Critical Design Review SPOREFINS

Changes Since PDR Changes made to vehicle criteria: Our length went from 71.63 inches to 89.25 inches long to allow for extra room for our experiment packing and drogue parachute. Our weight has changed from 216.32 ounces to 234.39 ounces because we changed our motor which weighs more and the extra length adds weight, as well. We changed our motor to get closer to the target altitude, per your request. We also lengthened our coupler, per your request. Changes to the payload criteria: The packaging around the petri dishes has changed slightly. Same foam being used but not all in the shape of one tube. Two petri dishes per foam capsule with three capsules total stacked on top of each other. This allows for more protection between petri dishes. Changes made to project plan: We were not able to launch our scale model in December because of burn bans. We were able to launch it January 7th by driving to another county. Another elementary school has asked us to come out and we are working on a date. We are also pushing more fundraising with the increase in hotel and airfare.  

Mission Statement The KSAT SL team will launch a rocket to a minimum of +8Gs in order to determine if spores can germinate after exposure to increased acceleration and g force. The KSAT SL team will also determine if fin design effects the altitude, acceleration and stability of a rocket in flight. Success Criteria: If the KSAT SL rocket travels the required height (a mile), pulls +8 Gs, is recovered relatively undamaged, the team is able to retrieve readable data, and the spores that were exposed to G either germinate the same as the unaccelerated spores or germinate at a different rate then, and only then, can the mission be declared a success.

Final Vehicle Dimensions, Materials, and Justification Blue tube for our airframe (strong but light) Polystyrene for our nose cone (strong but light) Plywood for the fins/centering rings/bulkheads/payload boards (durable, light) 1/2 inch tubular Kevlar for our shock cords (strong)

Discuss Key Design Features - Fins Our fin selection was done in a very unique fashion. After researching types of fins, three were selected and glued to identical motor mounts. Each fin type was then able to slide in and out of the same airframe. This allowed for minimal variances between the fin sets. The fins surface areas were the same for all three fin types, as well. The fin with the most acceleration is needed to reach our goal to fly over 8Gs—the clipped delta won!

Scale model flight test—January 7th   TRAPEZOID CLIPPED DELTA ELLIPTICAL Weight with motor (oz) 85.71 85.91 85.81 Predicted Stability Margin 3.02 2.24 2.18 Predicted Altitude (ft) 1448 1456 1451 Actual Altitude (ft) 1130 1310 1156 Actual Acceleration (ft/s/s) 220 240 160 Observations Major arc to left Slight arc to left No arc to left Wind (mph) 10 8 Time of launch 11:10 am 12:50 pm 1:45 pm

Scale model flight test Based on the results from the previous slide, we concluded that the clipped delta fin pattern would give us the highest acceleration and therefore be the best to obtain over 8Gs.

Final Motor Choice—-Aerotech K695 Based on the information above, we believe the Aerotech K695 will get us the best results. The acceleration predictions will allow for about 620 ft/s/s and give us about 19Gs. We anticipate a slight weight gain which will bring the altitude closer to the desired 5280 feet.

Rocket Flight Stability in Static Margin Diagram

Thrust-to-Weight Ratio & Rail Exit Velocity 665.10 N x 1 lb./4.45 N = 149.46 lbs Thrust from Motor 234.39 oz. X 1 lb./16 oz = 14.65 lbs. Weight from Rocket Thrust/Weight Ratio = 10.20 Velocity at launch guide departure: 73.04 ft/s User specified minimum velocity for stable flight: 50 ft/s

Mass Statement And Mass Margin The mass margin before the vehicle is too heavy to launch is about 70%. However, just launching is not the goal. A very heavy vehicle will fall short of the design altitude goal. The motor selected for the flight is based on the mass and altitude requirements. If the mass grows, the selection of the thrust delivered by the motor will have to increase to accommodate the addition of more mass. It is our experience with this set design tool that growth of mass is usually in the area of 10-15% and in a few cases the growth of mass was as high as 20%. As the mass growth increases our design will accommodate for it. The Aerotech K695 motor will result in the ability to achieve the altitude goal. The design starts with our rule of thumb for the ratio of thrust to weight. That rule of thumb is 5:1. This ratio has worked well for us over the years and usually results in very vertical and stable flights.

Parachute size, Recovery harness type, Size, Length, and Descent rates Drogue Parachute: Main Parachute: 12 inch diameter 98 inch diameter Descent rate = 141.37 ft/s Descent rate = 17.3 ft/s The aft shock cord is 25 feet long and upper shock cord is 25 feet. They are both made of 1/2 inch tubular Kevlar.

Kinetic energy at key phases of the mission Kinetic energy under drogue Weight of Nose section 17.1 oz 0.49 kg 359.41 ft-lbs Weight of upper airframe 98.7 oz 2.80 kg 2074.49 Weight of fin can 85.56 oz 2.43 kg 1798.31 Kinetic Energy on landing Weight of Nose section 17.1 oz 0.49 kg 4.98 ft-lbs Weight of upper airframe 98.7 oz 2.80 kg 28.75 Weight of fin can 85.56 oz 2.43 24.92

Predicted drift from the launch pad Wind in mph Wind in ft/sec Drift under drogue Drift under main Total drift 20 29.33 1116.24 1271.68 2387.92 15 22 837.18 953.76 1790.94 10 14.67 558.12 635.84 1193.96 5 7.33 279.06 317.92 596.98

Test plans and procedures We have received all our parts and are starting construction of our full scale rocket. Our scale model results provided data for our fin selection- the clipped delta. After construction, we will test fit all components and perform ejection charge testing—just like we did for the scale model. We then plan on flying the full scale in February.

Tests of the staged recovery system Upon completion of the full scale rocket, the recovery system will be tested by putting a deployment charge into the top and bottom airframes. We will set off the bottom first and then the top. This will all occur on the football field using proper safety protocol.

Final payload design overview

Payload - Spore Experiment The Question: Will increased acceleration impede spore germination? Purpose: The purpose of launching spores is to study the effects of acceleration on spores to determine if the spores could survive a trip to Mars, so scientists could study a food chain on Mars? Hypothesis: The spore growth will be slowed by the forces acting upon it during flight such as but not limited to G forces. The spores after returning to the ground will germinate slower than ones that were not exposed to high G force. This will be different than a spore being brought up to an orbiting object for a day or 2 then being brought down because this is a flight to apogee and back. We believe this will have different results as this will be a short exposure.

Payload Integration Design-Spores All payloads (altimeters and experiment) have been successfully fitted into the airframe with sufficient protection so that no damage will occur.

Interfaces Internal-- 2 Stratologger CF Altimeters: (controls deployment of chutes) External-- Big Red Bee GPS: (communicates to handheld locator)

Status of requirement verification 1. Perform analysis of altimeters and GPS using Original Equipment Manufacturer (OEM) provided dimensions to ensure mounting. - IN PROCESS 2. Once the payload tray is constructed, perform a fit check to verify placement. –IN PROCESS 3. Verify payload is secure in the payload section of the rocket. – IN PROCESS 4. Make sure altimeters are mounted using shock mounts to avoid stress. – IN PROCESS Preliminary integration plan: The integration plan of the scientific payload will consist primarily of a layout using the dimensions provided by the OEM. Once payload parts are received and the tray is constructed, a fit check will be performed to ensure the feasibility of the mounting design. –IN PROGRESS Instrumentation, repeatability of measurement and recovery system : Testing of the scientific payload is planned prior to launch. Primary tests include accuracy and repeatability tests in a controlled environment. –IN PROCESS -EXPERIMENT #2-IN PROCESS

Full scale practice Our planned date for the full scale rocket is on February 10th. We have a scheduled back up date of February 24th. If both days are bad…we will fly the first week in March or drive to another county if we are still in a burn ban.

Conclusion In conclusion, we had a successful scale launch. We are now constructing our full scale. We plan to launch in February. We have booked our hotel. We will book airfare by the end of the month. We are on track with our timeline and do not anticipate any problems. We look forward to our trip to Huntsville!