critical design review - cal poly pomona rocketrycritical design review january 26, 2018 california...

Critical Design ReviewJanuary 26, 2018

California State Polytechnic University, Pomona

3801 W. Temple Ave,

Pomona, CA 91768

7.0 Subscale Vehicle Overview

6.0 Test Plans and Procedures

5.0 Mission Performance Predictions

4.0 Recovery Subsystem

Agenda

1.0 Introduction

2.0 Final Launch Vehicle Overview

3.0 Launch Vehicle Performance

8.0 Payload Overview

9.0 Launch Vehicle Interfaces

10.0 Project Plan

11.0 Closing

01/26/2018 California State Polytechnic University, Pomona | CDR 2017-2018 2

o Competition Week Attendees

o Major Changes from PDR

Agenda

1.0 Introduction



Competition Week Attendees2017-2018 Cal Poly Pomona NASA

Student Launch Initiative

Educator Administrators

Advisor

Donald Edberg, PhD

Mentor

Todd Coburn, PhD

L2 TRA Mentor

Rick Maschek

Lead Engineer

Casey

Aerodynamics

Aerodynamics Lead

Daniel R.

Ryan

Andrew

Verenice

Mauricio

Vanessa

Daniel A.

Structures

Structures Lead

Edgar

Kevin

Priya

Cory

Isaac

Jehosafat

Leara

Payload

Payload Lead

Richard

Juan

Ricardo

Praneeth

Courtney

Deputy, Systems Engineer

Megan

Safety Officer

Natalie

Changes Made Since PDR

Criteria Changes Made

Vehicle SizeOverall length increased from 7 ft-9

in to 8 ft-5 in

Vehicle MassOverall mass decreased from 46 lb

to 43.7 lb

Nose Cone

Material changed from PLA and

fiberglass reinforcement to PLA

only.

Fin

Material changed from PLA and

fiberglass reinforcement to PLA

only.


Recovery GPS

Redundancy added for GPS;

Trackimo GPS has been added in

addition to the Eggfinder

Drogue Parachute Size changed to 4 ft2

Main ParachuteDeployment altitude changed from

500 ft to 600 ft.

Motor Selection

Motor has changed from a

Cesaroni L1115 to an Aerotech

L1420R

• Vehicle Criteria Changes


Changes Made Since PDR


GPS Module

Adafruit module replaced by the Eggfinder

system; Adafruit transceivers replaced by

XBee modules.

Payload Observation Avionics

Live video feed and camera eliminated: The

ground station will now consist of a laptop

with the Eggfinder RX and the ground XBee

both connected independent from one

another via USB.

• Payload Criteria Changes






Agenda

1.0 Introduction





10.0 Project Plan

11.0 Closing


o Final Launch Vehicle: Dimensions

o Final Launch Vehicle: Full Configuration

o Mass Statement and Mass Margin

o Key Design Features: Hollowed Bulkhead

o Key Design Features: Plug

o Key Design Features: Recovery Avionics Bay

o Key Design Features: Fin Integration

o Final Motor Choice and Justification

Agenda



Final Launch Vehicle: Dimensions

● 3 Independent sections known as Modules

○ Module 1 : Nose cone, Payload Bay

○ Module 2 : Recovery system

○ Module 3 : Observation Bay and Motor Bay

● Total Length of Launch Vehicle: 101 in. (8 ft-5in)


Final Launch Vehicle: Full Configuration


Mass Statement and Mass Margin

● Total Mass of Launch vehicle

○ At Lift off: W = 43.7 lb

○ At Burnout: W = 38.1 lb

● Mass Margin

○ Desirable Altitude

■ Lift off weight between 43 lb and 52 lb

○ Desired Flight Stability

■ Payload must not exceed 5 lb and implement a 10% ballast


Key Design Features: Hollowed Bulkhead

● Located and epoxied to the

end of the Payload Bay

● Provides an opening for

DERIC Rover to exit

● Attached to main parachute

shock cord via Zinc-plated

Steel U-bolt


Key Design Features: Hollowed Bulkhead

● Manufactured using ¾’’

Birch Plywood and

sandwiched between two

0.032’’ 7075-T6 Al sheets

● Al sheets provide greater load

capabilities after main main

parachute deployment


Key Design Features: Plug

● Fitted to cover hollowed

bulkhead opening

○ Creates pressure seal for

main parachute deployment

○ Protects payload from

deployment charge debris

● Gets pulled off with main

parachute deployment by

attaching routing eye-bolt to

shock cord line

● Manufactured by 3-D printer

using PLA material


Key Design Features: Recovery Avionics Bay

• Made of Blue Tube 2.0 coupler• 12 in. length• OD:5.976in• ID: 5.835in• Enclosed by two ¾’’ Birch plywood

bulkheads• Two ½’’ holes will be created through

the collar to fit exterior controlled switches


Key Design Features: Recovery Avionics Bay

● Avionics plate

made of thin

plywood will hold

altimeters

● Two threaded rods

will hold avionics

plate in place

during flight


Key Design Feature: Fin Integration

• Consists of 3 fins, 4 centering rings, and 6 bolts

• Body Tube shrouds and protects Fin Integration System

• Allows for fast and easy replacement of fins

• Broken fins do not ground the launch vehicle


Key Design Feature: Fin Integration

• Centering rings at the end are fixed with bolts, middle centering rings are friction fit

• Bolts ensure a secure connection

• Fins can be replaced in under 5 minutes

• Less time repairing = More time flying


Final Motor Selection and Justification

Aerotech L1420 Performance Parameters:

Average Thrust: 319.23 lbfMaximum Thrust: 407.80 lbfTotal Impulse : 1034.80 lbf-sBurn Time: 3.2 secondsISP: 183 seconds

Aerotech L1420 Thrust Curve



Aerotech L1420 enabled:• Cost Savings:

• From $458 -> $208• Savings Factor: Aerotech

Casing available on site

• Satisfies Apogee Requirement (5331-5507 ft.)

• Satisfies Rail Exit Velocity Requirement (60.5 ft/s)

Aerotech L1420 Thrust Curve



• Apogee Simulations:

• OpenRocket: (5331-5507 ft.) from 0 to 20 mph winds

• MATLAB: 5745 ft.

• Difference (%): 2.38%

• Allows 0-10% ballast to further refine the altitude






Agenda

1.0 Introduction





10.0 Project Plan

11.0 Closing


o Rocket Flight Stability in Stability Margin Diagram

o Thrust-to-Weight Ratio and Rail Exit Velocity

Agenda



Center of Gravity

Center of Gravity

(OpenRocket)

62.695 Inches

Center of Gravity

(Hand Calculations)

63.52 Inches

Percent Difference 1.31%


Center of Pressure

Center of Pressure

(OpenRocket)

78.014 Inches

Center of Pressure

(Hand Calculation)

77.32 Inches

Percent Difference .89%


Stability Margin

Stability Margin

(OpenRocket)

2.62 Calipers

Stability Margin

(Hand Calculation)

2.24 Calipers

Percent Difference 14.5 %


Launch Vehicle Performance

● Thrust-to-Weight ratio

○ T / W = 7.3

● Rail Exit Velocity based on MGLOW = 43.7 lb

○ Using the 8 ft. 1515 rail: V = 60.7 ft/s

○ Using the 12 ft. 1515 rail: V = 75.1 ft/s






Agenda

1.0 Introduction





10.0 Project Plan

11.0 Closing


o Parachute Overview

o Parachute Sizes

o Recovery Harness

o Recovery Avionics: Altimeters

o Recovery Avionics: Ejection Charge

o Recovery Avionics: GPS

Agenda



Parachute Overview

Main Drogue

• Toroidal design• Manufactured by Fruity Chutes• Packing Volume: 199.9 ft3

• Weight: 3 lbs.• 400 lb. paraline

• Cruciform design• Manufactured in-house• Packing Volume: 56.5 ft3

• Weight: 1 lb.• 400 lb. paraline


Parachute Sizes

Main Drogue

• Diameter: 10 ft.

• Spill Hole Diameter: 1.77 ft.

• Aeff = ~80 ft2

• Cd of 2.2

• Gores: 34 in. x 10 in

• Aeff = 4 ft2

• Cd of 0.6


Recovery Harness

• ¼ in. Kevlar shock cord rated at 2200 lbs

• Measuring 30 ft each for both parachutes

• Attached using ⅜ in. steel quick links for main and ¼ in. steel quick links for the drogue


Recovery Avionics: Altimeters

● Two (2) PerfectFlite Stratologger CF altimeters will be

used for Drogue and Main parachute deployment

● Redundancy established using two separate altimeters

● Each will run on 9V batteries


Altimeter Specifications

StratologgerCF● Main chute deployment range from 100 to 9,999 feet in 1 foot demarcations

● Drogue Chute Deployment at Apogee

● Stores 16 eighteen minute flights

● 5 Amp output current

● Altitude, Temperature, Power Supply voltage data collection


Parachute Deployment Figures

Stratologger 1 Stratologger 2

Drogue Deployment At Apogee (5,280 ft) 2 seconds after Apogee

Main Deployment 600 ft 500 ft

● Each altimeter will be programmed with different main chute

deployment values

● In the case of main altimeter failure, the redundant altimeter

will deploy the drogue/main chute(s)


Recovery Avionics: Ejection Charge

• There are a total of 4 charges located on rocket• 2 for the Drogue Parachute• 2 for the Main Parachute

• 4F Black Powder will be used• Charge sized calculated taking into account changes

in bay size• Calculations will be verified using ground tests.

Charges will be optimized to ensure proper ejection• Ignition method : E match


Recovery Avionics: GPS

● Two GPS systems (Eggfinder and Trackimo) will be utilized

● Varying frequencies allow for additional redundancies in rocket

recovery

● Immediate uplink of data to ground command module with

integrated hardware


GPS Specifications

Eggfinder● 9 Volt power supply

● 8.2 ft accuracy

● 900 Mhz transmitting

● Range of 8000 ft

Trackimo● Rechargeable LiPo Battery

● 50 ft accuracy

● 850/900/1800/1900 MHz transmitting

● Unlimited Range with cell service

permitting


GPS Data Pathways

Eggfinder Trackimo

● Two separate location data pathways ensure higher success rate in recovery

as a failure of one system will not affect the alternative






Agenda

1.0 Introduction





10.0 Project Plan

11.0 Closing


o Descent Rates

o Kinetic Energy at Key Phases

o Drift Predictions from Launch Pad

Agenda



Descent Rates

• Descent Rate From Apogee to Main Deployment (when drogue is deployed) = 120 ft/s

• Descent Rate from Main Deployment to Touch Down = 14 ft/s

• Total time spent in air = 81.9 seconds


Kinetic Energy at Key Phases

• Max Kinetic Energy and Kinetic Energy at touchdown identified• Requirement 3.3 satisfied

Phase

KE of Nose Cone +

Payload Fairing

(0.247 slugs)

(ft-lbs)

KE of Main/Drogue

Bay + Recovery Bay

(0.291 slugs)

(ft-lbs)

KE of Observation

Bay + Motor Bay

(0.508 slugs+0.314

slugs for prop mass)

(ft-lbs)

Total Kinetic Energy

(ft-lbs)

Rail Exit (60.7 ft/s) 455.2 536.5 1515 2506.7

Apogee (0 ft/s) 0 0 0 0

Drogue Deployment

(120 ft/s)1779 2097 3661 737

Main Deployment &

Touchdown (14 ft/s)24.2 28.5 49.8 102.5


Drift Calculations

• To address concerns and meet the drift radius requirement, the main will now deploy at 600 ft (with backup charge at 500 ft).

• New descent rates = 120 ft/s with drogue deployed & 14 ft/s with main deployed

• Drift distance can be minimized further because main deployment velocity is conservative

Wind Velocity (mph) Drift Distance (ft)

0 0

5 624

10 1248

15 1873

20 2497






Agenda

1.0 Introduction





10.0 Project Plan

11.0 Closing


o Test Plan Matrix

o Safety Plan

Agenda



Test Plan Matrix


Safety Plan


Safety PlanSafety Plan






Agenda

1.0 Introduction





10.0 Project Plan

11.0 Closing


o Subscale Vehicle Overview

o Subscale Launch Vehicle Scaling

o Subscale Flight Results

o Predicted vs True

o Subscale Lessons Learned

Agenda



Subscale Vehicle Overview

• Scaling and Layout

• Flight Results

• Prediction Comparisons

• Lessons Learned


Subscale: Scaling and Layout

Geometric Scaling Factor - 1:2 Scale (B.T. Diameter)

Launch Vehicle

CharacteristicsFull-Scale Sub-Scale

Scaling Factor (Sub-

Scale/Full-Scale)

Body Tube Diameter

(in.)6.0 3.0 0.500

Overall Length (in.) 101 58 0.574

Overall Mass (lbs.) 43.7 7.84 0.178



Goals for Subscale

• Test flight electronics to be used in full scale

• Test scaled down recovery system

• Show rocket geometry and stability perform well in flight



Electronic

Component

Full-Scale

Usage

Sub-Scale

Usage

Raspberry Pi w/

Camera moduleYes Yes

EGGFINDER GPS Yes Yes

Stratologger CF

AltimeterYes (2) Yes (1)

Flight Electronics



Recovery System

F.S.

S.S.

Main Altimeter

Drogue



F.S.

S.S.

Characteristic Full-Scale Sub-Scale

Stability 2.62 Caliber 2.59 Caliber

Fins NACA 0008 Clipped Delta (Removable) NACA 0008 Clipped Delta (Removable)

Nose Cone Von-Karman Von-Karman

Geometry and Stability


Subscale Flight Results

● Flight data provided by two altimeters

● Apogee = 4313 feet

● Launch Conditions: cloudy skies, 59 degrees Fahrenheit, average wind speed of 16 mph


Predicted and Actual Flight Data

● Initial drag coefficient for subscale was 0.49

● Obtained from OpenRocketsimulations using launch day conditions

● Altitude predicted with MATLAB


Predicted and Actual Fight Data

● Drag coefficient of 0.64 obtained from flight data using MATLAB

● Altitude predicted with MATLAB


Calculated Drag Coefficients

Subscale Model Full Scale Model

OpenRocket 0.49 0.45

MATLAB 0.64 0.59

Error 30.6% 30.6%


Subscale Model: Lessons Learned

● MATLAB program assumes vertical flight and does not

simulate launch day conditions

● OpenRocket and MATLAB program can predict rocket

altitude accurately

● Flight test data needed to determine drag coefficient

● Ensure that all checklists for full scale model are

followed






Agenda

1.0 Introduction





10.0 Project Plan

11.0 Closing


o Final Payload Design Overview

o Payload Dimensions

o Key Design Features

o Payload Electronics Overview

o Payload Integration

Agenda



DARIC - Assembly


DARIC - Payload Dimensions

Drawing in inches, English units


DARIC - Key Design Features

• Compact design

• Easy Assembly

• Lightweight

• Simple Manufacturing Method

• Solar deployment system can be easily integrated to the top of the rover.


Key Design Features: SPOC System

• Pendulum system allows for orientation correction upon landing

• Pin restricts movement during flight

• Carriage system securely holds rover during descent


Key Design Features: SPD System

• Rotary servo holds down foldable solar panels

• Uses torsion springs to open up the solar panels

• Easily mounts on top of the rover allowing for easy access


Payload Electronics Overview

On the rover:• Motorized

• 2 servos (1 for the hook, 1 for the solar panels)• 1 main motor to drive the rover

• Electrical• Sixfab shield, Xbee Transceiver Unit, and Raspberry Pi• Eggfinder GPS module • micro SD card, and micro USB stick to record data


Payload Electronics Overview

A depiction of the schematic design


Payload Integration

• The coding system will be autonomous and run on a series of infinite loops

• Raspberry Pi, Sixfab Shield, and Xbee transceiver unit will be used to make coding easier

• Coding will be broken up into two sections• Code for electronic components• Code for motorized components

• When both sections have been tested enough, they will be merged together into a master program


Payload Integration

• Sources of data transmission• GPS data - due to NSL rules, the rover requires a GPS

module on the rover and will be wired accordingly• Transceiver data - due to NSL rules that the rover’s

sequence must be activated from a button, an Xbee transceiver module will be used to communicate• This transceiver module will send the GPS location over to the

team when the rover has completed its mission






Agenda

1.0 Introduction





10.0 Project Plan

11.0 Closing


Internal Interfaces Within Launch Vehicle

• 12 bolts hold SPOC

system to Launch

Vehicle

• Rotation Lock Pin is

tethered to the Main

Parachute via a steel

cable






Agenda

1.0 Introduction





10.0 Project Plan

11.0 Closing


o Status of Requirements Verification

o Timeline

Agenda

10.0 Project Plan


Verification Methods

Nomenclature -


Launch Vehicle Compliance Matrix

REQ# Description 1 2 3 4 V IP NV

VR2.2

The vehicle will carry one commercially

available, barometric altimeter for recording

the official altitude used in determining the

altitude award winner. Teams will receive the

maximum number of altitude points (5,280) if

the official scoring altimeter reads a value of

exactly 5280 feet AGL. The team will lose

one point for every foot above or below the

required altitude.

5.1.1 x

The team shall review the launch

vehicle system, subsystems and

components design verifying at

least one commercially available

altimeter.

1

Vehicle Requirements Verification Method

An altimeter will be

used to record flight

data such as altitude

and temperature and to

initiate parachute

deployment at

predetermined altitudes.

The vehicle was found

to deliver the payload

to approximately 5,280

feet and meet the

minimum rail exit

velocity of 52 ft/s.

VR2.1

Design Requirements Section

4.1.2 &

4.3.2x x 1

Status

OpenRocket simulations of final

design provide projected altitude,

launch tests shall showcase

altitude reached.

The vehicle will deliver the payload to an

apogee altitude of 5,280 feet above ground

level (AGL).

Verification Details


Recovery System Compliance Matrix


RS3.2

Each team must perform a successful ground

ejection test for both the drogue and main

parachutes. This must be done prior to the

initial subscale and full-scale launches.

4.2.5.1 x

Results of the ground ejection test

shall verify successful

performance.

1

The drogue parachute will deploy

immediately after reaching apogee and

maintain a steady velocity of 120 ft/s until

the main parachute is deployed. In order

to minimize wind drift, the main parachute

will be deployed at an altitude of 600 ft.

A recovery system test on November 18,

2017 will cover a ground ejection test for

both the drogue and main parachutes

prior to the subscale and full-scale

launches.

Design RequirementsRecovery System Requirements

Section

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.

Tumble or streamer recovery from apogee

to main parachute deployment is also

permissible, provided that kinetic energy

during drogue-stage descent is reasonable,

as deemed by the RSO.

RS3.1 4.4.8

Recovery testing will be done to

determine the proper deployment

of both parachutes.

StatusVerification Method

1x

Verification Details


Payload Compliance Matrix



ER4.5 Deployable rover

ER4.5.1

Teams will design a custom rover that will

deploy from the internal structure of the

launch vehicle.

6.1 xInspection of rover design

schematics 1

ER4.5.2At landing, the team will remotely activate a

trigger to deploy the rover from the rocket.6.1.1 x

Inspection of rover design

schematics 1

ER4.5.3

After deployment, the rover will

autonomously move at least 5 ft. (in any

direction) from the launch vehicle.

6.1.1 &

6.2.2.1x

Inspection of rover design

schematics 1

Experiment Requirements Option 2

The payload team will build a small,

condensed rover with a thin two-track

system. The leading system design

includes a tetrahedron system and a

pendulum system.

Verification DetailsStatus

The payload experiment is a deployable

rover that will be remotely triggered by

the team after the launch vehicle has

landed.

The payload obective is to successfully

deploy a rover from a safely landed

rocket that will travel 5 feet from its

landing site.

Design Requirements SectionVerification Method

Safety Compliance Matrix


SR5.2

Each team must identify a student safety

officer who will be responsible for all items in

Section 5.3.

5 xDemonstrated in team description

of PDR1

SR5.3The role and responsibilities of each safety

officer will include, but not limited to:

SR5.3.1Monitor team activities with an emphasis on

Safety during:

SR5.3.1.1 Design of vehicle and payload5.1.5 &

5.2x Demonstrate safety during design 1

SR5.3.1.2 Construction of vehicle and payload5.1.5 &

5.2x

Demonstrate safety during

construction1

Status

Each team will use a launch and safety

checklist. The final checklists will be included

in the FRR report.

and used during the Launch Readiness

Review (LRR) and any launch day

operations.

Safety Requirements Verification Method

Natalie Aparicio

Outlined for Safety Officer

responsibilities

Outlined for Safety Officer

responsibilities

SR5.1Safety Managers and Officers will create

a checklist prior to FRR and LRR.

At LRR, demonstration of the use

of the checklist5 x

Design Requirements Section Verification Details

1


General Compliance Matrix


GR1.2

The team shall provide and maintain a

project plan to include, but not limited to the

following items: project milestones, budget

and community support, checklists,

personnel assigned, education engagement

events, and risks and mitigations.

7 xDemonstration of the project

plan.1

StatusGeneral Requirements Verification Method

1

Project plan will be discussed in greater

detail in CDR and LRR.

Design Requirements Section Verification Details

1.4 xTeam members shall demonstrate

100% of the project.GR1.1

Team Lead, Casey, will distribute an

equal amount of work to each student,

both for writing and manufacturing.

Students on the team shall do 100% of the

project, including design, construction,

written reports, presentations, and flight

prepartion with the exception of assembling

the motors and handling black powder or

any variant of ejection charges, or preparing

and installing electric matches (to be done by

the team's mentor).


Derived Requirements Matrix


DR2.0

Bulkheads, including hollowed bulkhead,

must be strong enough to withstand impulse

forces generated by parachute shock cords.

7.1.1.3 x

Bulkhead loading tests will be

conducted to verify load

capabilities.

1 1

DR3.0

Plug for hollowed bulkhead must stay

attached during launch and flight, prior to

main parachute deployment.

7.1.1.3 x

Series of load tests will be

conducted to verify plug will stay

attached.

1 2

Body tube must be strong enough to

withstand the compressive launch forces and

must protect all avionics during launch and

landing.

System Requirements (Derived Requirements) Verification Method

Bulkheads will be constructed out of 3/4"

thick plywood capable of withstanding

impulse forces that will be experienced.

DR1.0

Body tube material is Blue Tube 2.0, a

commercially available tube capable of

withstanding mach 1 forces.

Plug will stay attached using friction fitting

during launch and flight prior to main

parachute deployment.

7.1.2.3 x

Design Requirements & Risk Mitigation Section Verification Details

1

Status

Conduct load verifications

Risk

Level

1


Gantt Chart


Important Milestones






Agenda

1.0 Introduction





10.0 Project Plan

11.0 Closing


Thank you, 2017-2018 CPP NSL Team

Questions or Comments?

critical design review - cal poly pomona rocketrycritical design review january 26, 2018 california...

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