Team Thumbs UpCritical Design Review

Nick LenkEddie CyrusBrian Inglis

Chase PrichettGreg NelsonJake Varey

Fall 2008 R

ev B

10-14-08

Team Thumbs UpCritical Design Review

Nick LenkEddie CyrusBrian Inglis

Chase PritchettGreg NelsonJake Varey

Mission Overview

• Objective: To measure the intensity of sunlight as the BalloonSat increases in altitude

• Expectations: – Discover the exact increase in light between ground level and 30

km above sea level– Discover if the efficiency of photodiodes and solar panels are

comparable

• Hypotheses: – As altitude increases, the intensity of the light will increase– Photodiodes and solar panels are comparable with respect to

surface area

• Why?– We are doing this mission to determine why solar panel

technology is so prevalent in today’s space industry.

RequirementsLevel Designation Requirement Reference

0

O1 The spacecraft shall be a BalloonSat which shall ascend/descend to/from 30 km over the course of a 2.5 hour flight.

MS

O2

The BalloonSat shall not exceed 1 kg of mass and shall have a tube through the center on which it shall be attached to the launch vehicle (high altitude balloon).

MS

O3The science missions of the BalloonSat shall not require

an excess of $150 in expense. MS

O4The BalloonSat shall be launched on November 15,

2008 from Windsor, Colorado. MS

S1The BalloonSat shall measure the voltage received by

solar cells and photodiodes throughout the flight. MS

S2The BalloonSat shall measure internal and external

temperatures, as well as the internal humidity throughout the flight.

MS

Requirements (cont.)

1

O1.1 The structure shall withstand all external conditions O1

O1.2 The structure shall remain intact through the course of the flight. O1

O2.1The BalloonSat shall distribute mass between the structure and science

objectives. O2

O2.2The BalloonSat shall remain in contact with the vehicle during ascent

and the parachute during decent via the tube through the center of the structure.

O2

O3.1The budget for the BalloonSat shall remain under $150 through

donations from COSGC.O3

O3.2The budget shall allow for miscellaneous expenses during the

construction and testing phases.O3

O4.1Team Thumbs Up shall leave from Boulder, CO at approximately 5:00

a.m. and shall launch the BalloonSat at 7:30 a.m. from Windsor, CO.

O4

S1.1The solar cells shall receive light separately and the voltage produced

shall be recorded by the HOBO data logger.S1

S1.2The photodiodes shall be connected together and shall receive light

from the sun on all six sides of the BalloonSat.S1

S2.1The HOBO data loggers shall measure and record internal temperature

using the preloaded software on the HOBO.S2

S2.2The HOBO data logger shall measure and record the external

temperature via a sensor placed outside the structure of the BalloonSat.

S2

S2.3The HOBO data logger shall measure and record the internal humidity

of the BalloonSat using a sensor inside the HOBO.S3

Design• How:

– Solar Cells / Photodiodes collect sunlight– HOBO records voltage buildup in each solar cell and in all photodiodes

every 15 seconds throughout the flight• Parts (Ordered / Donated / Received)

– Foam Core– Insulation– A570IS Canon Digital Camera– 2 four-channel HOBO data loggers– 6 photodiodes (EL-PD204-6C/L3)– 2 solar cells– 3 voltage cables– Small gauge insulated wire– External Temperature Sensor – Desiccant packets – Three 9 volt batteries – Two 1.5 volt batteries – Two 3 volt lithium batteries – Heater Assembly – Center Tube – 2 Washers – 2 Paper Clips

Item Cost Quantity Total Total / Remaining Balance

Photodiodes $.50 12 $6.00 $6.00 / $144.00

HOBO Data Logger (second) * 1 * $6.00 / $144.00

Voltage Cord for HOBO * 3 * $6.00 / $144.00

Insulated Aluminum Wire * 1 Meter * $6.00 / $144.00

Solar Cells * 2 * $6.00 / $144.00

Replacement 9V Batteries * 6 * $6.00 / $144.00

Desiccant * * $6.00 / $144.00

Estimated Shipping $4.75 - $4.75 $10.75 / $139.25

Monetary Budget

Mass Budget

Item Mass(g) Quantity Total(g)Total/Remaining

Mass(g)

Digital Camera 220 ± 2 1 220 220 / 780

HOBO data logger 35.8 ± .1 2 71.6 ± .1 291.6 / 708.4

9V Battery 46.4 ± .1 3 139.2 ± .1430.8 / 569.2

Structure (Foam core cube) 112 ± 1 1 112 ± 1 542.8 / 457.2

Photodiodes .166 ± .1 6 1 ± .1 543.8 / 456.2

Solar Cells 3.5 ± .5 2 7 ± 1 550.8 / 449.2

Heating Unit 31.3 ± .1 1 31.3 ± 2 582.1 / 417.9

Insulation 43.2 ± .1 - 43.2 ± .1 625.3 / 374.7

Voltage Cable 16.6 ± .1 3 49.8 ± .1675.1 / 324.9

Flight Support System 28.0 ± .1 1 28.0 ± .1 703.1 / 296.9

Photodiode Board 10 ± .1 1 10 ± .1 713.1 / 286.9

ScheduleSeptember 22nd Mission Proposal Completed

September 23rd Conceptual Design Review Presentation

September 26th Weekly Meeting – Project Planning

October 2nd Order all hardware

October 4th Weekly Meeting -- Foam core shell prototype shall be built; ready for Whip, Stair, and drop testing

October 8th Drop and Stair Tests Completed

October 9th All ordered hardware shall be receivedDesign Document Revision A

October 10th Weekly Meeting -- Photodiode Functionality Test

October 14th Critical Design Review PresentationDesign Document Revision B

October 17th Weekly Meeting – Complete Whip Test and Connected Photodiode Functionality Test

October 21st Final BalloonSat structure shall be built

October 24th Weekly Meeting -- Photodiode Calibration, HOBO/Photodiode Compatibility Test and HOBO Test

November 1st Weekly Meeting -- Digital Camera Test

November 5th Cold Test

November 6th Design Document Revision C

November 7th Weekly Meeting

November 11th Launch Readiness Review

November 14th Weekly Meeting and Final BalloonSat Weigh-In

November 15th Launch Day

December 2nd Design Document Revision D, Final Presentation

Test PlanTest Purpose Description/Comments

Drop Test (Structural) Determine if structural design is sound for landing

Drop the prototype structure from a distance of no less than 10 meters. The prototype was loaded to 992 g and was released from this height on 10/8/08 in two separate tests. The structure remained almost completely intact. There was slight separation at the edges after the second release, but none of the internal mass came free of the structure.

Stair/Kick Test (Structural) Determine if structural design is sound for a landing that drags the balloonsat several meters

Kick the prototype down a flight of stairs of no less than 10 meters in length. The prototype from the drop test was placed at the top of a flight of stairs on 10/8/08 (after the drop test). It was then given a forceful kick to begin its descent down the stairs. The prototype remained intact with the internal mass still inside. A second kick using enormous force caused complete failure of the structure and the internal mass to come free. The structure is still in a state that is able to be repaired however.

Whip Test (Structural) Determine if structural design is sound when the balloon bursts, causing a significant change in direction of motion along with several G's of force

Attach the prototype to a cord of no less than 2 meters in length. The cord will be swung around in a circle to reach a high velocity and then snapped quickly into an opposite direction.

Photodiode Functionality Test (Functional)

Determine if the photodiodes are functioning properly and creating voltage

Test each of the photodiodes under indoor lighting and sunlight with a multimeter to insure that a voltage can be measured. The photodiodes were tested on 10/10/08 under indoor lighting and were verified to produce a voltage.

Photodiode Calibration (Functional)

Determine the average voltage output of a photodiode

Place each photodiode under a light source with a known amount of output and with no other light sources present to determine the average voltage created by a photodiode.

Connected Photodiode Functionality Test (Functional)

Determine if the photodiodes connected together are producing a voltage and that the voltage measured is within reason

Test the array of photodiodes that are connected in parallel to under indoor lighting and outdoor lighting to insure that a voltage can be measured and that the measured voltage is within reasonable expectations.

HOBO/Photodiode Compatibility Test (Functional)

Determine if the HOBO data logger and connected photodiodes are compatible with each other and that the date being recorded is useful

Test the connections of the photodiode array and the HOBO data logger to insure they are compatible and can connect. Once connected, the HOBO shall be set to record information for 135 minutes to determine if the data recorded is similar to that seen in the Connected Photodiode Functionality Test

Digital Camera Test (Functional)

Determine if the camera is operational and taking photographs at the desired rate.

Program the camera to take pictures at a certain rate and then place the camera in a stationary position and allow it to take pictures over a span of 135 minutes. Compare the number of pictures taken to the expected number to determine if the camera is functioning properly.

HOBO Test (Functional)

Determine that the data logger is performing as expected and recording the desired data

Use software to program the data logger to take measurements of humidity and temperature over a period of 135 minutes. This data shall be retrieved and analyzed to determine if the data logger is recording as programmed and that the data being recorded is within reason.

Expected Results

• We expect the photodiodes to produce comparable voltage to solar cells with respect to surface area.

• As the altitude of the satellite increases we expect a linear increase in light intensity with respect to the density of the air at that altitude.

Biggest Worries

• Honestly, we are not worried