UNIVERSITY OF NORTH DAKOTA FROZEN FURY CRITICAL DESIGN REVIEW REPORT NASA STUDENT LAUNCH 2015

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2 UNIVERSITY OF NORTH DAKOTA FROZEN FURY CRITICAL DESIGN REVIEW REPORT NASA STUDENT LAUNCH

3 Table of Contents Summary Team Summary Launch Vehicle Summary AGSE/Payload Summary Changes Made Since PDR Changes to Launch Vehicle Change to AGSE/Payload Changes to Project Plan Vehicle Criteria Design and Verification of Launch Vehicle Subscale Flight Results Recovery Subsystem Mission Performance Predictions Launch Concerns and Operational Procedures Safety and Environment AGSE/Payload Criteria Testing and Design of AGSE/Payload Equipment AGSE/Payload Concept Features and Definition Science Value Project Plan Budget/Funding Timeline Educational Engagement 3

4 Summary Team Summary Name: UND Frozen Fury Location: Grand Forks, North Dakota Team Mentor: Dr. Timothy Young NAR # 76791, Certification Level 2 Launch Vehicle Summary Dimensions Length: 105 inches Diameter: inches Loaded Mass: 26.2 lb Motor: K480W Recovery System: Two main parachutes (58 inches and 115 inches) One drogue (36 inches) Rail Size: Length: 144 inches AGSE/Payload Summary The AGSE is comprised of three systems. The first is the payload grabbing apparatus that uses a linearly actuated slide rail and a claw to grab and move the payload from the ground to the payload compartment. The second is the payload loading system that uses a linear actuator to position the rail to an angle of 85 from the ground. The last is the ignition system that consists of a wire wrapped around a coil that will unravel and feed into the rocket s motor for ignition. 4

5 Changes Since PDR Notice It was requested after our PDR submission for an increase in some technical details in the form of an additional submission. The changes that will be described here are the changes made since that additional submission. Changes to Launch Vehicle No changes have been made to the design of the launch vehicle. The main parachute and the payload parachute diameters have changed. Changes to AGSE/Payload As we began constructing the frame we became aware of a necessary adjustment. The length of the frame of the AGSE has been reduced by 6 ft in order to ease transportation. Drawings of this change have been included in the AGSE/Payload section. We developed the code that will be run by the Arduino micro controller which is the basis of our electric system. This code will be included in an appendix at the end of this report. Changes to Project Plan The sub scale vehicle construction and launch was pushed forward due to a delay in product delivery and extreme winter weather conditions. Our funding plan has been revised after a misunderstanding about application deadlines. 5

6 Vehicle Criteria Design and Verification of Launch Vehicle Our Mission The primary objective of the University of North Dakota Frozen Fury Rocket Team is to design and construct a safe and stable rocket along with an automated ground support system. The ground support system is to be designed to secure a sample that will be safely loaded into the rocket Success Criteria The requirements of this launch are listed and described in the NASA Student Launch Handbook. This includes a single stage launch to an apogee not to exceed 3000 ft and recovery of the vehicle. Also the vehicle is to be autonomously loaded, erected and launched by our AGSE system. The mission will be considered successful if the AGSE and launch vehicle accomplish the goals of our mission statement in accordance with the NASA Student Launch Requirements. In addition to this the team strives to develop an understanding of Rocketry and Rocket Systems. Major Milestone Schedule Gantt Chart Figure 1: Gantt chart of major project milestones 6

7 Launch Vehicle Figure 2: 3 D model of complete launch vehicle (side view) Length: 105 inches Diameter: inches Mass with motors: 26.2 lb Center of Gravity: inches Center of Pressure: inches Safety Margin: 1.76 Figure 3: Breakdown of the critical flight and payload systems 7

8 I. Launch Ignition: The igniter was chosen to produce a suitable energy source to ignite the motor. It is also necessary that the igniter do not catch on the motor casting during automated insertion. The mechanism for this will be a coil dispenser operated by a motor protected in an steel box. If necessary, the wires on the igniter will be reinforced prior to insertion to prevent bending and failure of seating. Launch rod: The launch rod is 144 inches in long and allows for acceleration of 69.5 ft/s velocity off rod. Launch lugs: The number of launch lugs is set to two as friction becomes an issue with more lugs. If only two lugs are used there is a reduced friction coefficient allowing for a more rapid acceleration. It is also imperative that since there are fewer lugs that they be more heavily reinforced. This can be achieved by distributing the forces at the body tube lug joint with washers bent to the curvature of the body tube to prevent indentation and provide a more even contact surface. The lugs will be placed as follows: one near the center of gravity of the rocket and one near the aft of the motor mount. Figure 4: Locations of launch lugs with respect to the bottom of the body tube in inches. 8

9 Motor mount: Figure 5: Locations of centering rings with respect to the bottom of the body tube in inches. The motor mount will be located at the bottom of the launch vehicle with the bottom of the mount being flush with the bottom of the body tube. The centering rings will are located according to Figure 5. 9

10 Motor placement: The motor will protrude from the motor mount tube around one inch to prevent combustible material from impacting the body tube as frequently, therefore helping to preserve the useful lifespan of the launch vehicle. Motor specifications: Figure 6: Aerotech K480W Thrust per second The motor is Aerotech K480W. It is a a 78% K reloadable composite motor and was chosen for its ability to lift the mass of the launch vehicle and payload to a safety margin of 788 feet above the desired apogee (3000 feet). This is to insure that the apogee could still be reached if the launch vehicle has an increased coefficient of drag and/or increased mass relative to the designs and simulations. The motor was also selected because it is able to accelerate the launch vehicle to the necessary stable velocity for flight. The motor is currently being sold and is certified until 30 Jun 2015 for hobby rocketry. 10

11 Aerodynamics: The aerodynamics of the launch vehicle are affected by three major factors; nose cone shape, fins shape, and paint finish. The nose cone shape selected for the design was an ogive shape. It was decided that a nose cone with a pointed tip would be easier to construct that would a nose cone with a rounded tip. Even though there is a small aerodynamic sacrifice, the tradeoff is worthwhile because a higher degree of precision can be assured. These decisions were made with the knowledge that a rounded tip is more aerodynamic for subsonic velocities and a pointed tip is more aerodynamic for supersonic velocities. Figure 7: Nose cone dimensions (in mm) The base diameter of the nose cone is the same as the outer diameter of the body tube so that turbulence over the changing surfaces is minimized. Nose cones tend to work best at a length:diameter ratio of 3:1. The ratio for our nose cone is 4:1. There is nothing wrong with this ratio, but the team may consider 11

12 taking mm off the nose cone length to bring it to the 3:1 ratio in future designs. This will serve both to reduce mass and to decrease drag forces. Fins: The fins were designed with a wide tab that extends into the body of the launch vehicle. These tabs will be connected to the motor tube. This was the most effective method of reinforcement that the team found for the fin structure. The fins must necessarily be reinforced because of the high velocities and torque forces that will be applied to them during flight, especially during the acceleration phase. The wood selected for the fins needs to have a high tensile strength, resistance to bending, and resistance to breaking. A multi ply wood with perpendicularly oriented layers will provide the most strength. The fins will have a thickness of ½ inch. The fins are flush with the bottom of the body tube, but are drawn upwards to prevent damage due to recovery impact and combustible material from the motor. Figure 8: Fin dimensions (in mm) 12

13 Stability: Figure 9: Launch vehicle stability diagram The stability of the launch vehicle depends on the locations of the center of gravity and the center of pressure. The safe margin for stability is between 1.00 and 2.00 body tube diameters. The margin for our launch vehicle is This puts it on the higher end of stable, which would theoretically allow for a higher apogee to be obtained. Stability diagrams are in the appendix in the bottom of this document. Safety and Failure Analysis Analysis of Current Item of Function Analysis of Item of Function After Actions Taken Item or Functi on Battery Wiring Potenti al Failure Model High Level, altimeters fail, and parachutes never deploy Potential Effect(s) of Failure Unsafe return results in damages or injuries Sev erity 10 Potential Cause Wiring from the batteries to the altimeters wiggle loose over the flight Expect ed Occurr ence 5 Preventati ve Solder end of wires, and use bindings to keep the wires from wiggling during the flight Recomm ended Action Shake test, and addition of hot glue over joints Co m ple tio n Action Taken? New Severit y Friction Fit or Sheer Pins High level, if the sheer pins or friction fitting is too tight, the rocket will Unsafe deployment of parachute results in 10 The friction fitting is too tight, or too many sheer pins 3 Utilize techniques to ensure the rocket is properly friction fit, and the sheer The lifting test for friction fitting, and a blast test for sheer pins 13

14 not separate. damages or injuries. pin amount will break properly. Structural Failure High level, if any of the fins or structure of the rocket fail. Energetic deconstructi on. 10 Failure to inspect gluing surfaces, 3 Supervision of gluing surfaces. Pairing of new team members with old Exterior paint failure Low level, the paint could strip off due to high velocities. Striping of paint from the rocket, 1 High velocities over the rocket skin, and an uneven coat of paint 1 Even coats of paint, and consider limiting velocity of rocket Parachute events High level, if the parachutes fail or tangle. Unsafe return results in damages or injuries 10 Improper folding of parachutes, and stuffing into rocket 5 Experienced members handle parachute folding and stuffing. Pair new team members with old Payload door failure Payload bay door opens in flight Disruption of stable flight resulting in possible total failure, loss of payload. 10 Failure of locking mechanism 3 Extensive testing in lab Stress testing locking mechanism, double checking installation Subscale Flight Results: Notice: As stated in Changes Since PDR the launching of our sub scale vehicle has been delayed due to extreme winter weather conditions and the launch cannot be performed before the due date of this report. The launch is planned to be performed January The exact day is dependent on weather conditions. Recovery Subsystem: 14

15 Parachutes Drogue: 36inch ripstop nylon (deploys at apogee) Main: 115 inch ripstop nylon (deploys at 1000 feet at decent) Payload: 58 inch ripstop nylon (deploys at 1000 feet at decent) Parachute Deployment At 3000 ft the altimeters located in the altimeter bay will set off the rear charge to allow the 36in drogue parachute to deploy to slow the descent down to 62 ft/s. The compartment that contains this parachute is marked on the launch vehicle diagram. As the rocket approaches the 1000ft mark during the descent, the altimeter will set off the front charge to separate the altimeter bay and the motor compartment (that are connected) from the nose cone and payload bay. The two parachute sizes used are 115in for the main and 58in for the payload main parachute. These two parachute sizes will give a final descent velocity of ft/s for the payload (mass of 139 oz giving a kinetic energy of Joules or ft lbf) and ft/s for the rest of the launch vehicle (mass of 280 oz giving a kinetic energy of Joules or ft lbf). To make sure that the payload parachute is deployed instead of being pushed due to the charge, the team will place a loosely fitting nylon bag on the payload chute that encloses most of the harnesses and the chute that is connected by a patch or 2 of velcro by the top half of the bag that is held by a cable or harness to the main parachute of the other half of the rocket. So as the main parachute is pulled out of the body of the main rocket, it will pull out the bag but is loosely connected enough such that the bag will be ripped open and the payload chute pulled out. Safety Harness The components of the safety harness design are a ½ inch thickness multi ply, cross layered wood and a ¼ inch stainless steel U bolt. Parachute Attachment 15

16 The parachutes will be attached by tubular nylon. This material was chosen due to it s high tensile strength, durability, and light weight properties. The parachute will be using ½ inch thickness tubular nylon with a breaking strength of 2000 pounds. If the drogue parachute fails to open, but the main parachutes still open at 1000 feet, it is still possible for the tubular nylon to withstand the shock forces from the rapid deceleration from the free fall velocity. Figure 10a: overview of launch and parachute deployment 16

17 Figure 10b: Bulkhead with parachute harness attachment point Figure 11: Bulkhead schematics 17

18 Ejection Separation of the body tube will be accomplished by the ignition of a black powder charge at each separation point. In order to prevent inadvertent separations anytime during flight and recovery, four shear pins at each separation point will be included to maintain a specific force of separation. Four small pinholes will be created in the body tube of each separation section to prevent ejection failure due to abnormal pressure differences. Electronic control Electronics tend to be a major failure point on a launch vehicle. For this reason the team chose to have redundant power sources for each of our altimeters. This way if one power source fails, at least one altimeter is able to take a reading and control parachute ejections. Ejection will be controlled by two altimeters. The altimeters should be sealed from any other compartment to prevent erratic pressure readings. In order to guarantee precision of the altimeter readings, four small pin holes will be created in the body tube of the altimeter capsule. This will allow for pressure equalization. Tracking Altimeter: The altimeter that will be used is a StratoLogger Perfectflite Altimeter. Two outputs are provided for deploying a small chute at apogee to and the two larger chute at the same time at 1,000 foot. The StratoLogger collects flight data (altitude, temperature, and battery voltage) at a rate of 20 samples per second throughout the flight and up to 100,000 foot altitude. 18

19 Figure 12: StratoLogger Perfectflite Altimeter Figure 13: 3 D model of avionics compartment The PerfectFlite altimeters will be set to fire the parachutes at the appropriate altitude as well as keep track of the altitude that the launch vehicle attains. See Figure 14 for physical diagrams of the altimeter bay. A wiring diagram is shown below. Two altimeters will be utilized to make sure the charges are fired, in case one altimeter fails. 19

20 Figure 14: rough circuit diagram for the altimeter bay. Turbulence can have adverse effects on altimeter readings, so the placement of the altimeter bay is such that there will be minimal wind turbulence from the nose cone and fins. Radio Recovery: A Com Spec AT 2B radio transmitter that is small enough to fit easily within our payload electronics bay will be used. Figure 15: Recovery device schematic The device will use the paired radio finder to do long distance location of the payload after it has landed. Once the team is close enough to see the payload, the paint style should allow for easy identification and recovery. 20

21 Launch Vehicle Paint: The paint on the rocket will be a fluorescent with reflective helical stripes painted over the top. This will make the rocket incredibly easy to find and track visually. Analysis of Current Item of Function Analysis of Item of Function After Actions Taken Item or Functi on Potenti al Failure Model Potenti al Effect(s ) of Failure Sev erity Potential Cause Expe cted Occu rrenc e Preventative Recommende d Action Comp letion Acti on Tak en? New Severity Battery Batteries too weak, or fail. The altimeter batteries will not allow the ejection charges to fire 10 Too much testing, forgetting to replace or mislabeling used and unused batteries 3 Maintain a log of battery usage, check voltage using a voltmeter Will keep an extra set of batteries on hand Parachute s Payload parachute fails to eject With no parachute the payload will crash 10 Improperly packed or design failure 3 Testing, practice runs, half scale rocket test Parachute parachute fails Parachute ejects but gets tangled or snagged or is destroyed during some point 7 10 Improperly packed, design failure, poorly chosen material 3 Testing, practice runs, half scale rocket test 21

22 Rocket loss Failure to recover rocket Radio receiver fails or rocket is lost in the terrain 8 Battery failure, bad launch, luck 3 Paint in noticeable colors for snow will maintain visibility in regular terrain. keep good batteries for transmitter, make sure transmitter is in good working order and not blocked by other components Mission Performance Predictions For thrust curve see thrust curve in description of chosen motor Figure 16: Total motion vs. Time 22

23 Figure 17: Drift Analysis at 5mph Figure 18: Drift Analysis at 10mph 23

24 Figure 19: Drift Analysis at 15mph Figure 20: Drift Analysis at 20mph 24

25 Figure 21: Drag Coefficient at 5mph Launch Concerns and Operational Procedures Folding Parachutes 1. When the parachute is folded in a half circle, at least 3 team members begin to lay out the chute. 2. One person holds the lines to prevent them from becoming tangled. 3. The other two individuals hold the parachute along the folded edges. 4. The chute is folded in half three (3) times. 5. Starting from the top, it is folded into thirds by folding the tip of the chute to the middle, then folding down again. 6. The chute is placed into the bag. 7. The chute s rip cords are connected to the large quick link in the middle loop of the main shock cord. 8. On the top of the chute, but still in the bag, the parachute rip cords and some of the shock cord are carefully placed, to ensure they do not become tangled. 25

26 Parachute Assembly in the Rocket 1. The appropriate side of the main shock cord is attached to the fin can. 2. The appropriate side of the drogue shock cord is attached to the payload bay. 3. The main bag is attached to the bottom of the altimeter bay. 4. The drogue bag is attached to the bottom of the payload bay. 5. The rocket is pushed together, slowly. Altimeter Bay 1. The altimeters are calibrated, making sure that all parachute deployment numbers are correct. 2. Two (2) new 9 V batteries are placed on the altimeter board and secured. 3. Charges are placed in the charge cups, threading the electric matches through the holes. The charge for the main is placed on the bottom altimeter bay cup. 4. The charge for the drogue is placed at the top of the altimeter bay cup. 5. The wires are connected to the altimeters, making sure the positive and negative wires are in the appropriate places. 6. The batteries are attached. 7. The altimeter board is secured in place with wing nuts. 8. The area is cleared of unnecessary personnel and the continuity is checked by using the switch on the exterior of the rocket. If there is good continuity, two (2) beeps will be heard after the initial set of beeps. If the continuity is not good there will be double beeps after the initial set of beeps. 9. The appropriate side of the main shock is attached to the bottom of the altimeter bay using a large quick link. 10.The appropriate side of the drogue shock cord is attached to the top of the altimeter bay using a large quick link. Motor Preparation Motor Assembly 26

27 1. The booster section is attached to the main rocket. 2. The motor is placed into the metal casing, making sure the motor is placed fully in its casing and the motor closure is tightened 3. The casing is inserted into the motor mount tube 4. The rocket is secured with the motor retainer and three screws 5. The red safety cap is left on until the rocket is placed on the launch pad Safety and Enviroment (vehicle and AGSE/Payload) Potential Failure Modes and Effect Analysis of the Rocket For safety tables and discussion in regards to the launch vehicle and the AGSE, please see the respective sections. Potential Failure Modes of the Propulsion Systems Propulsion Risks Propulsion Mitigations Status Propellant failure would cause the delay of the launch. Motor casing failure can cause the rocket to burn up or not reach anticipated height and would cause a delay of the launch. Igniter failure could cause a delay in the launch because either the igniter burned out or was not connected properly to the system. If the Motor mount fail to do its intended job, the motor could fly out the top of the rocket and cause the rocket to have a rapid deconstruction mid flight Double check prior to launching Double check the structure of the motor casing prior to installing the engine in to the rocket Double check it to be fully installed prior to launch and if the ignition does burn out wait the approved time before approaching the rocket to replace the igniter. Check that the mount is properly installed during construction and installation. 27

28 Reloadable motor rocket system failure could stem from the propellant not fitting properly in to the motor casing and could fall out the back. Make sure that the propellant cells are of the right size and fit properly into the casing without sliding on launch day Potential Failures of the AGSE AGSE Failure Unscheduled ignition of motor due to errant currents. Battery failure Wire damage Damage of electrical components from heat and force of blast Payload doesn t fall properly into the rocket s payload area Payload Door doesn't completely close Rocket erector failure Mitigation Shielding as well as separating the ignition system as much as possible from rest of electronics Make sure batteries are properly charged and no damage to any of their components Careful inspections of wiring will be done prior to and after launches. Make appropriate blast plates and protection enclosures Careful testing and guide system to insure payload gets properly captured Careful testing in a laboratory environment. Keeping batteries properly charged. When testing, making sure to test a fully loaded rocket to take in account the full rocket payload and not just the safer laboratory usage of an empty rocket. Launch day, and launch travel provide a lot of risks, below is a table outlining some of the risks that could be associated with those events. Launch risks and their accompanying consequence Mitigations for consequences Status 28

29 Traveling failure, like a flat tire would cause the team to arrive late, thus having a late start setting up and launching the rocket Launch failure would cause the rocket to malfunction while on the pad Plan for such events and adjust travel plans in advance if possible Conducting test launches to get all of the kinks out of the system would be beneficial If the incorrect weight was calculated for the rocket the designated height might not be reached along with the safety margin might not be correct Parachute failure would cause the rocket to fall uncontrollable towards the ground Dual deployment failure could cause the rocket to fall faster than desired and potentially have a hard landing Structural damage while traveling down to launch site could cause a recovery failure along with damage to the payload section Motor/Propellant problems could cause the rocket to fail to reach projected altitude or be under powered If there was an ignition failure on launch day it would cause the rocket to stay on the pad during the automated launch procedures Wind conditions on launch day could cause the rocket to drift in dangerous direction towards a group of people Adequate test simulations and rocket components weights taken while building Double check that the recovery system on launch day and how the parachute is folded to make sure it will not tangle Double check the altimeters on launch day to make sure all wires are hooked up correctly Double check the rocket for any damages or cracks on launch day to ensure that the integrity is still there Simulations be conducted to make sure that the correct engine is use and do safety check on launch day to insure the motor is still useable Remove system from power before checking the ignition system to determine cause and if the problem is fixable at launch site. Make sure that the rocket can perform as intended in different wind speeds during simulations 29

30 If the weather is not behaving properly it could cause a launch delay or cancellation of the launch entirely Double check the weather while preparing the rocket so it can perform its job safely under the current conditions, If not met scrub the attempt Material Risk Degree of Risk Impact Mitigation Hazardous Substances Handling Ammonium Perchlorate High High Minor skin or gland irritation, decrease in work performance Minor to serious bodily injury Ventilation, Gloves, proper application of tools ( proper handling of product, briefing of hazardous material effects on the body) Proper use, and certified personnel use only Black Powder High Serious injuries Proper use, and certified personnel use only Power tools Moderate Serious injuries including loss of limbs, blindness Flammable Materials High Fire, burns, damaged equipment Proper handling of tools, use of safety equipment Certified team members only Material Safety Data Sheets The location of where the MSDS.pdf files were retrieved will be listed, as well as the title. It is important to note that these MSDS files have been printed out and are kept in the shop for easy access. They will be updated as new materials are introduced to the construction. The West Systems MSDS files were obtained from the manufactures website. West Systems Epoxy PRODUCT NAME:...WEST SYSTEM 105! Epoxy Resin. 30

31 PRODUCT CODE: CHEMICAL FAMILY:... Epoxy Resin. CHEMICAL NAME:...Bisphenol A based epoxy resin. resin.pdf West Systems Hardener PRODUCT NAME:...WEST SYSTEM 205! Fast Hardener. PRODUCT CODE: CHEMICAL FAMILY:...Amine. CHEMICAL NAME:...Modified aliphatic polyamine. West Systems Hardener CHEMICAL PRODUCT AND COMPANY IDENTIFICATION PRODUCT NAME:... WEST SYSTEM! 404" High Density Filler. PRODUCT CODE: CHEMICAL NAME:... Calcium Metasilicate, silicon dioxide blend. West Systems Fiber Glass CHEMICAL PRODUCT AND COMPANY IDENTIFICATION PRODUCT NAME:... WEST SYSTEM 727 Episize! Biaxial 4 Glass Tape, WEST SYSTEM 737 Episize Biaxial Fabric, and WEST SYSTEM 738 Episize Biaxial Fabric with Mat. PRODUCT CODE: , 737, or 738. CHEMICAL FAMILY:... No information. CHEMICAL NAME:... Fibrous Glass. FORMULA:... No information. Amonium Perchlorate Obtained from Sciencelab.com Product Name: Ammonium perchlorate Catalog Codes: SLA2725 CAS#: RTECS: SC TSCA: TSCA 8(b) inventory: Ammonium perchlorate CI#: Not available. Synonym: Chemical Formula: NH4ClO4 EPA Healthy Indoor Painting Practices 31

32 Translated from the NAR website, under the high powered rocketry safety code, the following information is important both for the scale test flight and full scale test flight. Current plans do not include the use of a motor larger than a L class. Total Impulse (Newton Seconds) Motor Minimum Diameter of Cleared Area (ft.) Minimum Personnel Distance (ft.) H or smaller I J , , K , , , L Source: From the High Power Rocket Safety Code on the NAR website. Minimum Personnel Distance (Complex Rocket) (ft.) As given by these rules, all team members were at least 100 feet away from the rocket at launch during the scale flight, and will be at least 300 feet away during the full scale test flight. This is a strict minimum distance. The team will use a battery to run power from the ignition box to the rocket s motor igniter. The following list contains mitigations towards the High Powered Rocket Safety Codes on the NAR website. 1. Certification. Team mentor Tim Y. is certified within the NAR. He will be present during each and every one of our flights. Tim Y. will handle obtaining the motors for us, as well as assisting in their construction. 2. Materials. The team will use only lightweight materials such as paper, wood, rubber, plastic, fiberglass, or when necessary ductile metal, for the construction of the rocket. Our rocket will be constructed of craft phenolic tubing with birch plywood fins. The AGSE will be of steel and other required building components. See part list, AGSE sections, and launch vehicle sections for a more complete discussion of component materials. 32

33 3. Motors. Proper safety will be observed by our team in regards to the motor, supervised by the safety officer and the mentor. 4. Ignition System. Our rocket ignition systems are electrically separate from the AGSE and will only be able to ignite after the system is at launch position. In case of a misfire, the NAR members present will ensure that the misfire guidelines are followed, as well as the team leaders to ensure that all team members and spectators in the area understand the dangers and will not approach the rocket for any means. 5. Launch Safety. The team will ensure all individuals present at a launch know the dangers present and will treat each flight attempt as a heads up flight. Meaning that, during the countdown and flight, someone will direct everyone to keep an eye on the rocket, and be alert for its descent back to the ground. A deadmans switch to halt all rocket activity during the automated launch procedure will be at hand during any possible issues. 6. Launcher. Our rocket will be launched 5 degrees off of the vertical, and the team will take necessary precautions if wind speed will affect our launch. Dry grass around our launch pad will be sufficiently cleared away. The rail is long enough, and has been simulated, to ensure the rocket reaches stable flight before exiting. 7. Size. The motor being used has 203 lbs of lift off thrust. Our launch vehicle will weigh 26.2 pounds, well below one third of the 203 pound thrust the motor will provide. 8. Flight Safety. Tim Y. has details on our FAA altitude clearance. The team will refrain from launching in high winds or cloudy conditions. There remains many flight paths around Grand Forks due to the UND being a large aviation school. A Waiver and/or NOTAM will be submitted prior to flight to ensure all aviation matters are directed away from our area. 9. Launch Site. Our launch site is of an adequate size for our planned altitude. 33

34 10. Launcher Location. Our launch site is 38 miles West of Grand Forks, ND. This location provides an adequate amount of space to satisfy minimum distance requirements. The agricultural area west of Grand Forks provides miles of flat, barren land. 11. Recovery System. The rocket will use a 36 inch parachute for drogue, and our two main parachutes are a 105 inch and a 38 inch for our motor section and payload recovery respectively, to ensure rocket recovery. The main parachute and drogue parachute will both be placed in flame retardant Nomex bags. 12. Recovery Safety. Power lines are scarce in the vicinity of our launch site, but the team will refrain from recovering it should it happen to land in a dangerous location such as up a tree or tangled in power lines. If such an event happens, the local power company will be notified. 34

35 Environmental concerns Environmental concerns and their explanations. Dissolution of rocket fuel into open water causes contamination of water source. Mitigations Careful planning of launch locations and recovery area. Fume inhalation of hazardous fumes due to proximity to rocket. Ignition produces sparks capable of setting fire to dry grass and other flammable material. Upon recovery, ground destruction may be discovered, such as loose rocket propellant. Potential hazard to wildlife if small rocket pieces are ingested. Rocket ash can have hazardous effects on the ground below the launch pad. Observe proper distances for spectators and keep minimum crew around rocket. Keep flammable material away from rocket and ensure the launch rail is metal. Prior to launch, all rocket components will be checked so that all materials are secured and contained to minimize potential ground damage. Team will function as cleanup crew at impact and launch site to ensure all rocket parts are recovered. An adequate blast shield will be used and when clean up occurs proper disposal of the cleaning materials will take place. 35

36 AGSE/Payload Criteria Figure 22: AGSE with Launch Vehicle (Down Position) Pictured above is our AGSE design. There are three main systems that make up our AGSE. The first is the payload acquisition system. This is where our claw grabs the payload and brings it up towards the rocket where it will be dropped into an opening in the rocket. The next system is for raising the rocket. This is done by a linear actuator that is connected to the frame and rail the rocket is on. The last system is the wire ignition insertion system. This will be done by the wire being fed through two rollers that are guided into the rocket motor. More on each system is addressed below. 36

37 Figure 23: AGSE with Launch Vehicle (Measurements) Frame: Pictured below is a drawing of our frame with dimensions. Our frame s material will be square tube steel. The team chose steel because of its cost compared with other materials and it won t be affected by any heat the rocket will produce during launch. Steel is also heavy enough to be a good base for stability purposes. Figure 24: Drawing of frame with dimensions 37

38 Figure 25a: AGSE with Launch Vehicle (Up Position) The picture above shows the launch vehicle position at angle of 85 degrees from the horizontal. The picture also shows how our linear actuator will be extended. There should be no issue of the launch vehicle tipping because the center of mass of the launch vehicle will be inside the frame at all times while the rocket is being raised.. 38

39 Figure 25b: Basic electrical diagram showing inside electrical box Electrical Box: The black box shown in the picture above houses all the electrical power system and the power sources for the AGSE. Not shown are the terminals connected to the gripper, linear actuator and igniter system. The wires will be be run along the outer rails to each of the component systems, each encased in a shielded wrap. Red will run two wires to the ignition wire system, one wire to the geared servo and a second, shielded again, to the ignition wire. The green wire will run to the linear actuator, and the blue wire to the payload system. The rocket will be using an Arduino Mega 2560 as a microcontroller Board, along with a Motor shield for controlling the gear motor of the linear actuator, the gear motor of the payload gripper, the two servo motors of the payload gripper and the two gear motors for the igniter system. Figure 25c: Arduino Mega 2560 board 39

40 Figure 25d: Arduino Motor/stepper shield from Adafruit The Arduino will also receive signals from the switches on the platform in order to run the different steps of the system. These switches will be triggered mechanically from each system. The team chose to use trigger switches because of its simplicity and accuracy compared to wireless sensors (i.e. sonar, IR). Further explanations on the use of these sensors can be found in the below sections. Sequence Code: Shown below is the sequence diagram that the code was based on. The diagram shows the start and stop points in circles. Each filled in rectangular box is an action, and each diamond is a procedural condition. If a procedural condition is false, an error message is received. All steps pertaining to the launch vehicle and its parts are shown in orange while all AGSE steps are shown in blue. 40

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42 Arduino Code: The arduino code for the AGSE can be found in the appendix on the end of this report. II. PAYLOAD SYSTEM The payload system is made up of a robotic claw attached to a motorized slide rail and a self securing payload bay that is part of the launch vehicle itself. Payload Gripper: The team chose this Robotic Claw MkII from Sparkfun because of its compact size and usability at a good price. The claw itself is composed of steel with a claw span of about 2 inches. Rubber grips on the claw allow it to more easily retrieve the payload. The schematics of the claw are shown below in Figure 26. Figure 26 also includes how the claw mounts onto the servo motor. Figure 27 shows the specs of the servo motor that the team chose as provided by Sparkfun. Figure 26: Robotic Claw (in mm) 42

43 Servo Motor: This is the servo motor (see Figure 27) the team have selected as it is designed to work with the other components of the AGSE. The torque of this servo motor is 2.8kg cm, which is overly sufficient for moving the 4 oz payload and 4.65 oz claw. Figure 27: Servo Details Claw Rotation: The claw will be used to raise the payload from the ground as well as to raise the payload into the launch vehicle. To achieve those motions a second servo motor as detailed above in Figure 27 will be mounted between the claw and the belt. This turn will require the addition of the robotic pan/tilt bracket seen in Figures 28 and 29. Also in Figure 28 you can see the attachment of the claw. 43

44 Figure 28: The Claw Assembly 44

45 Figure 29a:Pan/tilt bracket for the robotic claw assembly. It provide a pivot point for the robotic claw off of the slide rail described below. Figure 29b: claw with pan/tilt bracket Pictured above is the claw and pan/tilt bracket assembly. The assembly has two motors, the first lower one moves the claw left and right. The second motor will open and close the claw. Belt/Slider: The belt slider kit used to raise the claw from the ground to the launch vehicle is the Actobotics Kit Channel Slider Kit which is shown in Figure 30. The linear slider has an overall length of 24 which will be extended by ordering extension parts offered by Sparkfun for this slider to have a final overall length of 36. Each end of the slider has a limit sensor that will alert our microcontroller that the claw has reached either the top or 45

46 bottom of the slider. Also included in Figure 8 below is the motor used to rotate the belt. It is a precision gear motor, 90 RPM and a 6 12V rating. Figure 30: Belt Slider Figure 31: Drawings of Belt Slider 46

47 Payload Acquisition System: Figures 32 and 33 : Rendering of payload system to the top, general dimensions of payload system to the bottom The claw and pan/tilt bracket move along the channel by the belt which is powered by the motor at the end. and figure 32 shows, the claw go down to the bottom to grab the payload, and will then move up the channel until it gets near the launch vehicle. Once by the launch vehicle, it will be able to tilt towards the it and the payload will be able to drop inside and be secured. 47

48 III. LAUNCH VEHICLE ERECTION SYSTEM The linear actuator will be positioned as above in the AGSE. The actuator will be positioned at 30 degrees from the horizontal, or negative x axis, when the actuator is fully compressed. The actuator is attached to two MB1 brackets (shown below) that allow the actuator to change angles during movement to allow easy extension of actuator. A bracket is connected to the AGSE and the launch rail that is wide enough to prevent any damage as the launch vehicle is raised (as shown in Figures 34 36). The linear actuator will extend out until the launch vehicle rail is at 85 degrees. The rocket has two methods to achieve the 5 degree off of the normal as required. The control board can control the actuator to lift for either a certain distance or for a certain time until the 5 degrees is done. As a backup system, a switch placed upon the base of the AGSE, such that when the guiding rail encounters the switch, it will automatically stop the actuator from continuing its lifting. Figure 34: Dimensions of the actuator 48

49 Linear Actuator Calculations: Linear Actuator details: Figure 35: Rendering of Actuator at full extension 49

50 Linear Actuator Appendix Figure 36: MB1 Bracket for the linear actuator The selected bracket to mount the linear actuator to our frame is the MB1 from the table above. Here is a technical drawing provided by Firgelli Automations and the MB1 attached to the actuator. 50

51 Figure 37: Linear Actuator The AGSE will be using a light duty rod actuator. The actuator being used will be the 200 lb model from the table above (FA XX). Also included are several other of the manufacturer's specifications. Figure 38: Shown at left are the MB1 brackets as they are to be attached to the linear actuator on each end. 51

52 Ignition Insertion: The idea behind the ignition insertion device is a smaller and much less violent version of a pitching machine. Instead of propelling a ball, however, our device propels forward the ignition wire. The device uses a single gear motor and a simple series of gears to rotate two wheels at the same speed. The wheels are separated by a distance of.008 inches, the same distance as the diameter of the 32 gauge ignition wire. The gear motor the team have selected runs at 20 rpm. The wire will be spooled in an enclosure to protect it from any damage caused by the launch vehicle. A second benefit to the spooling, is that the only power source connected to the actual wire is the ignition controls, minimizing stray currents from causing an accidental launch. After the wire is fed through the two wheels, it will extend into a funnel, which will guide the wire into the launch vehicle motor. Figure 39: Ignition insertion system As shown above in Figure 39, the wire is spooled in the apparatus on the very end of the rail. Next is two rubber cylinders that will feed the wire forward. The rubber 52

53 material also helps minimize the risk of unwanted electrical charges going through the wire. There is an outer steel box to hold the motor, gears, and rubber cylinders together but are hidden for easier viewing (Figure 41 has the full model). The wire then goes through a funnel which directs it into the launch vehicle s motor. Gear Motor Specification: Figure 40: Gear Motor 53

54 Figure 41: Wire extension assembly The Wire extension assembly is powered by a 51 RPM geared motor. The motor will spin a 16 tooth gear which will be meshed with a 32 tooth. The 32 tooth is then meshed with another 32 tooth gear to spin the rubber wheels. A rubber wheel will be on the same shaft as each of the 32 tooth gears. This will allow the rubber wheels to spin inward or outward together to be able to retract or extend our ignition wire. 54

55 Figure 42: Wire Spool enclosure The wire spool enclosure will house a spool which the wire is wrapped around. It will be free spinning to allow the wire to unravel easily. The enclosure s purpose is to protect the wire, and it will be coated in a non conducting paint to ensure that the wire doesn t pick up stray electric charge. 55

56 Figure 43: Wire funnel The wire funnel s purpose is to guide the wire into the motor. It will be made of steel or aluminum to ensure no damage will be done to it during launch. Payload The loading of the payload will be achieved using the gripper system attached to the AGSE and dropped into the bay. 56

57 The payload will be brought to the capsule by the AGSE. It will be dropped into the opening on the outer surface area of the capsule, passing through the inner tube, through the locking mechanism, and coming to rest at the center of the chamber preventing movement during flight. After this point the payload can only be removed by manually pressing down the locking mechanism while the power is off. Figure 44: Payload compartment (3 D view) The dropping of the payload will trigger a switch that will cause the microcontroller to rotate the inner payload bay (inner tube) to a secure state. The rotation will be between 10 and 45, in order to keep the payload inside the compartment at normal state of the rocket (horizontal). This is an added security measure in case of locking mechanism failure. It also serves the purpose of reducing the coefficient of drag due to turbulence along the capsule. The rotating mechanism will work by aligning two holes cut specifically for the payload. One hole will be cut into the outer tube, the other cut into the inner tube. The only way for the payload to pass through these holes is for them to be fully aligned. This compartment should not be fully airtight since pressure differentials may cause locking of the moving components. 57

58 Figure 45: Payload compartment (rear view) The rotation of the payload compartment will be done by a servo motor (same as for the payload gripper as the torque will not be high because the compartment is coaxial with the outer tube). The microcontroller that will command this will be an arduino UNO. The team might change and choose a smaller Arduino board as it will only be needed to get a signal from a switch and send a PWM signal to the servo motor. The power supply will be given by a Nano Lipo of 3S by Turnigy. 58

59 Safety and Failure Analysis of AGSE/Payload Analysis of Current Item of Function Analysis of Item of Function After Actions Taken Item or Function Potentia l Failure Model Potential Effect(s) of Failure S e v e r i t y Potential Cause Exp ecte d Occ urre nce Preventativ e Recommende d Action Comp letion Action Taken? New Severity Battery Batteries too weak, or fail. Wont be able to completely lift the rocket to its launch position or not able to insert the ignition wire to the required location 10 Too much testing, forgetting to replace or mislabeling used and unused batteries 3 Maintain a log of battery usage, check voltage using a voltmeter Will keep an extra set of batteries on hand Ignition wire ignition wire failure Either ignition system fails to insert, wire fails to ignite 10 Battery might be weak 3 Extensive testing of ignition system, use an inert(or mock) motor as a test Early ignition Wire ignites early causing rocket to launch pre launch ready position High altitude rocket launched semi horizontally becomes a missle. 10 System or design failure. 3 testing for errant current at every stage of building electronic system. Keeping wire inserter separate electrically from system 59

60 until at launch position. Rocket Lift Failure to lift to the ascribed 5 degrees or beyond 90 degrees from the horizontal Failing competition or rocket becomes a missle (see above) 10 Design failure, under or overpowere d lift, misprogram med motor controller 3 Include a dead mans switch at base of AGSE to stop power if lifted beyond the 5 degrees off vertical Payload gripper Loses control of payload and drops before scheduled drop point Not able to secure payload so rocket launch will be a failure Controller error, system failure, battery issues Extensive testing, over select the ability of the payload gripper Payload Bay Payload bay doesn't fully secure payload Possible disruption of the flight of the rocket 8 Controller error, system failure, battery issues stress testing with a range of samples, including lighter/heavier and slight size differences Order of procedures Order of the operating procedures is off (IE, payload door closes before payload is dropped) Severity of effect depends on procedure order, but possible complete failure of launch to minor issues that do not effect launch 1 10 Controller error, system failure, wiring mistakes Include deadman switches, and error control in the programming. Will have multiple people program the controller, ideally should correct any mistake AGSE/Payload Concept, Features, and Definition Creativity and Originality Originally we developed several complex ideas. These designs seemed to demand too much. Our design is simple and practical based on the requirements of the launch. Our core design has not been modified drastically from the first month. The primary concept was the fewer systems, the better. This creates a lower probability 60

61 of failure. We found being simple was the best way to be original. Furthermore, our team has no previous rocket design experience, thus all of our ideas are uninfluenced by previous projects or other s projects. Uniqueness or Significance Each of the project s systems are designed to serve a unique purpose. For example linear sliders are used for many purposes, but we have chosen to attach a claw to it and use it as an escalator for the AGSE. The ignition insertion system is comprised of several parts that work together to perform the function of safely moving the ignition wire into the motor. Our lemonade pitcher design of securing the sample within the rocket is a unique application of that two cylinder mechanism. Suitable Level of Challenge The rocket team has no returning members so there was a significant learning curve to overcome. The team has no previous knowledge of rocketry so learning everything from scratch was very challenging to everyone in the team. The team s advisor informed the team that a automated launch platform has not been done before which adds another whole system to design and test. Science Value The AGSE design objectives mirror that of the NASA SLI requirements of the Maxi MAV in that the system will be automated with failsafes, both remote and onboard, in such a way to capture a payload from a specific point near the AGSE, load into a horizontal launch vehicle, seal the payload bay, raise to a launch ready position, and launch the rocket. As a team, we sought to design a robust system without the need for over complications. Our success criteria, as stated before, matches the NASA SLI requirements of the Maxi MAV. But to restate: Acquisition of payload 61