CYCLONE STUDENT LAUNCH INITIATIVE

Transcription

1 NSL PROPOSAL September 19, 2018 CYCLONE STUDENT LAUNCH INITIATIVE Iowa State University 537 Bissell Rd Howe Hall Ames, IA 50011

2 Table of Contents Table of Contents... 2 Table of Figures... 4 Table of Acronyms GENERAL INFORMATION Educators Technical Advisors Project Lead Safety Officer Student Team Students Participating Organizational Chart NAR Compliance FACILITIES/EQUIPMENT Howe Hall M:2:I Lab Hoover Hall Boyd Lab Test Launch Site SAFETY Safety Officer NAR Compliance Legal Compliance Risk Assessments Materials and Facilities Safety Motor Safety Safety Briefings CySLI Proposal

3 3.8 Caution Statements Safety Compliance Agreement TECHNICAL DESIGN Vehicle Design Summary Motor Mount Airframe Airbrakes Altitude Calculations Recovery System Drogue Parachute Main Parachute Piston Ejection System Altimeter Bay Drift and Impact Energies Motor Avionics Electronic Components Hardware Configuration System Model Software Software Environment Verification Subscale Testing Payload Design Objective Rendering of Proposed Design Orientation Control Mechanisms Design for In-Flight Stability Drivetrain Soil Collection Mechanisms Alternative Soil Collection Mechanisms Electronic Control Systems Chassis CySLI Proposal

4 Anticipated Challenges with Electronic Control Systems Anticipated Challenges with Alabama Red Clay Requirements Compliance Summary Technical Challenges and Solutions STEM ENGAGEMENT Ames High School Computer Class Plus Period Career Fair Girls in Aviation Day Girl Scouts of America FIRST Robotics Boy Scouts Crucifixion Elementary School Women in Science and Engineering STEM Fest PROJECT PLAN Timelines Budget Funding Sustainability CONCLUSION APPENDIX A: RISK ASSESSMENT TABLES Table of Figures Figure 1-1 CySLI Areas of Study CySLI Proposal

5 Figure 1-2 Makeup of CySLI by Year... 8 Figure M:2:I 3D Printers Figure M:2:I Lab Computers Figure Boyd Lab Figure Boyd Lab Figure Safety Compliance Agreement Form Figure Team Compliance Signatures Figure Fin Geometry Figure Fin Flutter Analysis Figure Flight Simulation Details Figure Airbrakes Opened Figure 4-5 OpenRocket Model Figure 4-6 OpenRocket Simulation Data Figure Piston Ejection System Figure AeroTech K1499 Thrust Curve Figure Animal Motor Works K450BB-P Thrust Curve Figure Hardware Configuration Figure System Overview Figure Software Control Flow Diagram Figure Rover and deployment mechanism assembly Figure 4-14 Rotating Plate Figure 4-15 Fixed Plate Figure 4-16 Side View of Rotating Plate Mechanism Figure 4-17 Isometric View of Rotating Plate Mechanism Figure 4-18 Rotating Plate Mechanism with Plates Removed Figure Decision Matrix for Compatible Controllers Figure Decision Matrix for Chassis Material Selection Figure 6-1 Avionics Team Timeline Figure 6-2 Payload Team Timeline Figure 6-3 Rocket Team Timeline Figure 6-4 Safety Team Timeline Table of Acronyms Acronym AGL CAD CDR Meaning Above Ground Level Computer Aided Design Critical Design Review 5 CySLI Proposal

6 CIL CNC DDABS EHS FAA FMEA Ft/s FRR IMU LRR M:2:I MSDS NAR NFPA NSL PCB PLA PWM RSO SO TRA Critical Items List Computer Numerical Control Machine Dynamically Deployable Air Brake System Environmental Health and Safety Federal Aviation Administration Failure Mode Effects Analysis Feet Per Second Flight Readiness Review Inertial Measurement Unit Launch Readiness Review Make To Innovate Material Safety Data Sheet National Association of Rocketry National Fire Protection Association NASA Student Launch Printed Circuit Board Polylactic Acid Pulse Width Modulation Range Safety Officer Safety Officer Tripoli Rocketry Association 6 CySLI Proposal

7 1 General Information 1.1 Educators Matthew Nelson Program Coordinator II (515) Christine Nelson Teaching Laboratory Associate (515) Technical Advisors Gary Stroick TRA Mentor, Tripoli Minnesota (952) Thomas Ward Associate Professor (515) Sheikh Ahamed Graduate Student (330) Becca Salter Previous Project Lead (970) Project Lead Alex Harpenau (608) Safety Officer Alex Sommers (309) *Please note that missing team pictures will be inserted for PDR. 7 CySLI Proposal

8 1.5 Student Team Students Participating Student Major Aerospace Computer Engineering Mechanical Communication Student Year Freshmen Sophomores Juniors Seniors Figure 1-1 CySLI Areas of Study Figure 1-2 Makeup of CySLI by Year Twenty-five students are participating in the project this year. Names and titles of all participating students can be found in the organizational chart in Section As Figure 1-1 shows, our team consists of mostly Aerospace Engineering majors with one student each hailing from majors such as Mechanical Engineering, Computer Engineering, and Communication. Figure 1-2 displays our makeup by student year. Due to M:2:I limiting the number of freshman this year, our team leans older than previous years. We consist of four teams of five, each of which then have a Team Lead, which reports to the Project Lead. Our teams are Safety, Rocket, Avionics, and Payload. Safety Team The Safety Team will rework our safety tables using Failure Mode Effect Analysis (FMEA). They will accomplish this by meeting with each team and going over each subsystem to identify safety risks and failure points. We will attempt to design out all risks identified. For risks that cannot be designed out, we will create a mitigation plan. The Safety team will also create a Critical Items List that will contain all risks that are mission critical. See Section 3 for Safety details. Rocket Team The Rocket Team will oversee the physical design of the rocket. They will model all parts in SolidWorks and complete a manufacturing plan to create the rocket. The Rocket and Avionics Teams will collaborate create the airbrakes and recovery systems, and the Rocket Team will work with the Payload Team to fit the rover inside and create the fail-safe containment system. As stated in section , the Rocket Team will work with the Safety Team to identify risks and possibly redesign based on the risk assessment. Avionics Team The Avionics Team will produce all code for the Dynamically Deployable Air Brake System (DDABS). They will decide upon all electronics for the DDABS and recovery systems. They will also create printed circuit boards for DDABS and recovery to reduce wire clutter in the rocket. The Avionics Team will work with the Payload Team if necessary to bring the rover to full autonomy. DDABS and safety risks in the code and electronics on the rocket are also the Avionics Team s responsibility. 8 CySLI Proposal

9 Payload Team The Payload team will design our experiment this year, which we have decided will be the autonomous rover. They will model it in CAD and create a manufacturing plan to bring it to reality. Working with the Rocket Team, they will design the fail-safe retention system and ensure the rover will fit. They may help the Avionics Team with software or electronics if needed. The Payload Team will also work with the Safety Team to identify risks to people and the mission. 9 CySLI Proposal

10 1.5.2 Organizational Chart 10 CySLI Proposal

11 1.6 NAR Compliance This year, we are continuing our partnership with the Tripoli Minnesota High Power Rocketry Club based in North Branch, Minnesota. They have been operational since 1995 with around 90 members at various levels of high-powered rocketry certification. Tripoli Minnesota is Prefecture #45 of the national Tripoli Rocket Association. CySLI has performed multiple full-scale test launches at their launch field in North Branch in the past and we intend to continue through our subscale launch. 2 Facilities/Equipment Howe Hall M:2:I Lab Hours: Mon-Thu 2-8 pm, Fri 2-6 pm, Sat 10 am - 4 pm The Make to Innovate (M:2:I) Lab is located on the bottom floor of the Aerospace Engineering building, Howe Hall, allowing quick and easy access during all phases of the project. The hours listed cover the hours that a lab monitor will be present and power tools are allowed. To be granted use of the power tools, we must complete a fire safety and personal protective equipment safety training through the university. A record of completed trainings is kept by the M:2:I program to ensure completion. The lab space is open 8 am -10:30 pm to work on any projects that do not require power tools. Major components of the M:2:I lab include a CNC machine, computers, soldering tables, a Formlabs II 3D printer, and two Mojo 3D printers (Error! Reference source not found. and Figure 2-2). This lab space is available exclusively for M:2:I projects such as ours. There is also an adjacent composites lab that is available for use during the hours lab monitors are present. In the past, we have utilized this lab for carbon fiber layups. Figure M:2:I 3D Printers Figure M:2:I Lab Computers Hoover Hall Boyd Lab Hours: Mon-Fri 8 am 7 pm, Sat-Sun 9 am 5pm 11 CySLI Proposal

12 Boyd Lab is in the building adjacent to Howe Hall, which allows easy access during the project. This lab contains heavier equipment such as a band saw and belt sander. To use any of the heavy machinery, team members must pass in-person lab training and an evaluation. If a part is not machinable within our capabilities, we will submit jobs to the technicians. Figure Boyd Lab Figure Boyd Lab 12 CySLI Proposal

13 2.1.3 Test Launch Site For our subscale, we plan to launch at an Indianola, Iowa field as our primary option with a backup date the weekend after in North Branch, Minnesota. While we have not used the Indianola field in past years, it cuts our driving time by more than half compared to North Branch. The Indianola field is used by the Iowa Society of Amateur Rocketeers and has seen many launches in the level two and below range. The problem we have had with Indianola in the past has been the lack of a 1515 launch rail, which then leads us to North Branch. Our fullscale for the past couple of years has been tested at the North Branch site. We plan to return there to test our full-scale again with the 1515 launch rail. 3 Safety 3.1 Safety Officer The Safety Team Lead, Alex Sommers, will act as CySLI s Safety Officer. Alongside the Safety Team, he will work with the Project Lead, Team Leads, and Team Advisors to ensure that team members are safe and compliant throughout the project. The Safety Officer s responsibilities include: Maintain knowledge of local, state, federal, NAR, and TRA laws, procedures, and regulations related to rocketry. Ensure compliance with these laws and regulations. Confirm that all EHS safety trainings (fire, PPE, and machine shop) are completed and that the safety and legal compliance form is read, understood, and signed. Participate in the design, manufacturing, testing, and flight of both subscale and full-scale rockets to identify hazards or compliance infractions and keep team members safe. Mitigate risks through communication with other Team Leads and Project Lead. Handle safety violations reported by Team Leads, including creating mitigation plans, damage assessments, and team member training. Oversee MSDS sheets and risk matrices, which will be used to identify and evaluate risk levels and priority. Provide risk assessment matrices and MSDS forms to all team members and ensure their understanding of each. Provide guidance on professionalism and safety for all team events including educational outreach activities, university sponsored events, and team activities. 3.2 NAR Compliance High Power Rocket Safety Code

14 1. Certification. I will only fly high power rockets or possess high power rocket motors that are within the scope of my user certification and required licensing. Our team mentor Gary Stroick and technical advisor Becca Salter are certified for Level 2 rockets. They are the only team members allowed to handle or arm competition rocket motors. Gary Stroick will purchase and transport the motors for test launches and competition launch. Hayden Hill will obtain Level 1 certification at subscale launch and will be able to handle the subscale motor. 2. Materials. I will use only lightweight materials such as paper, wood, rubber, plastic, fiberglass, or when necessary ductile metal, for the construction of my rocket. Our rocket is constructed of exclusively lightweight materials. See Vehicle Design. 3. Motors. I will use only certified, commercially made rocket motors, and will not tamper with these motors or use them for any purposes except those recommended by the manufacturer. I will not allow smoking, open flames, nor heat sources within 25 feet of these motors. Team safety procedures prohibit unauthorized handling or tampering with motors. They prohibit smoking, flames, and heat sources within 25 feet of rocket motors. Our motor is a certified commercial motor see Motor for technical specifications. All team members who handle motors are required to read the manufacturer s information sheets. 4. Ignition System. I will launch my rockets with an electrical launch system, and with electrical motor igniters that are installed in the motor only after my rocket is at the launch pad or in a designated prepping area. My launch system will have a safety interlock that is in series with the launch switch that is not installed until my rocket is ready for launch, and will use a launch switch that returns to the off position when released. The function of onboard energetics and firing circuits will be inhibited except when my rocket is in the launching position. The ignition system is electrical and the igniters are not installed until the rocket is ready for launch, as outlined in Launch Procedures. The switch returns to the OFF position when released as noted in the manufacturer s instructions for this igniter. The ignition system is never enabled until the rocket is ready to launch (See Launch Procedures). 5. Misfires. If my rocket does not launch when I press the button of my electrical launch system, I will remove the launcher s safety interlock or disconnect its battery, and will wait 60 seconds after the last launch attempt before allowing anyone to approach the rocket. The misfire procedures outlined in the Safety document and launch procedures conform to this rule. 6. Launch Safety. I will use a 5-second countdown before launch. I will ensure that a means is available to warn participants and spectators in the event of a problem. I will ensure that no person is closer to the launch pad than allowed by the accompanying Minimum Distance Table. When arming onboard energetics and firing circuits I will ensure that no person is at the pad except safety personnel and those required for arming and disarming operations. I will check the stability of my rocket before flight and will not fly it if it cannot be determined to be stable. When conducting a simultaneous launch of more than one high power rocket I will observe the additional requirements of NFPA These requirements are met by the Launch Procedures and checklists. The CySLI Safety Officer will ensure that launch safety procedures and checklists are followed at test launches and at competition, in cooperation with NASA s Range Safety Officer. 14 CySLI Proposal

15 7. Launcher. I will launch my rocket from a stable device that provides rigid guidance until the rocket has attained a speed that ensures a stable flight, and that is pointed to within 20 degrees of vertical. If the wind speed exceeds 5 miles per hour I will use a launcher length that permits the rocket to attain a safe velocity before separation from the launcher. I will use a blast deflector to prevent the motor s exhaust from hitting the ground. I will ensure that dry grass is cleared around each launch pad in accordance with the accompanying Minimum Distance table, and will increase this distance by a factor of 1.5 and clear that area of all combustible material if the rocket motor being launched uses titanium sponge in the propellant. Our rocket will be launched from a standard launch rail in a safe area clear of combustible substances. For subscale launch, we will use a made-in-house blast deflector; for full-scale testing, Gary Stroick will provide the blast deflector. In compliance with NSL requirements, our motor does not expel titanium sponges, so we will use the Minimum Distance Table without a multiplication factor to establish a safe launch area. 8. Size. My rocket will not contain any combination of motors that total more than 40,960 N-sec (9208 poundseconds) of total impulse. My rocket will not weigh more at liftoff than one-third of the certified average thrust of the high-power rocket motor(s) intended to be ignited at launch. Our motor, the AMW PRO-X K450BB-P, meets this rule. Its impulse is 1845 and its certified average thrust is Newtons. Our rocket s estimated weight is pounds. See Motor section for more details. 9. Flight Safety. I will not launch my rocket at targets, into clouds, near airplanes, nor on trajectories that take it directly over the heads of spectators or beyond the boundaries of the launch site, and will not put any flammable or explosive payload in my rocket. I will not launch my rockets if wind speeds exceed 20 miles per hour. I will comply with Federal Aviation Administration airspace regulations when flying, and will ensure that my rocket will not exceed any applicable altitude limit in effect at that launch site. Our rocket will never be launched at or toward people and objects. As outlined in Launch Procedures, the Safety Officer will conduct a safety evaluation of the launch area before launch to confirm that no airplanes or other objects are in the rocket s path. In the event of low clouds or fog, test launches will be canceled. Launch procedures will comply with FAA regulations, and apogee calculations must conform to altitude restrictions before launch. 10. Launch Site. I will launch my rocket outdoors, in an open area where trees, power lines, occupied buildings, and persons not involved in the launch do not present a hazard, and that is at least as large on its smallest dimension as one-half of the maximum altitude to which rockets are allowed to be flown at that site or 1500 feet, whichever is greater, or 1000 feet for rockets with a combined total impulse of less than 160 N-sec, a total liftoff weight of less than 1500 grams, and a maximum expected altitude of less than 610 meters (2000 feet). and 11. Launcher Location. My launcher will be 1500 feet from any occupied building or from any public highway on which traffic flow exceeds 10 vehicles per hour, not including traffic flow related to the launch. It will also be no closer than the appropriate Minimum Personnel Distance from the accompanying table from any boundary of the launch site. According to these regulations and our Launch Procedures, we will ensure a clear launch area that meets the requirements. We plan to test launch our subscale and fullscale rockets in large open fields in North Branch, MN, or Indianola, Iowa. See Resources for details about our planned test launch site. 15 CySLI Proposal

16 12. Recovery System. I will use a recovery system such as a parachute in my rocket so that all parts of my rocket return safely and undamaged and can be flown again, and I will use only flame-resistant or fireproof recovery system wadding in my rocket. Our rocket will have a non-flammable recovery system. See Design. 13. Recovery Safety. I will not attempt to recover my rocket from power lines, tall trees, or other dangerous places, fly it under conditions where it is likely to recover in spectator areas or outside the launch site, nor attempt to catch it as it approaches the ground. Our Launch Procedure checklist will specify that the rocket will not fly or be recovered in unsafe conditions. No team member will attempt to catch the rocket or any parts as it comes down. All team members are required to sign the team Safety Compliance Agreement, agreeing to abide by the NAR High Power Rocket Safety Code as well as all team procedures and directions from safety officials. 3.3 Legal Compliance Throughout the project, CySLI will comply with all federal, state, and local laws with respect to the launching of our high-powered rocket and motor handling. According to Federal Aviation Regulations 14 CFR, Subchapter F, Part 101, Subpart C, , no high-powered rocket may be launched: at any altitude where there is more than 50% cloud coverage. at any altitude where horizontal visibility is less than five miles. into any cloud. between sunset and sunrise without permission from the FAA. within 5 nautical miles of any airport boundary without prior authorization from the FAA. in controlled airspace without FAA permission. less than ¼ of the maximum expected altitude. less than 1,500 ft. if there is no person(s) 18 years of age or older charged with ensuring the safety of the launch and has final approval authority for initiating high-power rocket flight. if no reasonable precautions are provided to report and control a fire caused by rocket activities. High powered rockets also require a certificate of authorization from the FAA. To comply with the Code of Federal Regulation, Title 27, Chapter II, Subchapter C, Part 555, our team lead, Alex Harpenau, and Safety Officer, Alex Sommers, are applying for an Explosives Permit from the Bureau of Alcohol, Tobacco, Firearms, and Explosives. This will allow the two members to buy and handle the black powder for the mission. The safety officer has also read and will comply with all the regulations stated in the NFPA 1127 Code for High Power Rocket Motors. Although Iowa (sub-scale test launch site) and Minnesota (full-scale launch site) have no specific safety requirements, all NAR and TRA requirements will be used including launching from a designated high-power rocketry launch site. All launches will require a NAR certified individual and our full-scale launch will be carried out under supervision of our team advisor. 3.4 Risk Assessments This year, our risk assessments will be conducted through Failure Mode Effects Analysis of each component of the rocket and process. After completing FMEAs, we will identify mission-critical risks in a Critical Items List and review them with team mentors. If risk items pass this review, they will be presented to NASA for approval; 16 CySLI Proposal

17 if not, the rocket design will be adjusted to mitigate the risks. FMEAs and CILs will be presented along with design review documents throughout the year. FMEAs and CILs will be presented with PDR. In this proposal, Risk Assessment tables are appended. The risk assessment, outlined in Appendix A: Risk Assessment Tables, documents possible hazards that are posed to us in the manufacturing and testing of the rocket. Understanding the possible causes and outcomes of each hazard helps eliminate negative outcomes associated with the building and use of the project. The probability, risk level, and severity of each hazard are defined as well as solutions to prevent these hazards from ever happening. The following areas are listed in the Risk Assessment tables and will undergo FMEAs: Lab and Machine Shop Rocket Avionics Payload Environmental Hazards Subscale Build Procedure Full-Scale Build Procedure Outreach Bottle Rockets The FMEAs will identify all critical failure modes and their causes for each component of the rocket and payload, along with mitigations and/or design changes. The Safety Team will use the following process to analyze each component: 1. Review design with team members and obtain a system overview 2. Analyze failure modes 3. Determine effects of each failure mode 4. Determine criticality of each failure mode 5. Determine whether design changes are needed 6. List critical items 7. Review critical items with team mentors and NASA panel 3.5 Materials and Facilities Safety All CySLI team members have taken required safety trainings to begin work in all Iowa State labs. These include Fire Prevention and Personal Protective Training. The M:2:I program has documented these trainings by requiring them to be complete for the class. All members have agreed to follow all rules and instructions from lab monitors and use safe judgement under Team Lead supervision during build phases. The Iowa State Laboratory Safety Manual, which is accessible online and in-lab, contains the rules with which to abide by in the lab. Some of the rules that must be followed include: wearing Personal Protective Equipment when working with laboratory hazards, keeping aisles and work spaces clean and unobstructed, and specific precautions related to hazardous chemicals or flammables. Additionally, once in the lab, all students working with dangerous equipment or chemicals must read applicable Material Safety Data Sheets and warning labels, which are all located within the lab. Finally, the Safety Officer or a qualified Team Lead will be present during scheduled lab times to make sure all safety measures are being followed. 17 CySLI Proposal

18 3.6 Motor Safety We intend to purchase our chosen rocket motor from the online vendor, Apogee Rockets. Due to Iowa State University s Risk Management policies, motor purchase and handling will be done by our mentor, Gary Stroick. Our program adviser, Matthew Nelson, will serve as a middleman to handle the funding aspect of the purchase process. Our motors for the subscale and full-scale test launches will be shipped to Gary Stroick, who will serve as the range safety official on site for our test launches. In both processes of transit, motors will be properly stowed according to safety standards by officials well accustomed to regulation. Apogee Rockets will designate the package as hazardous material domestic shipping, considering the explosive potential of a class J, K, or L motor. This will be accompanied by a Hazmat fee on top of the original shipping cost, which is included in our budget. 3.7 Safety Briefings Several risk assessment matrices will be used to identify, react to, and mitigate hazards to CySLI team members. Alex will work with Team Leads and team members to find safe solutions to any issues that may arise concerning team conduct, rocket build, testing, and launch preparation scenarios. Any issues will be addressed using these tables to evaluate risk levels mitigation techniques. Alex Sommers has prepared a safety briefing and Safety Compliance form that every team member of CySLI will hear and agree to. Team Leads will maintain the safety codes and agreements; Alex Sommers and the Project Lead, Alex Harpenau, will handle any infractions. The safety briefing includes chemical, material, and machinery precautions, hazard scenarios, and response plans. It will be presented again before subscale build begins. We will also conduct pre-launch briefings reviewing safety and launch checklists. EH&S Fire Safety Training and Personal Protective Training are required online trainings for CySLI members. M:2:I has tracked these requirements and will enforce all safety precautions. 3.8 Caution Statements Our team checklists and procedures will include warning statements about urgent safety risks, including PPE requirements and chemical/explosive warnings. These warnings will be marked in large, red, boldface type, and include warning symbols: Caution! Put on safety glasses before starting belt sander. We will use our FMEAs, CILs, and Risk Assessment tables to determine where caution statements are necessary in procedure documents. 3.9 Safety Compliance Agreement All team members have signed the Safety Compliance Agreement form. The form can be seen in Figure 3-1, while the signatures are displayed in Figure 3-2. The Safety Compliance Agreement form states that all team members will maintain a safe environment and will follow directions when necessary to maintain that safe environment. It also states that all team members will abide by all federal, state, and local rocketry laws along with requirements put forth by the NASA Student Launch Handbook. 18 CySLI Proposal

19 19 CySLI Proposal Figure Safety Compliance Agreement Form

20 20 CySLI Proposal Figure Team Compliance Signatures

21 4 Technical Design 4.1 Vehicle Design Summary This year, the team has decided to build a minimum diameter design. The length will be 114 inches long and weigh 244 oz or pounds. The stability of the rocket is 2.29 calibers measured at 52 ft/s. The rocket is divided into three separable sections during flight, which will be nose cone, altimeter and payload bay, and empty parachute bays. Upon landing, main parachute deflation, and the approval of the Range Safety Officer, the main parachute bay will separate from the altimeter and experimental bay allowing the rover to exit the airframe. Our current projected apogee in OpenRocket is 5893 feet with the Animal Works K450BB-P which is under the 6000-foot ceiling. The nose cone is a 5.5:1 Von Karman with an overall length of and a 3-inch shoulder. It will weigh 1 pound. It is made of filament-wound fiberglass and features an aluminum tip. The motor mount section will be 21 inches long and 3.1 inches wide. Our motor retention system will be mounted in this section. More information on the motor retention can be found under Section The fins will be attached to the motor mount with JB Weld steel epoxy and will have a fiberglass fillet. The drogue parachute bay will be 30 inches long. It will hold the parachute that will be deployed at apogee. More information about the parachute we will be using can be found under Section 4.3. The altimeter bay will contain all required avionics for flight of the vehicle as well as the air brakes. It will be a minimum of 7 inches long, consisting of 3 inches of coupling on each side and a 1-inch switch band. Currently, the fore bulkplate will be shared with the payload bay. The main parachute bay will be 47 inches long. It will hold the pilot, main parachute, and payload bay. More information about the parachute we will be using can be found under Section Motor Mount Our launch vehicle will contain four G10 fiberglass fins placed symmetrically around the airframe. G10 Fiberglass is much stronger than any wood combination, but not as strong as carbon fiber. However, fiberglass is much cheaper to buy in stock sheets and is much easier to work on. Since we are building a minimum diameter rocket, we cannot mount the fins using the through-the-wall technique as we have done in the past. To ensure the fins are securely attached, the motor mount will be roughed with sandpaper to increase epoxy grip on the surface before using JB weld to attach the bottom of the fin to the airframe. This will be allowed to cure in a jig that is will be designed. Then, fillets will be created by laying up fiberglass sheets against the airframe and fin. The desired radius is 1/8th inch on both sides of each fin. We will investigate the maximum temperature of the fiberglass and its epoxy before PDR to ensure it will hold its strength near the high heat of the engine. In Figure 4-1, the dimensions used for our FinSim simulation are shown. The airbrakes will have an actual thickness of 1/3 rd inch, but the panels will be of 1/8 th inch G10 so 1/8 th inch is the value used. 21 CySLI Proposal

22 Figure Fin Geometry Given the dimensions shown in Figure 4-1, Figure 4-2 displays the results of the analysis in FinSim. The divergence velocity ( ft/s) and flutter velocity ( ft/s) are both well above the speed of sound ( ft/s at standard atmosphere) which the rocket will not approach. Figure Fin Flutter Analysis Because the motor needs are not final, the motor retainer design needs to be one that can be adapted. Our initial selection of the AeroPack 75mm minimum diameter motor retainer is not adaptable to changing motors. The current motor is from AMW PRO-X which does not always follow industry standards for hardware such as thrust ring size. Most AMW PRO-X thrust rings are larger than a comparable AeroTech or CTI motor. 22 CySLI Proposal

23 We are choosing to make our own to have the ability to change the threaded rod length and diameter. The motor retainer system we will be making is effectively the same design as the AeroPack system except it will seal the motor tube from the rest of the rocket and it will have a threaded rod that will match the motor casing. This will be epoxied into the airframe with AeroPoxy because of AeroPoxys high strength to weight ratio. The body will be machined from a cylinder of aluminum and have threaded sections on its outer diameter to add hold for epoxying like AeroPack s. The motor mount section will be made of a fiberglass wrapped tube designed for use as a motor mount from AMWPro-X. It has a mass of 16.1 oz for 34 inches. This will be cut to 21 inches which lowers its weight to 9.94 oz. The outside diameter is unknown, but will be determined by PDR. This material will be thicker than our carbon fiber tubing, so we will sand a taper from the leading edge of the tube to the attachment point. Our velocity at rail exit, based on when the foremost rail lug leaves the rail, can be seen in Figure 4-3 to accelerate above 52 ft/s in 66 inches for all potential engines. Our foremost rail lug will be placed on the switch band for the altimeter bay, 40 inches fore of aft end of rocket. We would be able to use an eight foot or 96-inch 1515 rail. Figure Flight Simulation Details We will use removable metal rivets to connect sections that are not designed to separate in flight. This will allow us to access these parts of the rocket before and after flights. One part is epoxied into a drilled hole in the airbrake bay while the other is epoxied into a drilled hole in the motor mount. These will be aligned so that the orientation of the rocket is consistent on every flight Airframe The exterior airframe of the rocket, excluding the motor mount, will be made of a Roll Wrapped Twill Carbon Fiber Tube from DragonPlate This material was chosen for its high strength, thin walls, and precision construction. This specific brand was chosen for its cost and thickness. This material will not be used for the motor mount due to its maximum temperature being 250 degrees F provided by the manufacturer. The maximum motor casing temperature is 392 degrees F as stated in National Fire Protection Association 1125: Code for the Manufacture of Model Rocket and High Power Rocket Motors contains the testing requirements for all hobby rocket motors. The preliminary coupling airframe material will be blue tube. Blue tube is a cheap and easy to work with material that is thicker than the exterior surface. Fiberglass was also an option. It has an average price, but the options available are much thicker than blue tube. Carbon fiber is expensive, hard to work with, and hard to find many options with an outer diameter of 3. These considerations will factor into our final choice for the airframe coupling. 23 CySLI Proposal

24 The bulkplates will be made of Finnish Birch for its quality, availability, and cost for all uses in the rocket. Some sections will likely have differing thickness to better control the stability and center of mass of the rocket. The bulkplate in the nose cone shoulder will be connected with rivets or a threaded system to allow access to nose cone for ballasting pre-launch if necessary. The main parachute bay will have an epoxied bulkhead 11 inches from the aft end of the bay. The bulkhead will have deployment charges for main parachute on fore side and servo on the other. This servo is connected to a disk that has rods and springs perpendicular to airframe. This mechanism connects the main parachute section to the payload section and altimeter section without shear pins or rivets. During flight, the springs act as a failsafe mechanism to connecting the sections. Upon landing, deflation of main parachute, and approval from the range safety officer, a radio signal will be set to servo to pull rods inward and a few seconds later, a black powder charge will fire to separate main parachute body from payload and altimeter section. The payload bay will house the main experiment and all electronics required for completion for the payload part of the competition. It will be five inches long, located immediately fore of the altimeter bay. The experiment bay will be deployed after landing by a black powder charge and will then deploy the rover. Further information on the rover experiment will be laid out in the Section 4.7. The nose cone for the launch vehicle will be fiberglass with an aluminum tip. It will be a Von Karman shape with a 5.5:1 length to diameter ratio for minimal drag and best efficiency cutting through the air. The entire nose cone is 16.5 inches long and 3.1 inches wide at the base. The aluminum tip is inches long. The entire nose cone weighs 1 pound with the coupler installed Airbrakes The airbrake bay will be 10 inches long and made of blue tube. It will hold the electronics to calculate the trajectory of the rocket during flight and deploy the airbrakes when necessary to reach the desired altitude. CFD analysis techniques will be used to determine drag coefficient at max deployment, how much force is required to deploy the airbrakes, and the optimal location of static portholes so that the altimeters see the current pressure. Over two meetings, the rocket team brainstormed and designed the airbrake system. The final ideas were: having a servo push out surfaces from the interior on rails a roll control system a fin that would be compressed lengthwise to increase its effective area The team decided against the servo pushing out surfaces perpendicularly because it would experience high friction with the slot it would come out of. The roll control was decided against because of its inefficiency compared to the other systems and could become uncontrollable. The fin concept is not perfect either because the fin cannot lay straight because it will lock in place and be unable to deploy. This can be overcome by having the minimum deployment skew from parallel with rocket body. In the final design, the fore cylinder is fixed either by epoxy or with a latching mechanism. This latching mechanism would allow us to remove the bar for repairs if needed. The lower bar is connected to the top bar by compressive springs that enable the system to fail closed. The lower bar is also connected to a bar that is attached to a servo arm on the other end. 24 CySLI Proposal

25 Connected to the aft most bar is a cover for the hole so airflow entering the airbrake bay is less turbulent. This should limit erroneous altimeter readings. Linear actuators were explored, but the options we considered are not strong enough, not small enough, or not fast enough. The exterior panels will be made from G10 fiberglass sheet, have collars on one end to allow rotation about bar, and be connected to the other panel with a small hinge. These will be cleaned and lubricated before flight. Each fin set comprised of two fins and we will have the two sets mounted perpendicularly and offset vertically. The second set of airbrakes will be lower than the first as the servo for the first set will be mounted on the bar of the second. The arbitrary distance between the two bars at rest was set at two inches and the max deployment was set as a half inch of travel for the lower bar. The height was set to one inch to get an area that we could use to reference against max drag of rocket with no deployment. These values were chosen so the CFD model can be run sooner to determine the position of static portholes. Figure 4-4 shows the full deployment position of the airbrakes that is being used in CFD. Figure Airbrakes Opened 25 CySLI Proposal

26 4.2 Altitude Calculations Figure 4-5 and Figure 4-6 show our OpenRocket model and simulation data. Our current projected apogee with the K450BB-P AMW PRO-X motor is 5893 feet. Figure 4-5 OpenRocket Model Figure 4-6 OpenRocket Simulation Data 4.3 Recovery System The recovery system used will feature a dual deployment system, redundant altimeters from different brands that fire separate black powder charges for each parachute, and reefed parachute deployment. All recovery electronics will be independent and have limited effect on all other systems within the launch vehicle during flight. We will have large spaces between wires of different systems and a copper tape lined altimeter bay. One altimeter will be a Stratologger and the other will be from a different brand to prevent inherent design errors. The altimeters will be armed with separate key switches that prevent in-flight disarmament Drogue Parachute The drogue will have a diameter of 12 inches. It will deploy at apogee and slow the rocket to an estimated 98 ft/s until arrival at 600 ft AGL for the main parachute deployment. It will be attached to a shock cord that leads to its piston. The exterior section of the drogue bay will be 30 inches and will be located in the section of airframe aft of the avionics bay and fore of the airbrakes bay. 26 CySLI Proposal

27 4.3.2 Main Parachute The main will have a diameter of 48 inches and will be guided by a pilot chute of 18 inches. The pilot is larger than the drogue to pull the main parachute above the drogue. We expect a decent rate of approximately 19 ft/s upon deployment with individual impact energies of each section being less than 75 ft-lb. The main parachute will be attached to a shock cord that attaches to its piston. The exterior section of the main parachute bay will be 25 inches long and will be located in the section of airframe above the altimeter bay and below the nose cone Piston Ejection System The piston ejection system will feature a low friction coupler and bulkhead assembly that, upon detonation of black powder, will supply enough force to separate desired sections and deploy the main and drogue parachutes out of their respective housings. This system was chosen to capture more gases, limit the need for parachute protectors, decrease the amount of black powder required, and prevent zippering. It is attached via a heat resistant strap that is epoxied to the piston one on end and the body on the other. The strap will go through a slot in the piston to a D ring and then threaded back through and epoxied to underside of this bulkplate. This two-step process can be seen in Figure 4-7 from Public Missiles LTD, who use this system on all the kits they design. Figure Piston Ejection System Shear pins will be used to hold inflight separation points of the rocket together until each deployment event. Upon finalization of design and prior to the first subscale launch, we will perform several ground ejection tests to ensure the reliability of this ejection system. We are considering the deployment of our main at a relatively high velocity of around 100 ft/s. Although a pilot chute will be used during the deployment of the main, it will 27 CySLI Proposal

28 be important for our team to evaluate strength of any parachute linkages, stitching methods for attaching shock cords to eyebolts, knots used for shock cords, and shear capabilities for bulkheads and eyebolts. We will be using a deployment bag and a reefing device to decrease the snatch forces. We will need 0.8g of individual black powder charges for drogue and main deployment. It will still be important to test the system multiple times. This is to ensure proper shear pin sizing and required mass of black powder for both parachute bays. Hardware required for one piston system: Nylon Strap.75 from PML 4in length coupler of Blue Tube Finnish Birch Bulkhead Two powder canisters D ring Kevlar shock cord #1500 Barrel Swivel Kwik Connect Oval ¼ U-bolt on altimeter bulkhead or Payload separation bulkhead U-bolt on Nose cone shoulder or Airbrake bay Main Parachute section from Altimeter Bay to Nose Cone: Black Powder Canisters U-bolt PML nylon strap Coupler section Bulkhead D-ring Kevlar shock cord Alpine butterfly knot Kwik connect Barrel swivel Parachute (in deployment bag with a pilot chute (which must be larger than drogue)) On the other side of alpine butterfly knot: shock cord, u bolt. Drogue section is identical without deployment bag and pilot. Piston Fit: Must be able to be pulled out with light tug on cord. Push all the way into airframe without forcing. Before putting parachute in, add talcum powder all along inner diameter to smooth walls Altimeter Bay The altimeter bay will be responsible for the staged deployment of the parachutes. It is a separate entity from any other on-board electronic system and is located in its own section of the rocket. It will be fitted with U-bolts on either side of its outer bulkheads for attachment of shock cords. They will also be mounted on Finnish birch plywood sleds capable of holding at least two altimeters and batteries for redundancy, reliability and safety Drift and Impact Energies Upon descent, shock cords will tether all sections of the rocket together. This will ensure that all sections are under the influence of the parachute respective to each deployment event and moving with the same descent velocity. With this constraint and using the known drogue and main descent velocities as well as 28 CySLI Proposal

29 our altitudes at apogee and main deployment, range as a function of crosswind speed is then calculated using the following method: Equation Drift Calculations In a similar fashion, impact energies for each individual section of the rocket are calculated using the following method: 29 CySLI Proposal

30 Equation Impact Energies 4.4 Motor This year s motor initial selection was the AeroTech K1499. Since we decided to go with a minimum diameter rocket the weight reduction meant we could use a much smaller initial motor. It has a diameter of 75.0 mm and a length of 260 mm. The total weight is 1741 grams with a burn time of 0.88 secs. It has a total impulse of Newton-seconds of impulse with an average thrust of Newtons and a maximum thrust of Newtons. Below is a graph of Thrust to Time during an average flight with the motor. The formula is Warp-9. We instead chose the Animal Motor Works K450BB-P motor. It has a total impulse of 1845 Newton-seconds and an average thrust of 464 Newtons and a maximum thrust of 661 Newtons. This is 44% higher than the minimum K impulse of 1280 and is 35.5% of maximum allowed impulse. It has a total mass of grams and will burn for 3.97 seconds. It has a diameter of 75.0 mm and a length of 244 mm. The main reason for switching motors is that the K450 gives us a much higher apogee which gives us more room to work with regarding weight. It also has a much lower average thrust which puts less stress on the vehicle. Below is the thrust curve of the motor. It is Animal Motor Works Blue Baboon propellant. We also considered the Animal Motor Works K470, K365 and K500. We did not use them because they were not as efficient and resulted in an apogee that was too low for our rocket. They also had a thrust to weight ratio that was low and would cause the rocket to be unstable during flight. 30 CySLI Proposal

31 Figure AeroTech K1499 Thrust Curve Figure Animal Motor Works K450BB-P Thrust Curve 4.5 Avionics Electronic Components Our drag-inducing airbrake system will be controlled by a microcontroller which processes flight data in realtime and calculates the predicted apogee and modifies the drag if the apogee is too high. This year we will be using the Teensy 3.5 as our flight computer because of its powerful ARM processor and small physical footprint. With a form factor of 2.5 by 0.7, it takes up 79% less space than our previous computer, the Arduino Mega 31 CySLI Proposal

32 2560. Teensy boards are compatible with the Arduino programming environment and with most of the software written for Arduino devices, allowing us to easily rebase our established software for this year s airbrake system. The Teensy s 120MHz clock also gives us 87% more processing power for faster calculations midflight. In addition, we plan on using the following hardware with the Teensy: Hardware Description Brand Model Accelerometer Bosch BNO055 Barometer / Temperature Bosch BMP280 GPS Receiver Adafruit Ultimate GPS Breakout (Tentative) Transceiver Adafruit RFM95 Battery TBD 5V max voltage, TBD Table Flight Computer Hardware The Bosch BNO055 is an Inertial Measurement Unit (IMU) with 9 Degrees Of Freedom (DOF). It combines data from its accelerometer, gyroscope, and magnetometer to generate a variety of kinematic measurements like acceleration vectors, gravity vectors, and absolute orientation. All this data can be fetched at a max rate of 100Hz, or 100 times every second, which is more than fast enough for our calculations. This sensor allows us to measure the vertical acceleration of the rocket to determine current velocity as well as trigger various software events. The BMP280, also made by Bosch, is a barometric pressure sensor that will be used to get the current altitude of the rocket. This data is used in calculating the estimated altitude as well as various software events, such as a safety mechanism to only turn on the brakes after motor burnout has completed. It has a relative pressure accuracy of ± 0.12 hpa, which is equivalent to ±1m. For our GPS module, we have chosen to use the Adafruit Ultimate GPS Breakout. This module was chosen because it boasts excellent specs and is easily connected to the Teensy 3.5. The module takes up little space with a size of.6 x.6 x.16. It also provides exceptional accuracy with a position accuracy of <10 ft. The GPS is powered by a VDC input, so it will be powered by connection from the VIN port on the GPS module to the 3.3V on the Teensy board. It will then transmit and receive data with the microcontroller via the Tx and Rx ports, respectively, as seen in Figure GPS data will then be parsed using the TinyGPS library and logged to the microsd card. We will also be using an onboard transmitter to transmit GPS data from the rocket to a receiving unit on the ground. The electronics above were chosen based on three criteria: size, accuracy, and software support. Since the Teensy is not official Arduino hardware, most library support for sensors comes from community contributions. All current sensor choices are well-documented and widely-used, making it easy to find resources to help utilize them with the Teensy Hardware Configuration In the past, our airbrake computer system was connected with simple jumper wires to provide data, power, and ground connections. However, this year we plan to design and produce a custom PCB to control the mechanical airbrake system. The PCB provides many benefits for the project, including a reduced spatial footprint within the rocket, and a flexibility of design that allows us to integrate all necessary components with more organization than before. The PCB also offers more durability in its compact design and it decreases the risk of 32 CySLI Proposal

33 damage or dislodging during launch or movement as there are fewer loose wires connecting components. The PCB will incorporate the GPS [Ultimate GPS Breakout V3], the barometric pressure sensor [BMP280], the inertial measurement unit [BNO055 IMU], a battery, transmitting device, and the microcontroller [Teensy 3.5]. The PCB will also provide a connection to a servo, which will control the air brakes. Each component will either be connected to the board using female/male headers or soldered into the PCB itself. The entire system will be mounted a sled on threaded rods inside the body of the rocket. Below is an early version of the electrical schematic we will implement: Figure Hardware Configuration 33 CySLI Proposal

34 4.5.3 System Model Figure System Overview Figure 4-11 shows a high-level overview of our airbrake system, including the electronics, software, and mechanical components. The two sensors that we have selected, the BNO055 and BMP280, will be measuring the acceleration and altitude, respectively, of the rocket. The two sensors will connect to the computer via a PCB and the computer program will use derivation and integration to determine the current velocity. An apogee estimation will be calculated using the current velocity and altitude to determine if the air brakes should be deployed. This will be done using a servo motor to actuate the physical brakes. Using these brakes should allow us to reach our desired altitude under any launch day conditions. The planned airbrake design will include variable drag, which will be controlled by the software, described in detail below Software Figure 4-12, shown below, is the control flow diagram of the planned program running during flight. Any words from here on out with parentheses following the word are defined as functions in our code, followed by numbers that correspond to their node within Figure The Setup() function, standard in Arduino IDE code, should initialize all sensors, serial pins, and files on the microsd card. At the end of Setup() will be a safety function, Burnout(). It will check first for positive velocity, which means the rocket is in the air, then for negative acceleration, which means the motor has burned out, hence the name. Burnout will trap the computer in a loop checking until the above criteria have been met. Once motor burnout is achieved, Loop() begins. Loop() starts by taking data from the sensors in UpdateData() [1], giving us an acceleration value from the BNO055 and an altitude or position value from the BMP280. These values can be filtered using a basic Kalman filter by using their previous values along with the assumption there is uncertainty in the measurement to give a real time estimate of the actual current state of sensor. The vehicle s velocity can then be calculated from both the filtered altitude and acceleration using derivation and integration rules to find two values of velocity that will then be fused. 34 CySLI Proposal

35 Figure Software Control Flow Diagram The processed data will run through EndGame() [4] to check for apogee or an abnormal flight, either of which will close the airbrakes permanently and log data continuously if true. Next, velocity and position will be given to ApogeePrediction() [5] to predict the current apogee. If the predicted apogee needs adjustment, ServoFunction() [6], detailed in a paragraph below, should be called to open or close the servo depending if it predicts higher or lower, respectively, our desired maximum height. The current variables will be saved to be used for the derivation and integration functions on the next loop. Finally, the data will be logged to a microsd card using WriteData() [7] and the loop will restart. When ApogeeFunction() needs the brakes to actuate, it will call ServoFunction() [6]. This function combines the opening and closing actions into one using a Boolean variable: brakes, which can only be set to true or false. The brakes will initially set to the closed position. We will also define a maximum degree at which the brakes can be deployed using ServoFunction() [6] With the checks inside of Endgame() [4] and Burnout(), the program will only allow the brakes to be deployed during the upward coast phase of the flight. Not shown in the loop is our GPS code, constantly updating coordinates and transmitting them to our ground unit at a rate of 1Hz. This will provide us with the current latitude and longitude of our vehicle, and will help locate in the case of a large wind drift. A transmitting device with an attached antenna will transmit this data to an identical ground unit only after apogee has been reached, so it does not interfere with the time sensitive calculations made during ascent, like the predicted apogee. This will be done by only utilizing the GPS within EndGame() [6] Software Environment Our software used in the flight computer is written in C++ and compiled for the Teensy 3.5 using the Arduino IDE and the Teensyduino add-on. We use Github which allows for organized version control between team members code contributions. Our program is broken up into two portions, the main program or sketch coded within the Arduino environment, and a generic C++ library called sensors.h. This contains all of our sensor related functions in one central location, which allows for increased portability by letting us use it in multiple test versions of our program. It also lets us change major signal setup variables, such as numerical pin assignments; useful for changing hardware configurations quickly. 35 CySLI Proposal

36 4.5.6 Verification Last year, our team attempted to use Simulink, an add-on for Matlab, to create a hardware-in-the-loop testing environment for our airbrake hardware and software. We were able to create an accurate simulation of the rocket launch and flight, we were not able to communicate with the computer due to limited documentation and resources available on the internet. This year, we plan to increase testing and be more thorough in both hardware and software testing. A modified version of the flight computer software allows us to feed in simulation data from programs like OpenRocket or data saved from our past launches. This variety of data allows software testing for numerous possible scenarios and gives an accurate depiction of how the system will perform on launch day. We will also be conducting unit testing with each of our electrical components to ensure their performance individually and together. 4.6 Subscale Testing The subscale rocket launch will be used to prove the stability and functionality of our rocket s construction techniques and recovery systems. It was designed to use a CTI 2-grain motor casing that was used last year. The length of the rocket will be 38 inches and will have a maximum outer diameter of inches. The total weight will be 14.9 oz. All tubular components will be made of carbon fiber. The nose cone will be made of plastic and weigh.41 oz. The parachute section will be inches long and weigh 3.77 oz. It will contain a piston ejection system and the main parachute. The altimeter bay will be three inches long and weigh about three oz. The altimeter bay will house a Stratologger altimeter and a 9V battery on a Finnish birch sled mounted on threaded rods. The drogue section will be 10.3 inches long and weigh two oz. The drogue section will separate at apogee but will not have a parachute. In OpenRocket, the parachute in the bay is to account for drag from the separation. The airbrake bay will be three inches long and weigh 0.5 oz. The airbrake bay will contain nothing. The motor mount will be 8.23 inches long and weigh oz without the motor. With the motor, the motor mount will weigh oz at launch and oz after burnout. The stability of the rocket is 2.54 cal at 52 ft/s. The main parachute will have an 18-inch diameter elliptical parachute with a coefficient of drag of 1.50 from Fruity Chutes. Because of the high speed involved with drogueless dual deployment, the parachute will be reefed with a small tube at the top of the shroud lines. The planned launch date is Sunday October 21st at the ISOAR monthly club launch with a backup launch date on the 28th at the Southern Minnesota Rocket Club s monthly launch. The material chosen for the main airframe of this year s rocket is carbon fiber roll wrapped twill tubing with a gloss finish at a standard modulus of 33 MSI. This standard modulus is the highest strength on the modulus scale for grades of carbon fiber. In previous years, blue tube was used due to the price and ease of working with. During last year s full-scale launch in the snow, the airframe became soaked in various spots, making for many repairs, reducing the structural integrity of rocket. We chose carbon fiber because of its structural tensile strength and easy availability compared to blue tube and fiberglass. A fiberglass airframe was considered but because of the cost the carbon fiber airframe was chosen and will be a concurrent structure for a reduced cost. The piston ejection system coupler will be made of blue tube because of its cost and availability. The nose cone is a Von Karman fiberglass 5.5:1 nose cone with an aluminum tip from Performance Hobbies. This aspect ratio was chosen to minimize drag on the nose section. 36 CySLI Proposal

37 4.7 Payload Design Objective For the 2019 NASA University Student Launch Initiative, CySLI has chosen to design a deployable rover with a soil sample recovery system. To complete this task, the team must accomplish the following: Design and build a rover that can fit within the diameter of the rocket and be retained if atypical flight forces are experienced Construct a deployment system that releases the rover after a trigger has been activated, and program the rover to autonomously move ten feet from the landing site Develop a collection system that allows the rover to recover and protect a ten-milliliter soil sample after it has reached its destination Additionally, the team must also ensure that the rover s batteries are protected from impact, clearly marked as a fire hazard, and distinguishable from the other rover parts Rendering of Proposed Design Orientation Control Mechanisms Figure Rover and deployment mechanism assembly One of the initial challenges upon the rocket s landing is the orientation of the rover inside the rocket relative to the ground. There will be no guarantees that the payload bay will be upright and the rover will be able to drive out directly; therefore, rotational orientation control of the payload bay will be necessary to ensure proper deployment. The proposed solution involves a rotating plate (Figure 4-14) on a fixed plate (Figure 4-15) in the rocket s payload bay. This system relies on the force of gravity to rotate the rover into the proper orientation. The fixed plate will be made of machined aluminum and have holes drilled in a radial pattern to allow for holding pins to constrain the system s movement during flight. These pins will be released by a servo-powered mechanism upon the receipt of a manual signal from the team s communication station. A screw will then turn, forcing the pin assembly to move away from the fixed plate. This will cause the pins to be released, allowing 37 CySLI Proposal

38 for the plate to rotate freely. The center of gravity of the combined rover and rotating plate will be kept far enough below the center of the profile of the rocket, so gravity will orient the rover before it drives out of the payload bay. Rails on both the fixed plate and the rotating plate will allow for the installation of ball bearings and grease to enable a free rotation upon landing. Figure 4-14 Rotating Plate Figure 4-16 Side View of Rotating Plate Mechanism Figure 4-17 Isometric View of Rotating Plate Mechanism Figure 4-15 Fixed Plate 38 CySLI Proposal

39 Figure 4-18 Rotating Plate Mechanism with Plates Removed Design for In-Flight Stability To combat the forces the rocket encounters during the launch, flight, and landing, the team has decided on including two main features to ensure the payload is secure. The first includes rods extruding from the orientation control plates and through the rover itself. These rods will be loose fitting in order to keep the rover from moving horizontally and vertically. The second feature includes latching servos attached to the backside of the orientation control. Cable will be wrapped around the back chassis of the rover and fed into each individual latching servo. These latching servos will keep a tension in the cables until deployment. The combination of the rod and latching servo system will keep the rover safe during each stage of the flight without obstructing the rover s deployment Drivetrain For the drivetrain system, rover will use a continuous track to maneuver across the terrain. This will ensure that the rover has smaller chance of getting stuck while moving. The drivetrain system will rely on a timed track belt powered by two separate motors. This allows for turning control, which will be necessary for obstacle avoidance and terrain negotiation during autonomous navigation. One method for engaging the track is to use 3D printed spools or sprockets. PLA and ABS are suggested materials, as they are the most common and readily available. Potential concerns include the brittle nature of certain 3D printed parts, as the team has yet to determine what loads will be placed on the drive train. Currently, stretchable rubber and plastic timing belts have been suggested as a possibility for the track. The final decision will be based on what materials will be best able to maneuver through the Alabama soil, which track provides the most traction, and which track will be best at handling repeated stress. 39 CySLI Proposal

40 4.7.6 Soil Collection Mechanisms When deciding on a soil collection mechanism, the team discussed multiple collection methods. The biggest constraint for the rover and its subsystems is the diameter of the payload bay, which will be approximately 2.85 inches. The team decided that a simple and robust design is needed. To collect the soil, the team decided on a scoop mounted in the center of the rover on the bottom. The scoop will be mounted to a hinge fixed to the rover. At the bottom of the scoop, there will be another hinge and a bar leading back from the scoop, which will be attached to a servo behind the scoop. A cap will be used to cover the scoop to ensure that the container is closed when the scoop isn t deployed. While the rover is driving, the scoop will remain inside the frame of the rover and held in place by the servo and bar. Once the rover reaches ten feet from the landing site, the servo will move the bar back, opening the scoop and angling the leading edge of the scoop towards the ground. Once the scoop is deployed, the rover will drive forward to skim the top level of the soil and collect the required ten milliliter sample. Finally, the servo will close the scoop, storing the soil in a concealed container and fulfilling the soil collection requirement Alternative Soil Collection Mechanisms Various soil collection mechanisms were proposed. These designs ultimately were turned down due to their mechanical complexity and larger size. A conveyor belt or elevator was one of the first ideas suggested. To collect the soil, scoops would be attached to a rotating belt that was placed in the body of the rover. The belt would be supported by two pulleys, one of which was powered by a motor. The scoop would be rotated to fit inside the chassis of the rover while the rover is moving. Once the rover reaches ten feet away from the landing site, the belt would be spun, moving the scoop around and underneath the body of the rover to collect soil. A soil collection drill was one of the more complex solutions that the team considered. To collect the soil, once the rover reached ten feet, a drill would be lowered into the ground from the body of the rover and begin spinning. All but the tip of the drill would be housed in a tube so that when the drill was spinning, the soil could travel up the threads of the drill without falling off. The soil would then be collected into a container near the top of the drill Electronic Control Systems For the software component, the team has selected Rover (created by ArduPilot) as a potential platform for development. This was selected because it offers a high amount of out-of-the-box compatibility with a wide range of controllers, motors, servos, and other equipment; therefore, more time will be dedicated to the development of an autonomous control system and less time will be spent on set up. The team has completed a decision matrix (Figure 4-19) to evaluate different controllers compatible with Rover. The main considerations involve sizing (due to the 2.85 diameter proposed by the Rocket team), cost, and ports (both quantity and compatibility with a variety of hardware). 40 CySLI Proposal

41 Figure Decision Matrix for Compatible Controllers Both the F4BY FMU and PXFmini controllers received positive marks due to their size and sufficient standardized PWM ports for motors and servos. Ultimately, the team anticipates that the first criterion will drive the final selection more than the second and third, since the 2.85 inner diameter makes fitting standard controllers and processors, such as the Pixhawk and Erle-Brain, difficult Chassis For the chassis of the rover, the team has used the decision matrix in Figure 4-20 to compare our options. Figure Decision Matrix for Chassis Material Selection Carbon fiber, 3D printed plastic, aluminum, and wood were the first materials considered. Carbon fiber is a lightweight, unyielding, and mildly flexible material; however, it is expensive and would have a lengthy fabrication process. Plastic is a mildly strong, flexible, lightweight material that has a quick fabrication process and is inexpensive. Aluminum is a strong, brittle, and slightly heavy metal that is mildly inexpensive, but it could take quite a long time to fabricate. Lastly, wood is a weak, brittle, lightweight, and inexpensive material, but would take a long time to fabricate. In the rover s chassis, many components need to be fitted within the limited amount of space. There needs to be room for everything that will make the rover function according to the requirements. This includes a soil collecting system to obtain a soil sample, batteries, motors, servos, computers, and a microcontroller Anticipated Challenges with Electronic Control Systems Due to the size constraints of the rocket, it will be difficult to design and build a rover to fit within the space. The Rocket team anticipates that there will be a 2.85 internal diameter for the payload bay. This is due to weight concerns, resulting in the rocket for this year s competition to be half the diameter of those built in the past. 41 CySLI Proposal

42 Fitting electronic control equipment, servos, motors, soil collection equipment, and other necessary components into this frame will require the team to carefully plan the rover s dimensions and will require building the rover with little tolerance for error. At this stage, design for both the rocket frame and the payload is still in its preliminary stages; therefore, the rocket diameter is subject to change if the payload team determines that it is necessary. Team members have suggested a payload fairing as a potential compromise. This would allow for a reduced rocket weight and more payload space. Further consideration of this and other solutions will come after the submission of an initial proposal and will be reviewed at the PDR Anticipated Challenges with Alabama Red Clay Since the exact soil consistency will be unknown until launch day, the team must design the rover s scoop to work in various conditions. Based on past experiences at the competition, the team decided that a clay-like consistency would be the most probable and the toughest of the potential soil consistencies; therefore, the soil collection system must be designed to withstand and successfully collect clay-like soil. One way to mitigate soil collection issues is by taking a sample. Alabama red clay is available on the Internet and sold by weight, meaning that the team could set up a testing area with artificial obstacles, wet soil, and various terrain scenarios. This option will be further considered as the team progresses through the design and building phases. 4.8 Requirements Compliance Summary Requirement: Vehicle 2.1 The vehicle will deliver the payload to an apogee altitude between 4,000 and 5,500 feet above ground level (AGL). Teams flying below 3,500 feet or above 6,000 feet on Launch Day will be disqualified and receive zero altitude points towards their overall project score. Solution The vehicle will use flight computers and an air brake system to reduce the speed of the rocket to reach the target apogee. Our current projected apogee with the K450BB-P AMW PRO-X motor is 5893 feet. 2.2 NA to proposal 2.3 The vehicle shall carry one commercially available, barometric altimeter for recording the official altitude used in determining the altitude award winner. 2.4 Each altimeter will be armed by a dedicated mechanical arming switch that is accessible from the exterior of the rocket airframe when the rocket is in the launch configuration on the launch pad. 2.6 Each arming switch will be capable of being locked in the ON position for launch (i.e. cannot be disarmed due to flight forces). There will be a Stratologger inside the rocket tracking and taking data throughout the entire flight to read the apogee of the rocket. To ensure redundancy there will be a second altimeter on board from a different company to prevent batch error. We will use two key switches, one for altimeter to meet this requirement. A key switch cannot be turned without its key thus locking each switch in the on position. 42 CySLI Proposal

43 2.5 Each altimeter will have a dedicated power supply. We plan to use a store bought 9-volt batteries for each altimeter. All recovery electronics shall be powered by commercially available batteries. 1.4 The launch vehicle shall be designed to be recoverable and reusable. 2.8 The launch vehicle shall have a maximum of four independent sections. 2.9 The launch vehicle shall be limited to a single stage The launch vehicle shall be capable of being prepared for flight at the launch site within 2 hours, from the time the FAA flight waiver opens The launch vehicle shall be capable of remaining in launch-ready configuration at the pad for a minimum of 2 hours without losing the functionality of any critical on-board component The launch vehicle shall be capable of being launched by a standard 12 volt direct current firing system. The firing system will be provided by the NASA-designated Range Services Provider The launch vehicle shall require no external circuitry or special ground support equipment to initiate launch (other than what is provided by Range Services) The launch vehicle shall use a commercially available solid motor propulsion system using ammonium perchlorate composite propellant (APCP) which is approved and certified by NAR, TRA, and/or CAR. The choice in materials for all parts of the rocket will be chosen to survive the maximum landing impact expected from flight. The vehicle will be built in three sections held by shear pins with an additional separation point. There will be a drogue and main parachute that will be ejection charge tested to ensure proper separation during flight. The rocket will be composed of three independent sections during recovery, which will then split into four sections upon radio signal; the motor mount, nose cone, and altimeter bay with parachute sections. The nose cone shoulder is 2.85 inches. Even though the altimeter bay and payload bay does not separate during flight, the coupler length for both sides of the altimeter bay is 3 inches, which is our body diameter. The altimeter bay coupling where the separation will occur is 5 inches which is above what is required. The rocket will be designed to be a single stage and only contains a single motor. The team will have practiced assembly the rocket without energetics prior to launch day to ensure assembly is under two hours. There will be a preflight assembly checklist to ensure that steps are not forgotten. The launch vehicle will have all hardware on and functioning using batteries with capability to power the entire rocket for two hour at minimum at idle with enough spare battery remaining for a safe flight. Tests will be ran before launch day to validate power usage for the rocket. The team will be using igniters designed to be launched by a standard 12-volt direct current firing system. The rocket will not require any external circuitry or special group support equipment to initiate launch. The rocket will be equipped with an AMW PRO-X K450BB-P motor which is certified by the NAR for the fullscale launch. All motors considered are commercially available ammonium perchlorate composite propellant and are certified by the NAR. 43 CySLI Proposal

44 2.15 Pressure vessels on the vehicle shall be approved by the RSO The total impulse provided by a College and/or University launch vehicle shall not exceed 5,120 Newton-Seconds (L-class) The launch vehicle shall have a minimum static stability margin of 2.0 at the point of rail exit The launch vehicle shall accelerate to a minimum velocity of 52 ft/s at rail exit All teams shall successfully launch and recover a sub-scale model of their rocket prior to CDR All teams shall successfully launch and recover their full-scale rocket prior to FRR in its final flight configuration Any major structural protuberance on the rocket shall be located aft of the burnout center of gravity. The rocket will contain no pressure vessels on board. It has a total impulse of 1845 Newton-seconds and an average thrust of 464 Newtons and a maximum thrust of 661 Newtons. This is 44% higher than the minimum K impulse of 1280 and is 35.5% of maximum allowed impulse. Using Open Rocket, our minimum static stability margin is 2.29 calibers measured at 52ft/s which using 1125 ft/s as the speed of sound is 5% of speed of sound. Our minimum velocity at rail exit based on when the foremost rail lug leaves the rail which will be placed on the switch band for the altimeter bay 40 inches fore of aft end of rocket. We would be able to use an eight foot or 96-inch 1515 rail. All potential engines can accelerate to above 52ft/s in 66in. The team plans to have a sub-scale test launch in late October prior to PDR. The team plans to have a full-scale test launch in mid- February prior to FRR in the final flight configuration. All structural protuberances such as the fins and air brakes will be below the aft of the burnout center of gravity The final rocket surface will have contact info on fore section and aft section. Section are determined as fore or aft of payload separation point All teams will be required to use the launch pads provided by Student Launch s launch services provider. No custom pads will be permitted on the launch field. The launch vehicle will be designed to lift off the provided launch pads from the service provider. Requirements: Recovery 3.1 The launch vehicle will stage the deployment of its recovery devices, where a drogue parachute is deployed at apogee and a main parachute is deployed at a lower altitude. 3.2 Each team must perform a successful ground ejection test for both the drogue and main parachutes prior to initial subscale and full-scale launches. Solution The drogue parachute will take place at apogee altitude. Then shortly thereafter at 600 feet, the main event will take place, bringing the vehicle safely to the ground. Calculations and ejection testing will take place well before all the launches to ensure for a safe and successful ejection for the parachutes. 44 CySLI Proposal

45 3.3 At landing, each independent section of the launch vehicle will have a maximum kinetic energy of 75 ft-lbf. 3.4 All recovery system electrical circuits will be completely independent of any payload electrical circuits. 3.5 The recovery electronics will be powered by commercially available batteries. 3.6 The recovery system will contain redundant, commercially available altimeters. 3.7 Motor ejection is not a permissible form of primary and secondary deployment. 3.8 Removable shear pins will be used for both the main parachute compartment and the drogue parachute compartment. 3.9 Recovery area will be limited to a 2,500 ft. radius from the launch pads Descent time will be limited to 90 seconds (apogee to touch down) 3.11 An electronic tracking device will be installed in the launch vehicle and will transmit the position of the tethered vehicle or any independent section to a ground receiver. The maximum descent velocity of the heaviest section of the vehicle will determine the maximum kinetic energy of the rocket. Current calculations show that the highest kinetic impact energy is ft-lbf. The two systems will be connected to four independent batteries, one for each, and one redundant battery for each. Both systems will have separate electrical circuits to initiate and conduct independent functions. The 9-volt batteries will be bought from a standard commercial store. There will be a Stratologger inside the rocket tracking and taking data throughout the entire flight to read the apogee of the rocket. To ensure redundancy there will be a second altimeter on board from a different company to prevent batch error. The motor for our launch vehicle will be securely fastened to the rocket and tested at each launch. The three separate sections of the vehicle will be held together by shear pins to allow for separation upon reaching apogee. The appropriate tests and calculations will be run in Open Rocket to approximate and validate that the launch vehicle will land within the required range. The current recovery range for the rocket is 2,490 ft. Using Open Rocket, calculations and tests will be conducted to estimate the descent time for the vehicle. The current descent time is 76.8 seconds. Our GPS module is the Adafruit Ultimate GPS Breakout. We will use an onboard transmitter to transmit GPS data from the rocket to a receiving unit on the ground The recovery system electronics will not be adversely affected by any other on-board electronic devices during flight (from launch until landing). All electronics will be independent and have limited effect on all other systems within the launch vehicle during flight because we will have large spaces between wires and a copper tape lined altimeter bay. Requirements: Avionics Safety 3.1.2: The recovery system electronics will not be adversely affected by any other on-board electronic devices during flight (from launch until landing). Solution The airbrake computer system will be in a separate compartment from the recovery electronics. Altimeter bay will also use copper foil to block any exterior signals like the transmitting of GPS coordinates. 45 CySLI Proposal

46 2.24.9: Transmissions from onboard transmitters will not exceed 250 mw of power. GPS data transmissions will come from a low power radio configured and tested to operate below the 250mW limit. 4.9 Technical Challenges and Solutions Technical challenges for rocket, airbrake, and recovery design will include designing a safe and reliable rover deployment mechanism, designing a completely repairable airbrake bay, and designing and testing a reefed parachute system. The current deployment mechanism for the rover is challenging because it requires fail-safe servo retractable connection rods and electronic protection. This will be especially important when under the high un-reefed parachute snatch load. To make the airbrake bay repairable, the team will need to design bars to be latched and be able to withstand high loads. This will require many tests to determine factor of safety. The main parachute will currently deploy at 98 ft/s, which will cause the parachute to inflate very quickly and have high snatch forces. One idea to deal with this are to use a sliding tube along shroud lines that will slide down as tension increases in shroud lines. Another involves modifying the parachute to use a permanent skirt line around the lower lip of parachute. This would prevent over-inflation and has been shown to decrease snatch forces. 5 STEM Engagement 5.1 Ames High School Computer Class We have contacted the Ames High School and are working with them to come in and give a computer vision tutorial. We are creating a program that will take in the basic image of coins and will be able to identify and count the monetary amount in the photo. We are working to complete the tutorial in Google Colaboratory, so the students do not have to install packages on school computers and it can be accessed from anywhere through Google Drive Plus Period We got in touch with another Ames High School teacher that helps with Plus Period. This is a study hall-like class. We are currently working on creating a hand-on activity that would allow the students to create and launch two-liter bottle rockets. We are in the process of creating them ourselves first to identify safety risks and how to properly create them Career Fair We will be participating in the Ames High School Career Fair on October 10 th. We will be presenting on who we are and what we do with a hands-on activity at the end. We will be presenting eight times throughout the day in 40 minute blocks. 46 CySLI Proposal

47 5.2 Girls in Aviation Day We will be setting up a booth at Girls in Aviation Day at the Ames Airport on October 13 th. We will be displaying last year s rocket and color detection payload to generate enthusiasm over rocketry. 5.3 Girl Scouts of America We have contacted the Girl Scouts of America and are working with the Girl Scouts to develop a hands-on activity to help girls of all ages reach the requirements of their badges. At the middle and high school level, we are looking to help students receive their programming patches. In the elementary school range, we are looking to help girls receive their space science patches. We are currently in the process of creating a curriculum to meet their patch requirements. 5.4 FIRST Robotics We have presented on our project during the FRC Kickoff in West Des Moines for a few local FRC teams. We also plan to volunteer during the FIRST Lego League State Tournament at Iowa State University as they compete in our home building Howe Hall. During the tournament, we will also have a booth to display our past rockets and payloads. We aim to spark interest in Aerospace Engineering since they are already developing the problem solving skills necessary for engineering. 5.5 Boy Scouts We are currently in the process of contacting the Boy Scout troops in the Ames area. We believe we can partner with them to help them achieve STEM related patches as we are doing with the Girl Scouts. 5.6 Crucifixion Elementary School We are planning to start out quickly this year. We will be presenting about who we are and what we do to grades 3-6 at Crucifixion Elementary School in La Crescent, Minnesota. The current industry including NASA, Boeing, and SpaceX will also be covered. The presentation will be around 20 minutes long. We plan to return to the school to launch bottle rockets when possible. 5.7 Women in Science and Engineering STEM Fest We have contacted the WiSE chapter on the Iowa State campus to be able to display our rocket and payloads at their annual STEM Fest and engage the elementary school kids in engineering and rocketry. The date has changed this year to the spring semester, so we will be re-contacting them next semester for this opportunity. 6 Project Plan 6.1 Milestone Summary Our project will complete the following milestones: 1. A reusable rocket with required payload system ready for official launch. Milestone Date: LRR April 4. See Rocket and Payload Team timelines. 47 CySLI Proposal

48 2. A scale model of the rocket design must be flown before CDR and a report of the flight data brought to CDR. Milestone Date: Launch - October 28; CDR January 4. See Rocket Team Timeline. 3. A full-scale Vehicle Demonstration Flight and Payload Demonstration Flight must be flown and flight data reported in the FRR and/or FRR Addendum. Milestone Date: Launch February 25, FRR March 4. See Rocket and Payload Team timelines. 4. A team social media presence that is maintained/updated throughout the project year. Milestone Date: Social media handles turned in October 26; Updates - continuous (at each milestone, community outreach, etc.) 5. Reports, PDF slideshows, and Milestone Review Flysheets completed and submitted to the Student Launch Projects management team by applicable due dates. Milestone Dates: Each Design Review date (PDR November 2, CDR January 4, FRR March 4, PLAR April 26). 6. Electronic copies of the STEM Engagement form(s) submitted prior to FRR and within two weeks of the STEM engagement event. The Team Lead, Alex Harpenau, will submit the STEM Engagement forms. See Section 5, STEM Engagement. 7. Participation in PDR, CDR, FRR, LRR, and PLAR. Milestone Dates: PDR November 2, CDR January 4, FRR March 4, LRR April 4, PLAR April Timelines Note that our timelines have a gap between the Critical Design Review and Full Scale Launch Milestones. Our winter break is from December 15 th, 2018 January 13 th, As such, we plan to have the CDR done by the end of our fall semester because we realize that progress slows considerably over break. 48 CySLI Proposal

49 Figure 6-1 Avionics Team Timeline Figure 6-2 Payload Team Timeline 49 CySLI Proposal

50 50 CySLI Proposal Figure 6-3 Rocket Team Timeline

51 51 CySLI Proposal Figure 6-4 Safety Team Timeline

52 6.3 Budget 52 CySLI Proposal