NASA CDR Presentation
Spring Grove Area High School
2015 Full-Scale Rocket
Length: 114.50 inches
Weight: 23.35 pounds
Diameter: 4.0 inches
Body Tube : Fiberglass Wrapped Phenolic Tubing
Center of Pressure: 81.97 inches
Center of Gravity: 71.09 inches
Static Stability Margin: 2.72
Drag: 1.2 based on nose-cone shape, body material, and fin shape
Rocket Continued……
•We will use a 75 mm Motor Retainer that is
epoxied onto the ¾” lip of the motor tube that is
exposed from the back centering ring.
•The fins will be made from 1/8th inch thick G-10
Fiberglass that will allow the rocket to have low
drag and also allow the rocket to have a stable
stability margin.
Payload
Will determine the effect of size of single
port holes on the measurements taken
by Stratologger CF altimeters
 Variance between measurements can
help us potentially find a way to
calculate the ideal port hole size
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Payload (cont.)
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Four 3D printed bulkheads
 ½” in thickness
 Holes for all thread and U-bolts are printed
on piece
Payload (cont.)
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Three of the bulkheads will have walls to
accommodate altimeters
 Three altimeters per section
 One 9V battery in each section
will power the three altimeters
 9V battery will be secured to
the bulkheads
Payload (cont.)
Battery will be wired to the altimeter in
parallel
 Payload can be
activated for
hours, in case
the rocket
would remain
on the launch pad
for a long period of time
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Payload (cont.)
Two lines of ¼” all thread will run
through the entire payload
 A U-bolt will be attached to each end to
connect the payload to the other
components of the rocket
 Entire payload will be approximately 15”
in length
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Fin Brackets
The fin brackets will provide a way to
easily secure fins to the body of the
rocket
 The fins or the bracket can be replaced
if any damage were to occur
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Fin Brackets (cont.)
The fin bracket is two pieces, which will
be bolted together
 The fins are bolted within the fin slots,
and the entire piece is then attached to
the body tube
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Fin Brackets (cont.)
A single piece of the fin bracket can print
overnight: one complete bracket can be
made in two days
 Full scale bracket is two separate parts,
due to the size restraints of the 3D
printer

Plastic Material
Material used for 3D printing: polylactic
acid plastic
 Melting temperature between 315 and
338 degrees Fahrenheit

Electronics Bay
Dual Deployment
 Two Altimeters with a
separate battery for each.
 They will be wired in series to
9 Volt batteries
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Final Motor Selection
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Our final motor selection for the full-scale rocket will be the
K-510 Classic motor made by Cesaroni Technologies
Incorporated.
Impulse of 2,486 Newton*Seconds
75 mm, two grain motor
13.78 inches long.
Static Stability Margin Diagram
Rocket Data
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Thrust-to-Weight Ratio- 4.949
Rail Size/Length- 1515 Rail,
120 inches in length
Rail Exit Velocity- 53.1 ft/s
Center of Pressure- 81.87 in
from nose cone
Center of Gravity- 71.09 in
from nose cone
Static Stability Margin- 2.72
Mass Statement
There is a 198 ounce mass limit that could be added to the
rocket and the rocket still be capable of flying. This number was found to
be the limit where the rocket would still be stable by the time it left the
launch rail.
Recovery Systems
The chutes we are using are a Fruity Chutes Standard 24 inch
drogue chute and a Iris Ultra 72 inch main parachute.
• The 24 inch drogue chute will come out at apogee. A charge
in the electronics bay will push out the payload and the chute
from the back half of the rocket.
• There will be a second charge that goes off two seconds after
the first charge to ensure everything was deployed properly.
This charge will come from the redundant altimeter.
•
Recovery Systems
The second chute is our 72 inch main parachute,
being a Fruity Chutes Iris Ultra with a Coefficent
of Drag of 2.2, enough to slow the rocket to a
velocity of 17.1 feet per second on impact.
• This chute will be deployed at 700 feet by another
charge in the electronics bay. This charge will
separate the electronics bay and the 72 inch
parachute from the front half of the rocket.
• This charge will also have a backup delayed at 600
feet to ensure proper deployment.
•
Recovery Systems
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Parachute Size- 24” Drogue
Harness Length- 15 ft
Harness Material- Tubular Nylon
Harness Size- 1 inch
Terminal Velocity- 52.03 ft/s
Size- 72” inch Iris Ultra Main
Length- 25 feet
Material- Tubular Nylon
Size- 1 in
Terminal Velocity- 17.1 ft/s
Kinetic Energies
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At Apogee
 Payload- 59.63 Ft/lbs
 Back Half- 365.1 Ft/lbs
 Front Half- 293.2 Ft/lbs
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At 700 feet / Landing
 Payload- 9.07 Ft/lbs
 Electronics Bay- 6.53 Ft/lbs
 Back Half- 53.65 Ft/lbs
 Front Half- 42.3 Ft/lbs
Drift Calculations
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With the 24 inch drogue and 72 inch main parachute….
Testing Results
The fin bracket held up on flight and was
very strong and durable, taking no damage
and holding up on both flight and landing
 The ground ejection test went well and
according to plan. The rocket with 3.5
grams of black powder easily ejected the
front half of the rocket from the electronics
bay.
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Subscale Data
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On Flight 1, the rocket achieved a height of 2,075
feet.
The rocket was very stable and maintained a nice
straight path on flight
The rocket with its’ dual deployment payload
deployed the payload and drogue chute at apogee
correctly and the main at 600 feet.
The payload had one altimeter in it to make sure
that data could be recorded. That altimeter read
2,071 feet and functioned correctly allowing us
with confidence building the full-scale rocket.
Subscale cont….
Failure Modes
Rocket being too massive for proposed
motor
 To mitigate this we will check the
masses of the material compared to the
mass on RockSim
 Construction will be carefully monitored
so that every part of the rocket will be
strong
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Failure Modes
Looking at the design of our payload
conceivable failures are the payload
exerting to great of a force on the shock
cord and it snapping.
 To mitigate this failure we will use shock
cord tested to hold 2000 pounds of force
and a U-Bolt bolted into the top
bulkhead of payload.
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Personnel hazards
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Some new personnel hazards that have
came up during subscale building
include:
 Sawdust going on floor and having the tile
be very slick to walk on.
 Using superglue and having sharp pieces of
it go into your hand.
 To mitigate these risks we will clean up
as we work and be more careful when
using any type of adhesive
Interfaces and Integration
Educational Engagement
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Rocketry Camp:
 After presentation participation slip
 7th and 8th graders build rockets with
supervision
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Other Activities
 6th grade and under
○ Able to watch
○ Rocket poem and dance
○ Rocket building snack activity
Educational Engagement
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Rocketry Presentation:
 We will be holding presentations:
○ February 9th and 10th
○ 7th and 8th grade
○ Survey
 We will explain the NASA Student Launch
rocketry program, as well as our Team America
Rocketry Challenge Program.
○ Middle School TARC team
 PowerPoint:
○ Mission
○ Instructions on building a basic rocket
WGAL Preview
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https://www.youtube.com/watch?v=UHcsiUWZ5U
Conclusion
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We are currently right on target with the
suggested timeline. The building and
testing of the full-scale rocket is next.
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ANY QUESTIONS?