RRC²
Battery
Microcontroller Pressure sensor
LED
+
-
J1 (Output 1)
+
-
J2 (Output 2)
J3 (Power switch)
Piezo Beeper
Switch Bank 2
The switches are labeled 1 through 4 accordingly, switch 1 being the leftmost switch as illustrated in figure 1. The
ON/OFF position is also labeled, with the ON position being UP, the OFF position being DOWN. The following table
describes the switch functions and the corresponding modes of operation:
Table 1 - Switch positions and function
Switch 1
Switch 2
Switch 3
Switch 4
ON
Stage 2 (J2)
deployment altitude is
set to 1000 feet above
the initial launch
elevation
Redundant apogee
deployment operation (stage 2
fires at apogee and overrides
SW.1 setting)
4 seconds of delay time
is added to the mach
delay timer.
8 seconds of delay time
is added to the mach
delay timer.
OFF
Stage 2 (J2)
deployment altitude is
set to 500 feet above
the initial launch
elevation
Standard two stage
deployment operation (stage 2
altitude selected by SW.1
setting)
0 seconds of delay is
added to the mach
delay timer
0 seconds of delay is
added to the mach
delay timer
IMPORTANT The Mach Delay settings MUST be made prior to powering up the unit. These switch positions
are read at power up ONLY. Always set the switch positions prior to turning the unit on.
Standard two-stage deployment
Two-stage recovery of high power rockets is preferable as previously described in the "Overview" section of this
document. Operational progression of standard two-stage deployment is as follows: Initial launch, boost and coast phases of flight Apogee of flight detected, airframe separation or drogue chute/streamer deployed Rapid/controlled descent phase to pre programmed second-stage deployment level Main parachute deployment and touchdown
Single-Stage / Redundant Apogee Deployment
Single-stage deployment has its own set of advantages for rocket recovery when the launch site size or weather
conditions permit main parachute deployment at apogee. Single stage deployment systems are much simpler in
design and are simpler to operate and prepare. The RRC² can operate in a redundant mode wherein both ejection
charges can be fired at apogee, further increasing recovery system reliability. Single-stage deployment operation is as
follows: Initial launch, boost, and coast phases of flight Apogee of flight detected, main parachute/streamer deployed Slow descent and touchdown
Mach Delay timer
For extremely high-performance rocket flights approaching or exceeding the speed of sound (mach), the unit can be
configured to employ a time delay just after lift-off is detected. This time delay prevents the possibility of premature
apogee detection caused by the high/low pressure effects present along the rocket airframe during transition into and
out of mach. During the time delay, all barometric samples from the sensor are ignored so these pressure effects
cannot falsely trigger the apogee charge. After the expiration of time delay, normal barometric sampling resumes.
The unit can be programmed for 4, 8, or 12 seconds of total delay.
Modes of Operation
The RRC² has several distinct modes throughout the course of its normal operation. These modes of operation are
easily identified by the piezo beeper and the status LED.
Power-up and initialization mode
After initially powering on the RRC² unit, it goes through a 15-second initialization and start-up delay. The LED flashes
at a fast rate of 5 times per second. There is no audible sound from the piezo beeper. This start-up delay allows
stabilization of the electronics and establishes an initial barometric history. 3
Pre-launch mode
After the 15-second power up and initialization delay, the unit goes into the pre launch mode. The LED will flash at a
slow 2 second rate, and the piezo beeper will indicate the continuity of the ejection charges as follows: 0 Beeps
No continuity on either channel 1 Beep
Continuity on channel 1 2 Beeps
Continuity on channel 2 3 Beeps
Continuity on channel 1 & 2
The unit also monitors the barometric sensor for a change of 300 feet in elevation to determine the launch of the
rocket. After this change, the unit transitions into mach delay mode (if selected) or apogee detection mode.
Mach Delay mode
When either SW. 3 or SW. 4 is in the ON position, the unit will enter the mach delay mode. The LED flashes again at
its fast rate of 5 times per second. There is no audible sound from the piezo beeper. After the expiration of the mach
delay (if selected), the unit transitions into apogee detect mode.
Apogee Detection Mode
At this point, the rocket has detected launch and is in flight. The LED continues to flash at its fast rate of 5 times per
second. The piezo beeper will beep at a fast rate of ½ second. During this mode the unit is sampling for apogee
(indicated by an increase in pressure). When this pressure increase is detected, the unit transitions into deployment
mode.
Deployment mode
Now that the unit has detected apogee, it will fire the channel 1 (J1) output. The LED will continue to flash at its fast
rate of 5 times per second. There is no output from the piezo beeper. If the unit was set to operate in standard dual
deployment mode, it will continue to sample barometric pressure until it is either 1000 or 500 feet above the initial
launch elevation before firing the channel 2 (J2) output. Otherwise the unit is operating in redundant apogee mode,
and it will then fire the channel 2 output immediately following the channel 1 output. After the unit has fired both output
channels, it transitions into report mode.
Report mode
After deployment of the recovery system, the unit will report the peak altitude it measured during flight. The LED will
c