Summary of Critical Design Report Readiness Revi… · Web viewThese values will be different...

The University of ToledoFlight Readiness Review

Table of ContentsSummary of Critical Design Report

Team Summary

Launch Vehicle Summary

Size and Mass Statement

Final Motor Choice

Recovery System

Launch Rail Size

Payload Summary

Payload Title

Payload Summary

Changes Made Since Critical Design Review

Changes Made to Vehicle Criteria

Changes Made to Payload Criteria

Changes Made to Project Plan

Vehicle Criteria

Design and Construction of Vehicle

Structural Elements

Electrical Elements

Flight Reliability1

Testing Data

Safety and Failure Analysis

Full-Scale Test Results

Mass Statement

Recovery Subsystem

Structural Elements

Electrical Elements

Redundancy Features

Parachutes

Drawings and Schematics

Rocket-Locating Transmitters

Sensitivity of Subsystem

Failure Modes

Mission Performance Predictions

Performance Criteria

Simulations

Drag Assessment

Stability Margin

Kinetic Energy

Drift Simulations

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Verification

Safety and Environment (Vehicle)

Payload Integration

Integration and Compatibility

Integrity

Payload Criteria

Experiment Concept

Creativity

Significance

Suitable Level of Challenge

Science Value

Payload Objectives

Payload Success Criteria

Method of Investigation

Relevance of Data

Process Procedures

Payload Design

Structural Elements

Electrical Elements

Atmospheric Measurement Suite Code

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Ground Station Code

Drawings and Schematics

Instrument Precision

Flight Performance Predictions

Workmanship

Verification

Safety and Environment (Payload)

Launch Operations Procedures

Checklists

Recovery Preparation

Payload Preparation

Motor Preparation

Setup on Launcher

Igniter Installation

Launch Procedure

Troubleshooting

Post-Flight Inspection

Safety and Quality Assurance

Risk Assessment

Environmental Concerns

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Pacer Technology (Zap) Pacer Technology (Zap) Z-Poxy 30 Minute Set -

Responsible Individual

Project Plan

Budget Plan

Payload Budget

Sub-Scale Launch Budget

Propulsion and Fuselage Budget

Recovery System Budget

Travel Expenses

Funding Plan

Timeline

Educational Engagement

Conclusion

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Table of FiguresFigure 1: Milestone ScheduleFigure 2: Full Side View of RocketFigure 3: Additional Cutaway View of RocketFigure 4: Side View Cutaway of RocketFigure 5: Electronics BayFigure 6: Thrust Curve of K454-SK Figure 7: Flight SimulationFigure 8: Stability MarginFigure 9: Payload BayFigure 10: Payload Bay and SledFigure 11: Payload Bay IntegratedFigure 12: Power Boost DiagramFigure 13: TimelineFigure 14: Education Timeline

Table of TablesTable 1: Planned TestsTable 2: Mass StatementTable 3: Failure ModesTable 4: Manufacturing SafetyTable 5: Flight RisksTable 6: Completed Payload TestingTable 7: Planned Payload TestingTable 8: Sensor PrecisionTable 9: Fluid SafetyTable 10: Aggregate Expected CostsTable 11: Sub-scale BudgetTable 12: Propulsion and Fuselage BudgetTable 13: Recovery System BudgetTable 14: Payload BudgetTable 15: Travel BudgetTable 16: Funding Plan

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1 Summary of Critical Design Report

1.1 Team SummaryThe University of Toledo Rocketry Club

University of ToledoRocketry Club 2801 W Bancroft St.MS 105Toledo, OH 43606

Team Mentor:Art [email protected] #26255 L3 Certified

1.2 Launch Vehicle Summary

1.2.1 Size and Mass StatementThe vehicle is 79 inches long, 4 inches in diameter and weighs approximately 10.3 pounds. This weight is derived from the weights of the components of the vehicle in addition to the estimated weight of the motor. A general breakdown of the rocket weight follows, finer detail weights of subsystems are provided later in this document.

Vehicle Section Weight

Fuselage (motor mount, fins, main body of vehicle)

2.79 lb.

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Electronics Bay 1.45 lb.

Parachutes and Recovery Harnesses

1.60 lb.

Payload Bay and Scientific Payload

1.94 lb.

Motor (estimated) 2.50 lb.

Total (estimated) 10.28

1.2.2 Final Motor ChoiceThe vehicle will be powered by a Cesaroni J295. This motor will propel the rocket and its payload to an altitude of 4623 feet. A concern brought up during Critical Design Review was the dangers of the high velocity shearing the fins off of the rocket body. The decision was made to use a slower motor, at the cost of maximum altitude, to ensure the fins of the rocket would withstand flight. Peak velocity of the flight is now 626 ft/s or 0.56 mach. This will provide for a safe flight for the rocket.

1.2.3 Recovery SystemThe recovery system uses a fully redundant system comprised of two StrattoLoggerCF altimeters. When the vehicle reaches apogee, the altimeters will both trigger the drogue parachute ejection charge in quick succession. The rocket will separate between the Electronics Bay and the aft segment. A 12 inch drogue parachute is attached to both segments by shock cord, under which the rocket will descend at 66 ft/s. When the vehicle reaches 700 feet AGL, both altimeters will again fire ejection charges. The force of the charges will cause nylon shear pins to break and separate the Payload Bay from the Electronics Bay,

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deploying the main parachute. The main parachute will bring the rocket down to a landing at 21 ft/s.

1.2.4 Launch Rail SizeThe vehicle will be launched using a 1.5 in x 96 in. launch rail. Rail exit velocity will be 66.8 ft/s. Stability will be reached before leaving the rail, at 3.23 ft. This rail was selected as it allows for the rocket to reach stable flight before leaving the rail. Reaching stability before leaving the rail is crucial to allow for a controlled flight.

1.3 Payload Summary

1.3.1 Payload TitleTwo scientific payloads are being flown aboard the vehicle, the Atmospheric Measurement Suite and the Liquid Sloshing Experiment

1.3.2 Payload SummaryThe vehicle will be delivering two scientific payloads. For the Atmospheric Measurements Suite, we utilize a Raspberry Pi microcomputer and sensors that detect UV light, temperature, humidity, and air pressure. The goal of this experiment is to practice basic data collection and transmission and sample atmospheric conditions at a mile up to further our future rocket designs. Once transmitted, the data will be graphed against the rockets height so the data is easily readable. As a first year team the data collected will be invaluable for future competitions and this basic experiment will build necessary skills for the future. This data will also be used as a baseline control sample for future experiments, building a catalog of data for the club to use.

The liquid sloshing experiment utilizes a payload bay containing three individual test tubes and a video camera. Each compartment will hold a different type of liquid, the video camera will record the liquids for the duration of the flight. The data collected from the video will show how different liquids behave under various launch conditions such as takeoff, flight and descent. The goal of the experiment is to help us to understand how liquid fuel in a full size rocket behaves. Future tests will be performed based on the data received during this

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test, on rocket launches done after USLI. This data will help us to further our program and have a more thorough understanding of liquid fueled rockets, and fluid mechanics. This will also give the team a parallel view at the same kind of design problems NASA has with its liquid fueled rockets.

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2 Changes Made Since Critical Design Review

2.1 Changes Made to Vehicle CriteriaBased on feedback the team received during Critical Design Review multiple small changes were made to the design of the rocket. During the full scale test of the vehicle, the team discovered the main parachute can fit in the forward section of the rocket. The drogue and main parachutes are now switched from their CDR locations, with the drogue at the center of the rocket and the main at the front, following the more traditional parachute layout. Fiberglass was also added to the connection between the fins and the rocket for additional strength to minimize the fins shearing off during flight. The weight of the rocket has also increased during construction of the rocket, this was due to not considering the weight of the glue and additional elements and will be discussed in detail later in this document.

2.2 Changes Made to Payload CriteriaTo eliminate the chance that interference from the GPS transmitter could cause premature activation of the recovery system, the TeleGPS has been repositioned into the nose of the vehicle.

2.3 Changes Made to Project PlanEducation Outreach was completed as detailed later in this document. We have also successfully purchased all products necessary for the club. The majority of these items will be remain valuable and useful for the team moving forward. This helps us ensure the longevity of the team.

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3 Vehicle Criteria3.1 Design and Construction of Vehicle

3.1.1 Structural ElementsThe rocket is composed primarily of phenolic tubing along with wooden and fiberglass structural elements. The motor mount pictured and dimensioned below is constructed from a phenolic inner tube. There are three wooden centering rings that attach the inner tube of the motor mount to the outer tube of the rocket body. These are attached with Zap 30 minute epoxy to both the inner and outer tube. Also attached to the inner tube are our rocket fins. Our rocket fins are made from 1/8 inch thick fiberglass. They are also pictured and dimensioned below. They are attached to the inner tube with the same epoxy used to attach the centering rings to the rocket. We also used fiberglass to more securely attach the fins to the inner tube. Adding the fiberglass to the fins increases the chance that the fins will stay attached to the rocket body at high velocities and prevent noodling of the fins, which can cause damage to the rocket, above speeds of 500 ft/s. The uppermost centering ring holds a welded eyebolt. This welded eye bolt attaches the motor mount section of the rocket to the drogue parachute. It is important that this bolt is very securely attached to the rocket because the lower section of the rocket has the most mass and the most kinetic energy so we want to ensure this section does not come detached from the rest of the rocket when our recovery system activates. To ensure the structural integrity of the connection, epoxy was applied over the nut.

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Continuing up to the center of the rocket is the recovery system. This structure of this system is similar to that of the motor mount. It is built primarily of a phenolic tubing body with wood bulkhead on either end of the section. The recovery system is where we see the greatest amounts of tensile stresses in the rocket. That happens when the top portion of the rocket containing the payload detaches from the rocket and main parachute deploys. At this point the rocket is slowed from 73 ft/s to 23 ft/s over a time of 1.5 seconds. This causes the connection from shock cord that attaches to the main chute to recovery bay to undergo an estimated 333.2 N of force with a maximum instantaneous G-load of 29.6 G. Because of this, the recovery bay was constructed with these high loads in mind. The recovery bay is built so that very little of the force it is subjected to is applied to the relatively weak phenolic tube body. The bay is built with two 1/4 inch steel bolts running through where the majority of the loads are transferred to. On either side of the recovery bay are 1/2 inch thick wooden bulkheads with welded eye bolts attach either ends to the parachutes. Next to the eye bolts are the threaded steel rods that go through the bay.These threaded rods secure the electronics sled and the bulkheads to the electronics bay. Along the bolts passing through the bay are the recovery instruments and electronics. These are all attached to a piece of wood that is attached to the bolts that pass through the bay. This ensures that the electronics are attached to a solid section of the bay and prevents them from moving around in the bay which could possibly damage them or cause them to receive false data caused by jarring movements.

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Finishing at the top of the rocket is the payload bay, main parachute, and nose cone. The portion of rocket body where our main parachute is stowed in made from phenolic tubing. This part is secured to the recovery bay by nylon sheer pins and friction caused the phenolic tubing from each section rubbing against each other. On the bottom of the payload bay is a welded eyebolt that is further secured with epoxy. Attached to this eyebolt is the main parachute. This eyebolt is subjected to 100% of the tensile stress caused during parachute deployment

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so we wanted to ensure that this bolt is very heavily secured to the rocket body. This eyebolt is secured into a 1/2 inch wooden bulkhead that acts as the bottom cap to our payload bay. This bulkhead is attached to the rocket with a ring of Zap 30 minute epoxy on both sides of the bulkhead to ensure a solid attachment to the body of the rocket. The bulkhead is also recessed one inch into the section of phenolic tubing it is built into so if the epoxy fails and the bulkhead starts to slip out it will rotate slightly and bind against the inside of the body tube. Past the bulkhead is our payload bay. It contains our experiments and our GPS unit. The experiments are secured into the payload bay with 3D printed brackets. Two of these brackets are glued onto the inside wall of our payload bay with Zap Medium CA+ superglue with Zap CA Accelerator applied to the glue to speed up the curing time. Epoxy will then be applied to the edges of the brackets to strengthen their hold on the wall of the payload bay. The other six brackets are superglued to the payload sled. This allows us to secure the payload sled to the payload bay without having to worry about lining all our brackets up perfectly with each other. Each of the 3D printed brackets we printed them to the dimensioned sizes shown below and were sanded to the true dimensions to ensure a snug fit into the bay. The payload sled, where the electronics for our different payloads are mounted, is made of 1/4 inch thick plywood. This gives us a proper mix between strength and weight savings. Above that is our nose cone. The nose cone is made of high density polypropylene which was shown to be strong enough to withstand the impact of landing without cracking or deforming. The nose cone is secured to the rest of the vehicle with screws going through the phenolic tubing and through the nose cone where the two sections overlap. This secures the nose cone on enough because the majority of the forces that act on the nose cone, like drag and the force on impact, will be directly down into the rest of the rocket and will be distributed along the rocket body and not on the attachment screws.

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3.1.2 Electrical ElementsThe vehicle carries five devices that require electricity. These are the two altimeters, two science computers and the GPS tracking device. Each device is completely separate from the other devices on board, none share any connections of power sources. This isolated design ensures that if a problem occurs in one system, it cannot cross over into another any potentially cause a failure. Additionally each electrical subsystem is also isolated from each other. The two recovery altimeters are located in the electronics bay at the center of the rocket. The two science payload computers are located inside of the payload bay. The GPS tracker is then located inside of the nose cone of the vehicle. It was particularly important to position devices that transmit with radio frequencies, like the TeleGPS or the XBee transmitter in a different area of the rocket, to

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prevent them from creating a charge in the recovery system wires and trigger the recovery charges erroneously.

3.1.3 Flight ReliabilityThrough our two full scale test we have proven reusability and reliability of our rocket and the overall design. After flying the rocket twice on the same day within one hour we have proven that the rocket was built with very solid construction practices and that the recovery system works as planned. For each flight the rocket came very close to our predicted height and velocity values, showing that our rocket is built in a robust and consistent way. The rocket should not have any issues for the competition launch after proving its reliability, consistency, and robustness.

3.1.4 Testing DataTo verify the quality of the of the rocket and components multiple strength tests were performed using a universal testing machine in our university lab. Using a spare piece of phenolic tubing we measured the compressive strength of the tubing to ensure it was up to manufacturer standards and would survive an impact at our expected descent velocity. The rocket body passed this test easily. This test was performed in both a horizontal and vertical position.

The same testing routine was performed on duplicate fiberglass components and plastic from the nose cone. We are aware that our nose cone will most likely crack if subjected to a large force but that would only happen if the rocket goes ballistic and impacts nose first. In that situation we have larger issues in the recovery system to address. The fiberglass fins held up to the forces predicted during flight.

Testing proved our rocket will perform to all standards set by the team. Testing results follow this section.

Test ID

Test Name Description Goal Status

V-1 Normal Fin Stress Apply expected load normal to surface of fin

Ensure fins can withstand normal

Passed

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forces during flight

V-2 In-line Fin Stress Apply load in-line with axis of rocket to fins

Ensure fins can withstand forces along axis of rocket during flight

Passed

V-3 Body Compression Apply force to phenolic body tube sample

Ensure rocket can withstand compressive forces during flight

Passed

V-4 Payload Bay Compression

Apply force to craft tube Payload Bay sample

Ensure Payload Bay can withstand forces during flight

Passed

V-5 Shock Cord Tension Apply expected tension along shock cord sample

Ensure shock cord can withstand tension forces during recovery deployment

Passed

V-6 Eye Bolt Stress Apply expected forces to eyebolts on Electronics Bay, Motor Mount and Payload Bay

Ensure eye bolt connections will not fail during recovery deployment

Passed

V-7 Electronics Bay Drop Tests

Dropped electronics bay and checked continuity of altimeters

Ensure that in case of mishandling during assembly, electronics bay will remain functional.

Passed

V-8 Recovery Ejection Altimeters were checked for continuity followed by a vacuum being pulled over the electronics bay, and released

Ensure both altimeters can properly sense the change in pressure and activate recovery ejection charges

Passed

3.1.5 Safety and Failure Analysis

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Potential Failures Effects of Failure Failure Prevention

Altimeters are not powered

Parachutes do not deploy, rocket becomes ballistic which is a danger to people and property.

We will confirm it is hooked up by using the safety checklist that requires 2 people to sign off before flight.

Wires to altimeters are tangled and pulled out.

Altimeters will not arm. The wires will be organized so their is little chance of becoming tangled.

Ejection charge fail Parachutes do not deploy, rocket becomes ballistic and can cause damage to the surrounding area and people.

Test the terminal blocks by shorting the connections and listening for the correct number of beeps from altimeter.

Fin failure Fins fall of and causes unstable flight.

Reinforce fincan with fiberglass and test connections points to ensure strength of attachment.

Ignition failure Rocket fails to launch. Follow proper procedures when attaching igniter to rocket motor.

Launch buttons break Rocket will separate from launch rail and may become unstable.

Make sure the correct launch rail is being used and that the launch buttons slide easily into rail.

Motor failure Motor explodes and rocket is Follow manufacturer's

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destroyed. instructions when assembling the motor.

Nomex cloth not inserted into rocket properly

Parachutes could become burned and fail to slow the rocket effectively becoming a danger to people and property.

Follow Launch Checklist, attach nomex cloth to shock cord before parachute is inserted into appropriate bay.

Shock cords are not attached to designated sections

Sections of the rocket will separate and become a danger to people and property.

Follow Launch Checklist,ensure shock cords are connected to each tethered section using appropriate knots.

Motor retention failure Motor casing falls out. Test reliability of motor retention system.

3.1.6 Full-Scale Test ResultsFull-scale tests of the rocket were performed on February 20, 2016 in Three Oaks Michigan. The rocket flew in final configuration, with a partial science payload with mass simulator. The vehicle was powered by a Cessaroni J270 motor, using a 38mm to 54mm adapter, as the rocket is designed for a 54mm solid motor. The rocket also flew unpainted.

Data collected by the altimeters are displayed in FIGURE GOES HERE below. Data from the OpenRocket simulation is displayed for comparison.

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3.1.7 Mass StatementThe Mass of the scientific payload is detailed in the following chart.

Part Weight

Raspberry Pi Computers 0.286 lb.

Pi Cameras 0.044 lb.

Batteries 0.176 lb.

Xbee 0.033 lb.

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Sense Hat 0.066 lb.

Light Sensor 0.022 lb.

Misc Hardware 0.066 lb.

3D Parts 0.120 lb.

Sled 0.200 lb.

Total 1.013 lb.

3.2 Recovery Subsystem

3.2.1 Structural ElementsThe recovery system is all built into one electronics bay (e-bay). The e-bay is the EB-3.90L from LOC Precision. It is 3.9 inches in its inner diameter and 8 inch long bay. The e-bay is made from phenolic tubing, like the rest of our rocket, with welded eye bolts which both the main and drogue parachutes attach to. There are also ½ inch thick wooden bulkhead with ¼”-20 threaded rods that pass through the whole bay. Along the rods is a mounting platform where our electronics for our system are attached to. There are also screw switches built through the center of the e-bay that are anchored into the body with epoxy. The whole bay is built with the ability to remove the electronics sled from the body of the e-bay by removing the nuts on one of the bulkheads and pulling on the eyebolt that is on the opposite bulkhead. From here we can service the electronics and replace batteries located on the sled.

3.2.2 Electrical ElementsThe recovery system includes two StratoLoggerCf altimeters. The altimeters are powered by their own 9 volt battery. Each flight will require a new pair of batteries to ensure they have a charge, rather than risking a launch with faulty

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used batteries. As well as replacing the batteries, the wires from the altimeters to the charges are also replaced after each launch. The altimeters are activated via a pair of exterior screws which are then tightened on the pad in order to complete the circuit. The primary altimeter is programmed to activate when the rocket reaches apogee. At this point the altimeter sends a charge to ignite a charge cap filled with two grams of black powder. This force will then separate the upper end of the rocket, releasing the drogue parachute. The backup altimeter will set off a similar charge shortly after, in case the primary malfunctioned. The main parachute is released at the programmed altitude of 700 feet AGL during the descent by the primary altimeter, again, sending a charge to ignite the cap at the top of the electronics bay. The backup, again, follows this detonation at 650 feet AGL in-case issues arise from the primary ignition. The electronics bay also includes a TeleGPS tracking unit that transmits live flight data to our ground control via HAM band radio. The data is written onto the TeleGPS which is then downloaded to locate the rocket’s impact location as well to validate data collected by alternate sensors onboard.

3.2.3 Redundancy FeaturesThe inclusion of the second altimeter is for the purpose of a backup in the case that the primary altimeter fails to either ignite the charge or in case the charge was too little to eject the section in order to deploy the chutes. The second altimeter is powered by its own separate battery as well as having its own two blast caps filled with two grams of black powder to include second detonations shortly after the primaries to ensure the rocket divides properly and parachutes are deployed.

3.2.4 Parachutes Our recovery system is a dual-deployment system using two parachutes, one drogue and one main. Our drogue chute is made from 20 inch diameter ripstop nylon. It has 4 shroud lines made from nylon shock cord that attach the edges of the chute to the main line that goes to the rocket.

Or main chute is constructed from silicone-coated ripstop nylon. It has a diameter of 60 inches, a total surface area of 39.3 sq ft., a coefficient of drag of 1.89, and a mass of 10 ounces base and 15 ounces with all the rigging attached. It attaches to the rocket with 3/8 inch military spec. tubular nylon rigging tested

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to 950 pounds. To attach the parachutes to the eye bolts we used the double overhand with follow through knot to safeguard against loosening of the knots. The drogue deploys at 1.5 ft/s, as it is deploying at apogee. The rocket then begins to fall under drogue and accelerates to 66.3 ft/s. The rocket coasts at that velocity until an altitude of 700 feet AGL where the main chute deploys. The main chute slows the rocket to a velocity of 20.7 ft/s. It then coasts until ground impact. The drogue chute is located in the bottom section of the rocket and the main chute is located in the top portion of the rocket.

3.2.5 Rocket-Locating TransmittersThe rocket will be located using a AltusMetrum TeleGPS locator. This device tracks the rocket using GPS satellites and stores this data onboard. Live data is also transmitted by the device using HAM band radio. The TeleGPS transmits at 434.550 MHz. This signal is received by a ground station antenna and software displays the position of the rocket against a satellite map of the area, along with the current velocity and altitude of rocket. This system will be crucial in tracking our rocket through the duration of the flight.

3.2.6 Sensitivity of SubsystemThe recovery system is the most pertinent part of the rocket and we need to make sure that the quick succession of actions made by this system are done correctly. This is why we have built in backups and redundancies into this system. Even with these redundancies built in it is still a sensitive subsystem. In the table below are issues the subsystem may have, consequences of those issues, and ways to mitigate those issues.

3.2.7 Failure Modes

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Issue Consequence Mitigation Method

Loss of Black Powder Failure to eject parachutes.

Black power will be taped and secured in

firing caps.Multiple power charges

will be used.

E-match failure Failure to light black powder.

E-matches will be checked before launch.

E-matches will be handled carefully.

Premature E-match triggering

Parachutes may deploy before apogee.

E-matches will be handled carefully.

Radio Interference

Interference with electronics can cause

abnormalities with the system.

Recovery system will be placed in a different

section of rocket from payload.

Altimeter Failure Will prevent the E-matches from firing.

Backup altimeter will be used.

Altimeter will be checked before launch.

Loss of Power to System Will cause a total failure of all modules of system.

Battery voltage will be checked before launch.

Batteries will be replaced every two

launches.

3.3 Mission Performance Predictions

3.3.1 Performance CriteriaUsing simulations and full scale testing of the rocket design, the following performance is expected from the vehicle should it perform nominally. Further

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statistics of the flight performance are detailed in the Flight Readiness Review Flysheet.

Maximum Altitude 4623 ft

Maximum Velocity 626 ft/s

Maximum Mach Number 0.56

Velocity Under Drogue 66.3 ft/s

Velocity Under Main 20.7 ft/s

3.3.2 SimulationsThe following simulations detail the performance of the rocket during flight, as described in section 3.3.1. Additionally, the thrust curve of the J295 motor is provided.

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3.3.3 Drag AssessmentSimulations do not provide data that are completely accurate to real life values. This holds true for the drag approximations made by OpenRocket when simulating the flight of the rocket. During the full scale test flight of the rocket, altimeters were flown on board which tracked the altitude of the rocket over time. After the flight this data was compared to the altitude as simulated by OpenRocket. As shown previously in this document, the flight profile of the full-scale test was similar to the simulated profile. Given the similarity and the effects of other variables such as differences in motor performance, temperature, weather, it was determined that the drag estimated by OpenRocket is a useful approximation for the full flight of the vehicle. Drag coefficients for the rocket in comparison to mach number can be found in a following chart.

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3.3.4 Stability MarginOur overall margin of stability is 4.02 calibers with a center of gravity 48.3 inches from the nose of the rocket and a center of pressure 64.4 inches from the nose of the rocket. Stability margin peaks at 5 calibers during flight. The location of these points can be seen in the following figures, along with simulated stability margin over time.

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3.3.5 Kinetic EnergyThe kinetic energy of our rocket changes depending on the speed of the rocket and the mass of the section of the rocket being measured. An important requirement in terms of kinetic energy is to keep it below 75 ft-lbs limit. We sized our parachutes make sure that we kept our rocket below the required value. The kinetic energy is obtained from the standard equation for kinetic energy where kinetic energy in joules (J) is the product of one-half the mass of the rocket section in kilograms(kg) multiplied by the velocity of the

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rocket section squared, in meters per second(m/s). This gives us an answer in joules. In order to convert from joules to ft-lbs we multiply our value in joules by .73756. These values will be different than real-world values, as this is an ideal situation with data pulled from a simulation. With this in mind we made sure to give ourselves plenty of leeway so we can ensure that the rocket avoids going over the limit during the competition.

Under drogue:

Bottom section: 249.34 ft-lbs

Top and Middle section: 265.73 ft-lbs

Under Main:

Bottom section: 25.31 ft-lbs

Middle section: 12.59 ft-lbs

Top section: 13.52 ft-lbs

3.3.6 Drift SimulationsDrift calculations were performed in OpenRocket by plotting lateral distance. The simulations for each speed can be found after this section, along with a chart listing the values. The drift distances projected by OpenRocket should be within the safe limits of the event.

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Wind Speed Distances

5 mph 180 ft

10 mph 250 ft

15 mph 700 ft

20 mph 1025 ft

3.4 Verification

Requirement Source Verification Method Design Feature Status

The Launch Vehicle shall carry a payload.

SL Handbook Inspection Scientific payload Passed

The Launch Vehicle shall have a maximum of four (4) independent or tethered sections.

SL Handbook Inspection The four (4) locations we have tethered are

the nose cone, The recovery bay both top and bottom, and the

motor mount.

Passed

The launch vehicle shall carry a payload to an altitude of a mile above the ground.

SL Handbook Testing Motor choice Passed

The launch vehicle shall use a commercially available and NAR approved and certified solid motor propulsion system

SL Handbook Inspection Motor choice Passed

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using ammonium perchlorate composite propellant (APCP).

The total impulse provided by a launch vehicle shall not exceed 5,120 Newton-seconds (L-class).

SL Handbook Inspection Use of a “J” motor class Passed

The vehicle shall carry one commercially available, barometric altimeter for recording the official altitude used in the competition scoring.

SL Handbook Inspection Use of a StratoLogger altimeter for recording

Passed

The launch vehicle shall be designed to be recoverable and reusable.

SL Handbook Testing Rocket will be designed with strong materials

and reusability in mind

Passed

The launch vehicle shall be limited to a single stage.

SL Handbook Inspection The rocket will only use a single motor

Passed

The launch vehicle shall be capable of remaining in launch-ready configuration at the pad for a minimum of 1 hour without losing the functionality of any

SL Handbook Testing We will use new batteries for each flight

to ensure there's enough power

Passed

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critical on-board component.

The launch vehicle shall be capable of being launched by a standard 12 volt direct current firing system.

SL Handbook Testing The NASA-designatedRange ServicesProvider will providethe firing system.

Passed

The launch vehicle will have a drogue parachute deploy at apogee and a main parachute deploy at a much lower altitude

SL Handbook Testing Altimeters will fire the drogue parachute at apogee and then the main at an altitude of

700 feet.

Passed

The recovery system shall contain redundant commercially available altimeters.

SL Handbook Inspection Dual Stratologger altimeters will be used

for the recovery system.

Passed

Each altimeter shall have a dedicated power supply.

SL Handbook Inspection Each StratoLogger altimeter will utilize their own 9V power

supply.

Passed

Each arming switch shall be capable of being locked in the ON position for launch.

SL Handbook Inspection We will be using a screw type arming

switch.

Passed

An electronic tracking device shall

SL Handbook Inspection A GPS unit and XBee transmitter will be

Passed

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be installed in the launch vehicle and shall transmit the position of the tethered vehicle or any independent section to a ground receiver.

used.

The recovery system electrical circuits shall be completely independent of any payload electrical circuits.

SL Handbook Inspection The payload and recovery systems are located in separate

bays.

Passed

The payload container must utilize a parachute for recovery and contain a GPS or radio locator.

SL Handbook Inspection Payload bay is attached to the main parachute and the nose cone will

house the GPS unit.

Passed

3.5 Safety and Environment (Vehicle)

Environmental Impact on Rocket

HazardDetails of

Hazard

Likelihood of

Hazard (1-10)

Severity of Hazard (1-

10)Mitigation Method

Rain Rain may cause electronics to

short or rocket

4 7 Rocket will be kept out of direct rain and launch may be rescheduled to a later date.

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body to deform.

High Temps. (>105°)

High Temps. may cause

electronics to overheat.

3 3 Rocket will be kept in a cooler area.

Low Temps. (<32°)

Low Temps. Will decrease battery

life or voltage output.

2 3 Rocket will be kept in a warmer area.

Wind (>20 mph)

High winds can cause excess drift to the

rocket or high levels of

weathercocking.

6 8Launch may be delayed until wind speeds

decrease and launch may be rescheduled to a later date.

Puddles/ Lakes

Rocket may land in a puddle/lake causing damage

to electronic and rocket body.

3 6Rocket will not be launched near lakes and

aimed away from large puddles.

Vegetation

Rocket may land in a tree or bush

causing the rocket to get

caught.

7 4Rocket will not be launched near large trees

and aimed away from general vegetation.

Environmental Impact of Rocket

Hazard Details of Hazard Likelihood of Hazard

Severity of Hazard (1-

Mitigation Method

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(1-10) 10)

Littering

Littering caused by humans can harm vegetation

and nature.

7 2 Team members will be instructed to throw/recycle trash.

Fire at location

Short in electronics or flames from

motor may cause a fire that can

damage the area or harm humans.

2 8Launch rails with blast deflectors will be used and

rocket will be inspected by our safety officer for issues.

Explosion of Rocket

Motor

Explosion of motor may litter

the area with debris

2 7 Motor and motor casing will be inspected prior to launch.

Leaching of batteries

Leaching of battery acid may

harm animals and vegetation.

1 4 Batteries will be inspected and replaced often to ensure they are in new working condition.

Excess drift of rocket

During descent the rocket may drift out of the

safety zone and possibly damage objects outside it.

6 5 Rocket will not be launched under high wind conditions.

Recovery system failure

During descent the recovery

system may fail to deploy

causing the rocket to fall

ballistically into the ground.

3 3

Redundancies will be implemented to reduce chances of failure. The system as a whole will be inspected before launch to ensure it is in working

condition.

3.6 Payload Integration

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3.6.1 Integration and CompatibilityThe payload bay is located above the forward body tube of the rocket, immediately behind the nose cone. The nose cone of the rocket will be removable with screws to allow access to the inside of the payload bay. The aft end of the payload bay will be comprised of a tubing coupler capped off with a bulkhead for recovery system attachments. As shown in the following figures, at the rear of the payload bay there are two sets of 3D printed brackets, which will be attached via epoxy to both the sides of the coupler tube and the bulkhead. These brackets are designed to accommodate the payload sled, which is a 1/4 inch thick plywood sheet. The payload sled contains both sets of experiments and all their associated hardware and equipment. On the sides of the sled there are pairs of 3D printed mounts, these are designed to give the sled a snug fit within the payload bay and will be attached with epoxy to the payload sled. To integrate the sled into the payload bay, the sled will be lowered into the bay until the end of the sled rests inside the mounting brackets. To secure the payload sled, the nose cone will then be mounted and held in place by screws.

This design allows for relatively simple integration with the rocket, along with allow the team to remove the payload for software of physical maintenance with limited interference with the rest of the vehicle.

3.6.2 IntegrationAn important part of the construction and verification of our rocket is making sure that the materials we are using can withstand the forces that are present when launching a high mass rocket at high speeds. As it is with all engineering, we are on a mission to find the lightest, strongest, cheapest materials to construct our rocket out of. Our rocket is made from four main materials; phenolic tubing, epoxy, nylon, and wood. For the level of rockets that we are aiming for, these materials fit the bill.

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4 Payload Criteria

4.1 Experiment Concept

4.1.1 Creativity

4.1.1.1 Atmospheric Measurement Experiment

A key part of the design is how few components are required. Excluding the power supply components, the payload is comprised of five main parts. A focus was given towards multitasking components, where the

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payload now has less sensor boards than individual items being sensed. The key to this design is the Raspberry Pi Sense Hat. The Sense Hat contains a variety of sensors, not all required for this payload. This provides us with a single board with most of our sensors that will mount directly onto the Raspberry Pi without additional wires. The camera board is designed to be connected directly to the Raspberry Pi as well, through a CSI port. Only the L1145 sensor will need to be wired into the Raspberry Pi. The XBee transceiver will be attached to the Raspberry Pi via USB adapter. Even though the Sense Hat will have unused sensors, overall this design saves mass by not having an individual board for each sensor.

4.1.1.2 Liquid Sloshing Experiment

As with the atmospheric measurement payload, the aim for this payload was to keep it as simple as possible mechanically, to allow for more complexity in the code and experiment. The decision was made to use a separate Raspberry Pi for this experiment as the difficulty cost of using two cameras on one Raspberry Pi outweighed the additional mass needed to run a second computer. However, the atmospheric measurement payload Sense Hat will also be used indirectly with this payload. The Sense Hat has an array of RGB LED lights on it. The Sense Hat will be positioned in such a way that its lights will shine down onto the test tubes so they can be properly filmed during flight. This was a simple adjustment

4.1.2 Significance The liquid sloshing experiment is particularly unique. Due to the small size of the camera board, this leaves additional room between the tubes of fluid and the camera. This allows there to be more visible in the frame of the camera, providing there to be longer tubes of fluid and more tubes. The fluids being tested are of various viscosities, which can be used to determine if fuel in a tank need to be thinned or thickened to have better control of sloshing during flights.

4.1.3 Suitable Level of ChallengeThe main challenge the Atmospheric Measurement Suite will present is the amount of code, and its complexity, that will need to be written. Six sensors will

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be used to collect data, an accelerometer to change how we collect data, a camera, and then the transmitter. This paired with the amount of time needed to properly test and verify the software is why the hardware is kept simple. For the liquid sloshing experiment the challenge comes with the fluids and how they are contained. The fluids being tested need to remain stationary through the entire flight, as test tubes moving during the flight independent of each other will add difficulty to analyzing the footage afterward. The containers for the fluids must also be reliably water tight and able to handle the change in pressure as the flight progresses. If a tube of fluid breaks or leaks, the fluid will be released into the payload bay and could damage the electronics.

4.2 Science Value

4.2.1 Payload ObjectivesCollect accurate data on the following environmental areas:

○ Air pressure○ UV Radiation○ Solar Irradiance○ Temperature○ Relative Humidity

● Capture still images of the world outside the rocket during descent and landing.

● Capture video observation of liquids moving in containers during the flight.

● Store data sensibly onboard the microcomputers.● Transmit required data to ground station at completion of flight.

4.2.2 Payload Success CriteriaSuccess will be determined by completing the following baseline goals:

● Data collected, saved and transmitted to ground station.● Images and video are captured and transmitted or recovered.

Secondary goals we intend to achieve are:

● Collect accurate data from sensors.50

● Analyze data to find trends and other useful statistics we can apply to our rocketry program.

● Collect photos in proper orientation.● Collect video showing how fluids move during flight and analyze frame-

by-frame how they move.

4.2.3 Method of InvestigationSensors in the payload suites will gather data on the atmosphere the rocket is traveling in. The goal here is to gather information on what our rocket will be flying in. This will be done by gathering data as the rocket flies, and after landing loading the data into a spreadsheet and graphing the changes over time. The team is investigating what the atmosphere is like where the rocket flies. This data will be applied to future rocket designs by the club, and to further our knowledge of how our rockets fly.

Liquids of various viscosities will be flown on board as well, with frame-by-frame video analyzed after the flight. This will be used to understand how fluids move during every part of the flight, particularly in microgravity. On future flights, outside of USLI, we will continue research by changing other variables around the fluids. Current plans for the next test will be changing the shape of the containers the fluids are stored in, such as baffling, to control sloshing. So, the test being run on our rocket is the first step in a series of research experiments regarding liquid sloshing.

4.2.4 Relevance of DataData collected during the Atmospheric Measurement Experiment will be vital in understanding the region of atmosphere where the vehicle will be flying. This data will also be helpful in the creation of future designs for our club as we endeavour to create more sophisticated designs. The same goes for the Liquid Sloshing Experiment, which will give us valuable insight into how fluids behave both under microgravity and under the various loads they will experience during flight. Both of these experiments give us a control baseline for future experiments, particularly in liquid sloshing, along with giving us a parallel view at the design challenges NASA faces with large liquid fueled rockets.

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4.2.5 Process ProceduresFor every sensor in the atmospheric measurement suite, the main software will poll the sensor for data. This data will be then interpolated into plain text and stored in a comma separated values (.CSV) file for transmission back to ground station, as described elsewhere in this document. CSV files can be loaded directly into a spreadsheet and used to create graphs comparing the data over time.

Images and video will be taken and stored onto the microcomputers as well. Videos of the liquid sloshing experiment will be loaded onto a computer after recovery. With a video processing program, the team will analyze, frame-by-frame how the fluids moved during the duration of the flight. Comparisons will be drawn between the fluids at rest and for every stage of flight, as well as how each fluid compares to each other.

4.3 Payload Design

4.3.1 Structural ElementsThe payload bay is comprised of a section of craft tube rocket body, which houses all of the science payload as well as the remaining structural elements. At the base of the payload bay there is a plywood bulkhead. This bulkhead is mounted using epoxy approximately 0.5 inches from base of the payload coupler, this allows for their to be binding of the bulkhead against the inside of the coupler if epoxy begins to fail, along with allowing more surface area for the epoxy to grip against. Attached to the inside of the payload coupler there are two 3D printed brackets, affixed with epoxy. These brackets serve as the mounting point of the payload sled to the inside of the payload bay, along with ensuring correct alignment of the sled.

The payload sled is made of 1/4 inch thick plywood. The remaining science and structural elements are attached to this sled. All science instruments are attached via screw standoffs to the payload sled, and other objects like batteries are attached using zipties. There are three 3D printed brackets that will be epoxied to the sled, two for holding cameras and sensors, and another designed to accommodate three test tubes. The test tubes will be held in place using zipties.

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Along both size of the payload sled there will be more 3D printed brackets, which will be epoxied to the sled. These will allow the payload sled to fit tightly inside of the payload bay tube. The radius of the brackets matches the internal radius of the payload bay.

The nose cone of the rocket completes the payload bay. The nosecone is slid into position and then screwed into place from the outside of the rocket. The nose can aligns with the top of the payload sled, preventing the sled from sliding back and forth along the axis of the rocket. Between the nose cone and bracket system, this allows for the payload sled to be easily removable, yet securely fastened inside of the payload bay.

4.3.2 Electrical ElementsBoth Raspberry Pi microcomputers are powered by LiIon batteries. The batteries connect to charge controllers which then fed into the computers. The camera boards ribbons are connected to the CSI ports on the computers. Each computer has a row of General Purpose Input/Output (GPIO) pins, onto the Atmospheric Measurement computer, the Raspberry Pi Sense Hat is mounted onto the entire row of GPIO pins. The UV/Light sensors is attached to the computer via the GPIO pins as well, by using i2c pins, which allow the computer to control both the Sense Hat and the light sensor. GPIO jumpers were attached to the sensor and the ends super glued together to create a plug, which attaches onto the GPIO pins on the computer board.

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4.3.3 Atmospheric Measurement Suite Code

Atmosherpic.py:

# Atmospheric Measurement Suite# University of Toledo Rocketry Club# Michael Blackwood, 2016#! /usr/bin/python

import pygame, math, time, csv, typesimport SI1145.SI1145 as SI1145from sense_hat import SenseHatfrom picamera import PiCamera

# Begin functions ----------

def loadAccelerationCSV(): with open('acceleration.csv', 'rb') as f: acceldict = dict() reader = csv.reader(f, delimiter=',', quoting=csv.QUOTE_NONE) for row in reader: temp = {'x':float(row[1]), 'y':0, 'z':0} acceldict[float(row[0])] = temp return acceldict

def get_accelerometer_raw(self): """ :param self: Don't actually provide an argument here :return: a fake dict of accerometer data for testing """ curtime = time.time() - start best = min(acceldict.keys(), key=lambda x:abs(x-curtime)) return acceldict[best]

def vectorMagnitude(sensor): """ :param sensor: sense hat instance :return: magnitude of vector """ vector = tuple(sense.get_accelerometer_raw().values()) return math.sqrt((vector[0]** 2) + (vector[1] ** 2) + (vector[2] ** 2))

def logAcceleration(acceleration, type=0): """ :param acceleration: :return: None """ if type == 0: logaccel.append(acceleration) logaccel.pop(0)

54

else: loglanding.append(acceleration) loglanding.pop(0) return None

def avgAcceleration(type=0): """ :return: average acceleration from logaccel """ if type == 0: total = 0 for tmp in logaccel: total += tmp return total / len(logaccel) else: total = 0 for tmp in loglanding: total += tmp return total / len(loglanding)

def leds(mode): if mode == 0:

x = (0,0,0) else: x = (255,255,255)

pixels = [ x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, x, ] sense.set_pixels(pixels)

# End functions ----------

sense = SenseHat()# Override accelerometer for testing# Comment this out to run off real accelerometer#sense.get_accelerometer_raw = types.MethodType(get_accelerometer_raw, sense)acceldict = loadAccelerationCSV()

lightsensor = SI1145.SI1145()

camera = PiCamera()camera.vflip = Truecamera.hlip = Truecamera.resolution = (480,270)

# turn off leds if they were left on

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leds(0)

#initialize pygamepygame.init()pygame.display.set_mode((640,480))# running fullscreen is only way to ensure keypresses are grabbedpygame.display.toggle_fullscreen()

pygamerunning = False

# Loop over pygame events wayting for joystick to be clicked (considered return key)while pygamerunning: for event in pygame.event.get(): if event.type == pygame.KEYDOWN: if event.key == pygame.K_RETURN: # kill pygame and exit loop pygame.quit() pygamerunning = False if event.type == pygame.QUIT: pygamerunning = False print 'pygame end'

# Create or open csv files for writingatmofile = open('atmospheric.csv', 'wb')atmowriter = csv.writer(atmofile, delimiter = ',', quotechar = '"', quoting = csv.QUOTE_NONNUMERIC)logfile = open('atmospheric_log.csv', 'wb')logwriter = csv.writer(logfile, delimiter = ',', quotechar = '"', quoting = csv.QUOTE_NONNUMERIC)

textcolor = (0,0,100)#sense.show_message('UT Rocketry', text_colour=textcolor)

# Create empty list of accleration over last 5 seconds:logaccel = []logseconds = 5for i in range(0,60 * logseconds): logaccel.append(0)

loglanding = []landedseconds = 15for i in range(0,60 * landedseconds): loglanding.append(0)

# Mark the time the script startedstart = time.time()# The following are palceholders to be populated by code later:# Mark time rocket lifted offliftoff = 0# Mark time of apogeeapogee = 0# Mark time of landinglanding = 0# previous data collection timestamp

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datatime = 0# timestamp of previous imageimagetime = 0# note: loops run about 60 times a second

# keep track of number of images takenimagestaken = 0

# Checking acceleration, waiting for launchonpad = Truewhile onpad: # get current acceleration and log it accel = vectorMagnitude(sense) logAcceleration(accel) logwriter.writerow((time.time() - start, 0, accel))

# Check if acceleration has averaged over 4G (consider this liftoff) ##EDIT THIS VALUE TO ADJUST LIFTOFF SENSOR if avgAcceleration() > 4: print 'liftoff' logwriter.writerow((time.time() - start, 0, accel, 'liftoff')) liftoff = time.time() # turn on LEDs for the liquid sloshing experiment leds(0) onpad = False

inflight = Truewhile inflight: # get current acceleration and log it accel = vectorMagnitude(sense) logAcceleration(accel) logwriter.writerow((time.time() - start, time.time() - liftoff, accel))

# check for nagative or low accleration, consider this freefall descent if avgAcceleration() < .5: print 'apogee' logwriter.writerow((time.time() - start, time.time() - liftoff, accel, 'apogee')) # start data collection datatime = time.time() apogee = time.time() inflight = False

descending = Truewhile descending: # get current acceleration and log it accel = vectorMagnitude(sense) logAcceleration(accel, 1) logwriter.writerow((time.time() - start, time.time() - liftoff, accel))

#check if it's been a second since last point of data #print datatime, time.time(), datatime - time.time()

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if time.time() - datatime >= 1: print 'collecting data' datatime = time.time() # data collection pressure = sense.get_pressure() temp = sense.get_temperature() humidty = sense.get_humidity() light = lightsensor.readVisible() uv = lightsensor.readUV() # Write this data to csv atmowriter.writerow((time.time() - liftoff, pressure, temp, humidty, light, uv))

# take two images during descent: if time.time() - apogee > 20 and imagestaken == 0: print "captured image" camera.capture('images/descent1.jpg') imagestaken += 1 if time.time() - apogee > 40 and imagestaken == 1: print "captured image" imagestaken += 1 camera.capture('images/descent2.jpg')

if avgAcceleration(1) > .98 and avgAcceleration(1) < 1.02: print 'landed' logwriter.writerow((time.time() - start, time.time() - liftoff, accel, 'landed')) # note the landing in the atmospheric csv atmowriter.writerow((time.time() - liftoff, 'landed')) descending = False # set datatime low enough that data collection will trigger soon after landing datatime = time.time() - 50 landing = time.time() imagestaken = 0

landed = Truewhile landed:

leds(0)

#check if it's been a 60 seconds since last point of data if time.time() - datatime >= 60: datatime = time.time() print "collecting data" # data collection pressure = sense.get_pressure() temp = sense.get_temperature() humidty = sense.get_humidity() light = lightsensor.readVisible() uv = lightsensor.readUV() # Write this data to csv atmowriter.writerow((time.time() - liftoff, pressure, temp, humidty, light, uv))

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# take 3 images after landing. We'll do one a minute after landing if imagestaken <= 2: print "captured image" imagestaken += 1 camera.capture('images/landed' + str(imagestaken) + '.jpg')

if time.time() - landing > 600: landed = False logwriter.writerow((time.time() - start, time.time() - liftoff, accel, 'end'))

execfile('transmit.py')

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Transmit.py:# Xbee Transmission# University of Toledo Rocketry Club# Michael Blackwood, 2016#! /usr/bin/python

import serial, time, base64, os

# Begin functions ----------

def imageToList(imagefile, breaks):

""" :param imagefile: filepath for image being prepared :param breaks: number of chars in each string chunk :return: list of strings that represent a base64 encoded image """

with open(imagefile, 'rb') as ifile: imgstr = base64.encodestring(ifile.read()) print 'Preparing {0} of length: '.format(imagefile) + str(len(imgstr)) imglist = [] for i in range(0, len(imgstr), breaks): imglist.append(imgstr[i:i+breaks])

return imglist

def sendImage(directory, imagefile, breaks):

""" :param directory: directory of image :param imagefile: filename for image being prepared :param breaks: number of chars in each string chunk :return: None """ start = time.time()

imglist = imageToList(directory + imagefile, breaks)

ser.write('image:start:' + imagefile +'\n')

time.sleep(1)

#ser.write(base64list + '\n') for data in imglist: time.sleep(.1) ser.write(data + '\n') #sendData(data)

time.sleep(1) ser.write('image:end\n')

print 'took {0} seconds'.format(time.time() - start)

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def sendData(data):

# Not in use, might add this for confirming messages were recieved.

trying = True while trying: ser.write(data + '\n')

time.sleep(.2)

received = ser.readline().strip() if data == received: print 'good' trying = False else: print 'bad'

# End functions ----------

ser = serial.Serial('/dev/ttyUSB0', 115200)

time.sleep(1)ser.write('UTRocketry\n')print 'contacting ground station'time.sleep(1)

ser.write('csv:start\n')time.sleep(1)print 'sending csv'csvstart = time.time()with open('atmospheric.csv') as csvfile: for line in csvfile.readlines(): ser.write(line) time.sleep(.1)print 'took {0} seconds'.format(time.time() - csvstart)ser.write('csv:end\n')print 'csv sent'time.sleep(1)

# send imagesfor file in os.listdir("images"): sendImage('images/', file, 1000)

time.sleep(2)ser.write('complete')

ser.close()

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4.3.4 Ground Station Code# XBee Receiver# University of Toledo Rocketry Club# Michael Blackwood, 2016#! /usr/bin/python

import serial, time, base64import serial.tools.list_portsimport timeimport sys

print 'UTRocketry Downlink Client'# add delay because it looks awesometime.sleep(1)

# Look for COM port that might have an XBee connectedportfound = Falseports = list(serial.tools.list_ports.comports())for p in ports: if "Serial Port" in p[1]: if not portfound: portfound = True portname = p[0] print "Using " + p[0] + " as XBee COM port" time.sleep(1) else: print "Ignoring this port, using the first one that was found"

if portfound: ser = serial.Serial(portname, 115200)else: sys.exit("No serial port seems to have an XBee connected")

def restartLine(): sys.stdout.write('\r') sys.stdout.flush()

# Wait for the payload to signal data collectionprint 'standing by for contact from rocket...'standby = Truecount = 0step = 10

while standby:

incoming = ser.readline().strip() if incoming == 'UTRocketry': standby = False print 'contact made' svfile = open('atmospheric.csv', 'wb')

csvloop = True

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downloadcsv = False

while csvloop: incoming = ser.readline().strip()

if incoming == 'csv:end': csvloop = False downloadcsv = False print 'atmospheric.csv saved' csvfile.close()

if downloadcsv: csvfile.write(incoming + '\n')

if incoming.startswith('csv:start'): csvfile = open('atmospheric.csv', 'wb') downloadcsv = True print 'receiving: atmospheric.csv'

image = ''downloadimage = Falsesaveimage = Falseimageloop = Truewhile imageloop: incoming = ser.readline().strip()

if incoming == 'complete': imageloop = False

if incoming == 'image:end': saveimage = True

if saveimage == True and downloadimage == True: fh = open(imagename + 'jpg', 'wb') fh.write(base64.decodestring(image)) fh.close() saveimage = False downloadimage = False image = '' print 'image saved'

if downloadimage: image += incoming

if incoming.startswith('image:start'): downloadimage = True imagename = incoming[12:] print 'receiving: {0}'.format(imagename)

print 'download complete, closing connection'ser.close()

raw_input("press Enter to close...")

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4.3.5 Drawings and Schematics

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4.3.6 Instrument Precision

Sensor Accuracy

Angular Rate 245 dps

Linear Acceleration 2 g

Barometer 4 Gauss

Temperature 2°C

Relative Humidity 4.5%

Ultra Violet 550nm-1000nm (centered on 800)

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Solar Irradiance 400nm-800nm (centered on 530)

4.3.7 Flight Performance Predictions During the flight, software on board of the atmospheric measurement suite will be monitoring the current acceleration of the vehicle, this information will be used to activate the various modes of data collection. During this time, the Liquid Sloshing Experiment will be running, collecting valuable video of the three fluids in motion. The payload will be able to detect the acceleration change when the rocket begins its return to earth. During this time the data collection will run as programmed. Again, the payload has been finely tuned to detect when the rocket has reached the ground and has become stationary and will again trigger code to collect data as programmed. Ten minutes after the rocket has landed, the data collection software will pass off duty to the data transmission program, which will send the data back in a comma separate file back to a ground station computer for later analysis. From bench top testing and bug fixing, along with lessons learned from the full scale test flights, the payload should perform as designed during the flight of the vehicle.

4.3.8 WorkmanshipWorkmanship of the rocket is crucial. The rocket was constructed with only quality components. Per NASA request, all of the eye-bolts in the design were switched to welded eye-bolts. Furthermore, most of the work completed on the rocket was done under the supervision of our mentors; this was done to ensure the techniques used in the construction of the rocket was safe and reliable.

To ensure that our epoxy holds, we used 30 minute cure time epoxy. Our mentor informed us that to use a quicker epoxy may compromise the strength of the bond. All components were tacked in with a quick-dry glue, and then secured fully with the 30 minute epoxy. This was done to allow proper alignment of the components and reliable construction.

All work completed was peer checked. Each item in the rocket serves a crucial task, meaning the rocket cannot function normally without each component/ system. A peer check consisted of a job/task being completed by one of the team members. The first team member (primary member) then would call over the

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secondary team member. The primary team member gave a short brief of the job that was done and critical aspects of the job (what it should look like, the alignment of parts, etc.) as well as what the certain component/ system was supposed to do. The secondary member then was suppose to look over the job and give feedback and adjustments. Along with every job being double-checked, team members were able to participate and be educated on every part of the rocket.

The whole rocket was built in accordance with the process described above.

4.4 Verification

Testing of the Payload Subsystem has been completed. There were two partial failures during payload testing. One Raspberry Pi had its CSI camera port stop functioning during benchtop static testing. We were able to acquire a replacement Raspberry Pi which has passed our checkout test.

During the Full-Scale Test the Atmospheric Measurement Suite was flown on-board the vehicle. The goal of the test was to prove the ability of the payload to collect and transmit data during an actual flight. In order for this test to be attempted, the payload had to first pass benchtop simulation testing. During the flight, however, the payload failed to collect data as intended or transmit after landing. In case of a failure, the payload also logged the raw accelerometer data throughout the time the computer was on, which allowed the team to debug the issue with the code after the flight. It was found that we failed to adjust the code enough for the lower powered engine we flew during the test flight. Tolerances on the launch parameter of the code have been loosened to ensure the payload recognizes launch has happened and will trigger correct data collection. Based on the data collected during the test flight, the work we did on finding the cause of the failure, and successful benchtop simulated testing, we are confident the payload will succeed during the final flight in Huntsville.

Test ID Test Name Description Goal Status

P-1 Raspberry Pi Checkout

Confirm both Raspberry Pis are operable. Ensure proper drivers are installed to

Have the microcomputers prepared to collect

1 Failed initially. Both Passed after

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communicate with sensors. data from the sensors. replacement.

P-2 Power Supply System Charge batteries and test that steady 5.5V is supplied through the USB cable. Test lifetime of battery.

Ensure power will be supplied to all the devices for the duration of the experiments.

Passed

P-3 Software Simulation Through simulated events in code, test that the testing code will gather the correct time of data, at the correct intervals, when needed.

Allow testing of software data collection, while also providing for a short turnaround time between code changes.

Passed

P-4 Cameras For both payloads, take multiple pictures, examine their size when saved on the disk, and their quality.

Ensure cameras will take pictures and videos that will be sufficient for payload requirements and for accurate analysis.

Passed

P-5 Transceiver Testing Test sending data from computers from multiple distances.

Ensure data will be received by team.

Passed

P-6 Static Physical Testing Using simulated acceleration data fed into sensors, run through software and ensure proper data collection and retrieval.

Ensure sensors can properly collect data given reasonable input.

Passed

P-7 Physical Drop Tests Under parachute, drop the integrated payload from various heights to test the software’s ability to collect data appropriately.

Prove the payload can perform under similar conditions to actual descent and landing.

Passed

P-8 Test of Atmospheric Measurement Suite on Full-Scale Flight

Have the software run the full data collection and retrieval system during flight.

Prove the payload can perform correctly during flight.

Partial Failure

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4.5 Safety and Environment (Payload)We will be using saline solution, distilled water and vegetable oil inside of our payload. None of these liquids are flammable. All of the fluids we will be testing are environmentally safe and will cause no harm to the planet or people.

We have done multiple tests on the payload to make sure it passes our requirements (see above for tests and status). We feel that these tests adequately test the payload we will be using for any major safety issues.

5 Launch Operations Procedures

5.1 Checklists

5.1.1 Recovery Preparation

Task to be completed Task Completed: Sign below

Needs Attention: Sign below

1 Install two fresh 9v batteries into battery clips inside of electronics bay. Apply tape to fasten the clips.

2 Insert batteries into the battery holders and fasten in place with zip ties.

3 Ensure altimeter switches are in off position

4 Connect leads from switches to respective altimeters

5 Connect wires from altimeters to terminal blocks on both ends of

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electronics bay

6 Final check of all wiring, ensuring wires lead to correct locations

7 Insert payload sled fully into electronics bay

8 Place electronics bay end cap into place and fasten with nuts

9 Cut four e-matches to length and strip ends

10 Insert e-match leads into terminal blocks and tighten

11 Place end of e-matches into charge caps, taping the leads down with electrical tape

12 Measure and pour in two grams of black powder into each charge cap

13 Insert recovery wadding into charge caps and secure with masking tape

14 Attach quick links to ends of both shock cords using double overhand knots

15 Attach one shock cord to the motor mount, tighten quick link

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16 On other end of shock cord, attach the main parachute and the nomex blanket through the quick link

17 Attach quick link to main parachute side of electronics bay through the eyebolt and tighten

18 Attach other shock cord to eyebolt on payload bay and tighten quick link

19 On other end of shock cord, attach drogue parachute and nomex blanket to eyebolt on drogue parachute side of electronics bay and tighten

20 Pack drogue parachute into upper body section of rocket

21 Insert electronics bay into upper body section

22 Insert four nylon shear pins into body of rocket, cover pins with electrical tape

23 Insert electronics bay into lower body section of rocket

24 Check fit of previous connection, lower body should slowly slide when rocket is shook

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5.1.2 Payload Preparation



1 Check charge on Li Ion batteries

2 Attach a battery to each Raspberry Pi, and another to the TeleGPS

3 Attach the batteries to the payload sled with zip ties

4 Fill each test tube with its intended fluid and tape lid shut with electrical tape

5 Attach each test tube to the test tube rack with a zip tie

6 Slide the payload sled into the payload bay, aligning sled with slots in mounting brackets

7 Wrap TeleGPS in bubble wrap

8 Insert TeleGPS into nosecone of rocket

9 Slide nosecone into top of payload bay

10 Screw in 4 screws tightly to attach nose cone

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5.1.3 Motor Preparation



1 Inspect motor retention, ensure all screws are tight

2 Inspect motor for visual defects

3 Insert motor into rocket body

4 Tighten motor retention ring down

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5.1.4 Setup on Launcher



1 Lower launch rail

2 Slide rocket onto launch rail making sure launch lugs are engaged onto rail

3 Raise rail to desired angle, based on wind speed and direction

4 Use a screw driver to activate one altimeter

5 Listen for a series of three quick beeps to signify continuity of the e-matches

6 Repeat above step for second altimeter

7 Insert screwdriver into hole in payload bay to press button that activates payload.

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5.1.5 Igniter Installation



1 Insert ignitor into motor until it stops, mark how far it goes inside

2 Slide ignitor cap over ignitor leads, tie in place at spot previously marked

3 Insert ignitor and cap into rocket motor

4 Tape cap in place with masking tape

5 Connect the ignitor leads to alligator clips

5.1.6 Launch Procedure



1 Ensure data collection software is running on ground station

2 Ensure the GPS software has GPS lock and map view loaded

3 Inform the LOC our rocket is ready.

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5.1.7 Troubleshooting

Issues Solutions

Shear pins are falling out Add or replace electrical tape over shear pins

Altimeters are failing e-match continuity test Remove electrical connections between altimeters and E-matches and recycle to Recovery Checklist

Payload will not turn on Change BatteriesEnsure continuity along line of power from batteries to computers.

Parachute not packing properly Remove parachute and re-roll, being mindful of tightness of roll

Shock cable shows tearing/ damage Replace damaged shock cable and inspect all other shock cable

Epoxy shows signs of cracking/ damage Add more epoxy and inspect all other epoxy sites. Inform mentors and team members. Adequate time is needed for epoxy to cure.

Bolt / screw found loose Tighten bolt/ screw. Add loctite as needed. Inspect other bolts and screws.

Bolt / screw missing Replace bolt / screw with spare. Notify other members to ensure adequate spares are available.

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5.1.8 Post-Flight Inspection



1 Turn off altimeters

2 Open payload bay and send payload sled to Payload Specialist for data collection

3 Disconnect all quick links

4 Inspect parachutes for burns or damage

5 Inspect shock cords for burns or damage

6 Remove motor when cool

7 Inspect motor mount for damage

8 Inspect fins for damage

9 Check for “zipper” damage along body tubes

10 Connect altimeters to computer to download flight data

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5.2 Safety and Quality Assurance

5.2.1 Risk AssessmentA thorough evaluation of the possible hazards associated with the rocket has been done with respect to the members, as well as the environment. The University of Toledo Rocketry club has come up with safety procedures that every member must follow. These safety procedures cover tools, equipment, chemicals, energetic materials, electronics, combustible/flammable materials, and any other substance or hazardous item. If any member of the UT Rocketry team is handling tools, chemicals, or energetic materials they must wear the required safety equipment. There must always be at least 2 members whenever the rocket is being assembled or transported to maintain safety and accountability.

The hazards associated with the vehicle involve the storage of combustible substances such as motors and black powder as well as the igniters and adhesives. The safety data sheets (SDS’s) pertaining to certain aspect of the vehicle and its operation have been obtained and made available for all team members. The UT Rocketry team has multiple storage containers that are used to keep the separate parts of the rocket safe. The electronics are kept in a waterproof container to prevent them from getting wet. All chemicals like epoxy are kept in a container with our tools, but separated with dividers and placed inside of plastic bags to prevent spilling. Energetic materials are stored separate from all other containers in another waterproof case to prevent accidental discharge from causing damage to any other components and/or people.

The UT Rocketry team has done many things to prevent failure of the rocket. We’ve done extensive testing of our components to make sure they can handle the amount of stress we will be applying. The electronics bay has been strength tested to see how it would fair against a rocket motor failure. The body tubing and fin can assembly were tested to make sure that they can withstand the speeds we will be sending the rocket at. We have done two full scale launches to make confirm that the recovery system does indeed work. The testing we’ve done to the rocket have helped us gain confidence in the design of the rocket.

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5.2.2 Environmental ConcernsEnvironmental concerns include any and all aspects of our rocket materials, preparation, and launch that may make a negative impact on our immediate and surrounding environment.

These include the negative repercussions of our materials:

Pacer Technology (Zap) Pacer Technology (Zap) Z-Poxy 30 Minute Set:

Epoxy is toxic and irritable when exposed to skin. Knowing this epoxy must be handled with care and disposed of in a proper receptacle not accessible to animals or humans.

Zap-A-Gap Medium CA+:

Super glue, just like epoxy is a chemical irritant and cannot be exposed to the environment.

Li-Ion 3.7V 2000 mAh Batteries:

Lithium batteries can explode and degrade becoming extremely toxic and a fire hazard. Batteries must not be punctured and must be supervised during the charging process to prevent degradation of the battery.

Safety officer Connor Blair will be tasked with making the team aware of some of the major environmental issues that components of our rocket can cause. Those major issues are stated above. A table of environmental concerns is displayed below.

INSERT ENVIRONMENTAL IMPACT OF ROCKET TABLE

5.2.3 Responsible IndividualConnor Blair will serve as the ideal choice for a safety officer. A sophomore mechanical engineer at The University of Toledo, Connor is an invaluable resource towards maintaining safety throughout the competition. Patrick Schermerhorn is the redundant safety officer and is well versed in the safety hazards that are associated with the construction of a high-powered rocket.

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6 Project Plan6.1 Budget Plan

In the Aggregate Expected Costs table below is listed the expected totals for each aspect of the SLI competition.

Aggregate Expected Costs

Payload $338.88

Propulsion and Fuselage $628.46

Recovery $268.68

Sub-Scale $59.48

Education $100.00

Travel $1,494.64

Total $2,890.14

Payload BudgetOur payload budget was broken up into two different parts, one for each experiment. In our atmospheric payload budget we see most of the cost going into the raspberry pi, the sense hat, and radio communication. For our liquid sloshing experiment the majority of the cost goes to another raspberry pi and the camera used to observe the liquids. Those can be found below.

For cost savings in the payload portion we chose to base our whole system off Raspberry Pi’s. These save us both money and time because of their relatively low complexity and the fact that they work well with cheaper yet still capable hardware options. Further breakdown of the budget is below.

Component Name Quantity Price Link

Atmospheric Payload Hardware

Raspberry Pi 2 Model B 1 $39.95 Link

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UV / Solar Irradiance Sensor 1 $9.95 Link

Raspberry Pi Sense Hat 1 $39.95 Link

XBee Radio Transceiver 2 $37.95 Link

PowerBoost 1000 Basic 1 $14.95 Link

Li-Ion 3.7V 2000 mAh Battery 1 $25.00 Link

Adafruit Micro Lipo charger 1 $5.95 Link

Raspberry Pi Camera Board 1 $29.95 Link

USB XBEE adapter 2 $49.90 Link

GPIO Stacking Header 1 $2.50 Link

SanDisk MicroSD 32GB 1 $11.99 Link

GPIO Jumpers 1 $2.95 Link

Liquid Sloshing Hardware

Raspberry Pi 2 Model B 1 $39.95 Link

PowerBoost 500 Basic 1 $9.95 Link

Li-Ion 3.7V 2000 mAh Battery 1 $25.00 Link

Adafruit Micro Lipo charger 1 $5.95 Link

Raspberry Pi Camera Board 1 $29.95 Link

KeL Scientific 25 pack Test Tubes 1 $4.74 Link

SanDisk MicroSD 32GB 1 $11.99 Link

Total Price $338.88

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Sub-Scale Launch BudgetFor our sub-scale launch we tried to keep the costs pretty low by using the altimeters from our recovery system. The motors were also already purchased by a team member so that was donated to the team. You can see that below.

Component Name Price LinkSub-scale Launch Hardware

G40-4W Composite Motor $26.99 Link

Pro Series II Argent $22.50 LinkMass Simulator $9.99 Link

Total Price $59.48

Propulsion and Fuselage BudgetIn our propulsion budget, most of our expenses go directly into different motors. Another large expense is the kit for a 54mm motor. Since the PDR we have upgraded our motor diameter from 39mm to 54mm, necessitating a larger motor tube. Our rocket body was donated to us, which helps us dodge some of the cost. You can see that below.


Propulsion and Fuselage System Hardware

J-295 Cesaroni Motors 1 $86.00 Link

Fantom 438 EXL Rocket Body 1 $151.75 Link

Retainer Body, 54 mm 1 $16.00 Link

Pro 54 Starter Kit 1 $219.95 Link

J-270 Cesaroni Motor 1 $57.91 Link

I-236 Cesaroni Motor 1 $41.35 Link91

Pacer Technology Z-Poxy 1 $15.50 Link

Various Hardware 1 $40.00

Total Price $628.46

Recovery System BudgetIn the recovery system the only large single expense is our StratoLogger altimeters. The other things are generally smaller $1-$10 items we need to build the structure behind the recovery system. You can see that below


Recovery System Hardware

Drogue Parachute 1 $11.50 Link

Main Parachute 1 $55.95 Link

Nylon Shock Cord 3 $20.64 Link

StratoLogger Altimeter 2 $117.60 Link

9v Battery Clip 1 $5.99 Link

Bag of Standoffs 1 $9.99 Link

9v Battery 4 $8.28 Link

9v Battery Plug 1 $4.57 Link

Fire Resistant Blanket 1 $8.45 Link

Cable Ties 1 $9.99 Link

Terminal Block 1 $3.25 Link

Ejection Canister 1 $3.00 Link

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Ejection Rotary Switch 1 $9.46 Link

Total Price $268.67

Travel ExpensesOur travel budget breaks down into two main expenses, travel and lodging. Our plan for travel is to rent a fifteen person passenger van that can be used to transport the whole team down to the competition along with our rocket and bags. Gas costs are calculated off EPA estimates for highway fuel economy and the number of miles we will travel on our trip.

Item Price

Travel Expenses

15-Person Van $494.70

Gas $187.38

Hotel $812.56

Total $1,494.64

6.2 Funding PlanReceived funding for the 2015/2016 competition year is listed below.

Donor Amount

Marathon Petroleum Corp. $1,500

Blair IT $226.04

Total $1,726

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We did not meet our overall funding goals for this competition year. Funding has been one of our weakest areas this year in terms of our program as a whole. It has not held back our overall goals, as we have still fully constructed our rocket, along with being able to take our whole team down to the competition. In this next month before the competition we will continue to pursue other companies and donors for support. The construction of the rocket was 100% funded by the team and donors, either of parts or money. Through donations of parts from local model rocket enthusiasts we were able to spend less than 2/3s of our received donations on rocket components and construction. The excess money from construction will be put towards travel and other club expenses including banners, memberships, and fees. We look forward to expanding our donor network in future years to different university sponsors and more corporate donors to ensure the longevity of the club.

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6.3 Timeline

Our schedule is portioned into 4 different sections, each corresponding to a certain part of the critical path with the education and outreach schedule separate. As of right now our team continues to be on schedule, We have attended the necessary JMRC launches and have finished all testing and verification of our rocket and its subsystems. With our full scale test completed on time, and now completion of the FRR, we have moved onto the final stage of our timeline; the competition. The only goals to be completed before then are the final painting of the rocket and construction of the team’s presentation for launch week. Below is our team’s critical path.

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6.4 Educational EngagementTo meet our educational engagement requirement our team met with the local Oregon City Schools high school and middle school. In a joint grade educational day we separated students into groups based off age. Younger students grades 6-8 were given a presentation on rocketry and NASA. This was followed by a Q&A session were we found the younger students were extremely interested in NASA and space exploration. Due to the huge amount of students we did not deem a hands on activity practical for this grouping. However the result was positive and gives us all hope for the future of space.

Older students taking high level math and physics classes were brought into the auditorium for a more advanced presentation on rocketry in general and the UT rocketry team’s rocket. We brought in the team rocket for the students to analyze and ask questions about. We also brought the students a large estes model rocket to assemble and decorate before launch. These students were thrilled to be participating in a hands on activity about projectile motion instead of running equations on non-relatable theoretical scenarios. The weather that day was to poor for a launch and we were short on time so we were forced to end the day. We have agreed to come back to Clay High School in April and launch the estes rocket which will run on a G class motor. We challenged the students to develop and build a small payload for the rocket before we get back. They all got very excited about that and agreed they would decorate the rocket and plan an experiment. The physics teacher Michael Heck also told us he would have the students weigh the rocket and take measurements and then attempt to guess its max height based off the G class motor. We will attach one of our altimeters to the rocket so they get an accurate reading to compare with.

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Overall the students had a great time, we reached over 200 students, mainly from the middle school class group but also we impacted roughly 80 high school students with hands on building that has caused some to consider going to college for engineering. The school has already given us great feedback and invited us back for next year which only validated our efforts. We entered with only a handful of hands saying they cared about what NASA was doing and left with almost the entire room saying they would vocally support our space program and look into rocketry on their own.

A quick excerpt from Mr. Heck a Clay high school physics teacher says , “Jay and his team will be back to Clay in April or May to help the students launch the rocket they left with us. The students plan to make an experiment and are extremely excited for this hands on education. We can't wait to have the group back.”

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7 ConclusionThis year has been a massive journey for the University of Toledo Rocketry Club. We started out with just an idea and couple students interested in rocket launches and Kerbal Space Program. We initially thought we would delay entering NASA’s USLI competition until 2017 because it seemed too daunting of a task. We decided we would give it our best attempt as a team and that has led to one of the best learning experiences in our lives.

The club started with very minimal knowledge of high powered rocketry both in theory and in practice. The most rocketry experience any of us had under our belts was launching 2 foot tall Estes rockets. This last year has been an absolute crash course in rocket design. Incrementally we got better. By PDR we still had very minimal knowledge but the big picture was starting to come together. By CDR the club overcame multiple challenges such as our website being hacked and ordering the wrong engine. Yet our sub-scale launch worked as planned and we were feeling confident enough to finish construction of our full scale rocket.

In February we finally launched the full scale rocket. We had put countless hours into building this rocket. We have lost some members along the way and gained others. All of our testing and simulations showed that this rocket should work flawlessly but it was the first high powered rocket we had ever built or launched so it was still nerve racking. We launched the full scale rocket perfectly the first time and got L1 certifications. Within an hour, we were able to recycle the rocket, reload the engine and get it back on the pad for launch. Again the rocket performed perfectly.

This club has went from knowing nothing about high powered rockets to successfully launching them. We may not have the best looking rocket, or the fanciest experiment, but we have learned so much from this endeavor and are so proud of what we have accomplished.

The club hopes to get all members L2 certified by next year and receive more funding so that we can design a more unique payload experiment. We are confident in our ability to launch a high powered rocket now and confident in our mastery of the basics. The club is fully committed and ready to launch in Huntsville and we look forward to making huge strides in the next year and years to come.

With love,

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UT Rocketry

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