Tarleton State University
Post Launch Assessment Review
2012-2013 NASA USLI
“I have learned to use the word 'impossible' with the greatest caution.”
~ Wernher von Braun
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Foreword
To facilitate the reading of the Post Launch Assessment Review, we have mirrored the
Student Launch Project Statement of Work. In the body of the PLAR, you will find
extensive analysis of our SMD payload’s performance and flight data. The payload’s
features are threefold; atmospheric data gathering sensors, a self-leveling camera
system, and a video camera. One of the two major strengths of our payload design is
the originality of our autonomous real-time camera orientation system (ARTCOS). The
other major strength can be found in the originality of our self-designed Printed Circuit
Board layouts. This feature alone represents over 250 man hours of work. The PCBs
provide major enhancement of the signal integrity of the sensor data in addition to their
space and power efficient qualities. The flight in Huntsville was a success, placing 3rd
closest in altitude. We attribute this to extensive testing and 8 full scale flights at our
launch field and the guidance of Pat Gordzelik, Tripoli Vice-president. Testing allowed
our designs and flight protocols to mature. We would like to express our appreciation to
the NASA judges, engineers, and NAR volunteers that donated their time to this
incredible experience. We have enjoyed analyzing the flight performance and submit
this document for your review.
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Table of Contents
Foreword ..........................................................................................................................ii
Project Summary ............................................................................................................. 1
Flight Analysis Summary ................................................................................................. 2
Flight Simulations and Recovery Analysis ................................................................... 2
On-site Pre-launch Simulations ................................................................................ 2
Variances Between Actual and Predicted Flight Data ............................................... 3
Recovery Electronics Data ....................................................................................... 4
Vehicle Analysis Summary .............................................................................................. 5
Vehicle Layout and Specifications ............................................................................... 5
Vehicle Data Analysis .................................................................................................. 6
Payload Analysis Summary............................................................................................. 7
Data Analysis ............................................................................................................... 7
Science Value ............................................................................................................... 12
Simulation Analysis ....................................................................................................... 12
Atmospheric Modeling ............................................................................................... 13
Educational Engagement .............................................................................................. 13
Budget Summary .......................................................................................................... 14
Lessons Learned ........................................................................................................... 14
Summary of Overall Experience .................................................................................... 15
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Table of Figures
Figure 1: Launch Vehicle ................................................................................................. 1
Figure 2: Simulated Launch Vehicle ................................................................................ 3
Figure 3: Simulated Flight Data ....................................................................................... 3
Figure 4: Stratologger Altimeter Data .............................................................................. 4
Figure 5: Exploded View of Vehicle ................................................................................. 5
Figure 6: Frames of Video Footage ................................................................................. 6
Figure 7: SMD Payload Design ....................................................................................... 7
Figure 8: Atmospheric Data ............................................................................................. 8
Figure 9: Frequency of Data Collection ........................................................................... 8
Figure 10: ARTCOS Images ........................................................................................... 9
Figure 11: Key-Fob Video Camera Screen Shot ........................................................... 10
Figure 12: Ground Station GUI ...................................................................................... 10
Figure 13: Payload Post-Flight ...................................................................................... 11
Figure 14: Google Flight Path Overlay .......................................................................... 11
Figure 15: Probability Density and Cumulative Density of Rocket Apogee ................... 12
Figure 16: Schools Influenced by Tarleton's Educational Outreach Program ............... 13
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List of Tables
Table 1: Project Design Summary ................................................................................... 1
Table 2: Flight Summary Chart ....................................................................................... 2
Table 3: Flight Stage Simulations .................................................................................... 3
Table 4: Simulated and Actual Launch Conditions .......................................................... 4
Table 6: Budget Overview ............................................................................................. 14
Table 7: Subsystem Budgets ........................................................................................ 14
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Project Summary
The Tarleton Aeronautical Team successfully designed, launched, and recovered a
launch vehicle that carried the Science Mission Directorate (SMD) payload to 5,311 feet
above ground level. Named “Gravity Always Wins,” the vehicle is 97.5 inches long and
has a diameter of 5.525 inches. The nose cone, fins, and body sections are G10
fiberglass with the exception of the UV-T acrylic payload housing section. Aerodynamic
characteristics of the vehicle include an elliptical nosecone and clipped delta fins. The
vehicle incorporated a Cesaroni L1720-WT-P motor, yielding a total vehicle mass of
37.7 pounds at launch. A ballast system was used for apogee control rather than a
complicated energy management system. Extensive simulation and statistical analysis
provided a basis for ballast weight needed, and ultimately the system achieved
elevation within 31 feet of the target altitude on launch day.
The SMD payload consists of the Atmospheric Data Gathering System (ADGS), the
Autonomous Real-Time Camera Orientation System (ARTCOS), and a Keyfob Video
Camera. The payload design was selected for the Science Mission Directorate (SMD)
funding from NASA and received the ATK SMD Payload Design Award. The design
satisfied all prescribed objectives with the addition of recording video footage. In order
to maximize functionality and safety, all payload operations take place internally within
the clear acrylic housing. Table 1 gives brief summary of the project design.
Summary
Tarleton Aeronautical Team
Cesaroni L1720 WT-P
Science Mission Directorate
97.5 inches (8 feet 1.5 inches)
5.525 inches
Team Name
Motor Used
Payload
Rocket Height (Length)
Rocket Diameter
Rocket Mass
Mass without Motor
Wet Mass
Dry Mass
Altitude Reached (Scoring Altimeter)
30.3125 pounds
37.6875 pounds
33.80625 pounds
5,311 feet
Table 1: Project Design Summary
Figure 1: Launch Vehicle
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Flight Analysis Summary
In order to facilitate efficient review of the flight analysis, the following chart shows
simulated data from Openrocket and actual flight data from onboard non-scoring
altimeters and video analysis. A more detailed analysis follows the flight summary chart.
Stage
Simulated
Actual
Time
0.280s
.29s
Velocity
77.839fps
78fps
Altitude
10ft
10ft
Time
18.151s
18.7s
Velocity
2.041fps
17fps
Altitude
5260ft
5388ft
Time
89.233s
73.2s
Velocity
63.957fps
90.78fps
Altitude
700ft
695ft
Time
147.930s
107.65s
Velocity
10.241fps
15.38fps
Altitude
0ft
0ft
Off-Rail
Drogue Deployment
Main Deployment
Impact
Table 2: Flight Summary Chart
Flight Simulations and Recovery Analysis
On-site Pre-launch Simulations
The recovery scheme for the flight functioned properly. A two foot diameter drogue
parachute deployed 5 feet below apogee and a ten foot main parachute deployed at
700 feet AGL. Although the official scoring altitude indicated 5,311 feet AGL, the rocket
was configured based on simulations calculated for a target of 5260 feet AGL The target
altitude was based on test flight data and game theory analysis due to competition
scoring rubric.
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Simulated rocket and flight path made using OpenRocket on launch day are shown
below is shown in figures 2 and 3 as well as table 3 flight stage calulations.
Figure 2: Simulated Launch Vehicle
Figure 3: Simulated Flight Data
Stage
Time
Velocity
Height AGL Lateral Displacement
Off-Rail
0.280s
77.839fps 10ft
Drogue Deployment 18.151s 2.041fps 5260ft
Main Deployment
89.233s 63.957fps 700ft
Impact
147.930s 10.241fps 0ft
0ft
299ft
368ft
973ft
Table 3: Flight Stage Simulations
Variances Between Actual and Predicted Flight Data
Several factors affect the flight path and the achieved altitude of the rocket and caused
variance between actual and simulated data; these factors include wind speed,
temperature, pressure, and angle of the launch rail. The achieved altitude variance is
attributed to the change in these values between the expected launch time of 8:00 am
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and the actual launch time of 8:43:40 am. Simulations took place approximately two
hour prior to launch, during which time the temperature and pressure changed. Thus
these changes were not accounted for in the simulation. Another factor was the angle of
the launch rod. The simulation used a launch rod angle of zero degrees while the actual
launch rod was angled three degrees by the NAR official. The changes in the factors
effecting ballast calculations are shown in Table 4.
Temperature
Simulated
550 F
Actual
570 F
Pressure
982 mbar
999 mbar
Launch Rod
Angle
00
30
Table 4: Simulated and Actual Launch Conditions
Recovery Electronics Data
The recovery system includes four Stratologger altimeters that worked as programed.
The primary drogue altimeter fired within 5 feet apogee while the secondary drogue
altimeter fired one second after. Similarly, there are two main parachute deployment
altimeters. The primary main altimeter fired at 700 feet while the secondary fired two
seconds later. The altitude and velocity data are shown in Figure 4.
Figure 4: Stratologger Altimeter Data
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Vehicle Analysis Summary
Vehicle Layout and Specifications
There are three main sections referenced as the upper body airframe, the payload
housing section, and the booster section. The upper body airframe serves as a coupler
attachment point for the elliptical nose cone at the front end and for the payload housing
section at the back end. The upper body airframe houses the 10 foot main parachute
along with respective attachment and deployment hardware. The main parachute
avionics are located in the coupler connecting the upper body airframe to the payload
housing section.
Figure 5: Exploded View of Vehicle
The payload housing section provides a clear body section such that all payload
operations can occur internally. The PCBs for the payload are mounted on an aluminum
frame that is secured via bulkheads. This body section provides a coupler attachment
point for the upper body airframe on the front end and one for the booster section on the
back end.
The booster section houses the motor and provides an attachment surface for the fins.
It provides a coupler attachment point to the payload housing section at the front end.
This section also houses the two foot drogue parachute and associated attachment and
deployment hardware. Clipped delta fins are epoxied into slots milled into the booster
section airframe. The dimensions of the fins include a root chord of 12 inches, tip chord
of 2.4 inches, height of four inches, sweep length of 7.85 inches, and a sweep angle of
63 degrees.
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Vehicle Data Analysis
The vehicle performed well during the launch. Prior to launch, the ballast was
configured for conditions predicted at 8 a.m. rather than 8:40 a.m. After re-simulation
with actual launch conditions, the simulation predicted an apogee of approximately
5,315 feet, a much closer simulation to the actual launch.
Visual data observed of the flight indicated the rocket remained very stable throughout
as confirmed by the slow motion video capture seen in Figure 7. Post flight assessment
demonstrated the integrity of the design as there was no damage, and the rocket
remained reusable.
Figure 6: Frames of Video Footage
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Payload Analysis Summary
The payload design was selected for the Science Mission Directorate (SMD) funding
from NASA and received the ATK SMD Payload Design Award. The payload
experiment fulfills the requirements of NASA’s SMD payload. The payload design is
shown in Figure 7.
Figure 7: SMD Payload Design
Data Analysis
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27
26
25
24
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8:42:00 AM
Pressure
8:42:43 AM
8:43:26 AM
8:44:10 AM
8:44:53 AM
8:45:36 AM
8:46:19 AM
Ultraviolet Radiation
30
20
W/m2
inHg
The flight of the payload demonstrated successful completion of ALL of the SMD
requirements. This section lists each requirement and provides data to confirm the
successful completion of each requirement.
3.1.3.1 The payload shall gather data for studying the atmosphere during descent
and after landing, including measurements of pressure, temperature,
relative humidity, solar irradiance and ultraviolet radiation
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0
8:42:00 AM
-10
8:42:43 AM
8:43:26 AM
8:44:10 AM
8:44:53 AM
8:45:36 AM
8:46:19 AM
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Humidity
% RH
40
30
20
8:42:00 AM
8:42:43 AM
8:43:26 AM
8:44:10 AM
8:44:53 AM
8:45:36 AM
8:46:19 AM
Solar Irradiance
1000
W/m2
8
500
0
8:42:00 AM
8:42:43 AM
8:43:26 AM
8:44:10 AM
8:44:53 AM
8:45:36 AM
8:46:19 AM
8:45:36 AM
8:46:19 AM
Temperature
Fahrenheit
90
88
86
84
8:42:00 AM
8:42:43 AM
8:43:26 AM
8:44:10 AM
8:44:53 AM
Figure 8: Atmospheric Data
3.1.3.2 Measurements shall be made at least every 5 seconds during descent,and
3.1.3.3 Measurements shall be made every 60 seconds after landing.
Figure 9: Frequency of Data Collection
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The atmospheric data gathered by the payload throughout the final flight is displayed in
the following graphs. Measurements are made approximately every 1.2 seconds.
Frequency of data gathering is shown in Figure 9.
3.1.3.4 Surface data collection operations shall terminate 10 minutes after landing.
The payload failed to autonomously terminate measurement gathering after ten
minutes, a wireless deactivation command and a magnetic switch provided secondary
forms of deactivation.
3.1.3.5 The payload shall take at least 2 pictures during descent and 3 after
landing, and
3.1.3.6 The payload shall remain in an orientation during descent and after landing
such that the pictures taken portray the sky toward the top of the frame and
the ground toward the bottom of the frame.
The ARTCOS successfully orientated the camera during descent and after landing. The
pictures taken by the ARTCOS are if Figure 10. Note: these Images have not been
edited in any way.
Figure 10: ARTCOS Images
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The Key-Fob video camera recorded video footage of the entire flight. A frame from the
Key-Fob video captures the flight line (Figure 12).
Figure 11: Key-Fob Video Camera Screen Shot
3.1.3.7 The data from the payload shall be stored onboard and transmitted
wirelessly to the team’s ground station at the time of completion of all
surface operations.
Data was stored onboard the payload to micro SD cards. The ground station displayed
the payload telemetry in real time as show in Figure 12. Humidity and UV
measurements contained inaccurate spikes due to interference from surrounding
wireless transmitters. The ground station is capable of deactivating, reactivating, and
controlling the frequency of telemetry transmission. The raw data packets were
displayed in the bottom window.
Figure 12: Ground Station GUI
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3.1.3.8 Separation of payload components at apogee will be allowed, but not
advised. Separating at apogee increases the risk of drifting outside the
recovery area.
The payload design maximizes safety by staying contained within the clear acrylic
housing throughout the flight. Components are securely mounted to aluminum rails,
thus no parts were damaged during the flight. A picture of the payload after flight is
shown in Figure 13.
Figure 13: Payload Post-Flight
3.1.3.9 The payload shall carry a GPS tracking unit.
GPS coordinates were measured by the Locosys GPS onboard the payload. GPS data
was stored and transmitted at the same frequency as other payload devices. The rocket
landed 1,012 feet from the launch rail according to the GPS coordinates, which are
graphed in Figure 14.
Figure 14: Google Flight Path Overlay
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Science Value
The scientific value of the rocket design centers on mathematical analyses of the rocket flight
and changes in the atmospheric variables involved. A statistical analyses across a large number
of simulations provides a thorough prediction model of the rocket flight under very specific
conditions. In addition, research into a nonlinear model representative of atmospheric
correlations holds tremendous potential in the realm of rocketry and aerodynamics.
Simulation Analysis
All flight simulations were created using the OpenRocket software suite. This program,
developed as a master’s thesis by an aeronautics student from Helsinki University of
Technology, allows the user to build a three-dimensional representation of the rocket and
simulate a full flight. The rocket rendering subprogram allows the user to build every component
to specification of size and mass. All simulations then use the virtual rocket model, in
conjunction with the desired motor and atmospheric conditions at the time of launch, to predict
the flight path at each 0.01-second interval.
Considering the number of variables involved, one simulation is insufficient to provide a
comprehensive representation of the expected results. That said, the prediction experimentation
involved a large number of simulations to demonstrate all likely outcomes of the flight. Using the
exact atmospheric measurements for the projected launch date 1000 simulations are created,
totaling to over 75 MB of data. A statistical analysis across these simulations produces a
projected flight path with the probabilities of meeting specific values of apogee, lateral distance,
etc.
The left side of Figure 15 demonstrates the resulting probability density curve for reaching one
mile exactly. Although the probability of hitting one mile exactly is demonstrated at roughly 6%,
with a larger margin of error the probability grows much higher. The right side of Figure 15
illustrates the probability of reaching an apogee below a specified height. Here the predicted
accuracy of the rocket becomes more apparent. The demonstrated probability of apogee being
below 5,290 feet is roughly 90 %. The results of this experiment show the importance of a large
number of simulations combined with a thorough mathematical inspection in a predictive
analysis.
Figure 15: Probability Density and Cumulative Density of Rocket Apogee
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Atmospheric Modeling
Preliminary referencing involves a prolonged and extensive process of determining crosscorrelation of variables. Using over 2.9 GB of data acquired from the National Oceanic and
Atmospheric Administration (NOAA) 48 variables will be modeled against one another in search
of any existing relationships.
The results of the pre-flight analysis are used to improve the predictive model provided by
OpenRocket simulations. A regressive model relating relevant atmospheric variables is
combined with a second-by-second prediction of the flight path. These combined results more
accurately show the projected flight path, as the impact of each atmospheric variable can be
introduced with more validity .The flight data acquired from the four onboard altimeters can then
be cross-referenced with a validated mathematical model for the flight path to check for
inconsistencies. This whole analysis allows for a better understanding of anomalies causing any
divergence from a predicted flight path. By introducing equations relating atmospheric variables,
measurements taken on the ground are more accurately related to atmospheric conditions at
higher altitudes. A more precise model will closely mirror the results of a real flight. Due to the
thoroughness of this investigation most factors of uncertainty are almost entirely removed and
the rocket is more easily controlled.
Future investigation into this experiment will involve modifying the OpenRocket code. As
OpenRocket is open-source software, the source code has been located and retrieved free of
charge. Upon determining adequate atmospheric models and a thorough validation of the
model, the portion of code used to simulate atmospheric conditions will be altered for more
accurate results.
Educational Engagement
The main goals of the educational outreach activities were to inspire students and foster
enthusiasm for the STEM fields including rocketry. Events were created to enlighten students
about the global necessity of math, science, engineering, and technology. A rocket launch at the
end of each presentation provided students with real world applications and a personal
experience to reinforce the STEM concepts of each outreach event. The team encouraged
interest in these subjects with the intent of increasing the number of people that choose to
pursue STEM related careers.
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

8 Events
3 Event Styles
o Large Group Presentation
o Problem Solving Lesson
o Rocket Fair
31 Participating Schools
1400+ Students & Teachers
Figure 16: Schools Influenced by Tarleton's
Educational Outreach Program
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Budget Summary
The following chart includes the budget for the project. The task of completing the NASA USLI is
a complex interdisciplinary endeavor that tests the team’s knowledge and skills, including
management of a budgetTable 6 breaks down the total budget. The budget for the final vehicle
build is charted in Table 7.
Cost Elemnet
Testing/Prototyping
Outreach
Final Build
Travel to Competition
Total
Est. Cost
$13,972.23
$3,669.77
$4,007.21
$8,200.00
$29,849.21
Table 5: Budget Overview
On Pad Cost
Recovery
Structure/Propulsion
Payload
On Pad Total
Est. Cost
$951.47
$1,189.61
$1,866.13
$4,007.21
Table 6: Subsystem Budgets
Lessons Learned
The team gained a wealth of knowledge throughout the project concerning engineering
principles and what it takes to be successful in the real world. Some of the most pivotal learning
experiences included the team’s understanding of how to work well in a team environment, be
professional, and how to apply what’s learned in the classroom to a real world project.
The team worked together to foster good communication throughout each subsystem involved.
This communication allowed for a positive working environment. The team also learned to work
in an interdisciplinary manner that incorporated many diverse talents into one cohesive unit.
Through the documentation and presentations, the professionalism of individuals and the group
benefitted a great deal. The importance of punctuality and preparedness for meetings and
deadlines became evident early in the project to adhere to the rigorous timeline that the team
created. The project timeline established a concrete set of goals and a list of plans to
coordinate between various subsystems and perform schedule tests. The team learned how to
balance expected outcomes with actual results and creatively solve problems in high pressure
situations.
We developed new understanding of the engineering life cycle. The complexity of the project,
managing personnel, and working within a limited budget stretched the team members to their
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limit. Taking a design into prototype and then production gave us new appreciation for the need
for extensive testing and documentation. Meticulous documentation was kept regarding every
stage of the design life cycle, but most changes came through test flights and analysis of failure
modes. The team also learned to practice and implement sound purchasing and inventory
process and budgeting.
Summary of Overall Experience
The USLI project has been one of the most valued learning experiences for each of the Tarleton
Aeronautical Team members in their academic career. An optimized rocket design was used
with the SMD payload sponsored by NASA. Though many teams employed electromechanical
systems to affect the aerodynamics of their rocket, Tarleton’s submission simply relied on
mathematics to predict, simulate and analyze the rocket’s flight path. A well-constructed launch
vehicle with thorough mathematical analyses to achieve the third-closest apogee to exactly one
mile resulted through the hard work of each team member.
The team recognized through test flights what seemed like a good decision on paper was not
always the best option in implementation. The design underwent significant changes to
enhance the accuracy and durability of the final product. Instances where testing significantly
impacted the project included: changes from the spark ejection canister to e-matches, the
adoption of a deployment bag, and the aluminum flash shielding for the avionics bays. The
team also learned to scrutinize parts received due to the shipment of several incorrect orders.
The team’s payload functioned fully according to all required specifications. The project was
overwhelmingly positive, and it demonstrated a massive success on the parts of all team
members involved. Completing a project of this scope built a new level of confidence in the
skills and abilities of the team.
The launch week at Marshall Space Flight Center was an incredible experience for everyone
involved. The opportunity to meet with NASA and ATK Aerospace Group executives was a
perfect culmination to the accomplishment of successfully completing the launch initiative. The
project opened new doors for many team members regarding their future careers and also
developed a new love and familiarity of rocketry for team members, family and friends.
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